‘E'HE fiFFECTS OF VARZOUS LEVELS GF NITROGfiN, F'HOSQHOfiUS AND S‘Q'TASSWM OH THE GRG'W‘W 01F COLEUS This}: for: Hus Dogm sf M. 5. MéCHEGAN HATE COLLKEE Chm-€03 Afion E‘wmrain Wdfl [ESIS \' ‘ ' '1 ‘ _ —. " .- - 0|. - / s ‘1 I MW :2, 1" C «U rn w ""o :3 $093 -———-—._————-—-A .. -_ ’ .0— _._A—__..;|_..' - This is to certify that the thesis entitled The Effects of Various leVPls of Nitrogen, Phosphorus and Potassium on the Growth of Coleus. presented by Charles Allen Fountain has been accepted towards fulfillment of the requirements for I"; Q _degree in_l{onticulture' 5“,)! W (I Major professor ‘ P}- Date August 22, 1/4”? _ l-795 m EFFECTS OF VARIOUS LEVELS OF NITROGEN . PHOSPHORUS AND POTASSIUM ON in GROWTH 01' com 33' WWWMH J A THESIS Submitted to the School of Graduate Studies of Michigan State College of Agriculture and tpplied Science in partial fulfillment of the requirements for the degree of mm 01' some: Department of Horticulture 191;: TH 5515' WOW The writer wishes to express his thanks to the following persons for their assistance during the period oi'this experi- ment: To Dr. Ray Lewis Cook, of Michigan State College Soil Science Department. for. his suggestions in selecting materials . and setting up this experiment: to Professor 0. I. Wildon of Michigan State College Horticulture Department (in charge of l'loriculture) . for his suggestions on the best cultural prac- tices to follow; and to Professor 0. H. Sherwood and Hr. l. P. Roberts for their assistance in the routine of the experiment. 20604.1 TABLE OF CONTENTS Introduction ReviewofLiterature. . . . . . . . . . . . Methods andProcedure . . . . . . . . . . . I Soil and Soil Testing . . . . . . . 1! Nutrient Levels Used . . . . . . . III Source of Nutrients . . . . . . . . 17 Method of Preparing Stock Solutions YculturalPracticee ........ Nutrient Consmnption. . . . . . . . . . . . Bosulte.................. Discussions and Conclusions . . . . . . . . Litaramncited eeeeeeeeeeeee 11 15 15 18 57 THE EFFECTS 01' VARIOUS LEVELS OF NITROGH, PHOSPHORUS AND POTASSIUM ON THE GROWTH OF OOLEUS INTRODUCTION be extensive use of coleus as foliage plants in window gardens. conservatories, formal beds and pots mkes it desirable to know what nutrient status is necessary for its best growth. A search of the literature reveals very little specific infor- mation on the nutrient requirements of coleus. It has been observed that optima growth and development of foliage color in other plants are largely dependent on their nutrient status. Realizing that the value of coleus is directly dependent on its foliage deveIOpment and color formation. this swdy was under- taken to determine the best combination and concentration of nitrogen. phosphorus. and potassium necessary for the most desirable growth and foliage color development of the coleus plant. muss 03' MW Dakers (2) has stated that one of the secrets in the culture of coleus is to give it plenty of food. He recommended that once rooted. grow in rich loan and peat to which two ounces of hoof and hem manure is added to each bushel of compost at each pott- ing. l'ree (3) suggested the use of a general potting mixture for coleus. He suggested s. mixture consisting of four parts loam. two parts send. one and one-half parts dried cow manure and two parts leafmold with the addition of one cup of bonemeal to each peek of the mixture. are above recoumendations readily show that very little is discussed concerning the optimum nutrient levels for calm. Jackson (’4) found that geranium responded to specific levels of nitrOgen, phosphorus and potassium. He found that below and above the Optimum levels stunted growth and other toxicity synptoms resulted. It was further observed that phosphorus was the most influential of all elements studied in determining the growth of geraniums. Iuhr (5) determined the option levels of nitrogen, phos- phorus and potassium for the growth of m gmgrflgren . He found that inproper nutrient levels and inproper hydrogen-ion concentrations caused inferior craps of stunted growth and dis- colored foliage. Scarseth (6) stated that the supplies of nitrates, inorganic -2... phosphates and potash are the most frequently encountered criti- cal factors in plant nutrition. Browne (7) stated that the presence of one element in the soil influences the absorptive powers of plants for other mineral nutrients of the soil and fertilizers. He also stated that “somewhere between the limits of excess and deficiency for the different essential elements - nitrogen, phosphorus. potassium. calcium. magnesium. sulphur, iron,‘ etc.. - is the optimum range of the well-balanced or harmonious mixture of nutrients which will be found to vary according to the nature of soil. variety of crops. supply of water. amount of sunshine and