THE ADAPTATION 0F GLOBE ARTICHOKE (CYNARA SCOLYMUS L.) T0 ANNUAL CULTURE Thesis for the Degree of Ph. D. MICHIGAN STATE UNIVERSITY PANTAZIS ALEXANDROS A. GERAKIS 1968 THESIS Umvc'raa fry This is to certify that the thesis entitled The Adaptation of Globe Artichoke (Cynara scolymus L.) to Annual Culture presented by Pantazis Alexandros A. Gerakis has been accepted towards fulfillment of the requirements for Ph. D. degree in Horticulture W Item I fiajor professor Date July 22. 1968 0-169 LRARY , no i -rfl‘ maze-u:- c4,~¢“ IVA: 1 . Tin V ‘ u I: anmc av “DAB 8 WW 300K BINDFPY INC. [MRARV P‘VHFQQ _ - w .v-o—w-v-mlf ABSTRACT THE ADAPTATION OF GLOBE ARTICHOKE (CYNARA SCOLYMUS L.) TO ANNUAL CULTURE by Pantazis Alexandros A. Gerakis The possibility of growing globe artichoke (Cynara scolymus L.) as an annual crop in Michigan organic soils was the object of this study. Seed vernalization by presoaking in water for A8 hours and exposing to temperatures from 35 to ASF for periods longer than l5 days under conditions of adequate moisture and oxygen resulted in a higher percentage of plants which produced buds. Mean daily air temperatures above 65 F immediately after sowing vernalized seed nullified vernali- zation while temperatures 50 to 65 F for a week had no effect. Temperatures below 50 F vernalized the plants. Fully vernalized plants were not devernalized even when subjected to temperatures higher than 120 F. Seed environ- ment during vernalization was critical. Seed treatment with CCC lowered the effectiveness of vernalization. The use of gibberellin (gibberellic acid 3) substituted the need of cold treatment in many plants although its effectiveness was influenced by the time of application. Pantazis Alexandros A. Gerakis Vernalization and gibberellin had a similar effect on the leaf morphology. Plants vernalized and treated with gibberellin bolted after the formation of the lOth leaf. An increase or decrease in the nutrient solution con- centration of most of the nutrient elements tested affected both the concentration in the leaves and the growth and appearance of the plants grown in solutions. Leaf lobes were more suitable for sampling than the leaf midribs. Field experiments on a Houghton muck soil showed a marked response of globe artichoke to nitrogen as measured from the fresh plant weight. Spacing studies showed that a spacing of 2 x 2 feet was feasible for plants grown annually in fertilized and irrigated organic soil since the larger spacings did not increase appreciably the total fresh plant weight and the main bud weight. By utilizing seed vernalization and by keeping seedlings at optimum temperature and light, the reproductive cycle can be shortened to 6.5 months, i.e., from the beginning of the cold treatment to the harvest of mature seeds. This study clearly indicated that globe artichoke can be grown commercially as an annual crOp on Michigan organic soils. THE ADAPTATION OF GLOBE ARTICHOKE (CYNARA SCOLYMUS L.) TO ANNUAL CULTURE By Pantazis Alexandros A. Gerakis A THESIS Submitted to Michigan State University in partial fulfillment of the requirements for the degree of DOCTOR OF PHILOSOPHY Department of Horticulture I968 ACKNOWLEDGMENTS The writer wishes to express his sincere appreciation to Dr. S. Honma for his assistance in the experiments and in the preparation of the manuscript. Appreciation is also expressed to Dr. D. Markarian for his help in the planning of the experiments and to Dr. C. M. Harrison, Dr. A. L. Kenworthy, Dr. J. C. Shickluna, Dr. S. K. Ries and Dr. L. Aung for their helpful suggestions. Gratitude is expressed to Dr. C. E. Peterson and Dr. H. J. Carew for their encouragement to pursue graduate studies at Michigan State University and to Dr. R. L. Carolus and Dr. J. D. Downes for their guidance during the first stage of the writer's graduate program at Michigan State University. Acknowledgement is also made to Mr. David Basore for providing land and material for this study at Stockbridge, Michigan. Finally, the writer extends his appreciation to his wife, SOphia and to his parents for their continuous encouragement throughout his graduate studies. TABLE OF CONTENTS ACKNOWLEDGMENTS. . . . . . . . . . . . . . . . . LIST OF TABLES . . . . . . . . . LIST OF FIGURES. INTRODUCTION . LITERATURE REVIEW. General Artichoke . VERNALIZATION STUDIES. Effect of Vernalization Temperature and Duration. Effect of Duration of Cold Treatment, Sowing Date and Gibberellin . . . . . . . . . . . Effect of Growth Regulators Conditions During Vernalization and Effect of Gibberellin . Effect of High Temperature. Effect of PhotOperiod . Conclusions NUTRITION STUDIES. Effect of Nutritional Environment on Leaf Composition . Effect of Different Levels of N,P and K Fertilizers Conclusions PLANT SPACING STUDIES. BIBLIOGRAPHY . . APPENDIX . I2 I7 I7 20 32 37 A7 A9 SI 53 53 58 69 70 78 9O Table IO LIST OF TABLES The effect of vernalization temperature on bolting and bud weight of globe artichoke (Stockbridge). . . . . . . . The effect of vernalization duration and vernalization temperatures on bolting per- centage and mean weight of the main bud of globe artichoke (Muck Farm). The response of globe artichoke to sowing dates, seed vernalization durations and gibberellin treatment of plants. The relationship between plant and bud characteristics to earliness of bolting of globe artichoke (simple linear correlation coefficients). The effect of presoaking globe artichoke seed with growth regulators on emergence . The effect of repeated gibberellin applica- tion on the nutrient composition of globe artichoke leaf tissue. . . . The effect of seed environment, germination stage and gibberellin on bolting, earliness and bud and plant characteristics of globe artichoke. Relationship between growth, deveIOpment and plant and bud characteristics to earliness of globe artichoke (simple linear corre- lation coefficients) Effect of nutritional environment on the composition of leaf lobes (L) and leaf midribs (M) of globe artichoke . Response of globe artichoke to various levels of N, P, and K fertilizers Page 19 28 3I 3A 36 A0 Lie 5A 62 Table II l2 l3 IA l5 Relationship between leaf nutrient compo- sition and chlorosis in globe artichoke (simple linear correlation coefficients) Leaf nutrient composition data from globe artichoke plants treated with three levels of N, P, and K fertilizers Relationship between the various nutrients in the globe artichoke leaves at two samplings (simple linear correlation coefficients). . Effect of various levels of soil and broad- cast P and K on the fresh plant weight of globe artichoke grown on a Houghton muck soil . . . The response of globe artichoke to intra- row and inter-row spacing. Page 6A 66 67 68 7A Figure .P'UJN IO ll LIST OF FIGURES The rating of leaf lobation, 5 to l. The rating of bract shape, 5 to l. The rating of bud firmness, 5 to l The effect of sowing dates, duration of cold treatment and gibberellin on bolting of globe artichoke. The effect of sowing dates, duration of cold treatment and gibberellin on the earliness of bolting of globe artichoke. The effect of seed environment during vernalization and gibberellin treatment of plants, on bolting of globe artichoke. The effect of seed environment during vernalization and gibberellin treatment of plants on earliness of bolting of globe artichoke. . . . . . . . The effect of seed environment during vernalization and germination stage at sowing on earliness of bolting of globe artichoke . The plant layout of one block of the two dimensional arithmetic design used for globe artichoke spacing studies. All blocks had identical arrangement of plants. . . . . . The effect of spacing on the fresh plant weight of globe artichoke. . . . Fourteen randomly selected buds from annual culture of globe artichoke at the Michigan State University Muck Farm compared to a bud from a perennial California plantation . Page 23 23 2A 25 29 Al A3 A3 7l 73 76 INTRODUCTION Globe artichoke (Cynara scolymus L.)* is not a well known vegetable in the United States being grown predominantly in California where 50% is consumed locally. The crop is grown as a perennial and is propagated from cuttings. The annual culture of artichoke through vernalization in areas where temperatures prevent overwintering of the plant has been practiced in the past by horticulturists in northern Russia. This practice has received little attention by scientists. Recent preliminary studies at Michigan State University suggested that artichoke could be induced to flower in one year by seedling or seed vernalization and that organic soils provided a better environment for growth than mineral soils. The object of the present study was to investigate methods for growing artichoke as an annual crOp on Michigan organic soils. The study was made in three parts. First, the phenomenon of seed vernalization as expressed in artichoke was studied to determine the appropriate technique. to induce flowering through the use of natural cold, artificial chilling or growth regulators. Second, the nutritional aspects of *For brevity, in this study artichoke will be used instead of globe artichoke. artichoke adaptation were studied to learn the plant's nutri- tional requirements on organic soils and the effect of different nutritional environments on the nutrient composi- tion of the leaves. Third, the growth of artichoke at high plant populations was evaluated. LITERATURE REVIEW General The phenomenon of vernalization as commonly understood is the acquisition of a plant of the ability to hasten or promote flowering by an exposure to low temperature. In this study this interpretation of vernalization will be used. Several reviews on the subject have been published since I960 (2I, A2, 70, 8A, 86, IO7). The early concepts on the related phenomena of vernalization and photOperiodism are discussed in a book edited by Murneek and Whyte (67). Vernalization is not equally effective at all stages of growth. In the case of the biennial Hyoscyamus fligeg Sarkar (87) reported that seed and seedlings younger than IO days could not be vernalized. Vernalization was effective in IO-day old seedlings and increased rapidly up to the age of 30 days. No further increase of the effect of the cold treat- ment was observed up to IlO-day old plants. According to Wellensiek (107), this plant and other biennials, had a ”juvenile phase” during which they were unvernalizable. In other biennials like Daucus carota and Lunaria biennis seed vernalization alone did not lead to flowering but needed further plant vernalization at a more mature stage. The two treatments had an additive effect. Studies with Cheiranthus allionii and Arabidopsis thaliana showed variable sensitivity in different growth stages (5, 70). Generally, sensitivity increased with age (2]). Wellensiek (l07) emphasized the variable requirement5" for seed vernalization as summarized by Napp-Zinn (70) and Chouard (2I). Although the Optimal temperature for most plants was slightly above 0 C, temperatures as high as l5 C and as low as -8 C have been reported to be effective. Temperature was closely related to the duration of the treat- ment and it was generally longer with lower temperature. For winter rye (Secale cereale) vernalization for 6 weeks was equally effective at all temperatures between I C and 7 C (81). Grant (3l) found in winter wheat that seed vernalization duration from 5 to 8 weeks was more effective than longer or shorter periods. The extremes were A days and lIO days (IO7). Another prerequisite for seed vernalization was that the seed should : be sufficiently moist. Although Sen and Chakravarti (90, 92) showed that mustard seed which did not split the seed coat could be vernalized to a limited degree this did not suggest (8A) that the embryo remained dormant. Ample supply of oxygen must be provided during vernalization (3A). From a practical viewpoint, the vernalized seed at the end of the treatment should show limited sprouting, because Sprouted seeds are difficult to handle. With respect to the locus of vernalization, it was shown (2A, 2la, l03) that it was the stem apex. Purvis (79) demonstrated by