The first symptoms of this disease appear on the leaf of teosinte (Euchlaena mexicana SCHRAD.) as small water-soaked dots, which gradually grow into oval diseased spots, gray in the interior, and brown in the margin. They, then, continue to get larger to stripes, the interior of which shows dirty white or light brown color, the margin being purplish brown or dark brown. The length of the stripe ranges from several milimeters to half of one leaf-length. This disease can be observed during the months from July to October, but in July and August it is most severe. As it has been found from most parts of Japan, it can be believed as a common disease of teosinte. The pathogen under consideration resembles Pseudomonas andropogonis in bacteriological characters, except that its colony is not viscid but butyrous and that it reduces nitrates. Spray inoculation of the isolate causes damage on Sudangrass and corn and the symptoms are the same as those by P. andropogonis on the above same plants. Therefore, the author has identified it as P. andropogonis (E. F. SMITH) STAPP, considering its bacteriological and parasitic characters. And it is the first time that P. andropogonis has been found to attack teosinte, so he has named the disease "bacterial stripe of teosinte". The bacteriological characters of the pathogen are as follows. It is a rod of 0.5×0.9 to 2.9μ in size, with 1 to 3 monopolar flagella and a few fimbriae. It is aerobic, Gram-negative and without capsules. On agar, the colonies are grayish-white, round, convex, smooth, glistening and butyrous. Green fluorescent pigment is not produced in. KING, WARD and RANEy agar. Gelatin is not liquefied. Milk is slowly peptonized, and both litmus and nitrates are reduced. Neither indole nor hydrogen sulphide develops, but ammonia is formed. Acid but no gas is formed from xylose, glucose, laevulose, galactose, mannose, glycerol, mannitol and sorbitol, and by certain strains, from rhamnose also in AYERS, JOHNSON agar with BTB as indicator ; neither acid nor gas from lactose, saccharose, maltose, raffinose, starch, inulin or dextrine. Starch is hydrolysed. There is slight growth in broth containing 4% sodium chloride. The optimum growth temperature is 35℃, its minimum below 10℃ ; the thermal death-points is at 52℃.

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Experiment has been carried out for two years to find the effects of heavy dressing of macronutrients (N, P_2O_5 and K_2O) on the regrowth of Pensacola Bahiagrass in clayey mineral soil. In this experiment regrowth behaviour and change of inorganic constituent were traced on every one week. The results are as follows ; 1. Regrowth were different each other in the seeding year and the second year. In the seeding year regrowth was divided into two stages ; in the beginning elongation of plant height was vigorous and in following stage creeping stem spread over the ground. Regrowth in the second year was promoted both elongation of plant height and increase of fresh weight together, because of the creeping stems completely covered the ground. 2. The regrowth of Bahiagrass was considerably affected by temperature. Increase of plant height and weight of new top were retarded below 20℃. The depression of growth by aridity was slight. Therefore, Bahiagrass grew relatively well on drier clayey mineral soil, in droughty summer season. 3. Contents of inorganic nutrients (N, P_2O_5 and K_2O) in new tops were high in the beginning of regrowth and decreased gradually. On the contrary content of calcium increased with advanced stage of growth. Phosphoric acid content in seeding year was higher than that in second year. The absorbing process of inorganic nutrient were follows ; in the early stage of the regrowth phsphoric acid was absorbed well and in following stage nitrogen and potassium were more absorbed. In the last stage, calcium was markedly absorbed and uptake of potassium and phosphoric acid were considerably reduced. 4. When fertilizer was multiplied, heavy dressing of nitrogen affected growth and yield of Bahiagrass very much ; in seeding year significantly it brought increased number of tillers and thereby it greatly hastened the spread of surface runners. in the following year start of the regrowth being promoted. And total yield increased about 40% in the first year and 20% in the second year than standard application plot. Heavy application of phosphatic fertilizer scarcely affected on the growth and yield, but depression of growth was less than other plots in dry summer season. High dressing of potassium was of little or no benefit to the regrowth of Bahiagrass.