numerous other environmental fae tors'. Shear, Orane and Myers (8) have stated that 'mximm growth and yield occur only upon the coincidence of optimm intensity and balance. it any level of nutritional intensity there exists a nutritional balance at which optiimm growth for that intensity level will result. his means that at any given level of nutri- tional intensity, provided all nutrient elements are in proper balance. it is possible to obtain plants that appear nornl in every respect in which all metabolic processes are probably quali- tatively normal. However. marinnm growth and yield result only when the proper balance of nutrient elements occur in combination with their optimum intensity". lleyers and Anderson (9) said. 'Lbsence or deficiency of any of the necessary mineral elements (including nitrogen) in the soil or other substratum iron which plants are rooted will -3— sooner or later become apparent in the development of that plant. an insufficient quantity of any of the essential elements in a plant in an available form will result in the production of growth aberrations which are syuptomtic of lack of an adequate internal supply of that element“. Hoagland (10) stated that h1g1 nitrate form of nitrogen may accelerate the injury produced when potassium is deficient. He also stated that it is evident that if nitrogen forms a limiting factor for growth. an increased supply will entail a greater demand for potassium and vice verse. 44- ME'EON AND PROM Coleus was grown in five-inch ordinary clay pots. Nitrogen. phosphorus and potassium fertilisers were applied in such pro- portions as to give all combinations of 5 levels of N03, 5 levels of I. and it levels of P. a total of 100 treatments. All pots were kept in clay saucers to avoid loss by leaching. §gil and Son meeting: 'Jhe soil chosen for this smeriment was Ostemo sanch soil which was collected from the vicinity of East Lansing by the Michigan State College Soil Science Department, and known to be very low in all plant nutrients. lhen tested at the beginning of' this eXperiment it was found to contain plant nutrients in parts per million as follows: nitrogen, 2 ppm; phosphorus 0 ppm; and potassium, 5 ppm. 'Jhosie levels above 0 ppm. tended to decrease soon after plants began to grow in the soil. The soil reaction showed a pH of 5.5. All soil tests were made by the Spurway (1) Soil Method. 'Ihe soil was tested to determine its fixation capacity for. nitrogen. phosphorus and potassium by the following procedure: 1. A quantity of soil was allowed to air-dry until it contained a minimum amount of moisture. 2. Twenty-four samples of 125 grams each were carefully weighed and placed in glass tumblers. Twelve samples were used for duplicate tests. 3. A stock solution of nitrogen was prepared by dissolving one-tenth grass of chemically pure sodium nitrate (RaNO3) in each milliliter of distilled water. Stock solution of potassium was prepared by dis- solving five-hundredth grams of chemically pure potas- sium sulphate (12801;) in each milliliter of distilled water. Phosphorus was used as the dry form of Monocalcium phosphate (Matron) 2). ll. Varying amounts of nitrogen. phosphorus and potassium were added to the soil samples as shown in fable 1. 5. Sauplee were allowed to stand for two weeks. after which time they were tested by the Spurway Test Method (1) to determine their fixation capacity for nitrates. phosphorus and potassium. fable 1 and the following graphs show the fixation capacity of the soil used in the experiment. -6— fable 1. Nutrient fixation Capacity of Ostemo Sandy Soil Distilled Amount of Solution Soil Level -' - 41-. .- .- _ -w - .- .— .. .. v - .. ..... 1. Nitrate rano3 1 .1 l 0 125 2I 2. I I I I 0.1 I . 5 3. I I I I 0.2 I 10 h. I I I I 0.3 I 15 5. I I I ' I 0.11 I 25- 6. I I I " 0-5 " 35 7. I I I I 0.6 I 50 s. I I I I 0.8 I 50I 9. I I I l I 1.0 I 75 10. I I I I 2.0 I 100I 11. I I I I 5.0 I 200I 12. I I I I 10.0 . I 500 1. Phosphorus seampomg 0 0 0 125 0II 2. ' ' ' .02 I " .5 3. I I I .03 I I 1.0 h. I I I .011 I I 1.5 5. " " " .05 " " 2.5 6. I I I .06 I I 3.5 7. I I I .08 I I 11.0 s. ‘ I I I .10 I I 5.0I 9. I I I .15 I I 10.0 10. " ' ' .20 ' ' 10.0" Table 1. Continued Distilled Amount of Solution Soil Level : ‘3 . e he or . .-_ u .- u - u . um 11. Phosphorus 0831100102 0 .25 0 125 18.0 12. I I I .30 I I 20.0I 1. Potassium reach 1 .05 0 125 5v 2. I I I I 0.h I 15I 3. s s s e 0.7 a 20 1;. s s s e 1.0 s 30‘ 5. s s s s 2.0 s ‘40 . s s a s 3.0 s 60* 7. s s e a tho I go 6. I I I I 5.0 I 100. 9. I I I I 6.0 I 120 f 10. I I I I 8.0 I 1110 11. I I I I 10.0 I 160 12. I I I I 20.0 I 320 'I Levels selected for use in the experiment. . — — . [.51 nllh‘llt I «1‘16 l .f 70.1.-.. lullllrul. l .uliuwlt.llfilllo.|0vtl|llllnllll|’l liailltllll . . 