vernalizing apices from excised embryos that the meristem itself could receive the vernalization stimulus. Wellensiek (l06) demonstrated that both isolated leaves and isolated roots of Lunaria biennis could be vernalized and concluded that vernalization took place only when dividing cells were present during the cold treatment. He further suggested that the vernalized condition was transmissable from cell to cell by mitosis. In Lunaria biennis physiological chimera occured consisting of both vernalized and unvernalized parts. Seed vernalization has been shown to have a marked effect on the morphology of the seedlings. In winter cereals, Thimann and Lane (l02) and Hansel (37) noted a shortening of the first leaf. Konovalov (A8) showed that the early leaves of vernalized cereals emerged earlier and matured more rapidly than the controls. Purvis and Hatcher (83) found shortening of the lamina in winter rye, reduction of the final length of the coleoptiles and absence of hairs on the first leaf sheaths as a result of the cold treatment. Chakravarti (l7) reported that all cold treated plants of Brassica campestris, Eggge sativa, Leg; esculenta, Eigeg arietinum, Lathyrus ddoratus and Pisum-sativum, were in a more mature anatomical condition than unvernalized plants of equal age. In Lolium rigidum and Lolium Qerenne, vernalization did not influence the growth in the vegetative phase but induced earlier heading and a greater pr0portion of repro- ductive tillers. Comparison of vernalized (reproductive) and unvernalized (vegetative) plants showed increased reproductive devel0pment to be associated with higher growth rates, lower tillering, and greater weight per tiller. However, a minimum number of leaves had to appear before flowering occured which was not influenced by the vernalization treatment, while the time required for the appearance of the minimum number of leaves could be influenced by environmental factors such as nutrition and temperature (8A). Photoperiod may interact strongly with vernalization. In winter rye, both cold and short day treatments shortened the vegetative phase but a period of long days was necessary for flowering to be completed (8l). Vlitos and Mendt (IOA) experimenting with vernalized spinach seed grown under different photoperiods found that the critical photoperiod necessary for flowering fell from IA to 8 hours as a result of vernalization. Rappaport and Wittwer (85) demonstrated that the flower promoting effects of seed vernalization in lettuce could be nullified if followed by short photOperiods. In Cheiranthus allionii, BarendSe (A) showed that plants subjected to short days before the cold treatment were difficult to vernalize. Wellensiek (IO7) differentiated between the effect of photoperiod in seed and plant vernalization. Seed vernali- zation should be followed by long days to be effective while plant vernalization should be followed by long days or is insensitive to day length. The author concluded that long days always favored vernalization whereas short days could be either harmful or neutral. Devernalization or the loss of ability to flower after vernalization, could be caused by a variety of factors, namely, by drying and storing the seed, by exposure to continuous high temperature (35 C), and by anaerobic conditions (3A, 82). Sen and Chakravarti (9]) found that sprouted mustard seed was devernalized by dry storage while unsprouted was not. In winter rye the effectiveness of devernalization by eXposure to high temperature was inversely pr0portional to the duration of the cold treatment (82). When vernalization was achieved, an exposure of the seed: to IE to 20 C for a few days before exposing to 35 C fixed the vernalized state. In Cheiranthus allionii partial devernalization in older plants was effected by exposure to 35 C while 20 C stabilized the vernalization (A). Similarly, the Hyoscyamus niger devernalization could be effected provided that the exposure to 35 C was made immediately after vernalization. An interval of 3 to A days at 20 C was sufficient to fix the vernalized state. In Chrysanthemum morifolium the vernalized condition was stable to high temperature but could be reversed by exposure to low light intensity. Devernalization by weak light was com- plete at 28 C but did not occur at relatively low temperatures (l8 C). Therefore, in this plant devernalization acted as a combination of both high temperature and low light (88, 89). The variability to the reSponse to vernalization and devernalization processes encountered within species was explained genetically. Different varieties and strains of various plants e.g.,of turnips (Brassica campestris) (I09), clary (Salvia sclarea) (59), Spinach (§Qinacia oleracea) (98, A7), cabbage (Brassica oleracea var. capitata) (68) and Cheiranthus allionii (5), showed unequal sensitivity to cold treatment. Detailed genetic studies on the mode of inheritance of the cold requirement were made in many plants, e.g., winter rye (78), winter wheat (35) and peas (2). Vernalization has failed to achieve the practical importance in crop production anticipated by the very early workers in the field. Vernalization (and devernalization) was used successfully as a tool for two main purposes. First, to shorten the reproductive cycle for accelerating breeding programs e.g., carrots (Daucus carota) (A9,25), lentils (Leg; esculenta) (95), cabbage (69) spinach (A5, A6, A7), beets (Beta vulgaris) (6), and second to select against high sensitivity to vernalization, e.g.,celery (Agium graveolens) (AA), onions (Aljyfligggé) (SO), lettuce (Lactuca sativa) (IDS). The role of auxins in the flower induction process has been established in many plants. Thimann and Lane (IOZ) accelerated flowering by soaking various seeds with synthetic auxins. Hatcher (Al) suggested that auxin was not involved in the vernalization process of winter rye. Clark and Kerns (22) effected acceleration of flowering in pineapple whereas Green and Fuller (32) found retardation in petunias. Leopold and Guernsey (55) found that acceleration or retardation of flowering was an interaction between concentration and temperature. Chakravarti and Pillai (l8) found acceleration of flowering in turnips by spraying seedlings with IAA, IBA, NAA, 2,A-D and TIBA, and retardation when the same auxins were used to soak vernalized or unvernalized seed. Kagawa (A6) noted acceleration of flowering by treating spinach seed- with NAA. Chakravarti (20) reported positive results for mustard when seed was partially vernalized and no effect when the seed was fully vernalized. Burg and Burg (ll) IO demonStrated the association between auxin treatment and ethylene formation in relation to the flowering of pineapple. Gibberellin-like substances were found to be closely related to flowering and vernalization. The discovery by Lang (52) that repeated applications of gibberellin could induce flowering in the cold-requiring biennial Hyoscyamus 3132; was followed by work with other biennials (9, IA, 25, 30, 53, 57, 99, III). This work was reviewed by Wittwer and Bukovac (ll5) who concluded that gibberellin accelerated flowering in cold-requiring biennials only when the biennial characteristic was very weak or when the photoperiodic requirement for flowering was satisfied, they were maintained at temperatures slightly above those inductive for flower formation, they were treated after the cold requirement was partially satisfied. Some varieties of Daucus carota, Digitalis purpurea and Matthiola incana were exceptions. With truly biennial cold-requiring sugar beet varieties, gibbere- llin was ineffective unless the plants were simultaneously or subsequently grown under long photoperiod, ; temperatures were maintained within 2 to 3 C of those normally inductive and repeated doses of gibberellin were applied. Extensive stem elongation preceded flower formation in other Species. Wittwer and Bukovac (ll2) reported that most cold requiring biennials of economic importance followed the pattern of sugar beet regarding the response to gibberellin. ll Work with other plants, annuals and biennials, demonstrated that gibberellin could act additively to other inductive factOrs like seed vernalization and photOperiod (l0, 5). In turnips gibberellin was leSs effective in inducing earliness than vernalization (l9). Gibberellin augmented the effect of vernalization in inducing earliness in the dwarf Telephone pea (6A) but did not influence the vernalizing effect in Brassica oleracea (69) . The variability of response to applied gibberellins and especially the lack of response of some plants was partly attributed to the specificity of the different gibberellins (6l) for some gibberellins caused flower initiation and stem elongation, others only stem elongation and still others neither. Cajhahjan and his co-workers (l2, l3) established that vernalization increased the amount of endogenous gibbere- llin-like substances which were found previously to exist in the plant (108). Some other growth regulators which were shown to be associated with the promotion of the flowering process were maleic hydrazide (llO), 2,A-D and TIBA (l8). Other chemicals like CCC (chlorocholine chloride) were shown to retard the growth of many plants primarily among the Dicotyledonae (l5) I2 and accelerate flower initiation. Zeevart and Lang (ll6) found that application of CCC in Brygphyllum daigremontianum suppressed both the stem-elongating and the flower-inducing effects of short photOperiods by decreasing the level of the physiologically active gibberellin below that which was normally required for flower initiation and stem elongation. Guenther (35) noted an inhibitory effect of CCC on the deveIOp- ment of vernalized winter and summer cereals which was more pronounced when CCC was added before cold treatment and decreased with the delay in CCC addition. Artichoke One of the earliest reports on artichoke vernalization _ was by Panov (72) who described the annual culture of the plant in the Leningrad area during the first part of this century. The vernalization technique used consisted of exposing Sprouted seed (with a sprout l to l.5 cm long) to snow in January for ID to l2 days followed by sowing in the greenhouse and transplanting in the field in May. Seed harvested in September was not mature. Panov suggested the perennial culture of artichoke in the warmer southern regions of USSR and recommended the restoration of the annual culture from seed in the northern regions. Shilova (9A) reported an I3 optimum vernalization requirement of 0 to 5 C for 8 to 12 days and an optimum temperature for growth and deveIOpment of the plant of l8 to 28 C. The bolting percentage from vernalized seed for the two Russian varieties was 8A to 90%. Bonnet (7) subjected pregerminated seed of the variety Gros Vert de Laon and Macau de Montauban (with a sprout I mm long) to l C for IS, 30, and A5 days and found an advancement in the reproductive stage by 2 months, a 30-day period being the optimum vernalization duration, and pointed out the usefulness of this method to shorten deveIOpment and obtain seed in a year. He also reported that dry seed subjected to cold was not vernalizable. Tavernetti (l0l) and Sims (97) mentioned the possibility of prOpagating from seed but rejected it as impractical due to the low quality of the buds. The idea of growing artichoke commercially from seed in Michigan organic soils was initiated by Markarian at Michigan State University. Preliminary results (A0) indicated that artichoke grown on organic soil from vernalized seed could be a commercially promising vegetable crOp. Seed and plant vernalization was successful in early sowings, whereas, late sowings were devernalized. No detailed study has been published on the effect of photOperiod after the cold treatment on flower induction and IA development of artichoke. Harwood and Markarian (A0) observed the effect of day length during the vernalization of young plants (after vernalization all plants grew under long days) and reported that bolting increased as day length during plant vernalization increased from I3 to l8 hours. They noted that an 8-hour