LIFE HISTORY STUDIES OF LADINO CLOVER (TRIFOLIUM REFERS L .) IE MICHIGAN By Fred Emerson Westbrooks AN. ABSTRACT Subm itted t o th e School o f Graduate S tu d ie s o f M ichigan S ta te C o lle g e o f A g r ic u ltu r e and A p p lied S cien ce i n p a r t ia l f u l f il lm e n t o f th e requirem ents f o r th e degree o f DOCTOR OF PHILOSOPHY Department o f Farm Crops Year L i t t l e i s known about the le n g th o f l i f e o f th e o r ig in a l ta p root and crown o f Ladino c lo v e r ( T rifo liu m re-pens L . ) because o f i t s s t o l o n i fe r o u s h a b it o f growth* I t may appear to be a l i v e b ecause o f new s t o lo n and sh a llo w fib r o u s root growth whereas i t s tsgp root may a c t u a lly be dead* Once th e tap root: i s dead, th e p r o d u c tiv ity o f t h i s legume drops, e s p e c ia l­ l y on dnsoUftiy s o il s * T h is p r o d u c tiv ity o f sta n d s, r e la te d to le n g th o f l i f e o f p la n t s , has been rep o rted to be from 2 to 10 years* To determ ine th e ex a ct le n g th o f l i f e o f Ladino c lo v e r tap r o o t s , in ­ d iv id u a lly - t r a n s p la n te d s e e d lin g s and s e e d lin g s e s ta b lis h e d from seed d ir e c t ­ l y i n the f i e l d were stu d ie d from August 1951 to August 195^» Loth o f th e s e s tu d ie s e s ta b lis h e d on d if f e r e n t s o i l ty p e s , a l l tap r o o ts were dead by J u ly o f th e second p ro d u ctio n y e a r . The p ercen tage o f dead tap r o o ts in c r e a se d p r o g r e s s iv e ly from th e f i r s t t o b h eiseco n d 'p ro d u ctio n year* More ta p r o o ts o f p la n ts to p -d r e sse d w ith 0—20-20 f e r t i l i z e r were a l i v e in September a f t e r th e f i r s t p ro d u ctio n year than when the p la n ts were not f e r t i l i z e d o r f e r t i l i z e d on ly w ith phosphorus* However, th e r e were no o th e r d if f e r e n c e s in tap root s u r v iv a l which co u ld be a t t r ib u t e d to d if f e r e n t f e r t i l i z e r s ( 0—20—20 and 0—20- 0 ) a p p lie d at two r a te s (200 and 600 pounds/ a c r e ) on fo u r d a te s during th e f i r s t p ro d u ctio n year* F e r t i l i z e r s a p p lie d i n 1953 in cr e a se d y i e l d s o f fo ra g e in 1954* The g r e a t e s t in c r e a s e was o b ta in ed where 600 pounds o f 0- 20-20 f e r t i l i z e r was a p p lie d . P e rcen ta g es o f t o t a l a v a ila b le carbohydrates were at a low l e v e l in r o o ts and s t o lo n s , e s p e c i a ll y th e form er in June b efo re a l l tap r o o ts were dead in July* This low carbohydrate l e v e l was probably th e r e s u lt , r a th e r than th e cau se, o f d eath o f th e tap roots* D is c o lo r a t io n and d e t e r io r a t io n o f th e c o r t i c a l t i s s u e o f th e ta p root s t a r t e d to appear i n June o f th e f i r s t p ro d u ctio n y ea r, two months b e fo re p la n t r o o ts s ta r te d t o d i e . F . 32iSSi-* an^ B h iz o c to n ia s p ., Fusarium oxvs-porum. F* roseum. gp. were p resen t* The f i r s t th r e e are p rob ab ly th e c a u s a l organism s b ecause o f t h e ir r e l a t i v e p a th o g e n ic ity and th e la r g e p e rc en ta g e o f is o l a t e s * I t i s probable th a t th e se d is e a s e organism s were d i r e c t l y r e s p o n s ib le f o r th e l e s i o n s and e v en tu a l d ea th o f th e roots* C u ttin g Ladino c lo v e r s e v e r e ly i n the f i r s t p ro d u ctio n y ea r (6 tim es to a h e ig h t o f 1 in c h ) a c c e le r a t e d th e m o r ta lity ra te o f th e second p ro d u ctio n year* c lo v e r i n th e A l l ta p r o o ts o f c lo v e r r e c e iv in g t h i s c u t tin g treatm en t were dead i n June o f the second p ro d u ctio n year* C lover cut more l e n i e n t l y l i v e d u h t i l J u ly , one month longer* P la n ts brought in to th e greenhouse m onthly from O ctober through January p re ce d in g th e second p ro d u ctio n year had as many dead tap r o o ts th ree months l a t e r as p la n ts a llo w ed to remain in the f i e l d f o r t h is p eriod * However, p la n t s brought in to th e greenhouse i n March and A p r il had s l i g h t l y low er m o r ta lit y r a t e s than p la n ts rem aining i n th e f i e l d . T his in d ic a t e s th at w in te r k i l l i n g i s not a major f a c t o r i n Ladino c lo v e r s u r v iv a l* A lte r n a tin g tem p eratu res o f sp r in g , however, may p la y a p a rt i n a c c e le r a t in g th e d ea th o f Ladino c lo v e r tap r o o t s . F ie ld s seed ed t o Ladino c lo v e r m ixtu res in nin e c o u n tie s i n M ichigan under f a m c o n d itio n s had no o r ig in a l tap ro o ts a l iv e i n J u ly o f th e second p ro d u c tio n y e a r . T h is c o rr o b o ra tes, on a f i e l d s c a le under v a ry in g c lim a t ic c o n d itio n s , d ata ob tain ed under c lo s e ly - c o n t r o lle d exp erim en tal p l o t s where in d iv id u a l p la n ts were s tu d ie d . A l l o f th e farmers* f i e l d s seeded i n 1950* 1951* s e e d lin g s p r e se n t when checked i n 1953* 195^ bad young When checked a g a in in 195^* some o f th e s e s e e d lin g s had become e s ta b lis h e d p la n ts and were c o n tr ib u tin g h e a v ily to th e p r o d u c tiv ity o f the sta n d . The p ercen ta g e th a t su rv iv ed to become e s t a b lis h e d p la n ts was in flu e n c e d by th e s o i l ty p e, f e r t i l i z e r s u sed a s to p -d r e s s in g , and g r a z in g management. I t appears th a t even though the o r ig in a l tap root and crown l i v e o n ly in to th e second p ro d u ctio n y ea r, Ladino c lo v e r may be p r o d u ctiv e f o r s e v e r a l y e a r s p rovid ed new p la n ts become e s ta b lis h e d from s e e d lin g s as shown i n t h i s study* LIFE HISTORY STUDIES OF L4DIH0 CLOVEE (TRIFOLIUM EEFEES L . ) IE MICHIGAN By Fred Emerson West "brooks A THESIS Subm itted to th e School o f Graduate S tu d ie s o f M ichigan S ta te C o lle g e o f A g r ic u ltu r e and A p p lied S cien ce i n p a r t ia l f u lf il lm e n t o f th e requirem ents f o r th e degree o f DOCTOR OE PHILOSOPHY Department o f Farm Crops 195^ ProQuest Number: 10008449 All rights reserved INFORMATION TO ALL USERS The quality o f this reproduction is dependent upon the quality of the copy submitted. In the unlikely event that the author did not send a complete manuscript and there are missing pages, these will be noted. Also, if material had to be removed, a note will indicate the deletion. uest ProQuest 10008449 Published by ProQuest LLC (2016). Copyright of the Dissertation is held by the Author. All rights reserved. This work is protected against unauthorized copying under Title 17, United States Code Microform Edition © ProQuest LLC. ProQuest LLC. 789 East Eisenhower Parkway P.O. Box 1346 Ann Arbor, Ml 4 8 1 0 6 - 1346 ACKNOWLEDGEMENT The author w ish es t o e x p ress h is a p p r e c ia tio n and acknowledge h is ii>d eb ted n ess to D octor M. B. Tesar f o r h is h e lp fu l a d v ice in p lan n in g and con d u ctin g t h i s in v e s t ig a t io n , and f o r h i s v a lu a b le a id i n the p rep a ra tio n o f t h i s m anuscript. A p p r ec ia tio n i s a ls o ex p ressed to P r o fe s so r H. M. Brown f o r h is a s s i s ­ ta n c e in s t a t i s t i c a l a n a ly se s , and to D octor E. J . Benne f o r h is a d v ice and a s s is t a n c e i n chem ical a n a ly s e s . To h is w ife , V ir g in ia , th e au thor i s d ee p ly in d eb ted f o r in s p ir a t io n and encouragement during the course o f t h i s in v e s t ig a t io n , and f o r a s s is t a n c e in p rep a ra tio n o f t h i s m anuscript. To a l l o th e r s who c o n tr ib u te d to th e in v e s t ig a t io n but go unmentioned, th e author i s d eep ly g r a te fu l* TABLE OF CONTENTS INTRODUCTION 1 REVIEW OF LITERATURE 3 WEATHER CONDITIONS PART I . STUDIES OF THE SURVIVAL OF ORIGINAL TAP ROOTS OF LADINO CLOVER 14 1? M a te r ia ls and Methods 18 R e s u lts 19 D eath o f Tap R oots Under F ie ld C on d ition s 19 Root T issu e D e te r io r a tio n and D is e a s e s 24 D eath o f Tap R oots Taken to Greenhouse 29 Forage P rod u ction in Greenhouse 32 Carbohydrate L evel o f Roots and S to lo n s 4-1 D is c u s s io n 44 Summary 46 PART I I . EFFECTS OF MANAGEMENT AND FERTILIZATION ON SURVIVAL OF TAP ROOTS AND PRODUCTION OF FORAGE IN THE FOLLOWING YEAR OF LADINO CLOVER. M a te r ia ls and Methods RESULTS 49 49 52 S u r v iv a l o f Tap R oots 52 E f f e c t s o f C u ttin g trea tm en ts 52 E ffe c ts o f f e r t iliz e r 54 P ro d u ctio n o f Forage 59 INTRODUCTION There i s l i t t l e in fo rm a tio n on th e o r ig in o f Ladino c lo v e r ( T r if o l­ ium ren en s L . ) The e a r l i e s t record i s o f i t s occu rrence i n I t a l y in 18*18, when i t was found growing on an e s t a t e i n the Po V a lle y , near th e town o f Lado, from which i t r e c e iv e s i t s name. The f i r s t record o f the in tr o d u c tio n o f Ladino c lo v e r in to the U n ited S ta te s i s 1891* was I t was not u n t i l th e e a r ly t h i r t i e s th a t Ladino c lo v e r i n th e W est. I t was a t t h is tim e a ls o th a t the e x te n s iv e u se o f Ladino c lo v e r was g e t t in g under way in th e N orth eastern S t a t e s . b ein g used w id ely From th e N orth east Ladino c lo v e r spread to the Corn B e lt and Lake S ta te s and th en in to th e upper p a rt o f the South. A lthough Ladino c lo v e r i s a r e l a t i v e l y new p la n t in th e U n ited S t a t e s , i t has become one o f th e most im portant p a stu r e s ila g e and hay crop s in t h i s cou n try. The le n g th o f l i f e o f t h is p la n t i s c o n t r o v e r s ia l. I t i s at p r e se n t c l a s s i f i e d as a p e r e n n ia l, and th e l i f e exp ectan cy o f sta n d s i s rep orted as b ein g from two to te n y e a r s, depending on manage­ ment p r a c t ic e s , f e r t i l i z e r s u sed, and p r e v a ilin g s o i l and c lim a t ic con­ d itio n s . Lim ited in fo rm a tio n i s a v a ila b le on th e le n g th o f l i f e o f in d iv id u a l p la n ts . I t i s im portant to know th e le n g th o f l i f e o f in d iv id u a l p la n ts so as to know i t s l im it a t io n s and to be a b le to approach th e problem o f management f o r lo n g e v ity o f s ta n d s. N atural r eseed in g has been m entioned a s a p o s s ib le answer, but c o n d itio n s n ecessa ry f o r r e se e d in g are not c l e a r l y d efined* The in v e s t ig a t io n rep o rted h e r e in was s e t up to determ ine ( l ) the e x a c t le n g th o f l i f e o f ta p r o o ts o f th e o r ig in a l p la n t s , (2 ) which f e r ­ t i l i z e r and management p r a c t ic e s under c lim a t ic c o n d itio n s such as p re­ v a i l i n M ichigan would he conducive to i t s con tin u ed s u r v iv a l and h ig h p r o d u c tio n , and (3 ) i f s e e d lin g s in o ld Ladino c lo v e r f i e l d s become e s ­ t a b lis h e d p la n ts and c o n tr ib u te to i t s p r o d u c tiv ity and lo n g e v it y . REVIEW OF LITERATURE A d a p tation and Use Ladino c lo v e r ( T rifo liu ia re-pens L. ) i s r a p id ly becoming the founda­ t i o n o f an e x te n s iv e g ra ssla n d a g r ic u ltu r e over a la r g e p a rt o f th e Uni­ t e d S ta tes# W heeler (3 7 ) s t a t e s th a t the d iv e r s it y o f i t s u s e s , i t s h ig h ca r ry in g c a p a c ity f o r a l l c la s s e s o f l i v e s t o c k and p o u ltr y , th e h ig h n u t r it i v e v a lu e o f th e fo r a g e , and i t s g e n e r a l a d a p ta tio n are im­ p o rta n t c h a r a c t e r is t ic s which g iv e i t a dominant p o s it i o n a s a p a stu re crop# A hlgren ( l ) r ep o r ts th at Ladino c lo v e r i s g e n e r a lly grown from Maine to V ir g in ia and westward to Ohio, and th a t i t i s in c r e a s in g in p o p u la r ity in North C arolin a, T ennessee, Kentucky, and th e d a iry s t a t e s o f M ichigan and W isconsin# Garber a l . (14) have su ggested th a t th e in tr o d u c tio n o f Ladino c lo v e r i s probably one o f the g r e a te s t s in g le f a c ­ t o r s in the in c r e a se d im portance o f r o t a tio n p a stu r e s on s o i l s o f moderate to h ig h f e r t i l i t y and good m oistu re c o n d itio n s i n the n o rth ea stern se c ­ t i o n o f th e U n ited S t a t e s . A hlgren and Burcalow (3 ) s t a t e th a t Ladino c lo v e r i s ra p id ly a t t a in ­ in g a p o s i t i o n o f g r e a t im portance in W isconsin as a source o f h ig h ly n u t r it io u s fo ra g e f o r a l l c l a s s e s o f l i v e s t o c k , in c lu d in g p o u ltr y and sw in e. They fu r th e r s t a t e th a t i t i s grown fo r th e most p a rt on th e h e a v ie r s o i l a rea s and i t s p r in c ip a l u se i s f o r g ra zin g ; however, w ith care i t can be used to make good q u a lity hay and g r a ss s il a g e when grown i n m ix tu res w ith o th e r g r a s s e s and legum es. Jones and Brown (2 1 ) in c lu d e A Ladino c lo v e r i n th e most im portant group o f legum es grown under i r r i g a ­ te d c o n d itio n s in C a lifo r n ia * Brown and M unsell (10) a f t e r much e x p e r i­ m en tation and ex p e rie n c e on farms have shown Ladino c lo v e r to he one o f th e most im portant legum es f o r C onnecticut* Response to Management I t has been found by p r e v io u s in v e s t ig a t o r s th a t h e ig h t o f c lip p in g g r e a t ly in flu e n c e s th e s u r v iv a l and p r o d u c tiv ity o f Ladino clover* Tesar and A hlgren (3*0 report th a t Ladino c lo v e r cu t fo u r tim es to a h e ig h t o f 3s in c h e s i n th e f i r s t h a r v est year produced s ig n i f i c a n t l y h ig h e r y i e l d s i n th e second h a rv est year than Ladino c lo v e r cut fo u r or f i v e tim es to a h e ig h t o f one in c h . Wagner (3 5 ) s t a t e s th a t one o f th e reasons f o r th e la c k o f drought r e s is t a n c e in Ladino c lo v e r might be a t tr ib u te d to i t s h ig h to p -r o o t r a t io , a s w e ll as i t s r e l a t i v e l y sh allow root system* C lip p in g tw ic e in c r e a se d the to p growth to root growth in 130-day o ld p la n ts* In th e l a t e r s ta g e s o f developm ent, c lip p in g a ls o d ecreased th e number o f le a v e s and the number a s w ell as le n g th o f s to lo n s in Ladino clo v e r* Robinson e t * a l * (2 8 ) s tr e s s e d th e e f f e c t s o f c lip p in g on y i e l d s o f herbage i n Ladino clo v er* Lowest y i e ld s were o b ta in ed on p l o t s c lip p e d to a h eig h t o f two in c h e s , and th e h ig h e s t average y i e l d s were o b ta in ed by c lip p in g to a h eig h t o f i in c h . T his l a t t e r treatm ent was too d r a s t ic fo r th e m aintenance o f a good stand* A hlgren and Burcalow (3 ) s t a t e th a t con tin uous and close' g ra zin g o f Ladino c lo v e r d e cr ea ses p ro d u ctio n , weakens th e p la n ts , and may r e s u lt i n summer k i l l i n g from h eat or w in ter k i l l i n g from e x c e s s iv e c o ld . They fu r th e r s t a t e th a t Ladino c lo v e r i s r e a d ily r e e s ta b lis h e d from n a tu ra l 5 r e s e e d in g when stan d s are e lim in a te d during sev ere w in te r s, p rovid ed s u f f i c i e n t growth, h as "been p erm itted p r io r t o g ra zin g to a llo w the p la n ts to produce seeds* Brown ( 7 ) found th a t c u t tin g Ladino c lo v e r - g r a s s mix­ t u r e s to a h e ig h t o f 4 in c h above the ground l e v e l as many as tw elve tim es in one sea so n , or o n ly once i n the l a t e hay sta g e o f th e accompanying g r a s s r e s u lt e d in a rap id th in n in g and weakening o f the Ladino c lo v e r . He fu r th e r s t a t e s th a