4L ur- I T- i 1 3 + I I 10.0 2.0 5.13 I! III 1'1, 170 0.8 ll lllva‘lllllt‘lllsllll Ili’llllelvlli.‘l'0lllllll1..lllll..!lfillllll iiil'Lvlal ‘1‘.i . h . . as 0.3 C. ll 0.5 stunner: of Stock Solution (“I09 .lll'l'l.‘ .- , u “ «4| W153: tn tea a P a ..I: is; _ _ fl 0.2 0.1 iiflsiii .5. I 1 i I v ‘I‘I'l. OIII. . ll 1!. 'l. .llllt II «I I‘ll: '0 L . .. ......e..___._L .....-“ __ ....-.i, hf n I illdl.’|l'lvllullllllllltll|LW nelflllilll.'l!llvtlltl L 1 L '1‘ II -'I'|l.|1'|1l'l T- ll! .l ...-.Iillllll l* —- ...-...— +qar~...-——ve “...“... m‘ w——— 1 ——y_-.— ittlL ‘nl‘l I‘ll’I I’llt.‘ It- rig. -2.__£h0£phcmnxatiunjapacitx got; 03. tom 83.11631 8011 i TID.|l.ItIll I 1‘ Y . lttllo lYl'l'llll-|lU Oil-Olin m ..-. ll. I utilllt .4 .dll|l‘lll- l' 0", l' -r 0 ll 1.“ «3° .25 .20 vlFl’fIl lillllll'l‘i A . O .f Cl ‘ll'llttll‘ l lll‘l‘ll‘lqlutr 1. . #71! W- 777-77. 7 - 77“ .7- 7 717 7 :7?! 7 r1.- 7- - 7 -.fi 7-14.77- --.-1a_ 77 ----13.77..-.74; 7 77-7.:- .. -i - 7. e.- -7 .- 77“, -..- 7 7- 7 :7. m . _. _ . . v n . _ n a. _ _ , .0 ml N . M . _ _ w L W o 7L1 . I _ - _ m. m . _ e H m8 0 n w . U _ ._ _ . ._ .- ..Dlv ..T .7 l E .ujanaci 37"... I7.|I|‘.Ill'| + el'.nt..lllllll ill.‘.lll.. I' -1' ‘“m“-‘qfl’k-—-CNI‘ -..--— . I17 .ol7t1.tl-.l.l7 {ll-III .“Il lllllnlllvllrl I . - .~——._--- ‘1‘ _ -7 .1019. L -- . c‘-___e_..._......_.._-.__ ”...—....“M ”---—H“ ...-AA. _ _ '6 " 5.0 14.0 3.0 of Stock Solution (12801;) --—.—---——-r—-—-.-——v -. .- + 7 I‘ll7e-l| -l I'll-'7 7.1Illlluill - 41,—- _—m- - .__—..._..-.+.— F—xu‘——‘_.-. ~_ ...- p. fl 4. ... - 77.7.7.7. . . .. . M _ . h 12 m _ W __ ..0 l _ n _ 0 1 1 e. 11 n I _ w . .1 a m ,7 u ‘ m 82:... eon . a M m o. a a Jilltl 1. .- l . ..0 p. .11.. W: rive levels of nitrogen, 0 ppm., 25 ppm.. 50 ppm., 100 ppm., and 200 ppm. were used. l'our levels of phosphorus. 0 ppm.. 5 ppm.. 10 ppm.. and 20 ppm. were used. rive levels of pots-sf sium. 0 ppm., 15 ppm.. 3) ppm” 60 ppm.. and 100 ppm. were used. All possible combinations of the above levels were used to ob- tain 100 different treatments. Therefore, each plant was grown - at a different nutrient level. the following table shows the treatment numbers and the total parts per million of each nutrient used in the treatments. -1 2- Nutrient Levels Maintained in Bach Pot. Table 2. Treatment NO; P X P Treatment 1122 25. l. 26. 15 2. 15 27. 3. 28. 29. 100 5. 100 25 25 25 25 25 15 25 25 25 25 7. 15 8. 33. 9. 10. 31k 35- 100 ll. 12. 13. in. 15 15- 16. 100 ‘40. 100 M1. 15 l7. 15 100 100 18. 19. 100 100 20. 100 100 21. 22. 23. 15 117. 217. -13- !able 2. Continued 'i'reatment 101 r 1: Treatment s03 p x be. 200 5 60 73. 200 10 30 50. 200 5 100 7b. 200 10 60 51. 0 10 0 75. 200 10 100 52. 0 10 15 76. 0 20 0 53- O 10 30 77. 0 20 15 5h. 0 10 60 78. 0 20 30 55. 0 10 100 79. 0 20 60 56. 25 10 0 80. 0 20 100 57. 25 10 15 81. 25 20 0 58. 25 10 30 82. 25 20 15 59. 25 10 60 83. 25 20 30 60. 25 10 100 81». 25 20 60 61. 50 10 0 85. 25 20 100 62. 50 1o 15 86. 50 20 0 63. 50 10 30 87. 50 20 15 an. 50 10 60 88. 50 20 30 65. 50 10 100 89. 50 20 60 66. 100 10 0 90. 50 so 100 67. 100 10 15 91. 100 20 0 68. 100 10 30 92. 100 20 15 69. 100 10 60 93. 100 20 30 70. 100 10 100 917. 100 20 60 71. 200 10 0 95. 100 20 100 72. 200 10 15 96. 200 20 0 -1ll- Table 2. Continued Treatment N03 P I Treatment NO: P I 97. 200 20 15 99. 200 20 60 98. 200 20 30 100. 200 20 100 W .15. of t nt : Sodium nitrate (NaNO3) and ammonium nitrate HHhNO3) were used as carriers of nitrogen monocalcium phosphate (Caprou) 2) for phosphorus and potassium sulphate (12801,) for potassium. n1 of the above coupounds were chemically pure. Amonium nitrate was substituted for one-half of the sodium nitrate required at each level to alleviate the possibility of sodium toxicity in pots requiring high levels of nitrogen. W: , Stock solutions for each nitrogen level were prepared as shown below for the level of 25 ppm: . is indicated by the preliminary tests-.0“ gms. H.303 were required to raise the level of 1103 in 125 ms. of soil to 25 ppm. (Figure 1.). Using that ratio of NaNO3 to soil. .1611 gas. were required for the 1’450 gas. of soil used in each pct. .01; x 11.6 . .1614 gas. rano3 One-half of the N03 was applied as 11.1103 and the re- mainder as mum}. 'i'cerefore. each pot received .232 ms. 1181103 and the equivalent of that quantity of 1121103 as 113171103 (.109 gm.) To the above chemicals a sufficient quantity of distilled water was added to give complete dissolution. Stock solution for each potassium level was prepared as shown -16— below for the level of 15 ppm. Al the preliminary test indicated .020 gms. 1250).; were required to raise the level of potassium in 125 gns. of soil to 15 ppm. (Figure 3.). Using that ratio of [£8017 to soil. .232 we. were required for the 11450 gas. of soil in each pot. .020 x 11.6 a .232 gm. 128017 To the above amount of chemical a sufficient quantity of distilled water was added to give couplets dissolution. Phosphorus was added to the pots in the dry form of (3831190102). The amount was determined as given below for the level of 5 ppm: All indicated by the preliminary test .10 grams of (0831190102) was required to raise the level of phosphorus in 125 gas. of soil to 5 ppm. (l'igure 2.). Using that ratio 01 (0831790192) to soil. 1.16 gas. were required for the 1H5) gas. of soil used in each pct. .10 x 11.6 . 