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As one like of varietal characters of Italian ryegrass, a survey was made of the diffenreces of heading time and grass vigor of 63 varieties (or strains) of Italian ryegrass including Wimmera and Westerwolds cultivated by spring sowing in western part of Japan. 1. On heading time, marked varietal differences among varieties were recognized, thereby the whole varieties tested being divided into five groups, i. e. the group 1, 1-Wimmera, 2, 2-Westerwolds and. 3. 2. These groups were related to the present areas in the world where the varieties belonging to each group were cultivated. Namely, the group 1 included varieties which were mainly cultivated in Australia and South America, the group 2 in Japan and the group 3 in Europe. 3. This grouping was also , related to the varietal growth characters obtained by another survey when the grass was sown in autumn which ordinarily having been taken in Japan. Each heading time group had roughly corresponding growth behaviors. 4. In grass vigor, conspicuous varietal differences were recognized, particularly close relationship being seen between vigor and heading time. Looking from heading time grouping, the varieties belonging to the group 1 had high vigor in early stage of growth but withered to death in midsummer, the varieties of the. group 3 had slightly inferior vigor in early growth stage but later higher vigor, and the varieties of the group 2 tended to show intermediate characters between them. This result seemed to give a practical significance to the varietal grouping mentioned above.

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Using 14 varieties of Italian ryegrass picked up from many places basing on their origins, heading times and grass types, a comparison was made to the relationship between sowing time and yielding ability. The result showed that there were marked varietal differences in regrowth, disease resistance, yielding ability and several other characters, and these differences were correlated with each other among various sowing times. In total grass yield, each variety showed following order of high yield to low : autumn sowing lot (sown in September), late autumn sowing lot (sown in October) and spring sowing lot (sown in next March). From the standpoint of forage utilization period, following several points were clarified. 1. By early autumn sowing, the variety with high utility from early winter of the year to early spring of the next year was a native variety of early maturity and of upright grass type, but other varieties also like Gulf F.C. (medium maturing, flat and expanded type) and Oobahikari (late maturing, medium type) showed high yield and worthwhile as varieties for short time utilization. 2. By sowing times mentioned above, the adaptable varieties for forage utilizationn from late spring to summer were the ones of late maturity and of flat-expanded type. Though late maturing varieties whenever having upright grass type were somewhat inferior because of their slightly weak regrowth for long time utilization, they seemed to be prospective as winter forage crops to lowland paddy because of their high yield obtained by spring time cutting. 3. By late autumn sowing comparing to early sowing, grass yield in early spring was rather low but varietal yielding ability showed similar tendencies. Further, when aiming forage utilization from April and thereafter, it was clarified sowing in late October could give enough high yield. 4. In case of spring sowing, Gulf F.C. and Kuroishi native were adaptable to forage utilization from May through early June, and Sceempter tetilla, B 2138 and English leafy looked to be prospective for utilization from middle June through summer. These varietal yielding abilities were well coincided with relationships between heading characters and. grass vigor reported in the former paper. 5. Disease resistance (to bacterial disease and crown rust) also showed varietal differences but naming the most resistant varieties needed further studies from both sides of cultivation and breeding because disease resistance was connected with yielding ability.

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In this trial, differences in some characters of red clover varieties, of which seed. were produced at different places and from different ages of stands, were studied. The used varieties were Hamidori, Sapporo and Local. variety in Hokkaido. The results were summarized as follows : 1. The seed lot derived from second year production followed winter (January) sowing in California, U.S.A., were earlier in flowering, higher in vigor, plant-height and yield in the first and second year than the seed lot derived from second year production followed spring sowing in Hokkaido ; the relations except flowering were, however, reversed in the third year and thereafter. 2. The seed lots derived from second year production followed spring sowing in Oregon and Idaho, U.S.A., tended to be a little more non-flowering in mean growth type, and accordingly, were rather later in flowering than the seed lot derived from the. production on the same methods in Hokkaido. But there were not so remarkable differences, as the above results in seed production in California, in yield and some other characters between both. 3. In case of seed production of local variety originated from North Kamikawa District in Hokkaido, there were little differences in some characters between seed lots passed through some seed generations in Sapporo and North Kamikawa Districts ; but the marked changes in flowering, plant-height, yield and some other characters from the original variety were observed in seed lot produced in Hidaka District of Hokkaido, through intensive selection during one seed generation. 4. There were relatively little differences in some characters between seed lots, which. were produced from different ages of stands, such as in the first, second and third.year, respectively, of early-flowering variety in Sapporo District.