t, i n g e n e r a l, th ree to f i v e c u t t in g s a sea so n , w ith th e f i r s t not l a t e r than June 1 5 , and the l a s t not e a r l i e r than September 15, have g iv e n q u ite s a t is f a c t o r y stan d s and y i e l d s in C o n n ecticu t. M ixtures A hlgren e t . a l . (4 ) have rep orted th a t m ixtu res o f Ladino c lo v e r brom egrass and Lacino c lo v eiv o rch a rd g r a ss produced y ie ld s th a t were not s i g n i f i c a n t l y d iff e r e n t from each o th er in a m od erately-grazed p a stu re but b oth m ix tu res produced y i e l d s which were s ig n i f i c a n t l y h ig h e r than th o s e o f Ladino c lo v e r grown alon e or w ith tim othy o r Kentucky b lu e g r a ss . In a c lo s e ly - g r a z e d p a stu r e , m ixtu res o f Ladino c lo v e r w ith e it h e r Ken­ tu ck y b lu e g r a ss o r orchard g r a s s produced s ig n i f i c a n t l y h ig h e r y i e l d s than Ladino c lo v e r grown a lon e or w ith tim othy or brom egrass. Brown and M unsell ( 9 ) s t a t e th a t e x is t i n g evid en ce shows th e Ladino c lo v e r - g r a s s se e d in g s have s e v e r a l im portant advantages over Ladino c lo v e r a lo n e , in c lu d in g ( l ) la r g e r y i e l d s o f dry m atter from e a r ly - c u t hay or r o t a tio n a lly -g r a z e d p a s tu r e s , (2 ) b e t te r balanced fe e d , ( 3 ) l e s s w in te r k i l l i n g , p a r t ic u la r ly by h eavin g o f th e c lo v e r on heavy or wet s o i l s , ( 4 ) f a c i l i t a t i o n o f h ayin g o p e r a tio n s, e s p e c ia lly cu rin g , ( 5 ) l e s s l i k e - 6 lih o o d o f com p lete f a il u r e , and (6 ) few er weeds* Tesar and A hlgren (3*0 rep o rt m ix tu res o f Ladino c lo v e r w ith smooth brom egrass, tim othy or or­ chard g r a s s were more p ro d u c tiv e than Ladino c lo v e r grown a lo n e . I t was found hy Brown and M unsell (10) i n working w ith Ladino c lo v e r in m ixtu res th a t i n a l l s e e d in g s , Ladino c lo v e r d ecreased w ith age o f stand r e g a r d le s s o f th e a s s o c ia t e d g ra ss s p e c ie s* Sprague and Eby ( 3 1 ) rep ort th a t a le g ­ ume g r a s s a s s o c ia t io n in c lu d in g hrom egrass, orchard g r a s s , or reed canary g r a s s w ith Ladino c lo v e r makes a more e f f i c i e n t u se o f m oistu re and f e r ­ t i l i t y in the s o i l la y e r than does c lo v e r alone* Ih ere i s some evid en ce th a t Ladino c lo v e r i s l e s s l i k e l y to he in ju r e d by h eavin g and fr e e z in g i n w in ter when seed ed w ith g ra sses* Brown (7 ) s t a t e s th a t the in c lu s io n o f red c lo v e r i n Ladino c lo v e r -g r a s s m ixtu res r e s u lte d i n la r g e r f i r s t y e a r y i e l d s but i n l e s s Ladino c lo v e r and low er y ie ld s i n subsequent seasons* S u rv iv a l o f Ladino C lover Stands J e f f e r s and A hlgren (2 0 ) found th at th e r e were no l i v i n g crowns o r tap r o o ts o f o r ig in a l p la n ts e s ta b lis h e d from seed in a th r e e -y e a r o ld stan d o f Ladino c lo v e r . T esar (33) rep orted th a t a f t e r two p a stu r in g sea so n s th ere were no o r ig in a l tap r o o ts i n a fo u r -a c r e f i e l d o f Ladino c lo v e r . Hughes e t * a l . (1 9 ) rep ort th a t stan d s o f Ladino c lo v e r are in ju r e d and th in n ed more fr e q u e n tly th an northern n a tu r a liz e d s t r a in s o f common w h ite c lo v e r by low and a lte r n a tin g tem peratures during the w in ter and sp r in g months. G en erally th e l o s s e s are much g r e a te r du rin g th e second 7 and fo llo w in g y e a r s than i n th e f i r s t y ea r o f esta b lish m en t* A hlgren and Burcalow (3 ) s t a t e th a t Ladino c lo v e r i s not a s w in te r hardy as common w h ite clo v er* U s u a lly i t w i l l not su r v iv e a sev ere w inter* e s ­ p e c i a l l y when grown on s o i l s o f low f e r t i l i t y or i f too c l o s e ly grazed i n September and October* Jhrtherm ore th e s e two workers s t a t e th a t La­ dino c lo v e r may be p u rp o sely undergrazed i n th e e a r ly p a rt o f th e sea so n t o perm it n a tu ra l reseed in g o f th e p lan t* Brown and M unsell (1 0 ) found th a t Ladino c lo v e r grown in associa?t i o n w ith tim oth y o r orchard g r a s s was in ju r e d much more s e v e r e ly by heav­ in g in th e sp r in g when i t was cut in the p rev io u s year to a h eig h t o f two in c h e s than when i t was cu t to a h eig h t o f k inches* They a ls o found th a t l e s s freq u en t but low er c u ttin g r e s u lte d i n much more w in t e r k illin g th an more freq u en t but h ig h er c u ttin g * M ille r et* a l * (2 5 ) s t a t e th a t Ladino c lo v e r grown f o r seed i s gen ­ e r a l l y most p r o d u c tiv e i n th e second year* B eginning i n th e th ir d year se e d y i e l d s u s u a lly d e c lin e ra th er r a p id ly under current customary man­ agement* T his d e c lin e i s rep o rted ly thought to be due p a r t ly to a t h in ­ n in g out o f th e stand o f Ladino clover* Bobinson at* al* (2 8 ) found that Ladino c lo v e r flu c t u a t e d w id ely in sta n d s and* i n general* th e stand d ecreased from f a l l to e a r ly spring* They fu r th e r s t a t e th a t t h i s tren d was p a r t ic u la r ly marked during th e w in te r o f 1945-^6 when th e c lo v e r was s e v e r e ly in ju r e d by S c l e r o t in i a * W heeler ( 3 7 ) r ep o r ts th a t Ladino c lo v e r i s r e e s ta b lis h e d from n a tu r a l re­ s e e d in g i f p r o p erly managed* Sprague and Eby ( 3 1 ) s t a t e th a t l o s s e s o f sta n d s from w in te r in ju r y and su m m er-k illin g can b est be avoided through 8 c a r e f u l management o f the p a stu re area to fa v o r th e c lo v e r , and th a t i n ­ ju red sta n d s may he th ick en e d by encouraging growth o f the sp read in g runners or by a llo w in g some o f the flo w er heads to mature seed* They f u r th e r s t a t e th a t n a tu r a l re se e d in g , during fa v o ra b le sea so n s, i s an e f f e c t i v e means o f r e p le n is h in g a thinned sta n d . Kennedy and Johnson (2 2 ) have rep o rted th a t l o s s o f Ladino c lo v e r sta n d s i s not u s u a lly a s s o c ia t e d w ith any one s o i l or weather c o n d itio n . B ather, i t i s more due to a com bination o f many f a c t o r s . Besponse to ^ F e r tiliz a tio n W heeler (3 7 ) s t a t e s th a t m ineral f e r t i l i z e r s should be a p p lie d gen­ e r o u s ly to Ladino c lo v e r f o r b e s t r e s u lt s . Experim ents by Brown and Jfan- s e l l (1 0 ) show th a t the b e st respon se from Ladino c lo v e r was secu red w ith lim e and phosphate and p o ta sh f e r t i l i z e r s and th a t i n f e r io r growth r e s u lte d from th e use o f e it h e r lim e o r m ineral f e r t i l i z e r s a lo n e . Sprague and Eby (3 1 ) recommend th a t Ladino c lo v e r be grown on s o i l s w e ll su p p lied w ith lim e and f e r t i l i z e r s in c e i t s rapid growth draws h e a v ily on phosphate and p o ta sh i n the s o i l . A hlgren and Sprague ( 5 ) have p resen ted r e s u lt s o f a greenhouse study which shows th a t a f t e r s o i l a c i d it y was c o rrected by lim in g , th e top growth produced by Ladino c lo v e r was s i g n i f i c a n t l y in crea sed by a p p lic a tio n o f e i t h e r phosphorus or p otassiu m f e r t i l i z e r s . In a d d itio n , top growth was in c r e a se d c o n sid e r a b ly more when both f e r t i l i z e r s were a p p lie d than when o n ly phosphate or o n ly p o ta sh f e r t i l i z e r s were added* Brown (7 ) s t a t e s th a t p o ta sh i s th e f e r t i l i z e r most l i k e l y to be de­ f i c i e n t on Ladino c lo v e r f i e l d s , and remarkable resp o n ses to l i b e r a l 9 a p p lic a t io n s may "be e x p ec ted . Furthermore i n c o n tr a st to lim e sto n e and superphosphate, enough o f which can be added to l a s t fo r s e v e r a l y e a r s , p o ta sh (o r s t a b le manure) sh ou ld be a p p lie d a t l e a s t once every y e a r . T h is n e c e s s it y a r i s e s from th e fa c t th at p la n ts absorb more p otash than th e y need as lo n g a s i t i s a v a ila b le in the s o i l . Thus, w ith heavy i n ­ freq u en t a p p lic a t io n s , th e f i r s t crops g e t to o much and subsequent ones to o l i t t l e p o ta sh . Stew art and Bear (3*0 have rep orted th a t because o f i t s sh a llo w root system , Ladino c lo v e r needs a r e a d ily a v a ila b le supply o f p o ta sh in th e plow depth o f s o i l . This was evidenced by th e f a c t th a t at th e end o f th r e e y e a r s , Ladino c lo v e r p l o t s th a t had r e c e iv e d annual top d r e s s in g s o f s i x t y pounds o f p o ta sh p e r acre y ie ld e d l^f p ercen t more hay than o th er p l o t s f e r t i l i z e d w ith 300 pounds o f p otash p e r acre at seed in g tim e . D ickey (13) s t a t e s th a t Ladino c lo v e r seems to need p le n ty o f phos­ p h o r ic a c id and p o ta sh i n th e s o i l and la c k o f them may be r e sp o n sib le f o r some c a s e s o f d isa p p ea ra n ce. He fu r th e r s t a t e s th a t i t i s w e ll to make a l i b e r a l a p p lic a tio n o f f e r t i l i z e r where seed in g i s to be made and t o top d r ess every y ea r o r two w ith at l e a s t ^00 pounds o f 0—12—12, O-l^J—7, o r 0 -2 0 -2 0 f e r t i l i z e r s . Carbohydrate Content o f Storage Organs I t has been reco g n ized by most in v e s t ig a t o r s th a t m a in ta in in g a r e l a ­ t i v e l y h ig h p ercen ta g e o f reser v e carbohydrates i n th e sto ra g e organs o f fo ra g e p la n ts as a source o f energy f o r th e p rod u ction o f new p la n t p a r t s f o llo w in g d e f o li a t i o n and w in ter dormancy i s not o n ly im portant but n e c e s sa r y . 10 D ata are a v a ila b le on th e r e serv e carbohydrates o f s t o lo n s o f Ladino c lo v e r but l i t t l e d a ta on the r e serv e carboh ydrates o f r o o ts have been pub­ lis h e d * The e f f e c t o f v a r io u s treatm en ts and methods o f management and environment on th e carbohydrate l e v e l i n fo ra g e crops have been determ ined by v a rio u s resea rch workers* Graber e t * a l * (1 5 ) s t a t e th a t th e most s t r i ­ k in g ev id en ce o f a re d u ctio n i n th e o rg a n ic food r e se r v e s o f a l f a l f a , tim othy, «nd b lu e g r a ss was th e pronounced d ecrease i n the r a te o f growth i n p l o t s th a t had been su b je c te d to in te n s e c u t tin g treatm ents* Experim ents conducted by Wood and Sprague ( 3 6 ) working w ith Ladino c lo v e r s to lo n s show th a t a s w in ter p r o g r e s s e s , p er ce n ta g e s o f reducing sugars and t o t a l p o ly sa c c h a r id e s (con ­ s i s t i n g o f sta r c h and h e m ic e llu lo s e ) d ecreased in a l l p la n t m a teria ls* Thqy fu r th e r s t a t e th a t t o t a l sugars remained r e l a t i v e l y co n sta n t u n t i l l a t e win­ t e r i n th e non-hardy c lo v e r s but d ecreased u n iform ly in th e hardy c lo v e r s throughout th e w inter* T esar and A hlgren (3*0 found th a t c lo s e and freq uent c u t t in g trea tm en ts a p p lie d during the growing season r e s u lt e d in lo w er p e r ­ c e n ta g e s o f t o t a l a v a ila b le carbohydrates i n th e s to lo n s Ju st a f t e r th e l a s t summer c u ttin g * These d iff e r e n c e s were no lo n g e r apparent in November, but p l o t s cut most fr e q u e n tly had th e p o o rest stand in the f e l l and a g a in th e fo llo w in g s p r in g . G reathouse and S tuart ( l 6 ) observed a g r e a te r q u a n tity o f carbohydrates in th e r o o ts o f w interhardy than in l e s s hardy red c lo v e r v a r i e t i e s . Smith ( 2 9 ) working w ith red c lo v e r found th a t th e carbohydrate root r e s e r v e s were d im in ish ed during w in ter dormancy and both carbohydrate and n itr o g e n root r e s e r v e s were reduced by th e e a r ly sp rin g growth, as w e ll a s by th e in itia * t io n o f new growth fo llo w in g each c u t tin g . 11 Bather and H arrison (2 ? ) working w ith s ta r c h r e s e r v e s i n the r o o ts o f p a stu re d a l f a l f a found th a t a l f a l f a r o o ts were lo w e st in s ta r c h r e s e r v e s d u rin g th e p e r io d o f most a c t iv e growth in the sp r in g , and th a t sta r c h re­ s e r v e s become d e p le te d w ith c lo s e g ra zin g or fo llo w in g a c lo s e cu ttin g * They found fu r th e r th a t s ta r c h r e s e r v e s in a l f a l f a r o o ts p rev io u s to k i l l i n g f r o s t s were n ec essa ry to p rev en t carbohydrates s ta r v a tio n o f th e p la n ts and subsequent w in te r k illin g * Brown ( 8 ) r e p o r ts th a t th e sto ra g e o f o rg a n ic food r e s e r v e s i n peren­ n i a l fo ra g e p la n ts i s e s s e n t i a l to t h e ir normal fu n c tio n in g , and th a t sugars and s ta r c h e s are th e most im portant o f th e sto red carbohydrates# He a ls o s t a t e s th a t carbohydrate sto r a g e in the rhizom es o f Kentucky b lu e g r a ss was most rap id a f t e r m id-O ctober when top growth had p r a c t ic a l ly cea sed . Stewart and Bear (3 2 ) found th a t th e sta r c h con ten t o f Ladino c lo v e r p la n ts showed a d e c lin e during th e f i r s t 3 t o 5 days a f t e r harvest# Replenishm ent o f s ta r c h r e s e r v e s began 11 days a f t e r h a r v e stin g and th e o r ig in a l l e v e l was reached in about 17 days# They s t a t e th a t t o t a l a v a ila b le carbohydrates (su g a r, s ta r c h , and h e m ic e llu lo s e ) fo llo w e d a curve s im ila r to th a t o f starch# Smith and G-raber (3 0 ) rep ort th a t when f i r s t —y ea r b ie n n ia l sw eet c lo v e r was cu t on or b efo re September 2, th e p ercen tage o f " r e a d ily a v a ila b le carbo­ h y d ra tes1* in th e r o o ts o f a l l p la n ts was about th e same on November 20, re­ g a r d le s s o f p rev io u s c u ttin g treatm en ts# However, t h e ir r e s u lt s show marked d if f e r e n c e s i n th e t o t a l amount o f " r e a d ily a v a ila b le carbohydrates" i n th e r o o ts o f the same p la n ts on November 20* Moran e t * a l # (26) working w ith Ladino c lo v e r found th a t th e concen­ t r a t io n s o f carbohydrates were g r e a te r i n s to lo n s than i n r o o t s , and th a t 12 th e amount o f new f o l i a r grow th produced a f t e r d e f o lia t i o n was c l o s e ly re­ la t e d to th e l e v e l o f carb oh yd rates a t th e tim e o f d e f o li a t i o n . These w orkers fu r th e r found th a t when s to lo n s grown in darkness d ied some carbo­ h y d ra tes s t i l l remained but th e y were a t a low l e v e l . D is e a s e s o f Ladino C lover A r e l a t i v e l y lim it e d amount o f in fo rm a tio n i s found in th e li t e r a t u r e on th e d is e a s e s a f f e c t i n g Ladino c lo v e r . H o llo w e ll (1 7 ) i& 19^2 s t a t e s th a t d is e a s e s o f Ladino c lo v e r are seldom o f im portance, alth ou gh th e c lo v e r may be s l i g h t l y in ju r e d by th e organism s th a t a tta c k common w hite c lo v e r . However, he s t a t e s l a t e r i n 1952 (1 8 ) th a t crown o r stem ro t ( S c le r o lin ia t r if o lio r u m ) th in s stan d s and o c c a s io n a lly d e str o y s la r g e a rea s w ith in f i e l d s du rin g w in te r and sp rin g months, and th a t in c e r t a in sea so n s much o f the l o s s a sc r ib e d to w in ter k i l l i n g may be caused by t h i s d is e a s e . He a ls o s t a t e s th a t i n th e South, south ern b lig h t ( S clerotiu m r o l f a i i ) . and root knot (H eterod era m a rio n i) . are h ig h ly d e s tr u c tiv e during th e summer months. Among o th er d is e a s e s m entioned were pepper spot (P seud oplea t r i f o l i i ) so o ty b lo c h ( Cymadothea t r i f o l i i ) . and b lack p a tch , caused by a n on ^ sp oru latin g fungus* K ilp a tr ic k e t . a l . (24) working w ith root and crown r o t s o f red c lo v e r in W isconsin found th a t p la n ts o f a l l ages were in f e c t e d but th e r o t s were more sev ere in second than i n f i r s t —year p la n t s . W ithin each o f th e s e groups, th e s e v e r it y in c r e a se d from th e beginn in g to the end o f th e se a so n . They a ls o found th a t stan d s d ecrea sed as th e s e v e r it y o f th e r o ts in c r e a s e d . Both c o r t i c a l and v a s c u la r t i s s u e s were a f f e c t e d but not alw ays sim u lta n e o u sly . 