1.16 gm. (CaHu(P02)2) fable 3 which follows shows the amount of nutrient carrier required in 1150 grams of soil to bring the level of each nutrient up to the total parts per ndllion desired for the treatments used in the experiment. -17- Table 3. Nutrient Carriers Required to Obtain the Desired.Levels ...-..-. i132? Wig.) Fifi-$.39 “a“ 3:33.23.- r03 1181103 11150 0 0 0 I Hippo; I 0 0 1703 saso3 11750 12.5 .232 I semi I 12.5 25 .109 1103 NaNO3 11750 25.0 .17617 I sumo-5 I 25.0 50 .21 1103 17.1103 11750 50.0 1.16 I sumo: I 50.0 100 .511 :03 11.1703 11150 100.0 2.9 I 112741101 I 100.0 200 1.3 r 0.7317(th 2 11150 0 5 0 I I I 5 10 1.16 I I I 10 15 2.32 I I I 20 20 3.18 x 12007. 11750 0 0 0 . s a 15 15 .232 s I I 30 30 .58 I I I 60 60 1.717 ' ' ' 100 100 2.9 W3 7 On May 25, 19118 coleus cuttings were taken from stock plants which appeared to be nearly uniform in growth and foliar color pattern. The cuttings were placed in a propagation bench contain- ing verndeulite as a rooting medium. On J'mie 19th 100 five-inch pots were filled with 13450 grams of Ostemo sandy soil to which the proper amount of nutrients had been added and thoroughly mixed with the soil. Rooted cuttings of uniform sizes were selected and one planted in each pot. The potted plants were placed on a greenhouse bench and carefully watered. Partial shade was pro- vided by covering the roof of the greenhouse with whitewash. During the ensuing growth period the plants were spot watered and kept uniformly moist. Periodic soil tests were made and sufficient nutrients added as their need was indicated by test results. The experiment was terndnated August 10th when the plants were cut-off at the soil-line and the green weights of the ground growth was determmed as given in Table 7. -19- 302mm oorsmmmon Elbe following tables give the bi-weekly consumption of nutrients by each plant and the total amount of nutrients con- sumed by each plant during the entire growth period. These data were obtained by subtracting the total parts per million of each nutrient present in soil sanples from each pot. taken during the growth period and at the end of the experiment. from the total parts per million present in each pot at the beginning of the emeriment. The total consunption of nutrients by each plant was determined by adding the total parts per million lost from the soil between successive periodic tests. -20- Table l4. Amount of Nutrients Used Prom Soil During Successive Two Week Growth Periods. Amount of Nutrients Used (ppm) Treat- Ni tratg 2h0 gphorue 20 tassium lent st 0. 31d 1st 2nd 3rd 1st 2nd_3rd 1. 0 0 0 0 0 0 0 0 0 2. 0 0 0 0 0 0 0 0 5 3. 0 0 0 0 0 0 0 0 0 17. o 0 0 0 0 0 0 20 0 5. 0 0 0 0 0 0 0 to 20 6. 0 23 15 0 0 0 0 0 0 7. 5 25 15 0 0 0 0 o 0 8. 0 20 15 0 0 0 0 10 5 9. 15 25 15 0 0 0 30 0 no 10. 5 10 15 0 0 0 3o 170 20 11. 25 25 25 o o 0 0 0 0 12. 0 3o 25 0 0 0 0 0 5 13. 0 50 25 0 0 0 0 10 5 1h. 0 30 25 0 0 0 0 0 20 15. 25 25 25 0 0 0 0 20 no 16. 0 100 50 0 0 0 0 0 0 17. 0 96 70 0 0 0 o 0 0 18. 0 100 70 0 0 0 0 10 10 19. 25 50 50 0 o 0 0 10 20 20. 0 100 50 0 0 0 0 6o 170 21. 0 175 100 0 0 0 0 0 0 Continued Table 1i. Amormt of Nutrients Used (ppm) 0t 81 1st 2nd 3rd Pho hrus 1st 2nd 3rd Treat- M 1st 2nd 3rd ment O O 175 100 0 175 75 0180100 22. 0 O 23. 2h. 25. O 0 019075 26. 10 25 27. 28. 29. 35 25 25 2020 31. 15 15 10 23 23 25 15 32. 25 33- 3h. 35. 36. 37. 38. 39. 15 25 20 07060 O 13 010 01520 2% 3° 10 60 0 30170170 60 50 170 85 O 170. hi. 95 50 0 0 010 10 10 O 90 75 O -22.- Continued Table ll. Amount of Nutrients Used (ppm) mm 19122211121“ lst 2nd 3rd 1st 2nd 3rd £39 ment 1st 2nd Treat- . m 85 0 160 75 lll’Se O O o 160 125 177. 116. O O 175 100 10 0160 75 O 0160 “9. 75 50. 51. 10 52. 53. 5h. 55. 25 20 25 25 25 20 20 56. 10 25 23 25 59. 61. 62. 20 no 25 no 170 25 50 “0 25 no 3. 1*5 63. 6h. 65e 10 “5 25 5075 66. -23.. Table )4. Continued Amount of Nutrients Used (ppm) Treat- M w ment 1st 2nd 3rd 1st 2nd 3rd 1st 2nd 3rd 67. 50 75 50 0 0 0 0 15 0 68. 50 75 25 0 0 0 15 10 0 69. 50 75 25 o 0 o 30 0 0 70- 50 75 25 0 0 0 70 60 0 71. 100 150 1140 0 0 0 0 0 o 72. 100 150 50 0 0 0 0 0 5 73. 100 170 120 0 0 0 15 0 10 717. 100 170 100 0 0 0 175 0 20 75. 100 150 200 0 0 0 85 20 90 76. 0 o 0 0 0 0 o 0 0 77. 0 o 0 0 0 0 o 0 0 78. 0 0 0 0 0 0 10 0 0 79. o 0 0 0 0 0 no 0 0 80. 