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This experiment was conducted in order to clarify the regrowth behavior after defoliation at the internode elongation stage in forage crops. Oats were selected for this purpose. In heavy density plots 100 plants per box and in light density plots 15 plants per box were grown. The size of each box was 43×15×17cm. The heavy density plots showed earlier development than light density plots. Defoliation were made on March 9th at 5cm levels above the ground. After defoliations, growing points remained uncut were 28.0% and 83.8% of the tillers in heavy density plots and light density plots respectively. Regrowth of plants was classified into two kinds. The first kind of regrowth was regrowth of already existing tillers and second kind, growth of new tillers. In heavy density plots, regrowth of already existing tillers was not seen, but in light density plots it was observed in about 30 tillers per box. The growth of new tillers took place in both of the plots. In heavy density plots it was. vigorous at first and then fell down considerably and in light density plots it showed more or less a steady increase. On 44th day after defoliation the dry weights of the plant materials resulted from the growth of new tillers were 9.5g (45.7 tillers) and 4.6g (32.0 tillers) in light density plots and in heavy density plots respectively. The total available carbohydrate (TAC) contents at the time of defoliations were more in the light density plots in comparison with the heavy density plots and hence it could be assumed that better regrowth in light density plots were due to their high carbohydrate contents. In this experiment it could be concluded that the regrowth of plants mainly depended on two factors. One was the conditions of growing points at the time of defoliation and the other was the quantity of reserve materials at the time of defoliation.

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Varietal difference in the growth habit of the adventitious roots of five white clover varieties, Oregon Ladino, Witte Cultuurklaver C.B., Welsh S-100, Kersey and Wilkla Witte Weideklaver was compared in relation to the denudation of the stand in the field after disappearance of the tap root system. In the seedling experiment, growth of the root was related to that of the top by means of the allometric formula, log Y=log b+K log X in which Y and X represent the weight of root and top respectively, b and K being constants. It was found that Wilkla showed more growth on the top rather than on the root, resulting in a decrease of regression coefficient, K. In the field experiment, the mean length of the internode positioned around the plant base was shortened in the following order ; Wilkla, Kersey, S-100, Ladino and Witte. Mean weight of adventitious root of each variety was 11.59mg in Ladino, 12.31mg in Witte, 15, 94mg in S-100, 15.06mg in Kersey and 7.40mg in Wilkla. Denuded area of the tops around the plant which tap root was removed artificially was produced more markedly in Wilkla and Kersey. From these resulrs, when the tap root system is lacking, the ability of nodal root to compensate the role of it seems to be higher in the variety which possesses the shortened internode and the better root growth around the plant base.

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This paper dealt with the results of writer's investigation of the relation of environ-mental factors and age of Ladino clover plants, Trifolium repens L., to occurrence of Curvularia leafspot of Ladino clover caused by Curvularia trifolii (KAUFF.) BOEDIJN. The spore germination of the causal fungus was shown between 15℃ and 37.5℃ and the optimum temperature was 30℃. The mycelial growth of the causal fungus on the culture medium was shown between 15℃ and 35℃ and optimum temperature was 27.5℃. The spore germination and the mycelial growth were almost not effected by the light. The disease was occurred at a wide range between 15℃ and 38℃ and the occurrence was severe at 25℃ to 30℃. The infection was accelerated under dark condition. The severity of the disease was increased by keeping the plants in high air humidity one to two days before inoculation. Ladino clover plants developed newly at 20℃ and 25℃ after defoliation were shown higher severity of the disease than that developed at 10℃. The severity of the disease in seedlings increased with the progress of growth stage untill seven to eight leave stages. In green house test, the severity of the disease was higher on young leaves than on older leaves in the adult plants. But little difference was shown in the severity of the disease depending on the age of stand of the plants.

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