13 Fuaarium oxys'porum. F* roseum. spp. , B h iz o c to n ia s p p ., and G lieclad iu m rosem were among th e most common fu n g i i s o la t e d from d ise a s e d roots* Decker (1 2 ) s t a t e s th a t th e d is e a s e organism S c le r o t in ia t r ifo lio r u m E rik s was o f some im portance in e lim in a tin g p la n ts o f Ladino c lo v e r in Mary­ la n d a f t e r sta n d s had been damaged by summer drought and heavin g d urin g th e w in te r and e a r ly s p r in g . K ilp a tr ic k e t » a l * (2 3 ) i n stu d yin g th e r e la t iv e p a th o g e n ic ity o f fu n g i a s s o c ia te d w ith r o o ts r o t s o f red c lo v e r in W isconsin s t a t e th a t th ere are wide d if f e r e n c e s in p a th o g e n ic ity between i s o l a t e s o f fu n g i concerned w ith th e d ise a s e d r o o ts o f red c lo v e r and th a t i s o l a t e s o f Pythium. Fusarium. B h iz o c to n ia . Phoma. G -iliocladium and th e b la ck p a tch fungus were among th e most p a th o g e n ic . The d is e a s e symptoms in clu d ed d is c o lo r a t io n and decay o f th e r o o ts and h y p o co ty ls, s tu n tin g , and sometimes death o f th e p la n ts* WEATHER CONDITIONS Due to th e in flu e n c e o f c lim a t ic c o n d itio n s o f th e l i f e o f Ladino c lo v e r , e s p e c i a ll y r a i n f a l l and h ig h as w e ll as low tem perature, a m onthly record o f t o t a l p r e c ip it a t io n , show, s l e e t , and h a i l to g e th e r w ith average minimum and maximum tem peratures are p r e se n te d in Tables 1, 2, and 3* Table 3 a ls o g iv e s the h ig h e st and lo w e st tem peratures recorded during each month f o r th e d u ra tio n o f th e experim ent* TABLE 1 . MONTHLY PRECIPITATION IN INCHES FROM AUGUST 1951 THROUGH JUNE 1954 AS RECORDED BY THE UNITED STATES WEATHER BUREAU AT EAST LANSING, MICHIGAN. Month 1951 January February March A p r il ------------------ . P r e c ip it a t io n . in ch es 1953 1952 1954 1 .8 6 ! • 64 2 .2 2 3 .3 2 2 .0 2 1 .0 3 2 .2 9 2.8 8 1 .6 1 4 .2 1 3 .2 5 2 .7 5 May June J u ly August ■■ — —» 2 .8 4 4 .9 8 1 .4 6 3 .2 4 3 .3 0 1 .7 5 2 .8 7 1 .0 3 3 .8 0 1 .1 4 4 .0 7 —— —— September O ctober November December 2*59 4 .1 7 2 .6 3 3 .0 9 1 .5 4 0 .3 5 3 .3 8 1 .8 4 1 .4 0 1 .4 3 0 .8 4 1 .4 8 —~— —, —- 3 1 .7 0 2 9 .1 3 2 2 .8 2 -------- Annual 15 TABLE 2 . MONTHLY SNOW, SLEET, AND HAIL IN INCHES FROM OCTOBER 1951 THROUGH MAY 195** AS BECOBDED BY THE UNITED STATES WEATHER BUREAU AT EAST LANSING, MICHIGAN Month 1951-52 1952-53 1953-5** O ctober ------------ 0 .1 November 1 6 .8 0 .8 2 .3 December 2 7 .8 5*3 7*5 January 1 2 .4 7*9 1 2 .1 February 1 0 .5 2 .4 13*3 March 9*8 2*5 13*8 A p r il 11*5 1 .2 0 .1 May — --------- -- 0 .3 2 0 .7 49. A T o ta l ■ — 8 8 .8 — - 16 o\ CM IV H «H CM -d- t o -dVS 2 NO ao nn C '- CO O n I I I I I I -d VS OS s o v sc * s • • • O s -d ’ o v \ s O CO !i i!1 • * • O 0 0 CO O s CfS v s 000 e n d I I ! ! !i C*'* VS CM 000 (V H OS C ^S d v \ I I i v s so v s os SO IV s o VS CQ V \ V \s O NON so • « • CM SO UN CM VS 00 • 0 0 H OS O v \s Q CO d CM d 00 COCV s o g s 00 so 3 - cn IV CM cv. *-) O o o s so 0 0 IV CM O CM CO CM CM CM d o CO 0 0 SO v \ d I * , C1M0 moO O «—I v s SO CM e n d C'Sd Cs- O s OS O r-J d 44r> CS CM - t sO sO Os Os Os 00 SO v s O s CO CO cn > O0 s t* \ 00 00 OS SO 0 0 v s d ♦ • * cn moo cn m m V S rH o s * * J Osr-I -4* rH CM CM O IV C S O• V^cn • • ST\ s o O • • • o s OS OS O CM OSGOIV IVSO vs d VS H H o s V \ vrs (V SO o v s s o 00 d o m CO CO IV Vsd cn CO m CM s o V S CM dO O O sO V S OS CM IV O s o V \ VS rs o s IV * t en d • vs 8 H v s n (M H H A • • 0 0 High and low are est te m p e ra tu re s m o n th s. TABLE 3. MINIMUM AND MAXIMUM MONTHLY TEMEEHATURES FROM AUGUST 1951 THROUGH JUNE I 9 5 A AS RECORDED AT THE UNITED STATES HEATHER BUREAU AT EAST LANSING, MICHIGAN V \ d CM r-t CM CM I low ­ th e W) w •H O SO 0 VS CO SO cm the h ig h est and recorded during * so m < n CM CM £ o hi y) I 3r m CM H I I I I I 1 I R » SO CQ CO v S SO C* Os I I CM v s • * C*- o s IV SO so o • 0 vs OS vsd CQ rCj f! o 2B HI s o I I I x\ •H V I I I | O CM O 0 0 0 cm c^ rs s o c n on OS H CM • • ♦ CM d CO 4-CMH ^ u u <0 u e> ® *2 •° s *° a O 0) o 0 0 © O 1^ fl VI e* PART I STUDIES OF THS SURVIVAL OF ORIGINAL TAP BOOTS OF LADINO CLOVER A s e r i e s o f f i e l d and greenhouse s tu d ie s was i n i t i a t e d in th e summer o f 1951 and con tin u ed through 195^ on the M ichigan S ta te C o lleg e farm near E ast L an sin g, M ichigan, to determ ine th e ex a ct tim e when the o r ig in a l tap ro o t o f th e Ladino c lo v e r p la n t d ie s and to a s c e r ta in , i f p o s s ib le , the cause o f d ea th o f the tap r o o t. Rapid th in n in g o f th e stan d i s an unmis­ ta k a b le c r i t e r i o n o f when th e o r ig in a l tap r o o ts o f n o n -v e g e ta tiv e ly propogated legum es l i k e a l f a l f a and red c lo v e r d ie . However, when the tap root o f a s to lo n ife r o u s legume l i k e Ladino c lo v e r d ie s , th e rap id th in n in g in d ic a t iv e o f a p oorer stand i s not im m ediately ev id en t because th e v e g e t a t iv e s to lo n s are a l i v e and con tin u e to spread; new le a v e s are e v id e n t even though th e main tap r o o ts may be dead. E s t a b lis h in g th e tim e o f death o f th e l i f e h is t o r y o f Ladino c lo v e r i s con sid ered im portant s in c e th e p ro d u ctio n o f even a s to lo n ife r o u s legume l i k e Ladino c lo v e r i s s e r io u s ly im paired once th e main tap root i s dead. S to lo n s c o n tin u in g to l i v e a f t e r th e main tap root i s dead have r e l a t i v e l y sh ort fib r o u s r o o ts Incapable o f deep s o i l p e n e tr a tio n so n ecessa ry f o r drouth r e s is t a n c e and s i g n i f i c a n t l y h ig h fo ra g e p ro d u ctio n . 18 M a te r ia ls and Methods In 1951* 1952, and 1953* in o c u la te d Ladino c lo v e r seed (F. C. 2 3 ,6 0 8 , r e c e n t ly named P ilg r im ) was p la n te d i n f l a t s in th e greenhouse i n July* I n d iv id u a l s e e d lin g s were tra n sp la n te d in August in to th e f i e l d s i x in c h e s apart i n each d ir e c t io n form ing a p e r fe c t square p a tte r n . This was done to s im p lify lo c a t in g th e o r ig in a l p la n ts , and to in su re th a t v o lu n te e r younger p la n ts e s ta b lis h e d a s a r e s u lt o f rese e d in g would not be counted as o r ig in a l p la n t s . Spike n a i l s 5 in ch es lo n g were p a in te d w h ite and d r iv e n in to th e s o i l one in ch n orth o f each o r ig in a l e s ta b lis h e d p la n t, so th a t each space co u ld be accounted f o r whether th e root was a liv e or dead. A f i e l d was s e le c t e d infoich had never been seeded to Ladino c lo v e r but had been used f o r o th er c lo v e r s (T rifo liu m s p p . , ) . The s o i l type was a Conover s i l t loam, an im p e r fe c tly —drained s o i l g e n e r a lly h ig h in f e r t i l i t y and w e ll adapted to corn, sm all g r a in s, and legum es. A randomized b lo ck exp erim ental d e s ig n w ith fou r r e p lic a t io n s was u sed w ith two a n a ly se s o f f e r t i l i z e r , 0-20—0 and 0—20-20, d r i l l e d in to th e s o i l at acre r a te s o f 400 pounds p r io r to tr a n s p la n tin g . In d iv id u a l p l o t s 10 by 15 f e e t in s iz e (10 by 10 in 1953) were lo c a te d over t i l e l i n e s to f a c i l i t a t e good d r a in a g e. 1200 p la n ts in 1951 Each o f the fo u r r e p lic a t io n s co n tain ed 1952, and 600 p la n ts in 1953* P la n ts were i r r i ­ g a ted im m ediately a f t e r tr a n sp la n tin g to f a c i l i t a t e b e t t e r s u r v iv a l. A ll p l o t s were c lip p e d fo u r tim es to a h eig h t o f in c h e s each sear- con to s tim u la te a r o t a tio n a l system o f g ra zin g o f Ladino c lo v e r in M ichigan. 19 A summary o f d a tes seed ed , d a tes e s ta b lis h e d , number o f p la n ts e s ta b ­ l i s h e d , and when sam pling began f o r carbohydrate a n a ly s is i s a s fo llo w s ! Seed p la n te d i n greenhouse J u ly 3 1 . J u ly 2 0 , J u ly 19, S e e d lin g s e s ta b l i s h e d in f i e l d 1951 1952 1953 August 27-30 August 19-20 August 20-22 Humber o f p la n ts e s t a t e lis h e d Date sam pling s ta r te d 4800 4800 2400 Aug. 1952 S e p t. 1952 In mid August 1952 and m onthly t h e r e a f t e r u n t il June 1953* a t o t a l o f 100 tap r o o ts were sampled from th e p la n ts e s ta b lis h e d in 1951 (50 p la n ts each from areas r e c e iv in g 0 -2 0 -0 and 0 -2 0 -2 0 f e r t i l i z e r ) f o r carbohydrate a n a ly sis * The b a sa l 6 in c h e s o f th e s to lo n s was a ls o h a rv ested from th e se p la n ts f o r a n a ly sis * Sampling o f r o o ts and s to lo n s began i n September 1952 and ended in June 1954 on p la n ts e s ta b lis h e d in 1952* A ll sam ples were washed f r e e o f s o i l w ith running w ater and d r ie d in a fo r c e d a ir d r ie r at 65° 0* f o r two weeks. Samples were th en ground s u f f i c i e n t l y f in e in a W iley M ill to p a ss through a 60-mesh s e iv e , and s to r e d in sto p p ered b o t t le s u n t i l th ey were an alyzed . The method d e scr ib e d by Weinman (3 6 ) was used to f r a c t io n a t e th e to ­ t a l a v a ila b le carbohydrates from the t o t a l amount o f carbohydrates p r e se n t i n th e r o o ts and sto lo n s* The reducing power o f the t o t a l a v a ila b le carbo­ h y d ra tes was determ ined by methods d escrib e d in A.Q.A.C. ( 6 ) . D u p lica te sam ples each o f 150 m illig ra m s in s iz e were used in a l l d ete r m in a tio n s. P e rc en ta g e s o f t o t a l a v a ila b le carbohydrates are ex p ressed on th e b a s is o f dry w eight o f r o o ts and s t o lo n s . A count o f th e p ercen ta g e o f dead p la n ts p resen t i n 100 marked spa­ c e s was made i n the f i e l d by exam ination o f r o o ts removed from th e f i e l d 20 from p la n t s e sta b lish ed , i n 1951* 1952 and. 1953* O b servation s were made on th e 100 r o o ts o b tain ed each month to determ ine v ig o r , soundness, and d is e a s e i n f e s t a t i o n . B egin n in g in O ctober 1953 and monthly t h e r e a ft e r u n t i l A p ril 195^» 50 p la n ts w ith a t l e a s t 2 in c h e s o f tap root (r e p r e se n tin g 50 p la n t sparc e s ) were o b ta in ed from th e 1952 and from th e 1953 e s ta b lis h e d p la n ts and tr a n sp la n te d in to th e greenhouse to determ ine: ( l ) i f p la n ts th at were n ot exposed to w eather c o n d itio n s a f t e r a c e r t a in month d ie , (2 ) where to draw th e l i n e o f dem arcation between dead and l i v i n g tap r o o ts , and ( 3 ) i f r o o ts o f secon d -year c lo v e r were as v ig o ro u s a s r o o ts o f f i r s t - y e a r c lo v e r . The s to lo n s o f th e 100 p la n ts were c lip p e d to a le n g th o f 1 in ch and tra n sp la n te d to 1 1 -in c h p o t s , f iv e p la n ts p er pot* A comparison o f th e recovery growth, p ercen t o f dead tap r o o t s , and root c h a r a c t e r is t ic s was made a f t e r a three-m onth p e r io d . Recovery growth o f le a v e s and s to ­ lo n s i n th e greenhouse was h a rv ested w ith sh ea rs, bagged, d rie d fo r 46 h ours in a fo r c e d a i r d r ie r a t 650 C ., and w eighed. Roots o f the p la n ts e s t a b lis h e d in 1952 and 1953 were removed from th e s o i l a f t e r the top growth was h a rv ested , examined, dead tap r o o ts counted, and l i v i n g r o o ts ra ted from 0 to 10 f o r v ig o r and amount o f new l a t e r a l root growth pro­ duced. RESULTS OF FIELD STUDIES D eath o f Tap R oots Under F ie l d C on d ition s No s ig n if ic a n t d iffe r e n c e in the s u r v iv a l o f tap r o o ts o f Ladino c lo v e r was n oted between the two a n a ly se s o f f e r t i l i z e r (0 -2 0 -0 and 0 -2 0 -2 0 ) u se d . For t h is reason th e data f o r th e two a n a ly se s o f f e r t i l i z e r have been averaged to s im p lify p r e s e n ta tio n o f d a ta . P la n t tap r o o ts e s ta b lis h e d in August 1951 s ta r te d dying in December 1952, 16 months a f t e r th e p la n ts were e s t a b lis h e d . The p ercen tage o f dead r o o ts in c r e a se d p r o g r e s s iv e ly from 9 in December to 100 in J u ly ( ta b le h, f ig u r e l ) . Tap r o o ts from p la n ts th a t were e s ta b lis h e d in August 1952 began dy­ in g in August 1953, 12 months a f t e r e sta b lish m e n t. The p ercen tage o f dead r o o ts in c r e a se d p r o g r e s s iv e ly from 10 in August 1953 to 100 in J u ly 19 5^* Tap r o o ts from p la n ts e s ta b lis h e d in August s ta r te d dying in August 195^* 12 months a f t e r e sta b lish m e n t, j u s t as th e 1952 e s ta b lis h e d p la n t s . It is s ig n i f i c a n t th at a l l o r ig in a l tap ro o ts were dead by J u ly o f th e second pro­ d u c tio n y ea r in each o f th e two spaced p la n tin g s e s ta b lis h e d in two d if f e r e n t years. The p e r io d o f h ig h e s t m o r ta lity o f tap ro o ts o f th e 1952 e s ta b lis h e d p la n t s in a s in g le month*s p e r io d occurred from A p r il 1954 to May 1954 when th e p ercen ta g e o f dead r o o ts ro se from 58 in A p ril to 80 in May; li k e w is e , p la n t s e s ta b lis h e d i n 1951 hod a near maximum death ra te during t h i s month­ l y in t e r v a l when th ey were o f th e same age a s th e 1952 p la n ts* 22 Table 4 . Sampling Month P ercen ta g e o f tap r o o ts dead i n the f i e l d b egin n in g one y ea r a f t e r esta b lish m en t* P la n ts e s ta b lis h e d i n August 1951, 1952, and 1953 Age o f Plant,, Months 1951 Year E s ta b lis h e d 1952 1953 # Dead J u ly Aug. S e p t. 0c t. 11 12 13 1^ 0 0 0 0 0 10 25 30 Nov. D ec. J an . P eb. 15 16 17 18 0 9 16 20 33 36 ko UQ Mar. Apr. May June J u ly 19 20 21 22 23 28 35 53 72 100 52 58 80 93 100 0 12 — — — — — — — — ‘— Figure 1. f£>oo © iH • O VO © 1-1 A •cJ o r -i ** »H CM 0> ON Q\ O s H iH c—I o v a v ti o CO v r\ © OO s^treid praap jpo aSa^ueoao,! CM o Percentage of dead roots in the field "beginning one year after eetablishment of 1951* 1952, and 1953 plants. 