0 0 o 0 0 0 60 20 90 81. 15 25 25 0 0 0 0 0 0 82. 10 25 20 0 0 0 0 10 0 83. 25 25 23 0 0 o 10 10 0 8h. 15 25 23 0 0 0 Mo 20 0 85. 25 25 15 0 0 0 60 0 95 86. 178 25 170 0 0 0 0 0 0 87. 50 25 0 0 0 0 0 0 0 88. 175 25 30 ' 0 0 0 10 0 10 -2M— Table 14. Continued Amount of Nutrients Used (ppm) Treat- nena 1st 2nd 3rd 1.1; 2nd 3rd 1.: 2nd 3rd 89. 50 25 M0 0 0 0 30 20 20 90. 5o 25 170 0 0 0 70 60 20 91. 75 50 25 0 0 0 0 0 0 92. 85 50 50 0 0 0 0 5 0 93. 75 50 25 o 0 0 10 0 5 9h. 75 50 25 0 0 0 30 20 10 95. 85 50 25 0 0 0 6o 20 Mo 96. 125 125 25 0 0 0 0 0 0 97. 150 125 25 0 0 0 0 0 0 98. 150 125 0 0 0 0 10 0 0 99. 190 125 25 0 0 0 no 0 I40 100. 150 150 0 0 0 0 6o 20 20 -2:- Table 5. Nutrients Consumed During the Entire Growth Period, ppm. Treatment Ni trate Phosphorus Potas sium 1. 0 0 0 2. 0 o 5 3. 0 0 0 . 0 o 20 5. 0 0 60 6. n8 0 0 7. us 0 0 s. ' 35 o 15 9- 1+5 0 20 - 10. 30 0 60 11. 75 0 0 12. 55 0 5 13. 75 0 15 1h. 55 0 20 15. 75 O 60 16. 150 0 0 17. 166 0 100 18. 170 0 20 19. 125 0 60 20. 150 0 100 21. 275 0 0 22. 275 0 0 23. 250 0 20 -26. Table 5. Continued Treatment Nitrate Phosphorus Po tension 21;. 280 0 so 25. 265 o 100 26. o 2% o 27. o o 15 28. o o 25 29. o o 20 3o. 0 o 1h5 31. 25 o o 32. 50 o 15 ' 33. 63 0 ho 3th 58 o 60 35. 50 0 130 36. 1140 o o 37. 105 2% 13 38. so 0 35 39. 80 2% 70 no. 90 o 160 111. 135 2% 0 ha. 115 o 5 1&3. 130 o 20 m. 165 o 50 1+5. 135 o 100 116. 235 o o -27- Table 5. Continued rroatmont m trate phosphorus Potassium 1VI. 285 o 0 us. 275 O 15 ‘49- 235 0 50 so. 235 2% 100 51. o o o 52. o o 10 53. O O 5 511. o o 60 55. o o 120 56. 7o 0 o 57. 55 0 15 58- 75 0 30 59. 63 0 to 60. 35 o 90 61. 120 o o 62. 85 0 1o 63. 115 o 20 6h. 115 o 75 55- 150 o 125 66. 175 o o 67. 150 o 15 68. 150 o 25 .3 g o \s ~28- m1. 5. Continued rrootmont m truto Phosphorua Potassium 70. 150 o 130 71. 390 o o 72. 300 o 5 73. 39° 0 25 71;. 370 o 65 75. I+50 0 195 76. o o o 77. o o o 78. o o 10 ' 79. o 0 ho 80. O O 170 81. 65 o o 82. 55 o 10 83. 73 o 20 8h. 63 o 60 ’ 85. 65 o 155 86. 113 o o 87. 75 o o 88. 100 0 2o 89. 115 o 70 90. 115 o 150 91. 150 o o 92. ' 185 o 5 -29.. Table 5. Continued Treatment Ni trate Phosphorus Potassium 93- 150 o 15 9h. 150 o 60 95. 160 o 120 96. 275 o o 97. goo o o 93 275 o 10 99. 310 0 so 100. 320 o 100 RESULTS he results given below are the general effects on growth and foliage color develOpment of coleus caused by the use of different levels of nitrogen. phosphorus and potassium. The effect different nutrient combinations and the balance between nutrients will be given later. Nitrogen Levels 9.1m This level resulted in stunted and chlorotic plants. Very few of the plants produced secondary shoots. he leaves which should normally have a very deep red or mean center surrounded by narrow margins of green along the edges of the leaf had centers which were light red or ' pink surrounded by wider margins of pale yellowish green. m his level resulted in plants of good size and color. Secondary shoots were produced profusely. lbs foliage had deep red centers and narrow nargins of a healthy green color. Il‘he plants of this group appeared to be as good as those of any group. 59.32112: his level resulted in plants of good size and color. They were very similar in growth and color to those growing -31. at the level of 25 ppm. MM 'i'his level resulted in plants of reduced size and poorer color. The leaves were reduced in size and of dull colors. Plants of this group were almost as small as those observed in any group. Pew secondary shoots were produced. {_,- 329.1122: m. level resulted in plants of the smilest sizes . observed in any group. They were very dull in color and the leaves were rosetted near the tips of the plants. here were very few secondary shoots produced. Plants from different nitrogen levels are shown in the following figures. Pig. tt. Response of coleus nu days after potting to 0. 50. and 200 ppm. of nitrate when grown at 0 ppm. of phosphorus and.0 ppmh ofjpotassiunh Left to right: 1. 0 ppm. nitrate 2. 50 ppm. nitrate 3. 200 ppm. nitrate Note the extremely ligit color of the plant which did not receive nitrates. Pig. 5. Response of coleus ‘45 days after potting to O. 50. and 200 ppm. of nitrate when grown at 5 ppm. of phosphorus, and 0 ppm. of potassium. Left to right: 1. 0 ppm. nitrate 2. 50 ppm. nitrate 3. 200 ppm. nitrate -317... Pig. 6. Response of coleus "-5 days after potting to O, 50. and 200 ppm. of nitrate when grown at 10 ppm. of phosphorus and 0 ppm. of potassium. Left to right: 1. 0 ppm. nitrate 2. 50 ppm. nitrate 3. 200 ppm. nitrate Pig. 7. Response of coleus 1L5 days after potting to O. 50. and 200 ppm. of nitrate when grown at 20 ppm. of phosphorus and 0 ppm. of potassium Left to right: 1. 0 ppm. nitrate 2. 