day length during plant vernalization produced more bolters then the l3- and l8-hour periods. The authors concluded from this observation that Purple Early could be termed a facultative short day variety. Pochard (7A) believed that there is no evidence that day length plays an important role in the induction of bolting, at least on the cuttings, because in the southern regions of France the main cr0p is grown during the winter while in the northern (Brittany) it is in June and July. The effects of maleic hydrazide and gibberellin on artichoke were studied by Bonnet (7). He found that sprays of 500 ppm maleic hydrazide were toxic to plants while lower concentrations had no effect on the suckers. Also, gibberellin applications of 0 to 20 ppm did not promote the earliness of bolting. Pochard (73) noted marked structural changes especially on the leaves and 5 to l5 days earlier appearance of bolters as a result of repeated gibberellin applications. The alteration gibberellin caused on the buds made them, according to the author, unmarketable. It must be pointed out that both of the above studies concerned perennial culture. l5 All the available information on the nutrient requirements of artichoke pertains to perennial culture on mineral soils. Foury (29) reported that artichoke could do well in a great variety of soils. The author quoted Simonneau's opinion (96) that in Algeria artichokes did well on heavy grey clays covered by a halophilous vegetation and with a NaCl content of 0.8 to 3.0%. In France, growers prefer "terres motteuses”, that is, soils sufficiently heavy and of good structure. Mercuri (60) observed that sandy soils were not particularly good for the variety Castellamare. Bonnet (7) found no effect of added mineral nutrients on earliness and yield of buds. Barbut (3) noticed no fertilized effect on the number of buds harvested but only a positve effect of potassium on mean bud weight. Millela (62) reported an effect of potassium on earliness. He also found increased yields from 300 kg/ha ammonium sulphate, 700 kg/ha superphosphate and 300 kg/ha potassium sulphate. Polano (75) obtained the highest yield from nitrogen applied at several dosages within the year. Sims e£_gl. (97) reported that in California, manure was found very essential so that many growers apply ID to l2 tons of manure per acre in addition to nitrogen from commercial fertilizers. Nitrogen is sometimes applied through irrigation water between May and November at a rate of I6 30 lb/acre of nitrogen per month. With regard to other nutrients Foury (29) referred to the special role of magnesium in Brittany and the possibility that certain bud deformities encountered in the Southeast of France may be due to boron deficiency. Eaton (27) sampled leaf laminae from plants grown in sand culture and found boron deficiency symptoms at 38 ppm while normal plants contained ll2 ppm. Toxicity symptoms were associated with 238 to I358 ppm. No values for other nutrients have been reported. VERNALIZATION STUDIES Effect of Vernalization Temperature and Duration Procedure Two experiments were sown on May 6 to determine the optimum vernalization temperature and duration, one at Stockbridge, Michigan and the other in the Michigan State University Muck Experimental Farm. The Stockbridge experiment compared four temperatures, 32, 35, A0 and A5 F. Seed was presoaked for A days and placed in punctured bags with moist peat. The duration was 3 weeks. The design was a randomized block with four replications. The Muck Farm experiment tested the same four temperatures together with four vernalization durations (7, IA, 2l and 28 days). Seed was presoaked for 2 days. A split pI6t design was utilized with four replications. The main treatments were durations and the subsidiary temperatures. Both experiments had single row plots 30 feet long with IS plants per row. Rows were spaced 36 inches apart. The variety Violetto di Bologna from Ansaloni, Bologna, Italy was used in all experiments to be discussed in this study. It must be pointed out that the seed was ununiform genetically. l7 I8 Mean daily air temperatures for Stockbridge and the Muck Farm for the period April to October I967 are shown in the Appendix I. Soil temperatures at a depth of 3.5 inches taken at the Muck Farm were A6 F to 52 F for April, A8 F to 52 F from May I to May IS, 50 F to 60 F from May l6 to May 29 and 60 F to 68 from May 30 to June 5. Observations on bolting were taken once or twice a week. A plant was noted as a bolter the day when it Showed a ”button" in the center of the rosette. Multiple comparisons between treatment means were based on Duncan's Multiple Range Test. Results and Discussion At Stockbridge, vernalization temperatures had no effect on bolting or bud weight (Table I). The experiment at the Michigan State University Muck Farm indicated that seed vernalization temperatures of 35, A0 and A5 F were more effective in inducing bolting than 32 F (Table 2). There were no differences between 35, A0 and A5 F. Seed vernalized for IA, 2l and 28 days did not differ in the number of bolters. Vernalization period of 7 days produced fewer bolters than the longer durations. The low effectiveness of the 32 F temperature may be due to the slower germination compared to the higher temperatures. l9 Table l. The effect of vernalization temperature on bolting and bud weight of globe artichoke (Stockbridge) Temperature (0F) Bolting Mean Bud Weight (g) Percentage Main PLateraIs 32 32.3 IAA.5 6A.7 35 38.0 ll7.8 78.8 A0 2A.2 l82.5 88.l A5 28.l I35.3 80.A Table 2. The effect of vernalization duration and vernal- ization temperatures on bolting percentage and mean weight of the main bud of globe artichoke (Muck Farm) Bolting Mean weight of Percentage the Main Bud (g) Vernalization Durations (days) 7 12.8 a‘ 75.6 a lA 26.5 b ll2.2 a 2l 23.9 b 90.5 a 28 28.l b 93.5 a Temperatures (OF) 32 l5.6 a 88.3 a 35 20.3 ab 97.6 a A0 22.9 ab 95.7 a A5 ' 32.3 b 89.6 a IValues followed by uncommon letters are significantly different at the 0.05 level. 20 The higher the temperature the faster the growth of the embryo and, since dividing cells are the locus of the vernalization stimulus, (106) the higher temperatures were more effective in vernalization. The reason no temperature effect was observed in the Stockbridge experiment where seed was, presoaked for 4 days instead of 2, may have been the more advanced germination stage of the seed prior to exposure to the cold treatment. Effect of Duration of Cold Treatment, Sowing Date and Gibberellin Procedure The effect of sowing dates on vernalized and unvernalized seed and gibberellin treatment of plants grown from unvernalized seed was studied in a factorial eXperiment conducted at Stockbridge. There were 10 main treatments consisting of sowing dates starting April I.and weekly thereafter until June 3 and 10 sub-treatments consisting of 8 seed vernalization durations (2, A, 7, 15, 21, 28, 35 and A2 days at A0 F), one gibberellin treatment on plants grown from unvernalized seed and the control. Each sub-plot was a single row 25 feet long with 12 plants per row. Rows were spaced 36 inches apart. Seed was pre- soaked for A8 hours and placed in punctured plastic bags filled 21 with peat moist enough to let water through fingers on gentle pressure. Seed removed at the end of 2-, A-, and 7-day treatments did not show any splitting of the pericarp; the 15-day treatment had about one third of the seed showing signs of slight Split tips; and 21- and 28-day treatments produced sprouts less than 3 mm long while the 35- and A2-day treatments produced Sprouts ranging from 3 to 10 mm long. Due to poor soil conditions, sowing for the April I, 8, and 15 dates were made in 2.5 inch peat pots filled with organic soil and were placed in a cold frame. The potted plants of April 1 and 8 were transplanted to the field on .April 29 while those of April 15 were left unplanted by error and dried out for A8 hours before they were planted. All seed sown in the peat pots had germinated prior to trans- planting. Sowing after April 22 was made directly in the field. Initial gibberellin applications were made for all sowing dates on July 6, except for the last two of May 27 and June 3 which began on July IA, and were continued weekly until the end of August. One hundred ppm of the potassium salt of gibberellic acid -3 was sprayed to runofff on the rosette. The same formulation was used throughout this Study. Obser- vations were made once or twice a week for bolters, bud weight, and morphological characteristics for buds and plants until October 12 when the experiment was terminated due to frost. 22 The morphological characteristics were rated on a scale of l (smallest) to 10 (largest) for plant size and 5 (maximum length) to I (qfineless) for leaf spines, 5 (fully purple) to I (fully green) for bract color and 5 to l for leaf lobation (Figure l) bract Shape (Figure 2) and bud firmness (Figure 3). Non-orthogonal comparisons were made on treatments with analysis of variance. Results from the April 15 sowing date were not included Since they were erratic due to the very uneven growth. Since vernalization durations of 2 to 15 days and 21 to A2 days gave similar results, they were grouped as ”short” and “long” durations, respectively. Results and Discussion Gibberellin treated plants gave higher bolting percent- ages compared to other treatments for all sowing dates (Figure A). Gibberellin induced more than 90% bolting when applied on plants sown from May 10 to May 20 (neutral temperatures) and A0% on plants sown under the devernalizing conditions of May 27 and June 3 (Figure A). These data showed that the effect of gibberellin on bolting of artichoke was additive. A comparison of the bolting percentages between plants (grown from unvernalized seed) treated with gibberellin Figure I. The rating of leaf lobation, 5 to I (left to right) Figure 2. The rating of bract shape, 5 to I (left to right columns) AmcE:_oo u;m_c ou pew—V _ cu m .mmocEC_m can mo mc_umc och .m on:m_u 0:3.» 3:; l4. 2 25 .mxo;o_utm mac—m mo mc_u_0b co c___mconn_m ocm ucmEummcu o_ou mo co_umc:o .moumo mc_30m mo uoommo one .: oc:m_u mmumo mc_zom mess snz . __ee< m mm om m. 0 mm mm m. m _ 1 a q u q a 1 q a .- G n/X <\ /‘ a mco_umL:ml///// uLoLm x _ocucoo fl/ mz _mca< m KN 0N m. 0 mm Nu m. m _ d d u ¢/m/. q i «III/III a x G D/X a/ . 00— ~94 ..\// .mm. .0m_ mco_umcap mcoa 4 a mco_umrap urOLm n u . _oLucou » n \\\\\\. c___mrmnb_u . . . I mn— BUIJIOQ on sAeq 30 No differences were found between treatments for the weight of the main and the lateral buds indicating that these characteristics were not influenced by the cold treat- ment and gibberellin. Gibberellin treated plants had a lower number of lateral buds per bolted plant as compared to other treatments. This was because this group of plants bolted late and since the experiment was terminated October 12, it was not possible to observe the lateral buds. Correlations between various morphological characters and plant responses showed that the degree of leaf lobation could be a Sign of the reproductive maturity of the plant (Table A). The appearance of some unlobed leaves preceded or accompanied the appearance of the bud. Regardless of vernalization, the first true leaves were unlobed. There- after, the number of lobed leaves produced before bolting and the degree of lobation appear to be associated with the effectiveness of vernalization. Non-bolters produced only lobed leaves after the first four. Although it has been shown in Ranunculus hirtus (28) and Armoracia rusticana (71) that several environmental factors influence the reversion to, or the appearance of, juvenile type leaves, the explanation that in artichoke the degree of lobation is strongly influenced by vernalization is supported by the work of 31 Hmeen Hoo.o as» u. usuonuaewam .«e Hm>oa Ho.o or» an unuuauanwam re A0>0H Mbhbosu um unuoamacwamR weaunoe on whom 659 Annoyed no usage: was name no unwaoz exeme. Ana sneeze eev me.I NRA. Armae. Ono.I troo¢.i *«mmm. med. trams. owa. owo. Hmo.i oaa. meo.I mma. nma.u nemu. eoA.- eso.