23 zk Boot T issu e D e te r io r a tio n and D is e a se s C o r tic a l t i s s u e d e t e r io r a t io n o f r o o ts was f i r s t ob served in th e 1951 e s t a b lis h e d p la n t s in O ctober 1952, 1^ months a f t e r p la n t s were e s t a b lis h e d in th e f i e l d ( t a b le 5)* There was a gradual in c r e a s e in th e p ercen ta g e o f a f f e c t e d r o o ts sampled, in c r e a s in g from 6 in O ctober t o 100 i n March 1953* Two months a f t e r th e i n i t i a l d e t e r io r a tio n o f th e r o o ts , 9 p ercen t o f th e r o o ts sampled were dead ( ta b le ty). I n March when a l l o f th e r o o ts were showing e x te r n a l t i s s u e d e t e r io r a tio n and many were b ad ly d is c o lo r e d , 28 p e rc en t o f th e 100 r o o ts sampled were dead, n a l r o o ts were dead. Pour months l a t e r , a l l o r i g i ­ During a c e r t a in sta g e i n th e l i f e o f th e Ladino c lo ­ v er p la n t , th e c o r t i c a l t i s s u e o f th e root may be d e t e r io r a tin g but the in n e r a rea o f th e root may s t i l l a c t u a lly be a l i v e . As tim e p r o g r e s s e s , th e ro o t may be dead f o r a l l p r a c t ic a l p u ip o ses o f t r a n s lo c a t io n or absorp­ t i o n o f n u tr ie n t s , even though the in n er p o r tio n o f th e root may appear to be a l i v e . C o r tic a l t i s s u e d e t e r io r a t io n was f i r s t observed in June 1953 on th e r o o ts o f p la n ts e s ta b lis h e d i n 1952, when th e p la n ts were 10 months o ld and g o in g in to t h e i r f i r s t p r o d u ctio n year ( ta b le 5)* o f the 100 r o o ts sampled were d e t e r io r a t in g . At t h is tim e kO p ercen t The p ercen tage o f the sampled r o o ts a f f e c t e d in c r e a se d r a p id ly and by August 100 p ercen t o f th e r o o ts were d e t e r io r a tin g , some very s e v e r e ly . At t h is tim e when 100 p ercen t o f th e r o o ts were showing s ig n s o f c o r t ic a l t is s u e d e t e r io r a tio n , te n p e r c e n t were dead. The d e t e r io r a t io n on r o o ts o f p la n ts e s ta b lis h e d i n 1953 was f i r s t observed i n June when kZ p ercen t o f th e t o t a l sampled r o o ts were 25 r F ig u re 2* B oots o f 1952 e sta b lish e d , p la n ts a s th ey appeared ins May 1953, when 9 months o ld (Top) June 1953* when 10 months o ld (L e ft m id d le) J u ly 1953* when 11 months o ld (B ig h t m iddle) O ctober 1953* when l h months o ld (L e ft bottom) May 195^* when. 21 months o ld (B ig h t bottom ) 26 27 a f f e c t e d ; by August 100 p ercen t o f th e r o o ts were d e t e r io r a t in g to some d eg ree and 12 p ercen t o f th e r o o ts were dead ( t a b le k, 5)* I t shou ld be noted th a t even though th e p la n ts e s ta b lis h e d i n 1951 showed c o r t i c a l t i s s u e d e t e r io r a t io n l a t e r (O ctober) than p la n ts esta b ­ l is h e d in 1952 and 1953 (J u n e ), th ere i s a s t r ik in g s im ila r it y among a l l th r e e y ea rs — r o o ts s ta r te d d yin g two months a f t e r d e t e r io r a tio n was f i r s t ob served i n th e th ree sta n d s e s ta b lis h e d in th r e e d if f e r e n t y e a r s . T able P e rcen ta g e o f Ladino c lo v e r r o o ts showing c o r t ic a l t i s s u e d e t e r io r a t io n b egin nin g in May, the f i r s t y ea r a f t e r esta b lish m en t in August* Month o f O b serv a tio n Age o f P la n t s , Months Year p la n ts were e s ta b lis h e d 1952 1951 195: May June J u ly Aug. 9 10 11 12 0 0 0 0 0 ko 90 100 S e p t. O ct. Hov. L ee. 13 Ik 15 16 0 6 2k 65 — — J an . F eb. Mar. 17 18 19 72 90 100 — — 0 kz 87 100 — i— —M —— —— 28 When symptoms o f c o r t i c a l t is s u e d e t e r io r a t io n were f i r s t d e te c te d on the r o o ts o f th e 1952 e s t a b lis h e d p la n ts in June 1953* a t o t a l o f 100 is o ­ l a t i o n s was made from th e d is e a s e d roots** Of th e t o t a l i s o l a t e s , 71 per­ cen t were Fusariuxa s p p ., and 19 p ercen t B h iz o c to n ia sp* ( t a b le 6)* Because o f th e r e l a t i v e p a th o g e n ic ity o f th e s e fu n g i, and th e la r g e p ercen ta g e p re­ s e n t, i t i s p rob ab le th a t th e se were th e organism s ca u sin g th e d e te r io r a ­ t i o n and death o f Ladino c lo v e r roots* I t i s p o s s ib le , however, th a t the d e t e r io r a t io n occu rred fo llo w e d by in v a sio n o f th e fu n g i, a c c e le r a t in g th e r a te o f d eath o f tap r o o t s . Table 6* P ercen tage d is t r ib u t io n o f organism s in 100 i s o l a t i o n s made in June 1953 from d ise a se d specim ens o f Ladino c lo v e r r o o ts o f p la n ts e s t a b lis h e d in August 1952. D is e a se organism P ercen t o f T otal I s o l a t e s Fusarium oxvsnorum 48 F . roseum 17 F . s o la n i 6 B h iz o c to n ia sn . 19 Mucor s o . 6 Bhizonus sn . 1 Basis-porium 1 O ther 2 T o ta l Ct 100 I s o l a t io n s made by Dr. E . W. Hansen, P a t h o lo g is t , D iv is io n o f For­ age Crops and D is e a s e s , U*S.D*A. U n iv. o f W isconsin, Madison, W isconsin* 29 Photographs i n f ig u r e 2 show th e p r o g r e s s iv e s ta g e s o f ro o t deteriora?t i o n o f d is e a s e d r o o ts o f p la n ts e s ta b lis h e d in 1952. There i s a s t r ik in g s im i l a r i t y i n th e appearance o f th e c o r t i c a l d is c o lo r a t io n o f th e s e r o o ts and th o se o f red c lo v e r a s shown by K ilp a tr ic k e t . al* (23)* Tap r o o ts were sound, v ig o r o u s, f r e e o f c o r t i c a l t i s s u e d e t e r io r a tio n and a p p aren tly h e a lth y a t th e age o f n in e months in May 1953. th e b egin n in g o f the f i r s t p r o d u c tio n year* Two months l a t e r i n J u ly 1953» th ere was c o n sid era b le c o r t i c a l t i s s u e d e t e r io r a t io n and d is e a s e symptoms which had s ta r te d in Ju n e. The r o o ts con tin u ed t h e ir d e t e r io r a tio n and in August a l l o f th e sampled r o o ts showed c o r t i c a l d e t e r io r a tio n and d is e a s e symptoms. p e r c e n t which were dead showed com plete root t is s u e d ise n te g r a tio n * The 10 Two months l a t e r , in O ctober 1953, a t th e end o f th e f i r s t p ro d u ctio n y e a r , a l l r o o ts showed s ig n s o f even g r e a te r c o r t ic a l t is s u e d e t e r io r a tio n than noted p r e v io u s ly and 30 p ercen t o f th e r o o ts were dead. At th e age o f 21 months, i n May 195h (b eg in n in g o f th e second p ro d u ctio n y e a r ), 80 p ercen t o f the r o o ts were dead and th e rem ainder was, n e v e r th e le s s , showing extreme c o r t i ­ c a l d e t e r io r a t io n w ith fa r few er l a t e r a l r o o ts than r o o ts sampled in the p r e v io u s y e a r . In J u ly when p la n ts were 23 months o ld , 100 p ercen t o f th e ta p r o o ts were dead, and o n ly s to lo n s o f the o r ig in a l p la n ts were l i v e . Death o f tan r o o ts tak en t o greenhouse* In O ctober 1953 and m onthly t h e r e a f t e r u n t i l A p r il 195^* 5^ tap r o o ts each from p la n ts e s ta b lis h e d in August 1952 and August 1953 were tr a n sp la n te d in to the greenhouse* Of th e 50 r o o ts from th e 1952 p la n t s tr a n sp la n te d to the greenhouse in O ctober I 9 5 3 , h/2. p ercen t were dead when h a rv ested th ree months la te r * The p ercen ta g e 30 o f dead ta p r o o ts o f th e s e p la n t s (g o in g through t h e ir second w in te r ) tr a n s p la n te d to th e greenhouse monthly from O ctober to A p r il in c r e a se d ea ch month u n t i l 87 p ercen t were dead by A p r il ( ta b le 7)* In s t r ik in g c o n tr a s t none o f th e tap r o o ts o f th e p la n ts e s ta b lis h e d i n 1953 (g o in g through t h e ir f i r s t w in te r ) d ie d when removed from f i e l d to greenhouse c o n d itio n s d uring th e p e r io d from O ctober to April*. R oots from 1952 e s t a b lis h e d p la n ts tr a n sp la n te d m onthly from O ctober 1953 through January 195^ showed a s im ila r m o r ta lity r a te a f t e r th r e e months' growth in th e greenhouse as r o o ts allow ed to remain in th e f i e l d under w in te r c o n d itio n s f o r th e three-m onth p e r io d ( ta b le 7» fig u r e 3)* T h is would in d ic a te th a t the age o f r o o ts (and accompanying d is e a s e on o ld e r p la n t s ) r a th e r than w in te r in ju r y o ccu rrin g i n th e f i e l d was th e im portant f a c t o r in ca u sin g death* I f w in te r in ju ry had been p r im a r ily r e s p o n s ib le f o r th e p r o g r e s s iv e in c r e a s e i n dead tap r o o ts as th e w in te r p r o g r e sse d , rea d in g s made on th e p ercen tage o f dead r o o ts, e .g * , in J a n ­ uary on r o o ts ta k en in to th e greenhouse i n O ctober, would have been about equal t o th e p ercen ta g e o f dead r o o ts determ ined in the f i e l d in October* T h is however, was not the ca se; r o o ts tak en from th e f i e l d during O ctober, November, December, and January and allow ed to grow f o r th ree months in th e greenhouse showed a s im ila r m o r ta lity as th o se allow ed to grow under ad verse w in te r c o n d itio n s in th e f i e l d . R oots taken from the f i e l d in March and A p r il are allo w ed to grow th ree months in th e greenhouse, however, showed a lo w er m o r ta lity than th o se allow ed t o sta y in th e f i e l d during t h i s th ree-m on th p eriod * T h is would in d ic a te th at e it h e r ( l ) i n i t i a t i o n o f new grow th u n d e r f i e l d c o n d itio n s in the sp rin g or (2 ) f lu c t u a t in g sp r in g te m p e r a ^ t u r e s might a c c e le r a t e th e ra te o f m o r ta lity under f i e l d c o n d itio n s , and •rl o O o H CO o vO *%OOJL d s % -cr puep JO 9^^U © O Jd ^ CM o Percentage of dead tap roots obtained from field at monthly in tervals compared to roots sampled three months earlier but allowed to grow in the greenhouse for a 3-no^h period* Plants established in 1952* o\ Figure 3* 31 32 would su g g e st th a t " w inter in ju ry" may take p la c e in th e sp r in g r a th e r th an in th e w in te r . Forage p r o d u ctio n in green h ou se. Hoots o f f i r s t p ro d u ctio n year p la n t s e s t a b lis h e d i n August 1953 were compared w ith second p rod u ction y e a r p la n ts e s t a b lis h e d i n August 195^ w ith r e fe r e n c e t o th e r e l a t i v e a b i l i t y o f th e s e p la n ts to produce ground co v er during two—, fo u r -, and six:—week p e r io d s and t o t a l v e g e t a tiv e growth in th r e e months. The r o o ts o f th e f i r s t p ro d u ctio n y ea r p la n ts c o n s is t e n t ly produced much more and d en ser ground co v er in a l l c a s e s than second p ro d u ctio n y ea r p la n ts ( t a ­ b le 8 , f ig u r e A ). At th e end o f th ree months* growth in th e greenhouse, r o o ts and p la n ts go in g in t o t h e ir f i r s t w in te r produced from 353 p ercen t to 698 p e rc en t more top growth (depending on th e month o b ta in ed from the f i e l d ) than r o o ts from p la n ts goin g in to th e second w in te r . Leaves and p e t i o l e s o f p la n ts goin g in to t h e ir f i r s t w in ter were t y p ic a l ly la r g e , whereas p la n ts g o in g in to t h e ir second w in ter had mhch l e s s v ig o ro u s s t o lo n s , and le a v e s , g r e a t ly resem bling th ose o f common w hite c lo v e r ( fig u r e 5)» D i f f i c u l t y was ex p erien ced in determ in in g a f t e r th r e e months' growth in th e greenhouse when tap r o o ts should be c l a s s i f i e d as dead. In con­ s id e r in g the f a c t th a t a p la n t th at i s alm ost dead i s s t i l l a l i v e , a r a tin g s c a le was d ev ise d i n which a l l the r o o ts c l a s s i f i e d as l i v i n g , a f t e r th ree months' growth in th e green h ou se, were ra ted from 0 to 10* Hoots th a t bad produced n e ith e r top growth nor l a t e r a l fib r o u s r o o ts but had l i v e t is s u e p r e se n t were ra ted as zero , w h ile t h r i f t y vigorou s r o o ts rated 10 ( f ig u r e 6 ) . Hone o f th e l i v e ro o ts from p la n ts goin g in t o t h e ir second w in ter p reced in g th e second p ro d u ctio n y ea r ra ted h ig h er than fo u r, w ith th e g r e a t e s t F igu re A# R e la tiv e amount o f ground cover from reco v ery growth produced from f i r s t and second p ro d u ctio n y ea r r o o ts in two—( t o p ) , fo u r -(m id d le ), and s ix — (b ottom ) week p e r io d s . 35 Table 7» S u rv iv a l o f 100 tap r o o ts brought in to th e greenrhouse a t monthly in t e r v a ls from p la n ts e s t a b l i s h ed i n 1952* P ercen tage read in gs were th ree months a f t e r r o o ts were tak en from f i e l d . Month T ran sp lan ted from F ie ld O ct. Nov. Dec. Jan . F eb. Mar. Apr. 1953 1953 1953 195^ 1954* 195^ 195^ Age o f P la n ts when H arvested, Months P ercen tage Dead Hoots 42 44 48 60 17 18 19 20 21 22 23 73 87 * No p la n ts tra n sp la n te d in February. Table 8 . P rod u ction fo r a 3-®o:nth p erio d by p la n ts from tap r o o ts goin g in to t h e ir f i r s t and second w int e r s p reced in g t h e i r f i r s t and second p ro d u ctio n y e a r s, r e s p e c t iv e ly . Month T ran sp lan ted from F ie ld O ct. Nov. D ec. Jan. F eb. Mar. Apr. 1953 1953 1953 195^ 195*1* 195^ 195^ Month H arvested Jan. Feb. Mar. Apr. 1954 1954 1954 195^ P ercen t In c rea se o f Younger over O lder P la n ts 510 353 590 465 -------------------------------------------- — — June 1954 J u ly 1954 698 588 * No p la n ts tra n sp la n te d i n February. 36 F igu re 5* Recovery growth, (to p ) produced, by f i r s t —( r i g h t ) and second—( l e f t ) p ro d u ctio n y e a r r o o ts in th ree months in th e greenhouse and th e r e l a t i v e s iz e and c h a r a c t e r is t ic s o f le a v e s and p e t i o l e s (bot­ tom) from th e s e p la n ts# L eaves on th e l e f t were produced by f i r s t p ro d u ctio n y ea r r o o t s , th o se on th e r ig h t by second p ro d u ctio n y ea r roots* 37 38 number o c cu rr in g in the zero and one category* PXants g o in g in to t h e i r f i r s t w in te r p reced in g t h e i r f i r s t p ro d u ctio n year ra ted 10* G en erally, a s th e sea so n p ro g ressed more o f th e l i v e r o o ts o f p la n ts g o in g in to the w in te r p re ce d in g t h e i r second p ro d u ctio n y ea r were c l a s s i f i e d in th e zero c a te g o r y ( t a b le 9 )* A ll o f the r o o ts o f p la n ts removed from th e f i e l d in January through A p r il p reced in g th e f i r s t p rod u ction y ea r grew when tr a n s­ p la n te d to th e f i e l d a f t e r th r e e months growth in the greenhouse* th e r o o ts r a tin g 0 to 5 Hone o f g o in g in to t h e ir second p rod u ction year liv e d when tr a n sp la n te d back t o th e f ie ld * T able 9* V igor r a tin g o f th o se l i v e ro o ts rem aining o f 50 r o o ts tak en from th e f i e l d and rated a f t e r th ree months' growth in th e greenhouse ( r a tin g 0 -s lo w e s t, 10 s h ig h e s t ) D ate He— moved Prom Y ie ld _____ ________________Year o f E stablish m en t__________ __________________1952___________________ 1953** Dumber o f L ive Hoots in H ating Groups T o ta l Oct* Nov. Dec* Jan* Feb. Mar. Apr. 1953 1953 1953 1954 1954* 195^ 19 5^ 29 28 26 12 0 1 2 3 4 5 6 7 8 9 10 9 12 9 _ — 8 4 10 0 1 2 3 4 5 6 7 8 9 10 8 6 4 1 9 6 3 1 8 3 3 12 50 50 50 50 --------------- — 5 3 3 l * No p la n ts tr a n sp la n te d in February* ** A l l 50 r o o ts a l i v e in 1953* 50 50 F ig u re 6* R e p r e s e n ta tiv e o f a r a tin g s c a le (O—IO) d e v ise d f o r r a tin g l i v i n g r o o ts on th e b a s is o f v ig o r , sound ness, and amount o f new r o o ts a t the end o f th r e e months i n th e greenhouse* 0 3 0 41 Carbohydrate L ev el o f B oots and S to lo n s The t o t a l a v a ila b le carbohydrate a n a ly s is o f r o o ts and s to lo n s o f p la n t s e s t a b lis h e d i n 1952 showed a p ercen ta g e o f 26*11 in th e r o o ts and 21*68 i n the s to lo n s fo r the month o f September, one month a f t e r p la n ts were e s t a b lis h e d , (ta b le 10, fig u r e 7)» There was a gradual r i s e i n the p er ce n ta g e o f t o t a l a v a ila b le carbohydrates from September t o November in both r o o ts and s t o l o n s , a t which tim e th e p ercen tage was 34*33 27*08 in sto lo n s* r o o ts and P er ce n ta g e s o f t o t a l a v a ila b le carbohydrates g ra d u a lly d ecrea sed from November to March* During t h i s p erio d th e p ercen tage i n r o o ts dropped from 34*33 to 20*48; in s t o lo n s , th e drop was from 27*08 to 12*65 p ercen t* Prom March to A p r il, th e r e was a d r a s t ic d ecrease in th e p e rc en ta g e o f t o t a l a v a ila b le carbohydrates i n r o o ts , d ecrea sin g from 20*48 in March to 9*25 in A p ril* T his was undoubtedly due to th e p ro d u ctio n o f new p la n t p a r ts and re g en e r a tio n o f o ld p a r ts a t the expense o f sto r e d car­ b o h y d ra tes. Prom A p r il through the summer months o f th e f i r s t p ro d u ctio n y e a r , th e p ercen ta g e o f t o t a l a v a ila b le carbohydrates in c r e a se d g ra d u a lly u n t i l November o f the f i r s t p rod u ction y ea r, at which tim e th e r o o ts had " a maximum p ercen ta g e o f 24*76 (about 10 p ercen t low er, however, than r o o ts sampled a year e a r l i e r ) . S to lo n s reached t h e ir maximum p ercen ta g e o f t o t a l a v a ila b le carbohydrates i n O ctober, one month e a r l i e r than th e r o o ts but t h e ir l e v e l was o n ly s l i g h t l y low er than s to lo n s sampled a year e a r lie r * A c tu a lly , th e p ercen ta g e o f t o t a l a v a ila b le carbohydrates i n Ladino c lo v e r s to lo n s was very s im ila r in coaparable months o f the f i r s t tw elv e and second tw elv e months o f growth ( fig u r e 7 ) . In s t r ik in g c o n tr a s t, the p er ce n ta g e o f t o t a l a v a ila b le carbohydrates o f r o o ts going in to t h e ir secon d w in ter was much low er than th a t o f t o o t s goin g in t o t h e ir f i r s t w inter* 42 Table 1 0 * Month o f Sampling P ercen ta g e o f t o t a l a v a ila b le carbohydrates in r o o ts and s to lo n s o f Ladino c lo v e r p la n ts e s ­ t a b lis h e d i n August I 95I and August 1952* Age o f P la n t s , Months Date o f E stablish m en t August 1951 August 1952 S to lo n s Hoots S to lo n s B oots S e p t. O ct. Nov. B ee. 1 2 3 4 Jan . P eb. Mar. Apr. 5 6 7 8 May June J u ly Aug. 9 10 11 12 _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ --------- 20 . 