50 ppm. nitrate Be 200 mm nitrate Phosphorus Levels 0 mm This level resulted in plants of norml appearance, but reduced in size. he colors of the foliage appeared to be slightly darker and smaller than on the phosphate treated Plantae 5.121228 This level resulted in plants of normal appearance as to color of foliage. hey were slightly larger than those of the first phosphorus level group. 12.1222: his level resulted in plants of normal appearance. hey were slightly larger than those of the second phos- phorus level group. m his level resulted in plants of normal appearance. hey were the largest of any group. being slightly larger than those of the previous level. Plants from the four phosphorus levels are shown in the following figures. -37.. A Pig. 8. Response of coleus 50 days after potting to O. 5. 10. and 20 ppm. of phosphorus when grown at 25 ppm. of nitrate and 15 ppm. of potassium. Left to right: 1. 0 ppm. phosphorus 2. 5 ppm. phosphorus 3. 10 ppm. phosphorus 1l. 20 ppm. phosphorus Potassium Levels 2m: his level resulted in plants of normal appearance and good size inpall' cases except where the 103 level was too high. hair colors were ideal and branching was profuse. In the 5th nitrate level the plant which did not receive potassium showed symptoms of potassium starvation as shown by Figure 12. 1.5.222: he plants of this group were very similar to those of the first potassium level group as to color, size and amount of branching. m This level resulted in plants very similar to those found in the first two groups. here was very little ap- parent difference as to size. color and branching. m: his level resulted in plants that were sligitly smaller in size. he colors of the foliage appeared to be slightly rattled by brown coloration. his was especially evident along the margins of the leaves. 2.29.1299: his level resulted in plants that were considerably ~39- reduced in size as shown by'the weights presented in Table 7. The brown coloration mentioned above was more prevalent and in many instances burning of the tips of leaves resulted. Branching was also partly restricted. Results of Nutrient Balance: he following results especially indicate the value of nutrient balance. Him-u. Low-P . High-x 'WeooPoKmo) 3 he plant was very small chlorotic and showed symptoms of potash toxicity by the browning and burning of leaves. I {1" U m @«t-N. Medium-P, High-I (17200133100): he plant was larger than the one above, but very dwarfed as conpared to many other plants in the experiment. Other than its dwarfness it was of normal appearance. with fair branching. Medium-N. Low-P, Medium-K (r5020x15): he plant was much larger than those above, of good color and branching. Medium-N. Medium-P. Medium-K (N50P5K15): he plant was the largest of this group, being of ideal size. color and branching. he above results are shown in the figure on the following P3690 -111- Fig. 9. Coleus as affected by balance. Plants 1 and 2 were grown at the highest levels of nitrate and po- tassium with the first level of phosphorus in l and the second level in 2. Note the response to phosphorus. Plant 3 was grown at the same phosphorus level as l but received a medium nitrate and potassium application. Plant 1‘ received nitrate and potas- sium equal to the application on 3 but with an application of phosphorus equal to that applied to 2. Left to rigit: l. 200 ppm. R03, 0 ppm. P, and 100 ppm. X. 2. 200 ppm. 303. 5ppm. P. and 100 ppm. X. . 5)ppm.NO3,Oppm.P.andl5ppm. I. . 50ppm.NO3,5ppm.P.andl5ppm.I. Results of Nutrient Combinations: The results discussed previously were those obtained when the presence and concentration of only one nutrient was con- sidered. regardless to the presence and concentration of other nutrients. he results given below were those obtained when the presence and concentration of a nutrient in combination with other nutrients are considered. Low-P. Low-N. Low-X (NOPOIO): he plant was of good height but its foliage was chlorotic. and branching lacking. Higher-P. Low-H. Low-K (HoPglo): he plant was slightly larger than above. but its foliage was chlorotic and it had very few branches. Higier-P, Low-N. Low-K (RoPloKo): he plant appeared to be about the same as the one abovee Highest-P. Low-n. Low-I (norm): he plant' s general appearance was about the same as the one above. Low-P. Medium-B. Low-l (N5OPOKO): The plant was of fair size, good color and fair branch- ingo -113. Higher-P. Medium-H, Low-K (N50P5Ko): The plant had good color, fair branching and was larger than the one above. Higher-P. Medium-N, Low-X (NsoPloIo): he plant was of increased size, good branching and good color. Highest-P. Medium-N. Low-K (NgonoKoh he plant's general appearance was the same as the one above. but it was of greater size. being the largest of this group. Low-P. Highest-N. Low-I (NgooPoKo): he plant was of very small size. it had no branching and was of poor color, showing synptoum of severe potassium deficiency. Higher-P. Highest-n. Low-K (Ngoor5ro): he plant was larger than the one above, and it showed decreased symptoms of potassium deficiency. Higher-P. Highest-N. Low-I (320015030): he plant was much smaller than one above and showed increased symptoms of potassium deficiency. Highest-P. Highest-N. Low-I (NgooPgoKoh he plant was larger than one above and potassium deficiency was not as pronounced. 