- enema. ewe. mun. woa I Arwom.I «mm 000. mag. ¢HH.u xrnme. moo.i ermm~.i «no. nrwmm . mmo rrnmm mac. ram cam one: God» Honouuq can: onam macaw Ieuam uoHoo mocamm Iunoq no mo ucdam uuuum ram uuuum mo mnam mung Arman: unwaoz onam undam «Adam uuuum muoaauau can Hoaoo uuuum morgue no onam .Amucowoauuooo coauuaouuoo Amanda o~aEamv oxonoauuu onoaw mo wcauaon mo mmmcaaumo ou modumaumuoeuuno can can unwam savanna manmcoauuaou one .a manme 32 Chakravarti (17) who reported for several species that cold treated plants were in a more mature anatomical condition than unvernalized plants of equal age. The association between the effects of gibberellin-like substances and vernalization was suggested in artichoke by the decrease in leaf lobation induced by gibberellin sprays on unvernalized plants. Pochard's report (73) on the morphological effects of gibberellin on artichoke is in agreement with the present results. The correlation between days to bolting and plant size agrees with Harwood and Markarian (A0) who noticed that late and non-bolters continued their vegetative growth until the end of the growing season. Plant size had some association with main bud weight but no association with lateral bud weight. Effect of Growth Regulators Procedure Two experiments were carried out at the Muck Farm in 1967 to find out whether gibberellin and various other growth regulators could replace the cold treatment. The first experiment studied the effects of seed treated at various concentrations of gibberellin (GA), NAA, ALAR, maleic hydra- zide (MH) and N6BA on bolting. Seed was soaked with the 33 above chemicals for 3 days in Petri dishes at room temperature. This seed was sown in the field on June I together with seed soaked in distilled water for the same period, vernalized seed (A0 F for A weeks) and dry seed (control). In the other experiment different concentrations of gibberellin, NAA, N68A, 2,A-D, TIBA and calcium carbide powder were applied on unvernalized plants. Sowing was carried out on May 30. The application of chemicals began on July 28 (when plants had six to eight leaves) and was followed at weekly intervals: until the middle of September. Application was by spraying to runoff on the rosette for the regulators and by placing one teaspoonful per plant on the rosette of calcium carbide. Multiple comparisOns between treatment means were based on Tukey's w-procedure. Results and Discussion In the experiment studying the effect of seed treatment with growth regulators no plants bolted until the middle of October. Emergence percentages showed that the highest concentrations of gibberellin, NAA and maleic hydrazide depressed emergence compared to the control whereas the low and intermediate concentrations of all chemicals enhanced emergence by increasing both the speed of emergence and the final emergence (Table 5). Soaking in water had no effect ' 3A Table 5. The effect of presoaking globe artichoke-seed with growth regulators on emergence. Treatments Days after sowing - AL; Chemicals and , M! 8 - 7 7718 i5 Concentrations F_§mergence Percent Emergence Percent inal (ppm) Percentage of Final Percentage of Final Emergence Percentage GA 10 18 35 42 81 52 " 100 24 41 50 86 58 ” 1000 20 54 33 89 37 ” 5000 4 20 13 65 20 NAA 10 29 49 52 88 59 " 100 26 43 48 79 61 ” 1000 1 14 5 71 7 Alar 10 13 30 49 100 49 " 100 11 25 40 91 44 " 1000 7 22 25 78 32 MB 10 14 25 45 82 55 ” 100 14 26 47 89 53 " 1000 3 15 15 75 20 N68A 1 9 19 37 79 47 “ 10 9 24 31 84 37 ” 100 7 17 31 76 41 Water soaked 15 27 47 85 45 Verna1ization 28 49 52 91 57 Control (dry) 8 23 24 71 34 W.05=23 W.Ol=27 35 while vernalization had the same enhancing effect as the low and intermediate concentrations of the chemicals, suggesting a probable association between vernalization and growth regulator effect. In the experiment studying the effect of growth regu- lators on plants two successive applications of 2,A-D at 100 ppm killed the plants while a lower concentration produced serious malformations and hardening of the leaf tissue similar to the symptoms described for artichoke by Prota (75). All gibberellin concentrations induced marked chlorosis and the leaves became more erect. Leaf tissue nutrient analysis data from gibberellin treated and untreated plants indicated a decrease in the nutrient composition due to gibberellin for all nutrients except N and P (Table 6). This decrease could be attributed to the sudden growth acceleration induced by the gibberellin treatment. The decrease was greater for Mn, Na, Ca and Cu. The reason gibberellin did cause bolting to the plants grown at Stockbridge whereas it was ineffective on the Muck Farm plants - although both groups of plants were sown on almost the same date - could be the earlier treatment of the plants grown at Stockbridge“ and the difference in maximum daily temperatures between the two locations for September which were 72.1 F for Stockbridge and 83.2 F for the Muck Farm. 36 .mucm_a 0. mo mu_moQEoo m_ o_aEmm comm— mN- Nm- :_- mNI m_- m:. mm- ON- mm- om- N- o Axv mocmcmcc_o cmm: MN- .e- N.. RN- mN- mm- ma- N_- m_- NN- m+ _+ any eucdcdcc_a am o. 4.0: m.m mm. mN Nae _N.o oe._ oc.m mme.o oa.m c___dceec_u a so. ca o.ce m.a emN ma omm a~.o Na._ oe.e mma.o ee.m .ocecoa M Na. _- m_- NN- m- om- we- mN- .m- m_- NN- _- Ase eucdcecc_a me m e.mm _.m ea. ON .mm m_.o e~._ om.m Nee.o oa.m c___eccee_o N mm o_ a..: m.c mm. o: oma m~.o ma._ om.e Nam.o ae.m .0cecou _ End End Ema Eda Eda Eda Ema & N N X & cmnssz _< CN m no mu :2 m2 m2 mo x a z ucmEummcb m_aEmm _ co_u_moaeoo uco_cu:c ecu co mco_umo__aam c_._mcobn_m poummamc mo uommmm orb .mzmm_u ewe. oxo;o_ucm who—m mo .0 d_eme 37 Conditions During Vernalization and Effect of Gibberellin Procedure Results obtained from a previous experiment showed that the critical period for flower induction of artichoke through vernalization and use of gibberellin was the period of germination. Although the maintenance of prOper seed environment during vernalization was always a point of special attention some of the variability noted in the previous experiments may have been due to undetected differences in seed environ- ment such as moisture and oxygen. An experiment to Study first the effect of low oxygen environment during seed vernalization, second the effect of a growth retardant and, third the importance of germination stage was conducted in the greenhouse. Gibberellin treatment of plants was also included to test the interaction with the above factors. Plants were grown at a temperature of 50 F to 65 F which a previous field trial indicated to be neutral regarding vernalization and devernalization. The factors and treatments were: 38 Seed environment during vernalization 1. Normal oxygen environment 2. Low oxygen environment 3. Normal oxygen environment plus CCC (Chloro- choline chloride) Germination Stage at sowing l. Sprouted seed 2. Unsprouted seed dGibberellin treatment of plants I. No gibberellin 2. Gibberellin The treatments were arranged in a randomized block design with 12 treatment combinations replicated twice. Each treat- ment combination consisted of six l-cubic foot pots filled with organic soil. The seed was soaked for A8 hours in room temperature and were placed in a punctured open plastic bag with moist peat so as to insure good aeration (for the normal oxygen treatment) while the low oxygen treatment seed was placed in a 500 m1 Pyrex flask half filled with moist peat. The flask was flushed with nitrogen for 5 minutes and sealed. In the CCC treatment the seed was placed in a punctured Open plastic bag with peat but instead of water, a solution of 100 ppm of CCC was used to moisten the peat. All three seed 39 lots were then placed at A0 F temperature for 25 days. At the end of this period, seed from each treatment was divided into sprouted (with a Sprout 5 to 10 mm long) and unsprouted (with slightly split pericarp) lots and was sown on November 29. The temperature of the greenhouse for the first A weeks was kept between 50 F and 65 F. Gibberellin Sprays at 100 ppm on the rosette to runoff began on February 19 and continued weekly to April 8. Non-orthogonal comparisons were made on treatments with analysis of variance. Results and Discussion Plants from sprouted seed grew faster than plants from unsprouted seed aSIwas, shown by a visual size rating made February 11 before gibberellin application started (Table 7). Bolting percentage data indicated an interaction between seed environment and gibberellin treatments (Figure 6). Gibberellin increased bolting percentage only when applied to plants grown from normally vernalized seed while it was ineffective on plants from seed vernalized at low oxygen environment or from seed treated with CCC. Vernalization under normal oxygen did not exhibit greater effectiveness A0 423 Sod 05 us unconfined..." .3. .Ho>oa ¥ an .o one an uduuacaawam u uses Iucowu cadao incanaw x uses icouw>no poem .N owdum Goa.» .daaeuow x pace Inoua>ao poem .H Mdmdmummmmmw ma «mu ¢.nm «o.ow oma t¥ooa «¢.mm «.mm II 539833 .N naaaouonnaw oz .H .lllmmmuamlumlmmma funds» eaaaouoceao m.¢ so.m -NN- mm o.mm «.mm m.ma m.m~ *¢.mo 0.5m mHH oHH ¢.m¢ m.o¢ epoch pounounmcs .N muoom vounoumm .A de30m UN Owflpm don—I wnauap AesdAAnAI. do ououonv HA suusueom co mwcaudm onam ucdmm xeuc. nuwcoA., sauna ~wy one name HO unwam: sue-ua< amouh “we wmflmz exonoauud onoaw no madumauouocudno uauam can one new amonaanuo .wcauaon no aaaaouonndw use owuum coauucaeuow .unoecoua>co comm no poomuo one .5 dance wqaunom on when fl waauaom unmanowa>co vcom Al lOOr x 75, U) Gibberellin treated plants C 13 '6 x CD 4.) g; 50- o L. o 0.. o\\. . Untreated plants 25- X 0 L l l Normal Low CCC Oxygen Oxygen Seed Environment Figure 6. The effect of seed environment during vernalization and gibberellin treatment of plants, on bolting of globe artichoke. ’ A2 compared to seed vernalized under low oxygen and vernalized with CCC except when these plants were subsequently treated with gibberellin. These results do not agree with the principle of ample supply of oxygen as a basic prerequisite for vernalization (3A) probably because the low oxygen level in this experiment was not low enough to prevent vernalization. Nonetheless, the inhibitory effect of low oxygen became evident after treating the plants with gibberellin Since gibberellin was more effective on plants grown from normally vernalized seed than on plants grown from seed vernalized under low oxygen environment. The interaction of seed environment treatments with gibberellin indicated that normal seed environment produced plants nearer to the threshold for bolting, compared to the other seed environment treatments. The interaction is another manifestation of the additivity of the vernalization and gibberellin effects encountered previously in this Study. Gibberellin treated plants from low oxygen and CCC treated seed took longer to bolt than treated plants from normally vernalized seed (Figure 7). Untreated plants bolted simul- taneously indicating again that both low oxygen environment and CCC during the vernalization process had a depressing effect on flower induction. Another interaction for days to A3 150 _ i Gibberellin UV x/ C .— X ‘3 ' C l .\. -. o '00 _ ontro 4..) U) > m D 50 . c. . Normal Low CCC Oxygen Oxygen Seed Environment Figure 7. The effect of seed environment during vernalization and gibberellin treatment of plants on earliness of bolting of globe artichoke. 