8*f Sept* 0 ct • Nov. D ec. 13 14 15 16 J an . P eb . Mar. Apr. May June 26.11 2 9 .1 5 3 4 .3 3 3 1 .7 7 2 1 .6 8 2 5 .8 7 2 7 .0 8 2 4 .3 4 2 4 .1 6 22. 66 2 0 .4 8 9 .6 2 1 9 .1 6 1 3 .7 6 1 2 .6 5 1 1 .3 8 1 6 .8 2 1 1 .2 5 1 1.38 1 3 .7 6 1 5 .1 9 1 2 .3 2 1 2.65 1 2 .7 0 1 9 .6 0 2 6 .5 1 3 0 .4 3 30 .7 2 2 3 .6 6 2 3 .5 0 2 7 .4 8 2 3 .1 4 2 2 .8 9 1 7 .2 5 21 .0 8 2 4 .7 6 2 3 .6 8 2 7 .7 7 2 9 .1 5 2 5 .8 7 2 4 .7 6 17 18 19 20 13*76 1 3 .3 7 1 2 .4 8 8 .1 0 1 4 .5 9 1 3 .9 6 1 2 .7 2 9 .2 5 1 8 .9 3 1 6 .6 2 1 3 .3 2 9 .2 5 20*57 1 7 .0 0 1 6 .0 2 1 4 .0 0 21 22 5*04 8 .7 5 7 .6 3 1 3 .3 2 7 .5 7 8 .7 6 8 .7 5 1 2 .0 2 --------------— ----------- ---------- - — — „ —, _ _ _ _ _ — ----------- -- ----------- ------- -------- ea^Q-tpAfoqjrao axqexT^a X^i<>^ J° s^B^uaojej Figure 7* The percentage of total available carbohydrates in the roots and stolons of Ladino clover established in August I 95 I and 1952, The p e rc e n ta g e o f t o t a l a v a ila b le carb oh yd rates in p la n t p a r ts was somewhat lo w er a t comparable a ges of p la n ts e s ta b lis h e d in 1951 as compared to p la n t s e s ta b lis h e d in 195^ but th e in c r e a s e in p ercen ta g e i n la t e f a l l . and gradual d ecrea se t h e r e a ft e r i s remarkably c o n s is t e n t , in p la n ts o f the two e s ta b lis h e d stan d s (fig u r e 7)* Data on th e p ercen ta g e o f t o t a l a v a il­ a b le carb oh yd rates f o r p la n ts e s ta b lis h e d in 1951 agree c l o s e l y w ith th o se o b ta in ed f o r th e p la n ts e s t a b lis h e d i n 195^ but th ey are incom plete because o f a l a t e s t a r t i n sam pling. D is c u ss io n D ata p r e se n te d show th a t r o o ts from Ladino c lo v e r p la n ts e s ta b lis h e d i n each o f 3 y e a r s s ta r t e d to d ie e it h e r in August or December a f t e r th e f i r s t p ro d u ctio n year but a l l r o o ts were dead in Ju ly th e su cceed in g — or second - p ro d u ctio n year* I t i s d i f f i c u l t to tr y to e x p la in why r o o ts o f p la n t s e s t a b lis h e d i n 1951 s ta r te d to d ie in December (16 months l a t e r ) w h ile th o se e s ta b lis h e d i n 195^ s h l 1953 s ta r te d to d ie in August (12 months la t e r ) * A p o s s ib le e x p la n a tio n i s th a t b lack en in g o f th e c o r t ic a l ro o t t i s s u e began e a r l i e r on th e r o o ts o f p la n ts e s ta b lis h e d th e l a t t e r two y e a r s (and dying e a r l i e r ) than th o se e s ta b lis h e d in 1951 (and d ying la te r ). T his c o r t i c a l b la ck en in g o f the root showed d is e a s e organism s which would have caused the d e t e r io r a tio n or may have r e s u lt e d in e a r l i e r d ea th o f th e root fo llo w in g in v a sio n by the organism s. There i s u nd eniab ly a c lo s e r e la t io n s h ip between i n i t i a l b lack en in g o f th e c o r t ic a l root t i s s u e and i n i t i a l dying o f some o f th e tap r o o ts - ro o ts o f some p la n ts were c l a s s i f i e d as dead two months a f t e r c o r t ic a l b lack en in g was observed i n each o f th r e e s u c c e s s iv e years* 45 Boot r o t s are r ec o g n ize d a s p r e s e n tin g very complex s it u a t io n s . may e a s i l y in v o lv e the in t e g r a t io n o f s e v e r a l l i v i n g organ ism s. They There i s a p o s s i b i l i t y th a t the r o o ts were f i r s t a tta ck ed by a Phycomycete w ith Fusarium and B h iz o c to n ia organism s fo llo w in g . F urther stu d y under h ig h ly s p e c ia liz e d and c o n tr o lle d c o n d itio n s i s needed to determ ine j u s t how im­ p o r ta n t ro o t r o ts are in c a u sin g th e death o f tap r o o ts o f Ladino c lo v e r . A lthough th e p ercen ta g e o f t o t a l a v a ila b le carbohydrates was low er i n th e r o o ts f o llo w in g th e second than th e f i r s t w in ter, i t i s d ou b tfu l th a t d eath o f r o o ts can be a ttr ib u te d p r im a r ily to the low l e v e l o f t o t a l a v a ila b le carbohydrates i n th e r o o ts . The monthly in c r e a s e i n root mor­ t a l i t y was g e n e r a lly gradual but i t d id show th e g r e a te s t monthly in c r e a s e d u rin g th e A p r il to June p erio d im m ediately p reced in g com plete death o f a l l r o o ts in J u ly . The low amount o f t o t a l a v a ila b le carbohydrates in th e r o o ts o f Ladino c lo v e r a t t h is tim e (May, 2 months b efo re a l l ro o ts were dead) may have been a r e s u lt , ra th er than a cau se, of th e d yin g o f the p la n t . D is e a se s which a tta ck ed th e p la n t th e p rev io u s summer or l a t e f a l l may have so weakened th e p la n t th a t th e low p ercen tage o f t o t a l a v a il­ a b le carbohydrates (n o ted in most p la n t p a r ts fo llo w in g e a r ly sprin g growth in p e r e n n ia l typ e p la n t s ) was in s u f f i c i e n t to carry on th e normal fu n c tio n s o f th e p la n t . (2 6 ) SUMMARY A s e r i e s o f f i e l d and greenhouse s t u d ie s was s ta r te d i n 1951 an(* t e r ­ m inated i n 195^ w ith sp a c e-p la n ted Ladino c lo v e r s e e d lin g s tr a n sp la n te d to th e f i e l d i n August 1951* 1952, and 1953 to determ ine e x a c tly when th e tap ro o t o f Ladino c lo v e r d ie s and th e probable cause o f d ea th . The r e s u lt s may be summarized as fo llo w s : 1. Tap r o o ts o f Ladino c lo v e r were a l l dead in th e second p rod u ction year o f a p la n t g e n e r a lly c l a s s i f i e d as a p e r e n n ia l. Tap r o o ts s ta r te d dying i n August o f th e f i r s t p ro d u ctio n year in two o f th e th r e e stan d s e s ta b lis h e d a n n u a lly in a th r e e -y e a r p e r io d . The m o r ta lity ra te in crea sed p r o g r e s s iv e ly u n t i l a l l tap r o o ts were dead i n J u ly o f the second p ro d u ctio n y e a r. 2. A p p lic a tio n o f *H)0 pounds p er acre o f 0—20—20 or 0-20—0 had no s i g n i f i ­ can t e f f e c t on th e r a te o f dying or tim e when a l l r o o ts were dead. 3. Ladino c lo v e r tap r o o ts began dying two months a f t e r th e tap ro o t showed s ig n s o f c o r t i c a l t is s u e darkening, p i t t i n g , and d e t e r io r a tio n . H'm D ise a se organism s p r ese n t i n d e t e r io r a tin g c o r t ic a l t is s u e o f r o o ts o f Ladino c lo v e r were Fusarium oxysnorum, F . roseum, F. s o la n i. o r B h iz o c to n ia s p . , and B asisnorium sp . > Fusarium oxysnorum. F. s o la n i , or B h iz o c to n ia spp. a re prob ab ly th e ca u sa l organism s o f d is e a s e s o f the root because o f the la r g e p ercen ta g e o f i s o l a t e s , and the p a th o g e n ic ity o f th e se organism s, and b eca u se o f th e n o n -p a th o g e n ic ity or weak p a th o g e n ic ity o f o th er fu n g i is o ­ la te d . 5» The p e rc en ta g e o f t o t a l a v a ila b le carb oh ydrates was h ig h e st in Ladino c lo v e r r o o ts and s to lo n s in November, and O ctober, r e s p e c t iv e ly , b efo re th e f i r s t p ro d u ctio n y e a r . I t dropped g ra d u a lly low er each month t h e r e a f t e r u n t i l A p r il o f th e f i r s t p ro d u ctio n y ea r, in c r e a se d a g a in u n t i l November f o llo w in g th e f i r s t p ro d u ctio n year, and th en continu ed to drop. 6* The p ercen ta g e o f t o t a l a v a ila b le carbohydrates was very s im ila r in th e s to lo n s during th e f i r s t and second w in te r s . The p ercen tage in th e r o o ts was co n sid e r a b ly low er during th e second w in ter and sp rin g p reced in g d ea th o f r o o ts in th e second p rod u ction year* 7* H oots from p la n ts tr a n sp la n te d p reced in g the f i r s t p rod u ction y ea r pro­ duced from 353 to 698 p ercen t more top growth in a three-m onth p erio d in th e greenhouse than r o o ts o f p la n ts going in to t h e ir second p rod u ction year* 8. W inter k i l l i n g i s not the ma&or f a c to r in th e s u r v iv a l o f tap r o o ts o f Ladino c lo v e r b ecau se f i r s t - y e a r tap r o o ts a l l l i v e through th e w in ter and seco n d -y ea r tap r o o ts (when brought in to th e greenhouse monthly s t a r t in g in O ctober and allow ed to grow th r e e months) d ie at about th e same r a te as tap r o o ts l e f t in th e f i e l d during th e three-m onth p e r io d . 9* Ladino c lo v e r perform s more lik e a b ie n n ia l than a p e r e n n ia l in M ichigan s in c e a l l o r ig in a l tap r o o ts were dead in J u ly o f the second p ro d u ctio n y e a r . C ontinued l i f e o f th e stan d would have to depend on ( l ) new or o ld s to lo n grow th or (2 ) new p la n ts e s ta b lis h e d from seed s produced by o r ig in a l p la n t s . 10. Ladino c lo v e r tap r o o ts a re a l l dead by J u ly o f th e second p ro d u ctio n y e a r but th e ex a c t f a c to r ca u sin g death needs fu r th e r in v e s t i g a t io n . Proba­ b le ca u se s o p er a tin g a lo n e or i n com bination are ( l ) th e d is e a s e organism s i s o l a t e d in th e d is c o lo r e d and d e te r io r a te d c o r t ic a l root t is s u e f i r s t ob serv ed two months "before tap r o o ts s ta r te d to d ie , (2 ) th e low p ercen ­ ta g e o f t o t a l a v a ila b le carbohydrates i n th e r o o ts in th e sp r in g imme­ d i a t e l y p rec ed in g th e second p ro d u ctio n year* PART I I EFFECTS OF MANAGEMENT AND FERTILIZATION ON SURVIVAL OF TAP ROOTS AND PRODUCTION OF FORAGE IN THE FOLLOW­ ING TEAR OF LADINO CLOVER S tu d ie s were i n i t i a t e d i n th e sp rin g o f 1953 on a Ladino c lo v e r f i e l d t h a t was d r i l l - s e e d e d i n August 1952 on th e M ichigan S ta te C o lleg e farm n ear E a st L an sin g, to determ ine th e e f f e c t s o f c u t tin g trea tm en ts, f e r t i l i ­ t y l e v e l s , a n a ly s e s o f f e r t i l i z e r s , and d a te s o f a p p lic a tio n o f f e r t i l i z e r s on th e s u r v iv a l o f Ladino c lo v e r tap r o o ts and th e p ro d u ctio n o f forage i n th e f o llo w in g year* M a ter ia ls and Methods A s p l i t - s p l i t —p lo t d e s ig n i n which a l l c u t tin g tr e a tm e n ts, f e r t i l i z e r s and d a te s o f a p p lic a tio n occurred in each o f fou r r e p lic a t e s was used* Four hundred pounds o f 0 -2 0 -2 0 f e r t i l i z e r p er acre was banded one in ch be­ low th e seed tim e o f se e d in g . (F.C* 23608, P ilg r im ) p la ced i n bands 7 in c h e s apart a t th e The s o i l ty p e , a H ills d a le sandy loam, i s g e n e r a lly found in u n d u la tin g to r o l l i n g a rea s and has a medium in h eren t f e r t i l i t y w ith good in te r n a l d ra in a g e. In d iv id u a l p lo t s were 7 by 1 2 .5 f e e t . The f i e l d s e le c t e d was r e l a t i v e l y f r e e o f weeds and con tain ed an e x c e l le n t , uniform stan d o f Ladino clo v er* Two and s i x hundred pounds p er acre o f 0—20—20 or 0—20—0 f e r t i l i z e r were to p d r e sse d on d if f e r e n t p l o t s on May 2 3 , June 23, or September 15, 1953, in th e f i r s t p ro d u ctio n y e a r . S im ila r amounts o f th e same f e r t i l i z e r s were 50 a p p lie d a s s p l i t a p p lic a tio n s ( i o f th e t o t a l amount on each d a te ) on o th e r p l o t s in May 2 3 , June 2 3 , August 20 and September 1 5 . A nother group o f p l o t s r e c e iv e d no to p d r e ss in g . Two c u t t in g trea tm en ts r e p r e se n tin g sev ere and l e n ie n t system s o f management were u sed i n 1953* C u ttin g d a te s on each treatm ent are g iv e n below : (1 ) (2 ) 4 tim es to a h e ig h t o f in ch es: May 23, J u ly 8 , August 20, and September 15* 6 tim es to a h e ig h t o f 1 in ch : May 23, June 23, J u ly 8 , J u ly 28, August 20, and September 15. The fo ra g e was raked and removed a f t e r each cu ttin g * On May 25, 1953, th e number o f l i v i n g r o o ts in a 2 - f o o t le n g th o f row o f c lo v e r seed ed in rows 7 in ch es apart was counted i n 32 p lo t s to ob­ t a i n an average o r ttbase count11 o f l i v i n g r o o ts i n th e f i e l d on th a t date* T h is le n g th o f row rep resen ted an area o f 1 .1 7 square f e e t . On September 25, 1953, th e l i v i n g tap r o o ts o f p la n ts o f th e 1952 seed in g were counted i n a 2 fo o t le n g th o f row, marked on th e two ends w ith w h ite sp ik e s d r iv e n down t o th e ground l e v e l . A s im ila r count o f Ladino c lo v e r tap r o o ts was made i n A p r il 195^, ©ad a g a in i n June 195^, by d ig g in g up p la n ts in a sim i­ l a r 2- f o o t le n g th o f row a d ja cen t to th e row marked i n September 1953* The number o f dead tap r o o ts was recorded* A recount o f th e o r ig in a l le n g th o f row (counted September 1953) th a t had been marked w ith sp ik e n a i l s was made i n J u ly 195^. A ll r e s u lt s are rep o rted on th e b a s is o f th e average number o f tap r o o ts f o r a 2- f o o t le n g th o f row o f Ladino clo v er* To measure th e e f f e c t s o f v a rio u s management and f e r t i l i z e r trea tm en ts imposed i n 1953 on y i e l d s i n 195^, th e fo ra g e was h a rv ested to a h e ig h t o f 51 1 in c h on May 29 and. J u ly 1 0 , 195^. A ll in d iv id u a l p l o t s were h a rv ested w ith a p ow er-d riven , s ic k le - b a r typ e J a r i mower w ith a c u ttin g bar 2 .8 7 5 f e e t w id e. The sample h a rv ested c o n s is te d o f one swath through the c e n te r o f a p lo t 12*5 f©et lo n g . The remainder o f th e fo ra g e was cut to th e same h e ig h t a s th e a rea h a rv e ste d f o r y i e l d . th