4414- he above results are shown in the figures on the following pages. 4&5- l'ig. 10. Response of coleus 50 days after potting to O, 30. and 100 ppm. of potassium when grown at 50 ppm. nitrate and 0 ppm. of potassium. Left to rigit: 1. 0 ppm. potassium 2. 30 ppm. potassium 3. 100 ppm. potassium 4&6- L +_. Fig. 11. Rasponse of coleus 50 days after potting to O. 30 and 100 ppm. potassium when grown at 200 ppm. of nitrate and 0 ppm. of phosphorus. Left to right: 1. 0 ppm. potassium 2. 30 ppm. potassium 3. 100 ppm. potassium ..h7. Potassium Toxicity: he results given below show the effect of nitrogen levels on deficiency and toxicity of potassium. Medium-ll. Low-P. Low-K (N50P0Ko): he plant was of good size. normal color and good branching. Medium-N. Low-P. Medium-K (N50POI30): he plant was about the same size and general appearance as the one above. Medium-N, LOW-P. High-K (NwPoxloo): I The plant was reduced in size and shows synptoms of potash tOfidWe Rigs-H. Low-P. Low-I (NZOOPOIO): he plant was severely reduced in size and showed synlptoms of extreme potassium deficiency. High-N. Low-P. Medium-K (N2OOPOK30)* he plant was larger than the one above and showed no synptoms of potassium deficiency or toxicity. High-N. Low-P. man-x (172001301100): he plant was of the same size and appearance as the first one above. It showed extreme synptoms of potash toxicity. he figure found on the following page shows a plant deficient in potassium. 4:8.- Pig. 12. Coleus showing potassium deficiency, as noted by the burning and curling of the tips and margin of leaves. Grown at 0 ppm. of potassium. 0 ppm. phosphorus and 200 ppm. nitrate. -hg- Table 6. he Effect of Nutrient Levels on the Green Weight of Coleus. Treatment Treatment No. Weight No. Weight 1. 21 Grams 23. 12 Grams 2. 22 I an. 8 I 3. 15 I 25. 6 I h. an I 26. ah I 5. 15 I 27. 33 s . 6. 10 I 28. 20 I 7. 12 I 29. eh. I 8. 32 I 30. 7 22 I 9. 2O " 31 59 s 10. 15 I I32. 16 I 11. no I 33. 85 I 12. 37 ' 3“. 56 ' 13. 50 ' 35. 32 ' 1h. 30 I 36. 50 ' 15. 15 I 37. 33 I 16. 30 I 38. 32 I 17. 12 I 39. 50 I 18. 20 I no. 26 I 19. 12 I In. 30 " 20. 6 I n2. 30 I 21. h I M3. 5n I 22. u I th. 32 I Table 6. Continued Treatment Treatment No. weight No. 17.: ght R5. 26 Crane 67. 80 Grams 146. 26 I 68. 7 I 1+7. 33 I 69. 16 I “8. 12 I 70'. 20 I ’49. 26 I 71. )4 s 50. 22 I 72. 20 I 51. 211 I 73. 2». I 52. 28 I 71+. 16 I 53. 22 I 75. 2 s 51”. 10 ' 76. 23 s I55. 6 I 77. 26 I 56. 82 I 78. 20 I 57. 7“ ' 79. 28 " 58. 87 I 80. ' 25 I 59. 70 I 81. 77 I 60. 29 I 82. 80 I 61. 7h I 83. 52 I 62. 614 I ah, 35 s I63. 12 I 85. 35 I 614. 32 I 86. 81; I I65. 1h I 87. 611 I 66. 30 I 88. 20 I Table 6. Continued Treatment Treatment 110. Weight No. Weight 89. 68 Grams 95. 13 Grams 90. 1414 I 96. 18 I 91. 31+ I 97. 6 I ’ 92. 78 I 98. h I 93’ 20 . 99e 12 ' ' 9t. 18 I 100. 1 I * Plants of different variety -52- I'Table 7. Average Green Weights of Plants Grown at Different Nutrient Levels. Nitrogen Phosphorus Potassium Level Isigit Level leigit Level Weight 0 22.6 o 18.9 o 3731 25 119.9 5 38.9 15 no.0 50 146.6 10 38.5 30 30.0 100 211.8 20 35.2 60 29.0 200 13.0 100 22.0 ‘I Above are data based on green weights as given in Table 6. -53- DISCUSSIONS AND CONCLUSIONS Prom the data presented in this study one can readily see that the presence of various levels of nitrogen, phosphorus. and - potassium greatly affect growth and foliage development in coleus. his information should be of great importance to the grower of coleus. he results show that nitrogen is the greatest limiting factor. A medium level of nitrate is required. as shown in Figures u. 5, 6 and 7 and also by Table 7. Table 7 indicates that the optianm level of nitrates was about 25 ppm. but the results obtained by the use of 3) ppm. was so very near those obtained with 25 ppm. that it would be better in commercial practice to use 50 ppm. because the application of a little excess would make it easier to maintain a sufficiently high level for a longer period. as nitrates are rapidly used by the growing plants. as shown by Table ‘4. he use of increased potassium levels did not very appreciably increase growth and inprove color. he plants grown at 0 ppm. po- tassium generally made as rapid growth as those grown at 15 ppm. and above the range of 15-30 ppm. the use of additional