150 - . Unsprouted CD C 9:, x / 3 > m D 50 l 1 1 Normal Low CCC Oxygen Oxygen Seed Environment Figure 8. The effect of seed environment during vernalization and germination Stage at sowing on earliness of bolting of globe artichoke. AA bolting was found between seed environment and germination stage (Figure 8). Irrespective of the seed environment during vernalization, plants from sprouted seed bolted simul- taneously. Unsprouted seed vernalized under normal oxygen environment bolted earlier than plants from unsprouted seed vernalized under low oxygen and under CCC environment indicating that the longer the Sprout the larger the quantity of dividing cells, the higher the production of flower inducing substances, therefore the earlier the bolting. These results are in agreement with other workers who demon- strated the importance of dividing cells as a prerequisite for vernalization (79, 106). The inhibitory effect of CCC on bolting could be explained by considering this substance to be an antimetabolite in the flower induction process (16) rather than as a specific antagonist for endogenous gibberellins. No matter how effective the various treatments in inducing bolting and earliness, leaf counts confirmed the previous observation that the minimum number of true leaves prior to bolting was 10. No differences between treatments were found for fresh and air-dry weights per plant. A5 Plants treated with gibberellin produced smaller main buds compared to the control, which is in agreement with the findings of Pochard (73) in artichoke but does not agree with the field results described earlier in this Study. Perhaps under the restricted root deveIOpment conditions of the container, the plant could not keep up with the fast repro- ductive rate induced by gibberellin and this resulted in smaller buds. Contrary to the marked stalk elongation observed in many plants as a result of gibberellin application (115) in this experiment gibberellin treated plants produced buds with a shorter stalk than the control. This is probably due to first, in artichoke, bud formation precedes seed stalk elongation and, second, gibberellin applications were discontinued on bud appearance. Plant size seems associated with the number of leaves produced rather than with the Size (Table 8). Weight of bud was associated with the size of the plant in Opposition to the results found in field experiments due perhaps to the different soil conditions. Size appeared more closely related to fresh than dry weight since at the time of rating no bolters were observed. A6 .ad>dn Hoo.o one an unuoauadwam«e. Hm>0a Ho.o on» um unuoauaawam «« ago." mod on“. an undouuanwam « coaunoaanau saaamuonnaw_ououon ma huuaupom so aoxnu npuooomH firmnw.o Hmm.o oom.o oao.o ow~.o Num.o unwama 91* 30* ¥ ¥ RH” fi< mca.o ma~.o oaa.o Ham.o . mem.o pawn»: ¥ ¥ ¥¥ nmflufl Huc.o eac.oi Hmm.o . use.o can name n# as as _ as no Aeneas omm.oi Hoa.o «on~.o nuwaea xanum H¢N.0I wmm.0I waauaon r rs on who: mom.o _u:nam an hem—mo>noq unflam unwaoz can name nuwcma wcauHom Mon cache no unwaoz xaoum on whom mO>uOA Honam pecan .Amucoaoaumooo coaunaouuoo Havana OHQEHmV Oxonoauun onon no mmOGAHnuO ou moaumwuouonnnnu can can unnam can ucOEmoHO>Op .suzouw consume awnmnoaunaom .w mannw A7 Plant morphological differences between treatments were Observed 7 days after emergence. About 90% of the seedlings grown from sprouted seed vernalized normally had cup-shaped cotyledons similar to the ones described by Linser e£_el, (58) in Galinsoga parviflora and Melandrium album, whereas the presence of such seedlings in the other treatments was sporadic. In Linser's report the appearance of such leaf structure was a result of application Of 2,A-D. In artichoke it was probably due to low light intensity since such a phenomenon was not observed in the field. It seems that low light intensity interacted with the substances present only in fully vernalized seed to produce this anomaly. In this experiment the first mature seed was obtained in the middle Of May indicating that for breeding purposes the reproductive cycle could be shortened to 6.5 months. Effect of High Temperature Procedure From field experiments discussed earlier the devernalizing effect of high temperature following vernalization was obvious. TO explore the subject further two experiments were conducted. In the first, 20 plants of approximately equal Size (four to five leaves) and vigor grown from vernalized seed sown November 29, were selected. The plants were grown from the beginning under neutral temperatures (50 F to 65 F). A8 On February 17, 10 plants were placed under 2A0 watt infra- red heating bulbs, one bulb per plant, for 1 week. The other 10 were used as control and were grown under temperatures not exceeding 70 F. Some leaf burning was noticed at the end of the 1 week treatment on the heated plants. The soil was kept sufficiently moist during the period of the treatment.- Maximum daily air temperatures exceeded 120 F in the immediate plant environment. In the other experiment, vernalized seed was sown in 100 peat pots on November 29 and kept under neutral temperatures (50 F to 65 F). On December 7, 50 plants were moved to another greenhouse and transplanted in l-cubic foot pots. A tempera- ‘ ture of 70 F to 75 F was maintained in this house while 50 other plants were transplanted in similar pots at the same date and kept at a temperature of 50 F to 65 F. Results and Discussion In the first experiment where high temperatures from infra-red bulbs were applied, after the completion of the heat treatment the plants looked stunted and never resumed their previous vigor and growth rate. Bolting started March 25 in the heated plants and April A in the control. Bolting was A0% in the treated and 20% in the control while fresh and dry weights were respectively 25 g/plant and 5 g/plant for the heated plants and 80 g/plant and 16 g/plant for the control. A9 The experiment showed the ineffectiveness of temperatures as high as 120 F to devernalize plants which were grown from vernalized seed under neutral temperatures for 80 days. In the second experiment where two different greenhouse temperatures were compared, a faster growth rate of the plants in the warm house was evident 1 week after transplanting. The first bolters in the warm house were recorded February 3 while in the cool house, February 18. No difference in the bolting percentage was found between the two treatments indicating that temperatures 50 F to 65 F may have stabilized the effect of cold treatment when the plants were placed subsequently in devernalizing temperatures of 70 F to 75 F. Effect of PhotOperiod Procedure To find the effect of day length after seed vernalization 2A plants from vernalized seed sown November 29, were kept under a natural short-day period until December 27 followed by a 15-hour day until February 9. At this time, no bolters were visible and growth was fairly uniform. On February 9, half of them were placed under 8-hour and the other half under 16-hour day in the same house at temperatures between 60 F and 70 F. 50 Results and Discussion Bolters in both groups appeared February 19 at an approximately equal frequency. By the beginning of March the short-day group Showed more vigorous growth and by April 15 the difference was very marked. Plant weights were sampled and the short-day group had a total of 1,550 g fresh weight while the long-day group had only 22A 9 indicating that although artichoke may be considered a photOperiodically insensitive plant in its reproductive processes (7A), short photoperiod enhanced its vegetative growth. Another indication of the lack of response of artichOke to photoperiod is the following observation. All plants sown on November 29 in the greenhouse were kept under natural short day length until December 27. At that date they were placed under artificial light for a 15-hour day length. These plants Showed a similar bolting pattern as those planted in the field under the long days of April and May indicating that artichoke was not sensitive to photoperiodism Since, as reported by other workers (85, A, 107), in long day plants short days following seed vernalization tend to nullify the effects of the cold treatment. 51 Conclusions Cold treatment for less than 15 days at A0 F was ineffective while 15 to 21 days seemed the threshold for bolting. Best bolting results were obtained with 21 to A2 days duration. Seed vernalization temperatures between 35 F and A5 F were equally effective. Mean daily temperatures above 65 F immediately after sowing Of vernalized seed appeared to nullify the vernalized state while temperatures 50 F to 65 F for a week after sowing had no nullifying effect and seemed to stabilize the vernalized state. Temperatures below 50 F vernalized the plants. Fully vernalized plants did not lose the vernalized state even when subjected to temperatures higher than 120 F for 1 week. The seed environment during vernalization of artichoke was critical. Low oxygen environment lowered, considerably, the effectiveness of the cold treatment. Seed treatment with CCC, inhibited vernalization. Gibberellin replaced completely the cold requirement in a large number of plants. Its effectiveness was influenced by the time of application. 52 Vernalization and gibberellin caused similar alterations in the morphology of the artichoke leaves. Bud characteris- tics were not associated with plant Size for plants grown in the field nor were they affected by vernalization treatments. The reproductive process in artichoke was not influenced by short day length. The latter appeared to enhance the vegetative growth. No matter how effective the vernalization the minimum number of true leaves before bolting was 10. By vernalizing the seed as described and by keeping the seedlings at prOper temperatures the reproductive cycle can be shortened to 6.5 months (beginning of cold treatment to harvest of mature seed). NUTRITION STUDIES Effect of Nutritional Environment on Leaf Composition Procedure To Obtain information on the concentration of several nutrients in the artichoke leaves, as influenced by various nutritional environments, an experiment was conducted with nutrient solutions in the greenhouse. Leaf sampling techniques were also investigated. Seven week old artichoke seedlings Of uniform size were grown in 15 different nutrient solutions (treatments). Each treatment was replicatedethree times. Each replication had two plants grown in 1 gallon jar. Solutions of the various treatments were‘as follows: Control (Hoagland Solution No. 2) (A3) and two levels (minus and excess) of N, P, K, Ca, Mg, Mn and Fe (Table 9). The minus solutions lacked the nutrient under study except for minus N which contained 10% Of the N of the control treatment. Prior to planting in jars on January 20, all seedlings were grown in organic soil in the greenhouse. For 1 week prior to applying the treatments, all seedlings were grown in a complete solution. Solution changes were made weekly. The 53 5A 5N nm 00 MN an No.0 3..— ¢5H 50a 00 5h 0.N N.0d 0.0a 0¢.0 00.0 50.0 nn.u 00 03 00 N0 «.0 5.0 “.0.— 3.0 0n.0 no.0 :10 05 men «A 00 A.a n.n N.aa 0A.0 nn.0 0n.0 55.0 oua 00A 0 ON n.N n.0 n.0a 0N.0 no.0 «0.0 ac.a tn «0 5N 0n 0.0 0.0 0.5 3.0 nn.0 0n.0 nn.0 00.n «0.0 500.0 005.0 00.n 3.0 Jan .3.— 03 «n on 0.0 n.n.— 0.: 3.0 50.0 50:— Nn..— 0n.n 05.n and; «an; 00.n «0.0 fl n0 05.— nn 50 a.“ 0.m n.0a 3.0 3.0 34 on; 00.n .3.n 000.0 500.0 34 00.n con 00» we" 50 on N.a n.o 0.0a 00.0 0N.A NQ.0 05.0 «0.5 au.n 000.A 0on.a 05.n 0n.c IUI 00 0a.— 00 50 0.5 0.5 0.: nn.0 00.0 0N... on; 5N.0 0n.n 555.0 03:— 5n... 00.0 an 00.— ..3 0n n3 0.0 5.3 n.0.— 50.0 5n.0 00.." an.~ N0.n «5.« new.“ 0054 no.n «0.0 an 05 05A «N 05 a. «.5 0.aa 05.0 00.0 00.n n0.u 00.N 0n.n na0.0 0N¢.a 00.n an.‘ mm nag 05N 0 0 n.a n.0 0.0M nN.0 00.0 00.0 NM.N 00.n N~.0 000.0 n0u.0 50.0 00.n he 00¢ 50a 0N at 0.0 «.0u 5.0a 05.0 00.0 05.0 00.n nn.0 c0.n Ha5.0 n5N.d dd.“ «0.0 In 00.— 0.: 0n 3 n.0 0.0.— n.na 3.0 cn.0 5N... 00.n 05.0 nn. nno.0 0no..— 50... 00.n .7 03 00a an n0 .10 «.3 5.0.— 5n.0 00.0 0n..— 00..— 00.N no.0 055.0 .30..— 0¢.N 00.0 #03800 . I . . Ari I {55 i fan Ea!”— ENNHM. can . weaning. .3838 33: do 0: 333.. an... 3. 30 .83 «a... no 8328.8 I.» 8 nag... 32.3353 do vacuum .5 .38. 