e p l o t s . A ll c lip p in g s were removed from The fo ra g e used f o r y ie ld was bagged, d ried i n a fo rced a i r d r i e r and w eighed. Dry w eig h ts o f th e f i r s t and second h a rv est were com­ b in ed and c a lc u la te d on the a cre b a s is . A ll d ata are rep orted as averages o f w e e d -fr e e , Ladino c lo v e r forage f o r the fo u r r e p lic a t io n s . A n a ly sis o f v a r ia n c e was a p p lie d a s d e sc r ib e d by Cochran and Cox ( l l ) f o r s p l i t —s p l i t — p l o t d e s ig n s . RESULTS S u rv iv a l o f Tap R oots The e f f e c t s o f two c u t tin g trea tm en ts, th ree l e v e l s o f f e r t i l i z e r , and two a n a ly se s o f f e r t i l i z e r a p p lie d in 1953 on the s u r v iv a l o f Ladino c lo v e r tap r o o ts i n 195^ ©re g iv e n in t a b le s 11 and 12* The e f f e c t s o f fo u r d a te s o f a p p lic a tio n o f a l l f e r t i l i z e r s on th e s u r v iv a l o f Ladino c lo ­ v e r tap r o o t s are g iv e n i n t a b le 13* E f f e c t s o f C u ttin g Treatm ents R e s u lts i n t a b le 11 show th a t th e r a te o f m o r ta lity o f tap r o o ts was somewhat low er when th e p la n ts were cu t m oderately ( 4 tim es to a h e ig h t o f 3§- in c h e s ) than when cu t s e v e r e ly (6 tim es to a h eig h t o f 1 in c h ) . A ll r o o ts o f th e s e v e r e ly cut c lo v e r were dead i n June o f th e second p ro d u ctio n y e a r but th ey su r v iv ed , i f o n ly to a s l i g h t l y g r e a te r degree (6 p e r c e n t) u n t i l J u ly in the l e n i e n t l y cut fclover. These r o o ts o f p la n ts e s ta b lis h e d by se ed in g i n th e f i e l d were a l l dead i n J u ly o f th e second p ro d u ctio n year* They r ea c te d e x a c t ly th e same as r o o ts o f spaced tr a n sp la n te d p la n t s g iv e n a s im ila r c u t tin g treatm en t (Part I)* 53 ir\ 4 a 0) *4 JCJ 4* +» a O o § 4 » 03 CM -£ \ n P ON 0/ r-H a +> a CO •H © u 4-> -S a> SP © •H +3 4> P o © u © > o o r~l O +> «H 8 o •H 03 4> CJ i-q • On O © V l r—1 o P © © •H ■p IS o «** 4* o 2P 00 £ 3 •rI > o O CM acu q.ooj-2 ■IQ(i s^ufXP®08 J ° JaqwnR 5^ V isu a l o b se r v a tio n s made i n th e l a t e w in ter and e a r ly sp r in g o f 195^ show t h a t p l o t s su b je c te d t o th e sev ere c u t t in g treatm en t i n the f i r s t p r o d u c tio n y e a r (1 9 5 3 ) heaved more s e v e r e ly than p l o t s su b je c te d to th e l e s s se v er e c u t t in g treatm en ts* Many p la n ts th a t were s t i l l a l i v e had heaved so s e v e r e ly th a t su sta in e d l i f e was o b v io u sly im p o s s ib le . There was v e r y l i t t l e mulch or ground co v er on p l o t s su b je c te d to the sev ere c u t t in g treatm ent* O b servation s made in A p ril and May show th a t p l o t s su b je c te d to th e sev ere c u t t in g treatm ent had co n sid era b ly more annual weeds p r e se n t than p lo t s su b jected to th e l e s s sev ere c u ttin g treatm en t. E ffe c ts o f F e r tiliz e r B e s u lts in t a b le 12 show th a t w ith a l l f e r t i l i z e r trea tm en ts, th e number o f l i v i n g tap r o o ts d ecreased from 100 p ercen t in May 1953* th e b eg in n in g o f th e f i r s t p ro d u ctio n year, p r o g r e s s iv e ly through September 1953, APri l # June and J u ly 195^ (th e m iddle o f th e second p ro d u ctio n y e a r ) a t which tim e th ere were no tap r o o ts a liv e * In September 1953* p l o t b ,t h a t had r e c e iv e d 200— and 600-pound r a t e s o f 0—20—20 f e r t i l i z e r s had s i g n i f i c a n t l y h ig h e r average numbers o f l i v i n g tap r o o ts than p l o t s r e c e iv in g no f e r t i l i z e r * This s ig n if ic a n t d iffe r e n c e was no lo n g e r e v i­ dent i n A p r il, June, or J u ly 195^* Data rep o rted h e r e in seem to in d ic a te th at 200— or 600—pound p e r acre a p p lic a t io n s o f 0 -2 0 -2 0 f e r t i l i z e r a p p lie d a s to p -d r e s s in g reta rd th e r a te o f m o r ta lity o f Ladino c lo v e r tap r o o ts u n t i l th e end o f th e f i r s t produc­ t i o n year* As th e p la n ts grow o ld e r and go in to t h e ir second p ro d u ctio n y e a r, t h i s advantage i s n u l l i f i e d . A p p lic a tio n o f 0 -2 0 -0 a t e it h e r th e 55 Taisle 1 1 . Treatm ent, 1953 Kumber and p ercen ta g e s u r v iv a l o f tap r o o ts o f Ladino c lo v e r seed ed i n 1952 and g iv e n d if f e r e n t c u t tin g trea tm en ts i n 1953* Average fo r a l l f e r t i l i t y t r e a t ­ m ents. Sampled area was 1 .1 ? square f e e t . f May *53* S ep t. *53 6 tim e s t o 1 in c h 2 3 .9 1 3 .6 56 1 .3 5 0 .0 0 0 .0 0 4 tim e s to in c h e s 2 3 .9 1 5 .0 63 3*7 15 1*5 6 0 .0 0 i Apr. 154 June *54 $ J u ly ’ 54 * Count made in May was co n sid ered 100 p ercen t (1 9 5 3 )• L .S .D . Table 1 2 . H a tes and F e r tiliz e r s A n n lie d . 1953 Hone 200 l b s . 0 -2 0 -0 600 l b s . 0 -2 0 -0 200 l b s . 0 -2 0 -2 0 600 l b s . 0 -2 0 -2 0 V$> 2 .4 5 1 .6 2 .1 (V e rtic a l) (H o riz o n ta l) 2 .9 Humber and p ercen tage su r v iv a l o f tap r o o ts or Ladino c lo v e r seed ed i n 1952 and g iv e n d if f e r e n t f e r t i l i z e r trea tm en ts i n 1953* Average fo r two c u t tin g tr e a tm e n ts. Sampled area was 1 .1 7 square f e e t . May *53* .............. Sam elins D ates and P ercen t S u rv iv a l S e p t.* 53 $ Apr. 154 $ June 154 * July* 54 i 2 3 .9 1 2 .8 53 2 .1 9 0 .9 4 0 .0 0 2 3 .9 1 4 .1 59 2 .5 10 0 .7 3 0 .0 0 2 3 .9 1 3 .6 57 2 .6 11 0 .8 3 0 .0 0 23*9 1 5 .2 64 2 .9 12 0 .8 3 0 .0 0 2 3 .9 1 5 .? 66 2 .4 10 0 .6 2 0 .0 0 + Count made in May was co n sid ered 100 ]percen t. 1 $> L .S .D . 5 2 .2 ( V e r t ic a l) 1 .6 2 .4 (H o r iz o n ta l) 1*6 f p Figure No f e r t i l i z e r ] Base count of f ie ld 0 0 OCM oCM A A A <4 cm CM CM CM A <4 4 A m «k at m Cfi 1 1B 0p< 0Pu 0p< 00 O0 00 O CM vO CM O o aoj t^ooj-2 «xad s^ooj ^upA^I jo ueqsmfl Average effects of fe rtiliz e rs applied in the first production year (1953) on the survival of tap roots in a 1952 seeded field sampled from May 1953 to July 195^» CO C^\ 9* HI i 56 57 low o r high, r a te had no s ig n if ic a n t e f f e c t on r e ta r d in g th e ra te o f mor­ t a l i t y o f tap r o o ts i n c o n tr a st to th e b e n e f ic ia l e f f e c t s o f 0—20—20 f e r t i ­ liz e r . Table 1 3 . D a tes o f F e r tiliz e r A p p li cap­ t i o n . 1953 Humber and p ercen tage s u r v iv a l o f tap r o o ts o f Ladino c lo v e r seed ed i n 1952 and f e r t i l i z e d at d if f e r e n t tim es i n 1953* Average fo r two c u ttin g treatm en ts and two l e v e l s o f two a n a ly ses o f f e r t i l i z e r a p p lie d . Sampled area was 1 . 1? square f e e t . May*53* Sampling D ates and P ercent S u rv iv a l Apr. *54 $ June154 July* 54 S e p t.* 53 i i Hone 23*9 1 2 .8 53 2 .1 9 0 .9 4 0 .0 0 May 23 23*9 1 4 .2 59 2 .6 11 0 .4 2 0 .0 0 June 23 23*9 1 5 .0 63 3*0 13 1 .0 4 0 .0 0 S e p t. 15 23*9 1 4 .6 61 1 .7 7 0 .7 3 0 .0 0 S p lit a p p li­ c a t io n s ** 23*9 1 4 .2 59 2. 6 11 1 .0 4 0 .0 0 * Count made in May 1953 was co n sid ered 100 p e rcen t. ** S p lit a p p lic a tio n s p l o t s r e c e iv e d i o f t h e ir r e s p e c tiv e f e r t i l i z e r s on May 23, June 23, Aug. 20, and S e p t. 15* L .S .D . ( V e r t ic a l) (H o r iz o n ta l) 5$ 1*8 2 .0 1J& 2 .4 2 .8 58 P l o t s f e r t i l i z e d in June and September bad a s i g n i f i c a n t l y h ig h e r number o f l i v i n g tap r o o ts -when sampled i n September than th o se r e c e iv in g no f e r t i l i z e r . When checked i n A p r il, June, and J u ly , 195^ t h i s s i g n i f i ­ cance was no lo n g e r p r e s e n t. Prom th e se d a ta , i t seems l o g i c a l to con­ clu d e th a t w h ile c e r t a in d a tes o f a p p lic a tio n o f f e r t i l i z e r s in c r e a s e the number o f l i v i n g tap r o o ts p r e se n t a t th e end o f the f i r s t p rod u ction y ea r, no permanent e f f e c t can be ex p ected th at w i l l cause th e tap ro o ts t o sur­ v iv e lo n g e r than when f e r t i l i z e r s are not a p p lie d . A ll tap r o o ts were dead by J u ly o f th e second p ro d u ctio n r e g a r d le ss o f any treatm ent imposed p r io r to th a t tim e . 59 I*orage P ro d u ctio n in th e Second H arvest Tear D ata i n t a b le 14- show th a t Ladino c lo v e r seeded in 1952 and cut s e v e r e ly in 1953 (6 tim es to a h e ig h t o f 1 in ch ) y ie ld e d 24? 5 pounds p er acre in 195*** C lo v er cu t l e n i e n t l y (4 tim es to a h eig h t o f 3 i in c h e s) y ie ld e d 3228 pounds, a s i g n i f i c a n t l y g r e a te r y i e l d . The d if f e r e n c e between c lo v e r y i e l d s i n 195** ob tain ed from p l o t s g iv e n d if f e r e n t f e r t i l i z e r a p p lic a tio n s in 1953 were h ig h ly s i g n i f i c a n t . The most s ig n i f i c a n t d iffe r e n c e was th a t between the y ie ld s when no f e r t i l i z e r was added (2 6 0 4 pounds) and when 600 pounds o f 0 -2 0 -2 0 were added (3252 p o u n d s). T h is s t r ik in g in c r e a s e shows th e d e c id e d ly b e n e f ic ia l e f f e c t o f to p -d r e s s in g Ladino c lo v e r w ith h ig h amounts o f a f e r t i l i z e r c o n ta in in g b oth phosphorus and p otassiu m i f h ig h e s t y ie ld s are to be o b ta in ed . A p p lic a tio n o f 600 pounds o f 0 -2 0 -0 , however, d id not produce y i e ld s h ig h e r than th o se o b ta in e d from 200 pound a p p lic a tio n s o f 0 -2 0 -0 or 0 -2 0 -2 0 . The a d d itio n o f la r g e amounts o f p otassiu m i s ap p aren tly n ecessa ry fo r h ig h er y i e l d s o f La­ d in o c lo v e r e x p e c ia lly on t h is s o i l which was o f a sandy ty p e . Because th e r e was no s ig n if ic a n t d iff e r e n c e among 195** y i e l d s o f Ladino c lo v e r f e r t i l i z e d at fou r d if f e r e n t tim es in 1953* (ta b le 1 5 ), th e d ata fo r th e two d if f e r e n t c u ttin g trea tm en ts were averaged, ( ta b le 1 6 ) . No s i g n i f i ­ can t d iff e r e n c e was noted betw een d iff e r e n t “tim es o f a p p lic a tio n 1* o f any one f e r t i l i z e r . The h ig h e st average y ie ld in 195** was o b ta in ed from c lo v e r f e r t i l i z e d in September 1953 (3°97 p o u n d s/a cre). The lo w e st y ie ld was from c lo v e r f e r t i l i z e d in June (2836 p ounds). The in t e r a c t io n time x f e r t i l i z e r was h ig h ly s ig n if ic a n t (ta b le 1 6 ) . T h is in d ic a t e s th a t f o r any one time o f a p p lic a tio n , th e d if f e r e n t f e r t i l i z e r s re­ a c te d d i f f e r e n t l y . 60 Table 1 4 . C u ttin g Treatm ent E f f e c t o f c u t tin g trea tm en ts and time o f a p p lic a tio n o f d if f e r e n t f e r t i l i z e r trea tm en ts on 1954 y i e l d s produced by Ladino c lo v e r seeded i n 1952* Check; Ho F e r t i l i z e r Treatment F e r t i l i z e r 200 lb s* 600 l b s . 200 l b s . 600 l b s . _ 0—20—0 0—20—0 0- 20-20 0- 20-20 Ave. lb s /a c r e lb s /a c r e lb s /a c r e lb s /a c r e lb s /a c r e lb s /a c r e Ave. A ll P lo t s _ lb s /a c r e 6 tim e s to 1 in ch 2240 2417 2410 2444 2862 2533 24?5 4 tim e s to 3a in c h e s 2969 3129 3162 3238 3641 3292 3228 2604 2773 2786 2841 3252 2913 Average A n a ly sis o f Variance Source Between C u ttin g s E rror (a ) OF Mean Square 1 3 22,711*244* 1 ,2 1 7 ,5 6 3 Between F e r t i l i z e r s Ho f e r t i l i z e r : f e r t i l i z e r 1 Between f e r t i l i z e r s 3 E rror ( c ) 96 L .S .D . O v era ll a v e. o f c u t tin g Same f e r t i l i z e r between c u t t in g s O v e ra ll averages o f f e r t i l i z e r s 5# 554 5^7 142 2,431 ,9 6 9 * * 1,659 ,6 0 9 * * 8 1 ,2 8 6 Vf> 1019 1013 188 61 T able 1 5 . E f f e c t s o f c u t tin g and f e r t i l i z e r trea tm en ts a p p lie d i n 1953 on th e 1954 y i e l d o f Ladino c lo v e r seeded i n 1952. F e r tiliz e r Treatment May 23 lb s / a c r e A n a ly ses Cut t i n s Treatments* 1953 Hard**Easy Hard Easy Hard Easy Time o f F e r t i l i z e r A u o lic a tio n . 1953 June 23 S p lit * Sept# 15 l b s / a cre None Hard Easy Average lb s /a c r e lb s /a c r e lb s /a c r e lb s /a c r e 1928 2748 2199 2926 2649 3404 2186 2798 2604 200 600 0- 20-0 0- 20-0 2143 2453 2994 3430 2625 3347 2315 3063 2755 3261 2572 3204 2145 2914 2299 2953 2773 2785 200 600 0- 20-20 0- 20-20 2270 2528 3512 3595 2219 2821 2694 3695 2669 3352 3195 377Q 2618 3268 3030 3596 2841 3252 Ave# o m ittin g no f e r t i l i z e r 2348 3385 2463 3231 2798 3397 2523 3183 2913 Average 2264 3256 2410 3152 2768 3398 2456 3126 2851 * S p lit a p p lic a tio n s re p resen t 4 o f th e f e r t i l i z e r a p p lie d on May 23, June 2 3 , Aug# 20, and Sept# 15# *+ Hard c u t t in g treatm ent - 6 tim es to a h eig h t o f 1 in ch . Easy c u t t in g treatm ent — 4 tim es to a h eig h t o f 3 i in c h e s . CO O (Vi -H 00 < D JCJ o ,d a o S5 £C O £U a) 0 a < D B + 3 0 +> 01 to D a> < m a < uo If +> fl) O t-4 +» vO o O O CVi CVi t Ci f4 53 5CD3 *r? 4^ 'O + <9 * '■C3 •P^ O « 3 ^1 1 o o u> ov • CO 63 T able 16* E f f e c t s o f f e r t i l i z e r s and tim e o f a p p lic a tio n o f f e r t i l i z e r treatm en ts a p p lie d i n 1953 on the 195^ y i e l d s o f Ladino c lo v e r seeded i n 1952* F e r tiliz e r I h s /a v e A n a ly ses Hone May 23 D ates o f A p p lic a tio n June 23 S e p t. 15 Sp3.it* l b s / acre lb s /a c r e lh s /a c r e lb s /a c r e lb s /a c r e 2338 2562 3026 2492 2604 Average 200 600 0*20*0 0- 2 0-0 2568 294-2 2986 2689 3008 2888 2529 2626 2773 2786 200 600 0- 20-20 0- 20-20 2891 3061 2520 314? 3010 3482 294-3 3313 2841 3252 A ve. o m ittin g no f e r t i l i z e r 2866 2836 3097 2853 2913 Average 2760 2781 3083 2781 2851 ♦ S p lit r e p r e s e n ts i and S e p t. 15* f e r t i l i z e r s a p p lied on May 2 3 , June 2 3 , Aug. 2 0 A n a ly sis o f Variance Source D .F . Time x f e r t i l i z e r s Time (no f e r t i l i z e r s f e r t i l i z e r 3 Time x f e r t i l i z e r 9 E rror (c ) 96 L .S .D . 