potassium had a decided toxic effect as shown in Figures 10 and ll and also in Table 7. his was especially evident where the higher nitrate levels were used. Therefore, it seems best when making nutrient applications to coleus to use nutrient carriers which contain the lower level of potassium. -511. he addition of phosphorus tended to improve growth and foliage color. Where phosphorus was totally absent growth was restricted and the leaves were narrow and slightly darker than nonml. Treatments with 5 ppm. of phosphorus caused a very definite increase in growth over the plants not receiving phos- phorus. as Table 6 indicates. Among plants grown at aptinmm nitrate and potassium levels application of phosphorus above 5 ppm. gave only a slight increase in growth. This is shown in Figure 8. ' * he importance of balance between the nutrients was very vividly shown. When high levels of nitrates and potassium were used in combinations with low phosphorus it was observed that a pronounced decrease in gowth resulted. There also occurred an increase in nitrogen and potassium toxicity syuptoms when those plants were compared with plants grown at medium nitrate and low potassium levels in combination with low phosphorus levels. Be- cause of the more balanced nutrient status the latter plants were of normal color and branching and were larger in size as conpared to the chlorotic and non-branched condition of those grown at high nitrate, low potassium and low phosphorus levels. Only phosphorus restricted madnfifn growth in the more normal plants. while all three nutrients were limiting factors in the chlorotic plants. When the level of phosphorus was increased where it was in combination with high nitrate and high potassium m increase in growth resulted due to phosphorus being at a level better suited for growth and an increase in balance between the three ~55- nutrients but greater growth was not obtained because of the limiting effects of high nitrogen and bias potassium. Where ”the phosphorus level was increased when in combination with medium nitrogen and low potassium madam growth was obtained because all nutrients were at the optimum levels for growth. Phosphorus was no longer a limiting factor as it was when the combination of medium nitrate. low potassium and low phosphorus was used. The above effect of nutrient balance was shewn in Figure 9. he effect of potassium on growth was greatly influenced by the nitrate status of the culture medium. This was observed p where plants grown at a medium nitrate level and varying potas- sium levels (Figure 10) are compared with those grown at high ~ nitrate levels and varying potassium levels (Figure ‘11). Where nitrates were low the lack of. or an excess of‘potassium did not affect growth as drastically as it did under conditions of mg: nitrate. in excess of potassium was limiting in both cases. It was shown that the use of relatively h1g1 potassium levels (30-60 ppm.) in combination with high nitrogen tended to increase growth while that amount decreased growth under conditions of low and medium nitrate levels. The results in the former instance was probably due to improved nutrient balance. In conclusion it can be stated that excessive nitrogen to- gether with excessive amounts of potassium tended to limit growth and foliage color development in coleus. he Optimum nutrient levels, as determined by the results obtained in this experiment -56.. were as follows: Nitrates 25—50 ppm; phosphorus lO-2O ppm; and potassium 5-15 ppm. Ar- 1. 5e 7. 8. 9. 10. -57.. LITERATURE CITED Spur-way. C. 3.. Soil Testing. Michigan State College Technical Bulletin 132. 19th. Dakers. J. 8.. he Modern Greenhouse. Page 96. 19%. rree. 11.. 111 About House Plants. Page 272. 19117. Jackson. 3.. A Report on the Determination of the Concentration of Nitrogen. Phosphorus. Potassium, Magnesium. and Calcium that are Necessary to Obtain the Best Growth 1 in Flower Production of the Geranium Plant. Dept. of Horticulture. Michigan State College. 1947. Puhr. E. J.. Nutrition of Begonia Senperflorens. hesis for Degree of M. 8.. Michigan State College. 191W. . Scarseth. G. D.. Methods of Diagnosing Plant Nutrient Needs. Journal Paper No. 56, Purdue University Agricultural nxperiment Station. 1912. Browne. C. A., Some Relationship of Soils to Plant. Yearbook of Asficulmfl. 1938. Po 7914-799. Shear. C. B.. Crane. R. L. and Myers. A. T.. Nutrient Element Balance: A Iundamental Concept of Plant Nutrition. Proceedings of the American Society for Horticulture Science. VOL-R7. p. 239-216. 19186. Meyers. B. S. and Anderson. D. 3.. Plant Physiology. Page 127. 1939- Hoagland. D. R.. Inorganic Plant Nutrition. Page 173-171;. 19th. ..‘fi-n- HICHIGQN STQTE UNIV. LIBRQRIES lllllll III II”! III Illllll MIMI I 9 7 3 312 31077 8 38