55 sixth, seventh and eighth leaves from both plants in each jar were sampled and used for analysis. Two samples were taken from each leaf - one from the leaf lobes and the other from the midrib as soon as disorder symptoms appeared in each of the treatments as compared to the control. Analysis of samples were made at the Michigan State University's Horticulture Department Plant Nutrition Laboratory by macro-Kjeldahl for N, by the flame photometer for K and by the emission photo-electric spectrometer (direct read- ingl. spectrograph), for P, Ca, Mg, Na, Mn, Fe, Cu, 8, Zn and Al. Multiple comparisons between treatment means were made by Tukey's w-procedure. Results and Discussion A comparison between the values from leaf lobes and midribs indicated that higher values for all nutrients except for Na were obtained from the former (Table 9). Leaf lobe samples were better indicators for the differences between the minus and the control for all nutrients except for Ca for which midrib samples showed greater sensitivity. Solutions with excess levels of N and K increased the con- centration in the midrib samples while excess P solutions 56' influenced the leaf lobe composition only. Also, higher coefficients of variation were found for the midrib samples than for the leaf lobes. These results showed that leaf lobes would be generally preferable to midrib samples for nutrient element analysis in artichoke. Further discussion will be based on data from leaf lobes. All of the minus treatments differed from the control. Only the excess levels of P and Mn differed from the control suggesting that these two elements accumulated in the arti- choke when supplied in excess in the nutritional environment under the conditions of this study. Nutrient interrelationships influenced leaf composition. Deficiency of P in the solution depressed the N composition of the leaves. Excess Ca and Mg decreased the concentration of P while excess of Fe increased it. Plants grown in solution where Mg was in excess contained less Ca than the control. An environment deficient in Ca caused higher accumulation of Mg indicating an increase in the uptake of Mg in a low Ca environment. A solution deficient in P and K increased the accumulation of Na. Excess Ca and Mg decreased the concen- tration of Mn but had no effect on the other trace elements. Excess K increased the concentration of Fe. Solutions deficient 57 in P increased the values for Cu, B and Al but depressed the concentration of Zn to a very low level. The levels of Zn were fairly constant between treatments except for the depressing effect of the minus P treatment and the enhancing effect of the minus K treatment. Plants grown in solution lacking N were stunted. 'Older leaves were yellow. Excess N in the solution had no effect on the plant. Solutions deficient in P produced plants which did not differ in size when compared to the control. Yellowing of lower leaves was similar to the pattern observed for N deficient plants. Excess P caused stunted growth. Plants growing in solutions lacking K were very stunted having much smaller leaves than the control. Yellowing was noted over the entire leaf area of both the new and old leaves. Some of the leaf lobes of the older leaves were twisted. Excess K caused stunted growth and twisted leaf lobes. Plants with symptoms of Ca deficiency were first to be noted. The new leaves showed the greatest effect which displayed a whitish color and were twisted. Plants showed signs of succumbing l5 days after the treatment was initiated. Excess Ca caused marginal chlorosis of leaves although the 58, plants were of normal size. This chlorosis may have been due to the lowering of the Mn content. Mg deficiency symptoms appeared on the older leaves. They showed yellow intervenal spaces with dark green veins. The plants were stunted. Excess Mg symptoms were the same as for the excess Ca treatment. Plants grown in an Fe deficient environment were of normal size. The lower leaves showed marginal yellowing. The new leaves were whitish. Excess Fe induced very stunted growth but no color change. Excess Mn did not have any effect on the appearance or size of the plants. The difference between the levels reported for B by Eaton (27) and the levels found by this study could be attributed to the different growing media, age of plants and possibly to a different sampling technique. Effect of Different Levels of N, P and K Fertilizers Procedure To study the response of artichoke to N, P and K fertilizers and to correlate yield with soil P and K three experiments were conducted at the Muck Farm. S9 The first experiment studied three levels of N (0, 100, 200 lb/acre of N as ammonium sulphate) three of P (0, l00, 200 lb/acre of P205 as triple superphosphate) and three of K (0, 200, 400 lb/acre of K20 as muriate of potash) combined factorially in a randomized block design with two replications. In the other two single factor experiments, six levels of P (0, 50, l00, ISO, 200 and 400 lb/acre of P205 as triple superphOSphate) and six levels of K (0, 50, 100, 200, 400 and 800 lb/acre of K20 as muriate of potash) were tested. The design was randomized block with two replications. Prior to fertilizer application soil samples were taken from each plot and were analyzed for P and K by the Michigan State University Soil Analysis Laboratory. Available P was extracted by 0.025 N HCl + 0.03 N NHhF and available K by l.N NHAAc.T Soil:extractant ratio and shaking time was for both nutrients 1:8 and 1 minute respectively. These data were used in an attempt to apply the elasticity or mobility concept as expressed by the following expansion by Bray (8) of Mitscherlich's equation: log (A-Y) = log A - c] b - cx where, A = maximum possibility of yield when all nutrients are adequate but not in harmful excess; Y = yield when no P (or K) is applied but other nutrients are adequate; b - the 60 amount of available P (or K) present; c] = prOportionality constant experimentally determined; c = efficiency factor of the method of applying the'fiuflfllizer and x = the quantity of fertilizer, of the form of nutrient b, that need be added for a desired percentage yield. Also, on the basis of the above formula the Baule units for P and K were 'determined A Baule unit of soil P (or K) is the amount of soil P (or K) necessary to produce a yield that is 50% of the maximum possible yield. All fertilizer experiments had 3-row plots 24 feet long. Inter- and intra-row Spacings were 3 and 2 feet, reSpectively. Records were taken from the middle row. Prior to sowing, all of the P and K fertilizer was applied when two-thirds of the N was applied prior to sowing and one-third l month after. All fertilizers were broadcast and disked in. Seed was pre-soaked for #8 hours and vernalized in moist peat at 40 F for 30 days and sown on May l2. Plant size was rated visually on a scale from i (smallest) to ID (largest) on July 2A and August 2l. On July 24 intensity of chlorosis was rated on a scale from i (minimum chlorosis) to l0 (maximum chlorosis). Leaf lobes were collected for nutrient analysis on July 2h and August Zl. 6l In the middle of June Mn deficiency symptoms appeared and were corrected by foliar application of manganese sulphate at 0.5 lb/acre elemental Mn. Records were taken for bolting, fresh plant weight and weight of main and lateral buds. The plants were harvested and fresh weights were taken on September l7. The soil type on which these experiments were conducted is described as Houghton muck. It is black to dark brown in color, granular and very friable and it is composed of fibrous plant remains consisting of grasses, sedges, reeds and other non-woody plants. The pH was 6.7. Multiple comparisons between treatment means were based on Duncan's Multiple Range Test. Results and Discussion In the factorial experiment testing three levels of N, P and K no interactions were found between treatments for any of the observations taken (Table ID). The appearance of bolters was greater from the application of 100 lb/acre of N as compared to the control. Increase in the N rate above l00 lb/acre did not hasten the appearance of bolters. Nitrogen increased the fresh weight per plant although it had no effect on the weight of buds, indicating that bud 62 2:53 00.0 in u. “30903:. 5.353005..- fiud 9:990.— cofluoog 50 09.5.33 uaaq>xa nan.e unosq u-c.o uohn.c ann.n cod.c no.0 10.5 un.n am.n5 an.A~A uoa.n -.- coo u~o.e uc~.c amoe.o coan.o ckn.n no~.o so.“ no.5 «m.n un.on no.mo n~o.n uo.- oo~ co~.n coo.n unac.c scan.o «on.n ¢5~.c c5.o no.5 c5.n «0.00 no.oc~ cod.n an.- o 3 ago.n .0<.¢ cune.o n0oc.o une.n c-.e cn.c :0.“ cm.n u~.on an.nod cuw.~ no.n~ oo~ nkm.n une.c nkfle.o nokn.o ”mo." uo~.c c¢.c «0.5 cm.» n5.no uo.oo~ «00.n an.n~ cod noo.n aNn.c noon.o comn.o umm.n ¢n~.¢ an.n n5.0 n~.n an.oo an.ooH noo.~ an.kd o Mm .mo.n nom.e cooe.o amkn.o coo.n uon.¢ oo.n pa.» no.5 an.~5 co.c~a pm~.¢ no.o~ oo~ uek.n uen.o uoon.o a-n.o ane.n c-.c a~.c no.5 pn.o an.50 co.-~ n¢m~.n n~.m~ cos ano.n ue~.c nuoe.o u-e.o can.n neo.c ca.“ an.n co.n «n.0n an.~o cn5.0 \ank.n~ o z AnN sannv A000 Annua\n~0 SN .n:< «N axon flu .n:< ea xdan Ha .n:< 0N mwmn .«.ouo~go Hulana< in" sans gnu-u. usage non Any .ou-x no lmdllcuuu an}... 0533 noufifluom ll 55 a «.04 3.0 .— 0.3 A5 a 0.04 mud-couaul on...» us: usako panda: 5E ..uoa«~«uuou a an- .m .z 0o .Agpou .ao«uu> ou axonuauuu cacao uo canon-cu .od ado-a 63 weight was influenced by genetic rather than by environmental factors. Plant size ratings showed that plant size was primarily influenced by N. A visual rating of chlorotic symptoms showed that the intensity decreased with increasing level of applied N. A correlation between intensity of chlorosis and nutrient concentrations in the leaves showed also the importance of N (Table ll). The appearance of bolters, the fresh plant weight, and the bud weights, were not influenced by added P and K fertilizers indicating that the soil of that experiment had sufficient P and K for the normal growth of artichoke. The effect of the added nutrients was apparent in the leaf composition of N, P, and K in the samplings of both July 24 and August 2l. The increase in the rate of the nutrient added was followed by an increase of its concentration in the leaf tissue, although the differences were significant only for the P values (Table 10). Increased N applications lowered the concentration of P in the leaves suggesting an antagonism between the two nutrients at those levels. The concentration of N and K in the leaves was higher on July 2h than on August 2]. The reverse was true for P. 6A Table ll. Relationship between leaf nutrient composition and chlorosis in globe artichoke (simple linear correlation coefficients) Nutrient Chlorosis N -O.6SO*** K 0.2l6 P O.h65*** Na -O.323* Ca -0.075 Mg -o.223 Mn -O.256 Fe 0.2ll Cu -0.030 B -O.l83 Zn -0.077 *Significant at the 0.05 level ***Significant at the 0.00l level 65 The concentrations of Mg, Na, Fe, Cu, Zn and Al in the leaves decreased in the second sampling while Ca, Mn, and B increased (Table 12). Correlations between the values for each element from the first and second samplings were noted only for N, K, Na, Mg and Fe suggesting the importance of the stage of growth of the plant in taking samples and interpreting the data (Table l3). Fresh weight per plant from the two single factor experi- ments and soil analysis data are shown in Table l4. By applying the data in Mitscherlich's formula as modified by Bray, the following two soil test correlation equations, for P and K, were established: For P: log (A - Y) = log A - 0.00905 b-0.003h8 x For K: log (A - Y) 109 A - 0.00hll b-0.00286 x On the basis of these equations and assuming no other factors were limiting growth, predictions can be made for the yield of fresh plant weight of artichoke (var. Violetto di Bologna) when the P (or K) analyzed as described and the amount of fertilizer P (or K) are known. These equations hold true for Houghton muck soil, for broadcast fertilizer application, for 3-feet inter-row and 2-feet intra-row spacing and for optimum supply of all nutrients except the one tested. The Baule units for soil P and K were 33 and 73, respectively. The results from these two experiments must be looked upon with caution due to the variability in the soil values for K (Table lh). 66 0N0 0N0 mm0 wn0 new ~00 on» un0 macs NOA~ wean NNNA NQNA ocau 00AA 0NNA N0oa 0na~ on em «.00 N.Nn N.0 ~.nN NnN NON Ona {AA 0AN~ Onnu an. on. 0°.N n0.u ooe 0N Nn 0.n¢ c.5n w.0 H.¢N NHN QNN neg n0 coca 0wcd nn. NM. nN.N o0.~ CON wN en o.n< N.mn 0.0 o.NN ANN onN aid 00“ conN onQN NM. Ac. wo.N eo.N o mfl an én o.c¢ N.Nn 0.0 m.nN 0aN “RN and mom omhd noun mm. 0n. No.N 00.~ CON wN en o.no n.5n n.0 w.