5# ( V e r t ic a l) w ith in one l e v e l o f tim e 28h (H o r iz o n ta l, w ith in one l e v e l o f f e r t i l i z e r , ana th e same and d if f e r e n t l e v e l s o f D ia g o n a l) f e r t i l i z e r , th e same and d if f e r e n t l e v e l s o f tim e. 4-51 Mean Square 231,480 * 299,051** 81,286 1# 375 610 DISCUSSION The prim ary o b j e c t iv e s o f s tu d ie s conducted and rep orted h e r e in were to a s c e r t a in what management p r a c t ic e s or f e r t i l i z e r treatm en ts would en­ hance th e s u r v iv a l o f Ladino c lo v e r tap r o o ts , and in c r e a se th e p r o d u c tiv ity i n the second h a rv e st year* The r e s u l t s show th a t on p l o t s cut s i x tim es to a h eig h t o f one in ch i n 1953, a l l tap r o o ts were dead when checked in June 1954* P lo t s cut fo u r tim e s to a h e ig h t o f jk in c h e s had an average o f 1*5 p la n ts p er 1*17 square f e e t area* There were no l i v i n g r o o ts a month l a t e r i n J u ly . T his corro­ b o r a te s data i n P art I which show th a t a l l tap r o o ts were dead by J u ly o f th e second p ro d u ctio n y e a r . The e f f e c t s o f v a rio u s f e r t i l i z e r trea tm en ts on th e s u r v iv a l o f Ladino c lo v e r tap r o o ts are s l i g h t and temporary. R e su lts show th a t p lo t s f e r t i ­ l i z e d w ith 600 pounds o f 0—20—20 f e r t i l i z e r had an average o f 15*7 l i v i n g ta p r o o ts p e r 1*17 square f e e t o f area when checked in September, a s com­ p ared to 1 2 .8 in p l o t s not f e r t i l i z e d . This d iffe r e n c e was no lo n g e r s ig ­ n i f i c a n t i n A p r il or t h e r e a f t e r when subsequent checks were made. In A p r il p l o t s f e r t i l i z e d w ith 600 pounds o f 0 -2 0 -2 0 had an average o f 2 ,4 l i v i n g tap r o o ts as compared to 2*1 in th e u n f e r t i liz e d p l o t s . In June, the num­ b er o f l i v i n g p la n ts were 0 .9 and 0 .6 i n fa v o r o f u n f e r t il iz e d p l o t s . J u ly , a l l tap r o o ts in a l l p l o t s were dead. This in d ic a t e s th a t w h ile f e r t i l i z e r s may slow down th e r a te o f d yin g i n tap r o o ts, th ey have no permanent e f f e c t on t h e ir s u r v iv a l. In 65 The tim e o f a p p lic a tio n o f f e r t i l i z e r s i n 1953 had no s ig n if ic a n t e f f e c t on th e s u r v iv a l o f Ladino c lo v e r tap r o o ts in 1953 or 195^* The a p p lic a tio n o f 200 o r 600 pounds p er acre o f 0 -2 0 -2 0 f e r t i l i z e r slow ed down th e ra te o f m o r ta lity o f tap r o o ts somewhat and a ls o in c r e a se d th e y i e l d o f fo ra g e th e fo llo w in g y e a r. The a d d itio n o f a f e r t i l i z e r con­ t a in in g o n ly phosphorus (0 -2 0 -0 ) was not a s e f f e c t i v e i n redu cing ro o t m o r ta lit y and in c r e a s in g fo ra g e p ro d u ctio n . T his corrob orates fin d in g s o f o th e r workers (5 ) (7 ) who s t a t e th a t p otassiu m i s v i t a l in reducing l o s s e s due t o “w in ter in ju r y 11 and should r e s u lt i n in crea sed y i e l d s . S in ce the a p p lic a tio n o f f e r t i l i z e r does not m a te r ia lly in c r e a s e the l i f e o f tap r o o ts o f Ladino c lo v e r , i t appears th a t th e continued p ro d u ctiv e l i f e o f t h i s legume must depend on th e rooted s to lo n s or new p la n ts e sta b ­ l i s h e d from s e e d lin g s . Rooted s to lo n s a re, at b e s t , drouth s u s c e p tib le * I t would seem th a t the p r o d u c tiv ity o f a stand o f Ladino c lo v e r w i l l be low u n le s s n a tu r a l r e see d in g ta k es p la c e and new p la n ts are e sta b lish e d * The freq u en cy o f n atu ral r eseed in g and new p la n t estab lish m en t w i l l be covered i n P art III* SUMMARY F ield , s t u d ie s to determ ine the e f f e c t s o f ( l ) two c u ttin g trea tm en ts, (2 ) th r e e f e r t i l i t y l e v e l s ( 3 ) two f e r t i l i z e r a n a ly se s , and (4 ) fou r d a te s o f a p p lic a tio n on th e s u r v iv a l o f Ladino c lo v e r tap r o o ts and the produc­ t i o n o f fo ra g e i n th e second p rod u ction y ea r were conducted from May 1953 to $ u ly 195^* A f i e l d which was d r i l l seeded i n 1952 was used in th e stu d ies* The r e s u lt s may he summarized a s fo llo w s : 1* The m o r ta lity r a te o f Ladino c lo v e r tap r o o ts was slow er i n th e f a l l , w in te r and sp r in g (1953—5*0 o*1 p lo t s cut fo u r tim es to a h e ig h t o f 3s in ch es than on p l o t s cu t s i x tim es to a h eig h t o f one in ch in 1953* A ll r o o ts were dead i n June (secon d p ro d u ction y ea r) in p lo t s cut s ix tim es to a h eig h t o f one in c h hut l iv e d one month lo n g er when g iv en th e more le n ie n t c u t t in g treatm ent* I t i s s ig n if ic a n t th a t, r e g a r d le ss o f c u ttin g or f e r ­ t i l i z e r tr ea tm en ts imposed during the f i r s t p rod u ction year, a l l tap r o o ts were dead in J u ly o f th e second p rod u ction y ea r. This data ob tain ed on Ladino c lo v e r e s ta b lis h e d d i r e c t l y in th e f i e l d from seed corrob orates p er­ f e c t l y d a ta o b ta in ed when s e e d lin g s o f Ladino c lo v e r were tra n sp la n te d to th e f i e l d (P art I)* 2* D iffe r e n t r a te s , a n a ly se s and d a te s o f a p p lic a tio n o f f e r t i l i z e r s used in th e s e s tu d ie s had no s ig n if ic a n t e f f e c t on th e s u r v iv a l o f Ladino c lo v a r # tap r o o ts in the sp rin g o f 195^* A p p lic a tio n s o f f e r t i l i z e r c o n ta in in g both phosphorus and p otassiu m , however did reduce root m o r ta lity in th e f a l l o f 1953* 67 3* Ladino c lo v e r cu t fou r tim es to a h e ig h t o f 3 i in c h e s in 1953 pro­ duced s i g n i f i c a n t l y h ig h e r y i e l d s in 195** than Ladino c lo v e r cut s i x tim es to a h e ig h t o f one in c h . T his p rod u ction was from s to lo n and fib r o u s root grow th o f o ld p la n t s , s in c e a l l o ld tap r o o ts were dead. 4* A verage 195** y i e l d s o f Ladino c lo v e r r e c e iv in g 600 pound a p p lic a tio n s o f 0—20—20 f e r t i l i z e r in 1953 were s ig n i f i c a n t l y h igh er than y i e ld s from p l o t s r e c e iv in g o th e r f e r t i l i z e r treatm en ts o r no f e r t i l i z e r * 5* Ladino c lo v e r cu t fo u r tim es to a h e ig h t o f 3 i iu ch es during the f i r s t p ro d u c tio n y ea r heaved l e s s i n the l a t e w in ter and sp r in g p reced in g th e second p ro d u ctio n y ea r than when cut s ix tim es to a h eig h t o f 1 inch* 6* Ladino c lo v e r p l o t s cut l e s s fr e q u e n tly i n 1953 had few er annual weeds i n 195h than c lo v e r cut fr e q u e n tly and more c l o s e ly . PART I I I LONGEVITY OP TAP ROOTS AND RE-ESTABLISHMENT OP LADINO CLOVER GROWN BY FARMERS UNDER PIE L D CONDITIONS IN MICHIGAN S tu d ie s were i n i t i a t e d in th e summer o f 1953 to a s c e r ta in whether th e b eh a v io r o f Ladino c lo v e r grown by farm ers under f i e l d c o n d itio n s in M ichigan c o rr o b o ra tes fin d in g s made on sm all exp erim en tal p l o t s near E ast L ansing and rep orted in P art I o f t h is study* The primary o b j e c t iv e s o f th e s t u d ie s were to determ ine ( l ) i f th e tap root o f the o r ig in a l Ladino c lo v e r p la n ts d ie s b efo re th e end o f th e second p rod u ction y ea r over the e n t ir e s t a t e a s i t d id a t East Lansing where i t was grown under c lo s e ly c o n t r o lle d ex p erim en tal c o n d itio n s , and (2 ) i f , and under what c o n d itio n s , n a tu r a l r e se e d in g r e s u lt s in new p la n ts which h elp m aintain th e stand and p r o d u c t iv it y o f Ladino c lo v e r which i s reported to be over f i v e years by many M ichigan farm ers. I t i s con sid ered extrem ely im portant to know th e answers to th e above q u e stio n s s in c e i f the o r ig in a l tap root o f th e Ladino c lo v e r p la n t d ie s under f i e l d c o n d itio n s b efore th e end o f th e second p ro d u ctio n y ea r, a s i t d id under experim en tal c o n d itio n s (rep o rted i n P a r ts I and I I ), subsequent maintenance o f the Ladino c lo v e r c o n s titu e n t o f m ixtu res would be dependent upon ( l ) s to lo n growth and (2 ) n a tu ra l re­ se e d in g r e s u lt in g i n new p la n t s . S to lo n s produce short fib r o u s r o o ts th a t are in ca p a b le o f deep p e n e tr a tio n , s u s c e p tib le to drouth, and, at b e s t, are a d v e n titio u s and never tak e th e p la c e o f th e main tap r o o t. This f a c t makes th e s u r v iv a l o f new s e e d lin g s in o ld stand s o f Ladino c lo v e r a su b je c t o f upmost im portance to farm ers in te n d in g to m aintain a p ro d u ctiv e stand o f Ladino c lo v e r lo n g e r than 2 y e a r s . 69 M a te ria ls and Methods In J u ly 1953, f i e l d s o f Ladino c lo v e r seeded i n 1950* I95I» a&d- 1952, were s e le c t e d in nine c o u n tie s in M ichigan f o r s tu d ie s on th e le n g th o f l i f e o f the o r ig in a l tap root and r e -e sta b lish m e n t o f p la n ts from n a tu r a l­ ly -r e s e e d e d c lo v e r . The c o u n tie s s e le c te d to g iv e a r e p r e s e n ta tiv e c r o s s s e c t io n o f c lim a t ic c o n d itio n s p r e v a ilin g in Michigan were Ingham, Kalama­ zoo, S t . J osep h , Washtenaw, Monroe, G enesee, I s a b e lla i n th e low er p en in ­ s u la and D e lta and Menominee in Counts o f tap r o o ts o f th e i n each f i e l d . th e upper p e n in su la . o r ig in a l Ladino c lo v e r p la n ts were made L in es were drawn through th e f i e l d and samples were taken a t 20—fo o t in t e r v a ls alon g the l i n e . An 8—in ch c ir c u la r spade (50 square in c h e s in a rea ) was used to cut and tu rn the sod. Tap root counts are re­ p o rted as a v era g es o f 25 sp a d in g s. L in es were drawn through th e f i e l d and tw enty 1*1—in ch quadrat (1*36 square f e e t in area) was p la c ed a t 25- f o o t in t e r v a ls along the l i n e . New s e e d lin g s in each o f th e 20 quadrats were counted and are reported a s an average f o r a l l the q u ad rats. Stakes were d riv en down to ground l e v e l in d ia g o n a l co rn ers o f the quadrat to f a c i l i t a t e lo c a t io n o f the same quadrat one yea r l a t e r . (J u ly 195*0> p la n ts in each quadrat con­ One year l a t e r t a in in g s e e d lin g s in J u ly 1953 were counted. The number and p ercen ta ge o f the s e e d lin g s th a t had become e s ta b lis h e d p la n ts w ith tap r o o ts were recorded* An e stim a te was made o f th e b o ta n ic a l com p osition o f th e f i e l d s , and th e amount and a n a ly se s o f f e r t i l i z e r an d /or the amount o f manure u sed as top d r e s sin g was recorded. 70 RESULTS AMD DISCUSSION The average number o f s e e d lin g s p er 1 ,3 6 square fo o t area, the ave­ rage number o f s e e d lin g s becoming e s ta b lis h e d p la n ts from J u ly 1953 to J u ly 1954, and th e average number o f o r ig in a l tap r o o ts p er $0 square in c h e s o f a rea i n f i e l d s seeded in 1950, 1951# 1953 195^ ( a l l stu d ie d in 195*0 a r© p resen ted in t a b le s 17, 18, and 19, r e s p e c t iv e ly , P i e l d s Seeded to Ladino Clover M ixtures in 1950 A t o t a l o f fo u r f i e l d s seeded to Ladino c lo v e r in 1950 was stu d ie d i n J u ly 1953 aud J u ly 1954. A H fou r f i e l d s were lo c a te d i n the low er p e n in s u la i n d if f e r e n t c o u n tie s (G enesee, Ingham, I s a b e lla , and S t. J o sep h ), f ig u r e 11, ta b le 17* Data rep orted h e r e in show th at none o f th e f i e l d s seed ed in 1950 and checked in 1953 (th e th ir d p rod u ction year) con tain ed r o o t s o f th e o r ig in a l p la n ts of Ladino c lo v e r . While th e se r e s u lt s show no o r ig in a l Ladino c lo v e r tap r o o ts p resen t in th e th ir d p rod u ction y ea r, th e y can not show whether the o r ig in a l tap ro o ts were l i v i n g or dead i n th e second p ro d u ctio n y ea r s in c e no d ata was ob tain ed u n t i l i n th e th ir d p ro d u ctio n y e a r. R e su lts o b ta in ed from s e e d lin g counts made in J u ly 1953 show th a t th e average number o f s e e d lin g s p er I .3 6 square f e e t o f area ranged from 7 .0 in S t, Joseph to 13*4 in Genesee County. The p ercen tage o f s e e d lin g s th a t had produced e s ta b lis h e d p la n ts by J u ly 1954 was h ig h e st in I s a b e lla w ith 57 fo llo w e d by G enesee, Ingham, and S t. Joseph w ith 3 8 , 9, and 0 r e s p e c tiv e ­ ly* 71 . ,S ~ ^ y f ’QNrovAaofi i *•"!» q goaeeic . |I d .i ^ '."ABQ r urm \ s \"MQurm' ^ jcJor/wsow"! yu—7 -^ -- ' j T T 2 a r v _; pomft « ^ |; f I L I MACK/NAC fs» r ~ r J0 JfiKNOM hl 1 w ._ . _ £\0 2 3 ^ fC rff Q £?v M IC H IG A N I^MRifVwr'i I .__ jprs&30W$mir&*Talpfna lANTfflM [^" I OVC/ ^ r ] V&LAKAU T O /J O fOSCODA lf(7j®4W W D^jGw*a|1c»lW S ^ b tn a e ^T P A vm s j ! _____ !____i . few-STEF / , :i / I —„_JL 0 - 1950 see d in g 1 - 1951 se e d in g S m ason .l I .ta k s . OGEMAv\i6sCO l! I j |_____ 1____ L josarcaA Td/tfte {gladwin ia w ^/m c \J j! ^ h (!__ i|_____* fOCFAKA,NEW AYGO.MECOSTA JiMBFUA^MIDLAND! 2 - 1952 se e d in g Iauon* y '3COM JJ < z "" J L l l 2 ^ Jw^Fwlw ^(GRATIOT^*™** -.itAPCfjTl V rlF w | j j __ Y , j • ___ 1_____• ____!CF , eses j gW en (jrawfl bOTOWAI POWA *>CLINTONijW MbfcSSnJ 0 ! jl » I i ! i 11 OAw 'd~Y'*<*»o\ fAU TfiHRfftr *ir«TW llNBMM JuwivMSw ! i i 1 2i i f _ .1_____ 1____ l _ 1____ 1•* • Jlitasin /VANOWEN(kALAkT^ CAUtOWt ^ 'j JACKSON W&SHTFAMt^ | WAYNE •1 i , ,£wN*^ jyyasfw jefta'fCH fHULsoaii| lenawce jwrnRcf ‘ 12 i I i ! \ \ l i i i i i 2 ^ / Jjx'e lo c a t io n o f Ladino c lo v e r f i e l d s s tu d ie d in J u ly i.953 and ... J u ly 195^, to determ ine the s u r v iv a l o f o r ig in a l Ladino c lo v e r ta p r o o ts , and the esta b lish m en t o f p la n ts from n a tu r a l-r e e e e d e d s e e d lin g s . 72 Of th e fo u r f i e l d s s tu d ie d , one ( i n S t , Joseph County) had r e c e iv e d no f e r t i l i s e r or manure as top d r e s sin g . R e s u lts show th a t none o f th e s e e d lin g s p r e se n t in th a t f i e l d in J u ly 1953 average o f 7*0 p er 1*36 square f o o t ) su rv iv ed and became e s ta b lis h e d p la n ts by J u ly 1954 (fig u r e 1 2 ). The f i e l d had been e s ta b lis h e d on a l i g h t sandy s o i l , which could p o s s ib ly be a f a c t o r i n th e non—su r v iv a l o f 1953 s e e d lin g s . An examina­ t i o n o f th e b o ta n ic a l com p osition o f t h is f i e l d shows th a t the Ladino c lo ­ v er c o n s tit u e n t i n th e m ixture d ecreased from 20 to 5 p ercen t during the p e r io d stu d ied * The th r e e f i e l d s stu d ie d th a t had r e c e iv e d top d r e s sin g a l l had e s ­ t a b lis h e d p la n ts p resen t in J u ly 195^* These p la n ts presumably became e s t a b lis h e d from th e s e e d lin g s counted in 1953* h ig h e s t average num­ b er p r e se n t in 195^ Per 1*36 square fo o t was obtain ed in Genesee County w ith 5 .1 fo llo w e d by I s a b e l l a and Ingham w ith 4 .3 and 1 .4 , r e s p e c t iv e ly . The d is t r ib u t io n o f s e e d lin g s th a t had produced e s ta b lis h e d p la n ts were p o o r e s t in Ingham s in c e o n ly 35 p ercen t o f th e sampled quadrats co n ta in ed one or more p la n t s . I f th e Ingham County average o f 1 .4 e s ta b lis h e d p la n ts p e r 1 .3 6 square f e e t had been even ly d is t r ib u te d over th e f i e l d and the p a stu r e managed p ro p e rly , t h i s would have co n trib u ted s u b s t a n t ia lly to th e p r o d u c tiv ity o f Ladino c lo v e r i n the m ixture. An exam ination o f th e bo­ t a n ic a l co m p o sitio n o f th e se f i e l d s show th a t the Ladino c lo v e r c o n s titu e n t o f th e m ixture in Ingham County decreased from 10 to 5 p e r c e n t, w h ile i t in c r e a s e d from 40 to 50 p ercen t in I s a b e lla County, and was m aintained at 10 p ercen t in Genesee f o r th e p erio d s tu d ie d . ■Ua_ ©U & o 5>» 43 H rH © 3 *H M■+* O O © d m 43 ■Os. d t-i © & >s 43 O fit tca CO CO I—I •H CO O O O O rH CM -j" ON * f\ O UN CO r-t o U>un UN UN ON rH o O O O HCO H S S S O UN UN CM - d ON •r-t n & o >» 43 H O CO UN UN 0 *0 a O -H «rl d 00 43 O pq d 0 .r l 43 *h © 0 0 £3 0 O o O Q iH CM C N -d' r-4 © 8> o © © « ua rH © © •H O « Pi *H a -h ■•rf rH 8 . O ,P

© P4 P ON > P4 ^ H Cl W t*D © & «C *P4 rH hM pq pq ©O fi> CM o w oON A ©O X> CM O CM INUN O O UN ON O On NO o NO M vn 00 CM CM CM 0 0 CM cn CM o o © © w $ © CN i-1 ON ci> -H cO fi1 2 M rH © Q 4« O Pi & >> 43 o }2i rf on rH H «I W © S ON CM -3* ON P ON }> S d •H 00 ON <$ © (0 q fl >» on • w pT «-) vr\ © a •4 > O iH O cd O «H J? 43 5 *C 3h o d r-i m d *4 ti O © iH © W O d r a d d 0 icOto (50 sq. in* each) (1*36 sq. ft. each) *4 ON © UN A# ON o £N u\ .d Pi © CO o *~3> 43 m * Averages for 25 samples ** Average for 20 quadrats Table 17* Average number of Ladino clover seedlings and original tap roots, top-dressing used, estim ated "botanical composition, and general nature of soil in four counties of Michigan* Mixtures seeded in 1950 and studied in 1953 and 195^* 73 SP TO rrf vr\ c r\ co VO f - t v r \ p > ■*2 © o ON • »H *H 3 +> - d o vO 3 d d © ON * rl • H * H as • P CO ►d O U O -W o ON r - t & T3 k © +> © d © © •3 © © r-4 £ H cr © P 3 © d © 'CJ 3 •H A p NO ,d a> C O * d © • © o •H H d •—i rO SP *h 3 © © © o P i o r© +> © ■+> c r\ SP P t3 m © $ © © to •3 IS M SP cvi t-J © I* 3) •H O cvi •%$ * b s 9 £ #l «i©d s ^ t o x ^ P © ^ x i puB s^aTXpQQ S j o J 9q u m u 75 These d a ta p r e se n te d in d ic a te th a t i f Ladino c lo v e r s e e d lin g s do not su r v iv e to "become e s ta b lis h e d p la n ts (a s i n S t . Joseph County), th e c lo v e r c o n s tit u e n t o f th e m ixture d ecr e a se s r a p id ly . L ik ew ise, i f a sm all p er­ cen ta g e o f th e s e e d lin g s su r v iv e to become e s ta b lis h e d p la n ts , and th e s e e d lin g s are p o o rly d is t r ib u t e d over th e f i e l d (a s i n Ingham County), th e c lo v e r c o n s tit u e n t d e c r e a se s rap id ly* The v ig o r o f stand s could be m ain tain ed or in c r e a se d ( e . g . , Genesee and I s a b e lla C ou n ties) p ro v id in g th e c lo v e r p la n ts become e s ta b lis h e d uniform ly over th e f i e l d . The e f f e c t s o f top d r e s sin g i n th e p ercen tage s u r v iv a l o f s e e d lin g s v a r ie d from 9 in- Ingham t o 57 i u I s a b e lla County. T his wide v a r ia t io n in d ic a t e s th a t w h ile top d r e ssin g may a id i n s e e d lin g s u r v iv a l, a p p aren tly f a c t o r s o th e r than top d r e s s in g , e . g . , management, may be e q u a lly or more im portant i n s e e d lin g e s ta b lish m e n ts. P i e ld s Seeded to Ladino M ixtures i n 1951 A t o t a l o f e ig h t f i e l d s seeded to Ladino c lo v e r in 1951 was s tu d ie d i n J u ly 1953 and J u ly 195^. Of th e e ig h t c o u n tie s , two were lo c a te d in th e upper p e n in su la (D e lta and Menominee) and s i x in th e low er p e n in su la (G enesee, I s a b e lla , Kalamazoo, Monroe, S t. Joseph, and Washtenaw), ta b le 18. Data rep o rted h e re in show th at none o f th e f i e l d s seeded in 1951 &ad checked i n 1953 (secon d p ro d u ctio n y ea r) co n tain ed r o o ts o f the o r ig in a l p la n t s o f Ladino c lo v e r . This corrob orates fin d in g s o f P a r ts I and I I o f t h i s study which showed th a t no l i v i n g tap r o o ts were p r e se n t a f t e r J u ly o f the second p ro d u ctio n y e a r. T his shows c o n c lu s iv e ly th a t Ladino c lo v e r ta p r o o ts under f i e l d c o n d itio n s in M ichigan d ie a s th ey d id under c l o s e ly 76 ch eck ed exp erim en tal c o n d itio n s near B ast Lansing# Ladino c lo v e r , h e r e to ­ f o r e c l a s s i f i e d a s a p e r e n n ia l, undoubtedly behaves in M ichigan more l i k e a b ie n n ia l# R e s u lts o b ta in ed from s e e d lin g cou n ts made i n 1953 show th a t th e num^b er o f s e e d lin g s p er 1*36 square fo o t o f area ranged from 12# 8 in Kalamazoo to 6*0 in Washtenaw County ( fig u r e 13)* The average p ercen ta g e o f s e e d lin g s th a t had become e s ta b lis h e d p la n ts by J u ly 195^ was h ig h e s t in I s a b e lla County w ith 6 l fo llo w e d by Genesee w ith 57# th e lo w est was i n Monroe w ith 2 fo llo w e d by Washtenaw and D e lta w ith 3 and 5» r e s p e c t iv e ly . G en erally th o se f i e l d s w ith a h igh number o f e s ta b lis h e d p la n ts u niform ly d is t r ib u te d o v e r th e f i e l d (in d ic a te d by th e p ercen tage o f quadrats having one o r more p la n t s ) were th o se which n ea rly m aintained or in crea sed t h e ir percen tage o f Ladino c lo v e r i n th e m ixture from 1953 to 195^» D ata p r e se n ted in ta b le 18, show th at f i e l d s top d ressed w ith commer­ c i a l f e r t i l i z e r were c o n s is t e n t ly h ig h er in p ercen tage o f s e e d lin g s e sta b ­ l i s h e d in 1953 which became e s ta b lis h e d p la n ts by 195^* The range was from 6 l p ercen t i n I s a b e lla to 37 p ercen t i n Kalamazoo County (37 p ercen t repre­ s e n t s A. 7 e s ta b lis h e d p la n ts p er 1 .3 6 square fo o t o f sampled a r e a ). On th e o th er hand, f i e l d s r e c e iv in g no f e r t i l i z e r a s to p -d r e s s in g had a per­ cen ta g e s u r v iv a l o f only 2, 3, and 5* t i e s , r e s p e c t iv e ly . Monroe, Washtenaw, and D e lta Coun­ These th ree f i e l d s were on a sandy loam s o i l . An exam ination o f th e b o ta n ic a l com p osition r e v e a ls th at Ladino c lo v e r i n th e m ix tu res d ecrea sed from 25 to 12 p ercen t i n D e lta , from *K> to 20 p ercen t i n Monroe, and from 10 to 5 p ercen t i n Washtenaw County during th e p erio d J u ly 1953 - J u ly 195^* to p -d re s s in g u sed , e s ti m a t e d M ixtures seeded in 195 ^ a*id 7? O On u \ un q CVI CN . 4 ON ■O3 rt and o r ig in a l tap ro o ts , 8 co u n ties of M ichigan. s § ■P *rl a s© o o 3 3 S " ' 1& 2 o 0 H © © ra © •H O © © 0> | © «H £Q 0 *icJ gp o rH O © rH aS O fn ©o 0> CM O 01 5 43 rH •H O 01 ft O O CM uO \ CjM ^ A CM O Cu> CN CN 3 © 01 H b H S U P 0 > © Q Vi 0 «H r—? © « rH 43 •iH «S a ti v» a2 t S 3 8 0> S Sh 3*H ah .S § © rH . © c8 © © 03 m > > -4" * J 43 ra r j V TN © © ON J> •H © 1-4 ^0 H <3 rH w 0» © 43 t © © rO qj)>»(*N * P3 ® fl r4 C © 43 *3 fli rH ft »> © O rH 0i i— 4 U" O © 0 * fL, -M © U ©.H O % © o § U © o ft CO * CCS rH O GO O CN © UN *4 Tahle 18. Average number of Ladino clover s e e d lin g s ■botanical co m p o sitio n , and general n ature of soil in stud ied in 1953 and 195^* s rH GO § O 01 o o _ o O O O o Q p cm o unI u n o ^ xn o o 2■*4 — 94 C0m ° CO rH CN3 — CM s ° -3- CM 4 CNC NCM-4 -4 H 4 4- CM cn "3 \ Is © 01 >5 00 0 01 ^5 43 0 01 *3 8 J-» rH 3 V l -H § 43 O O © 05 ft O tsi ON CN CO O CM ON CM . * CM 0*NO © CN o O rH UN^-^ © o © 43 (ft O 00 NO rH © CCS rH 0 * CN © & UN O CM CM © *4 & o cd Eh 43 P P 0 0 t ■a M 0J © © © & Oi o © * 0 s S o © © © ctf U o * * & ID 0) CT O) 09 tQ Sf CO CD •=t On 1953 *d S eed lin g s 1 in to 3 Pi JSro 3 4* rH un v r \ o vr rH CM £ 3 rH •H C/3 ■SI i o t-q 4> H 43 rH *ri rH § •rH 03 03 03 O O O UN XT' O O O UNOOO O OO cnuNCM hd* CM rH rH rH P-ON 8 3 ? 18 ON Pi +> rH •H 03 20 seed ed in HNrH ON 43 o 1A 3 mUNrH U N O O U > CM rHCM-3- O Q O u n u n o u n u " Q O ouNvno O Q O O Q U N U N Q vrvtn rHONrH^T CM-3^ CM CM J - rH CMCM tN-CM rH d" CMrHrH M ic h ig a n . P © > a o 4» -H o +> pq -h w o o rH L3 CQ © •rH Pi 03 © p 0 © © rH a aP > o ° a » O rH Crf b* O Vi ^JrH *rf g*uj O V i .d r H O Vi W)rH H wh ©r-j © rH 4 * 0 O d © drH 4° O -ri S (0Tb •rH trf g _ Vi r j a •H Crf O •n O Vi © ■ o p S ’o © rrt © ■gVi S tj *H O Trf Q rH -H © 0-- rH P ® Crf P rH © Crf rH vH © p crf P J-q**.EHPl 64 pipq td^EHpq ^ H 0 O NO ST> rH ©o rQCM rH I CM ^ i O CM 8 P § 08 n rl crf ,-J XT\ © H PJ ON t> Crf ■ {V. CO * NO CM rH CM UN CM CM -d' UN CM * cn CM un On nO CM O CM rH cn O cn o~ rH ON CM NO and 25 1•H CM w +s w) d •h crf P p O Pi 43 d d o o O NO • CM CM CM Crf 4» rH © -d rH © © © S © C*> On • CM vnnuN 00 O 1 H ON UN CM * UN CM O CM crf rH rH © © rO erf © © s P d o X • each) cn * A ve. s tu d ie d in •H 3 ON > m rl ^ H s W U> VO 12 «8 ©_. • y 1 1953 © y ) >» c n 1—• 6 .^ and PU ►*» rH <4 P4 -d sq,* O • cn ON (50 °8 fo r 195^* © each ) UN ■§ ft. * 00 UN « rH O Tb & o pqPi NT o o rH in . o TO P © -rH © M Vi C/3 rH 1952 u sed , M ix tu r e s D^o ON O Si O •H 03 o O *H c o u n tie s to p -d r e s s in g 03 1 si H * 8 r o o ts, u in tap Crf o un "d © so il o r ig in a l o n$- of s e e d lin g s , © 4* cb J2J n a tu r e c lo v e r general L a d in o and of num ber c o m p o s itio n , A verage d a si 0 o d «> !w H d «H iH * b o ta n ic a l 19# T a b le © © te d e s tim a ­ 80 * * * fields counted in July 1953, uud the average number of these seedlings that produced established plants by July 195^* Seedlings in 1953 81 s ^ o o ,! da* jo s ^ a -jip a e s jpo j e q m n K 82 e s ta b lis h e d , p la n t s by 195^« D e lta County. ®he range was from 29 in I s a b e lla to 57 i n On th e o th er hand., f i e l d s r e c e iv in g no f e r t i l i z e r or manure a s to p -d r e s s in g had p ercen ta g es o f 3, 7, and 22 f o r Washtenaw, Monroe, and Ingham C o u n ties, r e s p e c t iv e ly . D ata p r e se n te d i n t a b le 19 show th a t one f i e l d ( in Monroe County) was on a sandy s o i l and r e c e iv e d no to p -d r e s s in g . The f a c t th a t o n ly ? p ercen t o f th e s e e d lin g s p resen t i n 1953 produced e s ta b lis h e d p la n ts in 1954 cannot, t h e r e fo r e , be a ttr ib u te d to any one fa c to r but rath er to two or more un­ fa v o r a b le f a c t o r s , in c lu d in g no to p -d r e s sin g and a l i g h t sandy s o i l . An exam in ation o f th e b o ta n ic a l com p osition o f th e se f i e l d s shows th a t f i e l d s r e c e iv in g no f e r t i l i z e r or manure as to p -d r e s sin g had a pronounced d ec rea se i n th e c lo v e r c o n s titu e n t o f the m ixture, th e d ecrease b ein g from 40 to 25 p ercen t in Washtenaw, from 10 to 5 p ercent in Monroe, and from 70 to 30 p ercen t in Ingham County. F ie ld s r e c e iv in g to p -d r e s sin g m aintained o r in c r e a se d th e Ladino c lo v e r c o n s titu e n t w ith only one e x c e p tio n where a 3 -1 2 -1 2 f e r t i l i z e r was u sed . The c lo v e r c o n s titu e n t i n t h i s f i e l d showed a minor d ecrea se from 60 to $0 p e r c e n t. These d a ta seem to in d ic a te again th a t to p -d r e s sin g w ith f e r t i l i z e r o r manures a id ed in the esta b lish m en t o f s e e d lin g s , and th a t an in c r e a s e i n th e p ercen ta g e o f s e e d lin g s becoming e s ta b lis h e d p la n ts r e s u lte d i n an in c r e a s e i n th e c lo v e r c o n s titu e n t o f th e m ixture. I t i s to be ex p ected , a l s o , th a t in a d d itio n to s tim u la tin g rapid growth o f new s e e d lin g s and e s t a b lis h e d p la n ts , f e r t i l i z e r s or manure helped th e p r o d u c tiv ity and i n ­ cre a se d th e p ercen ta g e o f Ladino c lo v e r in th e f i e l d by in c r e a s in g th e v ig o r o f s t o lo n s . SUMMARY S tu d ie s were conducted i n J u ly 1953 and J u ly 1954 to determ ine i f any o r i g i n a l tap r o o ts were a l i v e i n f i e l d s o f Ladino c lo v e r seeded in 1950, 1951 and 1952 in n ine c o u n tie s lo c a te d i n th e upper and low er p e n in su la o f Michigan* L ik ew ise, s tu d ie s were conducted to determ ine i f th e se f i e l d s co n ta in ed s e e d lin g s from n a tu r a l reseed in g and to what ex ten t th e s e e d lin g s , i f p r e s e n t, d evelop ed in to e s ta b lis h e d p la n ts and co n trib u ted to th e pro­ d u c t iv it y o f Ladino c lo v e r i n m ixtu res. be summarized as fo llo w s : 1* The r e s u lt s o f th e se s tu d ie s may None o f fou r f i e l d s seeded i n 1950 dad o r i­ g in a l tap r o o ts in th e th ir d p rod u ction y e a r . L ik ew ise, none o f e ig h t f i e l d s seeded i n 1951 had o r ig in a l tap r o o ts p resen t in the second produc­ tio n year. These f i e l d d a ta check w ith C lo se ly c o n tr o lle d p lo t s (rep o rted i n P a r ts I and I I ) d esign ed to see when th e o r ig in a l tap root d ie s . The d a te are c o n c lu s iv e enough to s t a t e th a t in M ichigan th e o r ig in a l tap r o o ts o f Ladino c lo v e r are a l l dead in J u ly o f th e second p astu re year r e g a r d le ss o f where grown or what management or f e r t i l i z e r p r a c t ic e s have been a p p lie d . 2. A ll f i e l d s stu d ie d co n ta in ed young s e e d lin g s e s ta b lis h e d by n a tu ra l re­ se e d in g o f th e o r ig in a l p la n ts , r eg a rd less o f management p r a c t ic e s or f e r ­ t i l i z e r s used as to p -d r e s s in g . 3. The p ercen ta g e o f young s e e d lin g s d evelop in g in to e s ta b lis h e d p la n ts i n an o ld Ladino c lo v e r f i e l d v a ried w idely from f i e l d t o f i e l d , and from one area to an oth er w ith in a f i e l d . 4. There are in d ic a tio n s th a t f e r t i l i z e r or manure as top d r e ssin g in crea sed th e p ercen ta g e o f s e e d lin g s th a t produced e s ta b lis h e d p la n t s . N e v e r th e le ss , 8k f a c t o r s such as c lim a te and management may he even more im portant in main­ t a in in g stand than th e u se o f f e r t i l i z e r or manure whicn oth erw ise would he n ec essa r y fo r good p r o d u c tiv ity o f any stand* 5* G e n e ra lly , a h ig h p ercen ta g e esta b lish m en t o f s e e d lin g s r e s u lte d in a h ig h p ercen ta g e o f Ladino c lo v e r in th e m ixtu re. 6. P r a c t ic e s th a t in crea sed th e p ercen tage su r v iv a l o f Ladino c lo v e r s e e d lin g s i n m ixtu res in c re a sed th e Ladino c lo v e r c o n s titu e n t o f th e mix­ tu r e and v i s a v e r s a . This in d ic a t e s th a t th e continued h igh p rod u ction o f the c lo v e r c o n s titu e n t i s dependent on th e se s e e d lin g s . L ight sandy s o i l s were not conducive fo r esta b lish m en t o f n a tu r a lly reseed ed Ladino c lo v e r p la n t s . The c lo v e r c o n s titu e n t o f m ixtures on th e s e s o i l s d ecreased r a p id ly during th e p e r io d stu d ie d . LITERATURE CI1EED 1* A hlgreu, G. H. Porage Crops* 2. 3* McGraw-Hill Book Company In c . 19^9* Sprague, Howard B. A survey o f v a r i a b i l i t y i n w hite c lo v e r and i t s r e la t io n to p a stu re improvement* N. J* Agr. Exp* St a . B u i. 6?6. I 9A0. A hlgren, H* L. E f f e c t s o f f e r t i l i z a t i o n , c u ttin g treatm en ts and i r r i ­ g a tio n on y i e l d s o f forage and chem ical c o n p o sitio n o f the rhizom es o f Kentucky h lu e g r a s s . Jour. Amer. Soc. A gron., 30s 683-691* 1938. . and Burcalow, E . V. Ladino c lo v e r , a prom ising p a stu re cro p . W is. Agr. Exp. S ta . E x t. Circ* 367* I 9A6. 5* ___________, Smith, D. C. and H ie lse n , E. L. B ehavior o f v a rio u s s e le c ­ t io n s o f Kentucky h lu eg ra ss (Poa p r a t e n s is L. ) when grown as spaced p la n ts and in mass s e e d in g s . Jour. Amer. Soc. A gron., 3 7 ; 268- 281. 1945. 6* A s s o c ia t io n o f O f f i c i a l A g r ic u ltu r a l C hem ists. W ashington, D. C. I 95O. 7. Brown, B. A. R esearch on management o f Ladino c lo v e r . t i c u t , A gr. Exp. S ta . I n f . Sheet # 8 . 1950* 8. ______ 9. Methods o f a n a ly s is . S to r r s, Connec­ . and M unsell, R. I . An e v a lu a tio n o f Kentucky h lu e g r a ss . J o u r. Amer. Soc. A gron ., 37; 2^9-267* 19^5* ____________ ;_______ , P a stu re in v e s t ig a t io n s . (H inth rep o rt) Ladino c lo v e r ex p erim en ts. 1930-19^0* S to r r s, C onn ecticut; Agr. Exp. Sta* S ta . B u i. 235* 19^1* 10. Brown, E. Marion. S easonal v a r ia tio n s i n th e growth and chem ical p o s i t i o n o f Kentucky h lu e g r a ss. Mo. Agr. Exp. S ta . R es. 360. 19^3* 11. 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B u i. 370. 1934. 17. H o llo w e ll, E.A . Ladino w hite c lo v e r f o r th e N orth eastern S t a t e s . U .S .D .A . E arn ers1 B u i. 1910. 1942. 18. ___________ • 19. Hughes, H .D ., Heath, Maurice E ., M etca lfe, B arrel S. F orages. Iowa S ta te C o lle g e P r e s s . 1952. 20. J e f f e r s , Robert L ., and A lgren , H.L. L ife h is to r y s tu d ie s o f Ladino c lo v e r . Abs. J o u r. Amer. S oc. Agron. 1952. 21. J o n es, B urle J . , and Brown, J .B . I r r ig a te d p a stu res in C a lifo r n ia . C a l i f . Agr. E x t. S erv. C ir c . 125* 1947. 22. Kennedy, W. K eith , and Johnson, C.M. How to keep Ladino c lo v e r . Crops and S o i l s , 6* 20-23* 1954. 23. K ilp a tr ic k , R .A ., Hansen, E.W., and D ickson, J.G . R e la tiv e p athogen i­ c i t y o f fu n g i a s s o c ia te d w ith root rot o f red c lo v e r in Wis­ c o n s in . P h ytop athology, 44: 292- 297. 1954. 24. F orages. Iowa S ta te C o lleg e P r e s s . 1952. 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