¢N naN NON and mad ONoa Nona en. on. 0N.N 00.a cod 0N nn o.n¢ n.Nn o.o~ o.nN «QN NON nna Nod onna {nun en. Nn. No.N N0.a 0 mm on an N.N¢ n.0n w.0 n.nN «AN acN wed can mess mead an. 0n. ¢~.N 00.n ooN NN on 0.00 H.Nn N.0 N.wN n0u NNN 00d has has» moms en. an. 00.a n0.a 00H an Nn Q.N< c.0n 0.0 N.NN OON omN 0nd #0 oneu «find mm. on. 0N.N eo.N o z a 3 S 3 S «a 3 7.6.2.3 aN AN .AN has he: hasfi . haan . 0 :fi .n:< huafi ha: haafi QHGOEuoouH .Aiufjflflflilqfin. so as a! uoaauaquh .ouoaaddquN x v... .m .2 an :33 or!» :3) v.38.» 3:1... 2.2.0..qu 33m 88 a»... 8338.80 2.332. :3 .fi .38. 67 mo>om Hoo.o «so am ucoooomcmmo ... mo>mm Ho.o may on ucoomomcomo .. Hm>mm oo.o on» on ucooooocomo . .Niummuomnsm >9 mamamemm AN umsms< Eouw “Hiumfluomnsm >2 ooumcmmmon who mowHQEom «N hash Eouw muasmom\fl Nm N50 Now ch N02 Nmu Nmz N0 Nx Nz Has mmo. ..mom. moo. oom. mom. mom. ooo.- oom. ooo.- oom. oom.- moo omm.- oom...omo.u oom. Hmm.- mam. ».oom. ooo. ..ooo. oom.u mo oom. moo. oom. moo. ooo. omm.- mom.- ooo. ooo.- moo mom. oom. o.moo. oom.- mom.- ooo.- mom.- mmm.- moo ”.mmo. «.mmo. «mm. o.omo.- mom.- o.ooo.u moo.- ma: ».ooo. o.moo. oom. .mmm.- omo. omm.- moz mom. ooo.- oom.- mom.- .oom.- moo moo. .moo.- oom. mom.i moz ooo.- ".mmo. mmm.u mo ooo.- ooo. mo mom.- mz Ho Hso moo Ha: Hoz Hoo Hoz Ho Ho Hz ooo.- ooo.- moo. ooo.- ooo. omo. ooo.- moo. omm. mmo. mam vmm. .mom.- mom.- mmo.- mam. ooo.- mom. mmm.- mmm.- m.mmo. mmo mmo.- ooo. .mmm. oom.i omo. ooo. moo. moo. oom.- mmo.i so oom.- ooo.- mam. ooo.- omm. mmm.u oom.n mom. mom. ..ooo.- moo omo.- omo. moo. mom. ooo. ooo.- moo. moo. mmo.- .ooo.- max Hoo.- omm.- ooo. moo. ”.mmo. ova. ..moo. ooo.- .omm.- ooo. mo: ..ooo.- mom.i moo. mmm.- moo. Hmo. ooo.- oom. omo. ..omo.- moo omm.u moo.i ooo.- moo. ..moo. omm. ..mmo. mom.u u.omm.i ..ooo. moz ooo. mmo.- omm.- ooo.- moo. ooo.- ooo. moo. ooo. ..omo. mo omm. moo.- mmo. ooo.- mom. oom.u ..omo.- ooo. ..ooo. omm. mo omm. mom.i Hmm.- ooo. oom. moo. .mmo. .oom.- mom.i o.moo. mz .omoo. ~.oom. omm.- omo. ooo. ooo. ooo.- mmo. moo. omo.- moo moo. moo. ooo. mmm. mom. ooo. .ooo. ooo.- .ooo. Ho ooo.- omm. mmo. mmo. ooo.- omm. ooo.- ooo.- Hso mom. moo. mom. oom.u ooo.- oom. ooo.- moo oom. oom. mom. .mom.i ooo. moo.u we: ormmm.- u.oom. ooo.- mmo.i ..ooo. Po: mmo. moo. omo. moo. Moo ooo.- ooo.- ooo. oz ~.oom. o.oom.i Hm .mom.i imx \H mm>moa oxocowuum madam may no mucmmuusc msoHuo> mzu cwmzumn magmcoHumHmm .Amucomommuooo cOmumamuuoo Hmocma mamsmmv mmcwamEdm 03¢ um .MH mama? la .. III A A." l l 31‘ ALH\ .(l..- .MM H 68 Table 14. Effect of various levels of soil and broadcast P and K on the fresh plant weight of globe artichoke grown on a Houghton muck soil Treatments Fresh Weight Extractable Extractable per plant (lb) P* in soil K** in soil (lb/acre) (lb/acre) Phosphorus (lb/acre P905) Reg I Reg 11 Reg 1 Reg II Reg I Reg 11 o 3.90 3.80 35 ‘ 44 175 95 50 3.93 4.23 35 36 196 127 100 4.31 6.11 42 31 213 152 150 4.21 5.50 39 42 204 87 200 5.10 6.19 38 31 204 95 400 7.06 6.33 42 31 242 144 Potassium (lb/acre. K70) 0 4.96 4.70 25 35 190 103 50 5.08 5.00 36 35 144 80 100 5.15 5.06 42 41 243 87 200 5.05 5.30 36 31 196 ‘135 400 5.20 5.18 49 32 182 92 800 5 5.33 52 44 221 95 .25 *0.025 N HCl + 0.03 N NHqF extractable **1 N_NH4Ac extractabTe 04‘.“ .‘ :8 --‘A. -".1-..‘ s, 5:4'VT‘JII "Pr-"l i 69 Conclusions Various nutrient solutions markedly influenced the leaf composition of the artichoke. All minus treatments differed from the control while only the excess levels of P and Mn differed from the control. Nutrient interrelationships between several nutrient elements were noted for the leaf composition. Deficiency symptoms were most characteristic for minus Ca and minus N. Leaf lobe samples reflected better the effect of the various nutritional environments than midrib samples. Field experiments showed a marked response of artichoke to N as measured by the fresh plant weight. The P fertilizer treatments influenced the nutrient concentratiOn of the leaves. PLANT SPACING STUDIES Procedure To determine the density of plant pOpulation in Michigan organic soils, two experiments were conducted at the Muck Farm. The first experiment was factorial of split plot design. The main treatments were two intra-row spacings (1 and 2 feet) and the sub-treatments were three inter-row spacings (2, 3, and 4 feet) arranged in randomized block with four replica- tions. Each plot consisted of three rows 24 feet long. Sowing was carried out on May 13. Leaf samples for nutrient analysis were collected on August 24. Records were taken from the middle row for bolting, fresh plant weight and weight of main and lateral buds. The plants were harvested September 17. Multiple comparisons between treatments were based on Duncan's Multiple Range Test. The second experiment tested 32 spacing treatments ranging from 1 to 15 square feet per plant replicated eight times. Layout of the treatments is shown in Figure 9 (l, 66). Sowing was carried out on May 13. Fresh weight observations were taken on September 17. 70 71 feet . 0.0 . 3.5 . 3.0 , 2.5 .2.0.1.5.l..0 4.0 3.5 3.0 2.5 2.0 I. o o O 1.0 0 ' o o 0 O o c Figure 9. The plant layout of one block of the two dimensional arithmetic design used for globe artichoke spacing studies. All blocks had identical arrangement of plants. 72 In both experiments, prior to sowing, 100, 150 and 200 lb/acre of N, P205 and K20, respectively were broadcast and disked in. Six weeks after sowing, a side-dressing with 50 lb/acre of N was applied. Seed presoaked for 48 hours and vernalized in moist peat at 40 F for 30 days was SOWFl . Results and Discussion In the factorial experiment no interaction between intra- and inter-row treatments was found for all the various characters studied (Table 15). Two foot intra-row spacing gave higher values for all characters as compared to the 1 foot spacing but the difference was significant only for fresh plant weight and weight of main bud. Values for fresh plant weight and leaf P and K increased as the inter-row spacing increased but the differences were not significant. The data suggested that intra-row spacing under the conditions of the experiment was more critical than inter-row. In the second experiment no bolters were noted due to the late sowing. Fresh plant weight per acre did not change appreciably when the area per plant increased from 5 to 15 square feet (Figure 10). .oxo;o_ucm 060—0 00 u;m_oz “cm—o zmoew men :0 mc_omam mo poommo 05p .0_ oc:m_m paw—o coo uoom ocmsvm m._m_m_:o._mom.omomm_ . . o d u: l .1 .1 73 -um.o .oo.N .om.N .(q[) 100; aJenbs Jed JqBIBM usan 74 _o>o_ mo.o ogu um “cocomm_p >_ucmo_m_cm_m mom mcouuo_acoEEooc: >6 pogo—.00 mo:_m>_ mmo.: m:m:.o mno.: mo.m mo.mm mm.mo_ mo_.m mm.w_ : mom.m m:::.o ooo.: mo.m mm.om mm._m_ mmm.: m:.m_ m m_o.m 23.0 37: mom 3.3 3.00. mEi 2.2 m zomuoouc_ mom.m mom:.o omo.o mo.m mm.:o oo.om_ oom.m mm.m_ m o_m.m omoo.o m_o.e om.k o_.mm mo.mm mom.m .oo.m_ _ 30m1mtuc_ m .m:< Amy pan Aucm_a co .mcou Amy can \n_v Auoomv & x & oN_m um; 00 c_mz mo u;m_oz A&v mucoEumoLP x Logo e mom; 2 oooo oeo_m oem_oz uem_o3 emote me_o_0o me_0oeo .mc_omom 300-couc_ new 30cumcuc_ 00 oxo£o_uom 060—0 00 omcoomoe 05h .m. o_QMF 75 Conclusions Two-foot intra-row spacing gave higher yields of fresh plant weight and main bud weight as compared to 1 foot. No differences were found between inter-row spacings of 2, 3 and 4 feet. Fresh weight appeared to increase with increasing area per plant to about 5 square feet. A spacing of about 2 x 2 feet was adequate for artichoke when grown as an annual plant on sufficiently fertilized and irrigated organic soil. This Spacing would give 10,900 plants/acre or 32,700 buds/acre assuming that all plants will bolt and produce three buds. Figure 11 shows one bud from a perennial California plantation and 14. buds from annual). culture at the Muck Farm. 76 .Ao_op_Ev co_omucm_a m_cLOm__mo _m_ccocoa m Eocm pan 6 Cu UoLmano Econ x032 >o_mco>_c: oumum cmm_co_z ocu um oxo;o_ucm moo—m mo otsu_:o .msccm EoLm moan pouoo_om >_EoocmL cooucaoL .__ otom_m E rlllLll!ul{I_-l‘|i’1mlv\!a0w L BIBLIOGRAPHY BIBLIOGRAPHY Austin, M. E. 1964. Morphological studies on the tomato plant for predicting once-over harvest. Ph.D. Thesis, Mich. State University. Barber, H. N. 1959. Physiological genetics of Pisum. II. The genetics of photOperiodism and vernalization. Heredity 13:-3-60. Barbut, M. et G. Chevalier. 1940. Etudes‘sur la culture de l'artichaut en Algerie effectuées a l'lnstitut Agricole d'Alger. 1939-1940. Documents et renseignements agricoles. Bulletin No. 120. Alger. (Original not seen). Barendse, G. W. M. 1963. Devernalization in Cheiranthus allionii. Proc. kon. ned. Akad. Wetensch. Ser. C., 66:123-31 and 183-8. . 1965. Vernalization in Cheiranthus allionii Hogz. Mededel Landbouwhogesch Wageningen. 64(14): 1- . Beljdenkova, A. F., V. F. Korjakina and A. L. Smetanikova. 1945. How seed from some biennial vegetable crops can be produced in one year. Sovetsk. Bot. 13:29-35. (Hort. Abstr. 17:181). Bonnet, A. 1959. Contribution a l'étude de 1' artichaut. Thesis for doctoral degree, University of Toulouse, Printed by A. Gomes, Toulouse, France. Bray, R. H. 1948. Correlation of soil tests with crop response to added fertilizers and with fertilizer requirement. Diagnostic Techniques for Soils and CrOps. The American Potash Institute. 53-85. Bukovac, M. J. and S. H. Wittwer. 1956. Gibberellin and higher plants. II. Induction of flowering in biennials. Mich. Agr. Exp. Sta. Quart. Bull. 39:650-660. 78 10. ll. 12. 13. 14. 15. l6. l7. l8. 19. 20. 79 1958. Reproductive res onses of lettuce (Lactuca sativa var. Great Lakes to gibberellin as influenced by seed vernalization photOperiod and temperature. A.S.H.S. Proc. 71:405-411. Burg, S. P. and E. A. Burg. 1966. Auxin induced ethylene formation: Its relation to flowering in the pineapple. Science 152:1269. Cajlahjan, M. H. and V. N. Lozhnikova. 1962. Gibberellin like substances and the vernalization of plants. Soviet Plant Phys. 9:21-31 (Field CrOp Abstn 15:1629). Cajlahjan, M. H., T. V. Nekrasova, L. P. H10penkova and V. N. Lozhnikova. 1963. The role of gibberelins in the processes of photOperiodism, vernalization and stratification of plants. Soviet Plant Phys. 10: 465-76 (Hort. Abstr. 34:132). Carr, D. J., A. J. McComb and L. D. Osborne. 1957. Replacement of the requirement for vernalization in Centaurium minus Moench by gibberellic acid. Die Naturwiss. 447428-429. Cathey, H. M. and N. W. Stuart. 1961. Comparative plant growth retarding activity of Amo-l6l8, phosfon and CCC. Botan. Gaz. 123:51-57. 1964. Physiology of growth retarding chemiEals. Ann. Rev. of P1. Physiology, Vol. 15:271-302. Chakravarti, S. C. 1963. Anatomical studies in relation to vernalization. Indian Jour. Agr. Sci. 23:289-300. and V. N. K. Pillai. 1955. Studies in auxin vernalization relationships. I. The effects of certain synthetic auxins and their antagonists on the vernalization of Brassica campestris L. Phyton 5:1-17. . 1958. Gibberellic acid and vernalization. Nature 182:1612-13. 1965. Effect of certain chemicals on the vernalization of Indian crop plants. Nat. Acad. Sci. India Proc. Sect. B. (Biol. Sci.) 34(3):216-224. 21. 21a. 22. 23. 24. 25. 26. 27. 28. 29. 30. 31. 80- Chouard, P. 1960. Vernalization and its relations to dormancy. Ann. Rev. Plant Physiol. 11:191. Chroboczek, E. 1934. A study of some ecological factors influencin seed- stalk deve10pment in beets (Beta vulgaris L?. Cornell Univ. Agr. Exp. Sta. Memoir 154. Clark, E. H. and K. R. Kerns. 1942. Control of flowering with phytohormones. Science 95:536-537. Cooper, W. C. and P. C. Reece. 1942. Induced flowering of pineapples under Florida conditions. Proc. Florida State Hort. Soc. 54: 132- 38. Curtis, 0. F. and H. T. Chang. 1930. The relative effece tiveness of the temperature of the crown as contrasted with that of the rest of the plant upon the flowering of celery plants. )Amer. Jour. Bot. 17: 1047- 1048. (Origina not seen) Dickson, H. M. and C. E. Peterson. 1958. Hastening greenhouse seed production for carrot breeding. A. S. H. S. Proc. 71: 412. Dikshit, N. N. and(V. P. Singh. 1952. Vernalizatgon of cabbage seeds Brassica oleracea) var capitata Curr. Sci. 21: 249 (Hort. Abstr. 23: 709 Eaton, F. M. 1944. Deficiency, toxicity and accumulation of boron in plants. Jour. Agr. Res. 69: 237- 277. Fisher, F. J. F. 1954. Effect of temperature on leaf shape in Ranunculus. Nature 170: 406. Foury, C. 1964. Note bibliographique sur guelques exigences de l'artichaut. Station d'Am l. des Plantes Marafcheres, Centre Agron. du Sud-Est, Montfavet, Vaucluse. , Gaskill, J. O. .1957. A preliminary report on the use of gibberellic acid to hasten reproductive deve10pment in sugar beet seedlings. Jour. Amer. Soc. Sugar Beet Techn. 9: 521- 528. Grant, M. N. 1964. Vernalization and days to anthesis of winter wheat under controlled temperature and light. Can. J. Plant Sci. 44(5): 446- 450. { ~o“.77'"”7'. . ‘ fiqui-i‘ . .. . 32. 33. 34. 35. 36. 37. 38. 39. 40. 41. 42. 81 Green, M. and H. J. Fuller. 1948. Idole-3-Acetic acid and flowering. Science 180:415-416. Gregory, F. G. and O. N. Purvis. 1938a. Studies in vernalization of cereals. II. The vernalization of excised mature embryos and of developing ears. Ann. Bot., N. S. 2:237-251. 1938b. Studies in vernalization of cereals. Ill. The use of anaerobic conditions in the analysis of the vernalizing effect of low temperature during germination. Ann. Bot. N. S., 2:753-764. Guenther, G. 1966. Ist chlorocholinchlorid (CCC) ein spezifischer vernalisationsinhibitor? Naturwissenschaften 53(10):256-257. Halloran, G. M. 1967. Gene dosage and vernalization response in homologous group 5 of Triticum aestivum. Genetics 57(2):401-407. Hansel, H. 1953. Vernalization of winter rye by negative temperatures and the influence of vernalization upon the lamina length of the first and second leaf in winter rye, 5 ring barley and winter barley. Ann. Bot. N. S. 17:417- 32. Harrington, J. F., L. Rappaport and K. J. Hood. 1957. Influence of gibberellins on stem elongation and flowering of endive. Science 125:601. 1960. The use of gibberellic acid to induce bolting and increase seed yield of tight-heading lettuce. A.S.H.S. Proc. 75:476-479. Harwood, R. R. and D. Markarian. 1968. Annual culture of globe artichoke (Cynara scolymus L.) 1. Preliminary Report (in press). Hatcher, E. S. 1945. Studies in vernalization of cereals. IX. Auxin production during development and ripening of the anther and carpel of spring and winter rye. Ann. Bot. N. S. 9:235-266. Hillman, W. S. 1963. The physiology of flowering. New York, Holt, Rinehart and Wilson,’l64 pp. 43. LIA. 45. 46. 47. 48. 49. 50. 51. 52. 53. 54. 82. Hoagland, D. R. and D. I. Arnon. 1950. The water culture method for growing plants without soil. Calif. Agr. Exp. Station, Circular 347. Honma, S. 1959. A method for evaluatin resistance to bolting in celery. A.S.H.S. Proc. 7 :506-513. Junges, W. 1954. Vernalization of spinach and its ”after effects” in the following generation. Arch. Gartenb. 2:1-8 (Hort. Abstr. 24:2782). Kagawa, A. 1956. Studies on floral induction in slow bolting varieties of spinach. 1. Effect of chemical vernalization and low temperature treatment of seeds. J. Hort. Assn. Japan. 25:173-180. (Hort. Abstr. 27:1537). 1958. Studies on flower induction in slow- BSlting spinach (IV) Varietal differences in response to low temperature treatment. J. Hort. Assn. Japan. 27:234-240. (Hort. Abstr. 29:2543). Konovalov, I. N. 1944. Physiological characteristics of the effect of vernalization on the growth of plants. Sovetsk Bot. 3:21-36 (Biol. Abstr. 19:17395). Kumaki, Y. 1956. Vernalization experiment on carrots. J. Hort. Assn. Japan. 25:163-6 (Original not seen). Lachman, W. H. and E. L. Upham. 1954. Effect of warm storage on the bolting of onions grown from sets: a preliminary report. A.S.H.S. Proc. 63:342-346. Lang, A. 1951. Untersuchungen uber das Kaltebedurfnis von zweijahrigem Hyoscyamus niger. Zuchter 21:241-243. 1956. Induction of flower formation in TBiennial Hyoscyamus by treatment with gibberellins. Die Naturwis. 48:234-285. 1957. The effect of gibberellin upon flower formation. Proc. Nat. Acad. set. 43:709-717. Leopold, A. C. and K. V. Thimann. 1948. Auxin and flower initiation. Science 108:664. 55. 56. 57. 58. 59. 60. 61. 62. 63. 64. 65. 66. 83. Le0pold, A. C. and F. S. Guernsey. 1953. Modification of floral initiation with auxins and temperatures. Amer. J. Bot. 40:602-607. Le0pold, A. C. and M. Kawase. 1964. Benzyladenine effects on bean leaf growth and senescence. Am. J.Bot. 51:294-298. Lindstrom, R. S., S. H. Wittwer and M. J. Bukovac. 1957. Gibberellin and higher plants. IV. Flowering responses of some flower crOps. Mich. Agr. Exp. Sta. Quart. Bull. 39:673-681. Linser, H., W. Frohner and R. Kirshner. 1953. Formildende Wirkungen von Wuchsstoffen. Phyton 3:53-107. Markovic, A. A. 1949. The vernalization of clary. Doklgg Akad. Nauk SSR. 68:1117-20 (Hort. Abstr. 20:9 . Mercuri, S. 1954. La coltura dei carciofi romaneschi.. Ital. agric. 91:189-196 (Hort. Abstr. 24:2656) Michniewicz, M. and A. Lang. 1962. Effect of nine different gibberellins on stem elongation and flower formation in cold-requiring and photoperiodic lants grown under non-inductive condition. Planta 5 :549-563. Millela, A. 1955.‘ Effetti della concimazione minerale sulla precocita del carciofo in coltura annuale. Studi sassaresi, Sez. III 3:33. Moore, T. C. 1958. Effect of gibberellic acid on the growth of pea seedlings when imbibed through the seed coat. Nature 181:500. and E. K. Bonde. 1958. Interaction of gibberellic acid and vernalization in the dwarf Telephone pea. Physiol. Plant. 11:752-759. and . 1962. Physiology of flowering in peas. Plant Physiology 37:149-157. Morrison, F. D. 1966. Cultural and environmental para- meters for mechanically harvested cucumbers. Ph.D. Thesis, Michigan State University. 67. 68. 69. 70. 71. 72. 73. 74. 75. 76. 77. 84 Murneek, A. E. and R. O. Whyte. 1948. Vernalization and PhotOperiodism. Waltham, Chronica Botanica Co., 196 pp. Nakamura, E. 1961. Seed vernalization of cabbages (Brassica oleracea) I. Effect of seed vernalization on flowering in cabbage. J. Jap. Soc. Hort. Sci. 30:57-62. (Hort. Abstr: 32:831). and Y. Hatori. 1961. Seed vernalization of cabbages (Brassica oleracea) 11. Effects of a prolonged vernalizatiOn treatment and influence of gibberellin applied during vernalization. J. Jap. Soc. Hort. Sci. 30:167-70 (Hort. Abstr. 32:2879). Napp-Zinn, K. 1961. Vernalisation und vervandte Erscheinungen. Handbuch der Pflanzenphysiologie. Berlin, Springer XVI:24-75. Njoku, E. 1948. Leaf heteromorphism in Cochlearia armoracia L. M.S. Thesis, Univ. of Manchester (Original not seen). Panov, M. A. 1949. Producing artichoke seed. Sad i Ogorod 12:55-57. Pochard, E. 1964. Modifications de la croissance et du déveIOppement de 1' artichaut provoquées par la gibberelline. Ann. Amél. Plantes 14:219-225. 1968. Personal correspondence. Prota, U. 1964. Alterazioni causate nel carciofo (Cynara scolymus L.) da trattamenti con 2,4-D Studi sassaresi, Sez. III 11:89-108 (Hort. Abstr. 36:5574). Polano, P. 1959. La coltivazione del carciofo firecoce in Sardegna. Studi sassaresi Sez. III 5:118-13 . Purvis, O. N. 1934. An analysis of the influence of temperature during germination on the subsequent deve10pment of certain winter cereals and its relation to the effect of length of day. Ann. Bot. 48:919-955. 78. 79. 80. 81. 82. 83. 84. 85. 86. 87. 88. 85 1939. Studies in Vernalization of Cereals V. Thelnheritance of the spring and winter habit in hybrids of Petkus rye. Ann. Bot., N.S. 3:719-729. 1940. Vernalization of fragments of embryo tissue: Nature 145:462. 1944. Studies in the vernalization of cereals VIII. .The role of carbohydrate and N supply in the vernalization of excised embryos of Petkus winter rye. Ann. Bot., N. S. 8:285-314. 1948. Studies in vernalization XI. The effect of date of sowing and of excising the embryo upon the responses of Petkus winter rye to different periods of vernalization treatment. Ann. Bot., N. S. 12:183-206. and F. G. Gregory. 1952. Studies in vernalization of cereals XII. The reversibility by high temperature of the vernalized condition in Petkus winter rye. Ann. Bot., N.S. 16:1-21. and E. S. J. Hatcher. 1959. Some morphological responses of cereal seedlings to vernalization. J. Exp. Bot. 10:277-289. 1961. The physiological analysis of vernalization. In: W. Ruhland's Handbuch der Pflanzenphysiologie , Berlin, Springer, XVI: 76-122. Rappaport, L. and S. H. Wittwer. 1956. Flowering in head lettuce as influenced by seed vernalization temperature and photOperiod. A.S.H.S. Proc. 67:429-37. Salisbury, F. B. 1964. The flowering process. Oxford, Pergamon Press, 234 pp. Sarkar, S. 1958. Versuche zur Physiologie der vernalisation. Biol. Zbl. 77:1-49. Schwabe, W. W. 1955. Factors controlling flowering in the Chrysanthemum V. Devernalization in relation to high temperature and low light intensity treatments. J. Exp. Bot. 6:435-450. 89. 90. 91. 92. 93. 94. 95. 96. 97. 98. 99. 86 1957. Factors controlling flowering in the Chrysanthemum VI. Devernalization by low light intensity in relation to temperature and carbohydrate supply. J. Expt. Bot. 8:220-234. Sen, B. and S. C. Chakravarti. 1938. Studies in vernalization of mustard. A preliminary report. Indian J. Agri. SCi. 8:245-252. 1946. Effect of high temperature on vernalized mustard seed. Nature 157:266. 1947. Vernalization of excised mustard embryo.. Nature. 158:783-4. Shamel, A. D. 1917. Variation in artichoke. J. Heredity. 8:306-8 (Original not seen). Shilova, S. N. 1962. Artishok. Trudy Po Prikladnoi Bot. Genet. Selekt. 35:211-217. Shukla, T. C. 1953. Vernalization response in Lens esculenta Moench. Curr. Sci. 22:279-280. (Hort. Abstr. 24:462). Simonneau. I945. Etude sur la culture irriguée de ll artichaut en Oranie. Doc. et renseignements agricoles. Bull. No. 120, Alger. (Original not seen). Sims, W. L., R. H. Sciaroni and W. H. Lange. 1962. Growing globe artichoke in California. Univ. Calif. Agr. Ext. Serv. AXT-52, 15 pp. Sneep, J. and W. A. Wiebach. 1957. Seed vernalization of spinach (Spinacia oleracea L.) Zaadbelangen 11:246. (Hort. Abstr. 28:4797. Snyder, F. W. and S. H. Wittwer. 1958. Some effects of gibberellin on stem elongation and flowering in sugar beets. Ann. Meeting Amer. Soc. Sugar Beet Tech. Detroit, Mich. Feb. 4-6 (Original not seen). 1.345... :6, PM} ._ r 87 100. Stout, M. 1958. Some effects of gibberellic acid on the physiology of sugar beets. Jour. Amer. Soc, Sugar Beet Tech. 10. 101. Tavernetti, A. A. 1937. Production of the globe artichoke in California. Calif. Ag. Ext. Circ. 76:1-18 (33) reviewed. 102. Thimann, K. V. and R. H. Lane. 1938. After-effects of the treatment of seed with auxin. Amer. J. Bot. 25:535-543. 103. Thompson, H. C. 1929. Premature seeding in celery. N. Y. Agric. Exp. Sta. Bull. 480. 104. Vlitos, A. J. and W. Mendt. 1955. Interactions between vernalization and photOperiod in spinach. Cont. Boyce Thompson Inst. 18:159-66. 105. Warne, L. G. G. 1947. Vernalization of lettuce. Nature 159:31-2. 106 ' Wellensiek. .1964. Dividing cells as a prereguisite for verna ization. Plant Physiology. 39:832- 36. 107. Wellensiek, S. J. 1965. Recent develo ments in vernalization. Acta Bot. Neer. 14(3 :308-314. 108. West, C. A. and B. O. Phinney. 1956. Pr0perties of gibberellin-like factors from extracts of higher plants. Plant Physiology 31. Supplement XX. 109. Wester, R. E. and R. Magruder. 1937. Varietal and strain differences in the bolting of turnips. A.S.H.S. Proc. 35:504. 110. Wittwer, s. H., H. Jackson and 0. P. Watson. 1950. Control of seedstalk deve10pment in celery by maleic hydrazide. Am. Jour. Bot. 41:435. 111. and M. J. Bukovac. 1957a. Gibberellins, new chemicals for croE production. Mich. Agr. Exp. Sta. Quart. Bull. 39: 69-494. 112. 113. 114. 115. 116. 88‘ 1957b. Gibberellin effects on.temperature and photOperiodic requirements for flowering of some plants. Science 126:30-31. . 1957c. Gibberellin and higher plants: III Induction of flowering in long day annuals grown under short days. Mich. Agr. Exp. Sta. Quart. Bull. 39, No. 4:661-672. 1957d. Gibberellin and higher plants. VIII. Seed treatments for beans, peas, and sweet corn. Mich. Agr. Exp. Sta. Quart. Bull. 40:215-224. 1958. The effects of gibberellin on economic crOps. Econ. Botany 12:213-255. Zeevart, J. A. D. and A. Lang. 1963. Suppression of floral induction in BryOphyllum daigremontianum by a growth retardant. lPlanta 59(5):509-517. 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