Soil incorporated herbicides, EPTC, vernolate and pebulate not only gave fairly good control of purple nutsedege, large crabgrass as well as certain broadleaved weeds but also persisted for a long time under the heavy rainfall. The activity was superior in the order of vernolate, EPTC and pebulate at the same dosage. Sugar cane, variety N: CO 310, was slightly damaged by the herbicides in both emergence and initial growth of shoot, but root elongation and rooting was not reduced but somewhat enhanced. Granular vernolate at 300g/ha in active ingredient is practicable for weeding in sugar cane with variety N: CO. 310.

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This experiment was carried out as indoor experiment in Tokyo University of Agriculture in 1969.
Two Japonica and ten Indica type rice varieties were used. The provided depth of water was 0 cm, 5cm and 10cm at the temperature of 25°C, 30°C and 35°C respectively. Under these conditions, the differences in physiological and ecological characteristics of germination among the varieties were investigated. The results were summarized as follows.
1) In Japonica varieties under the deep watering conditions, coleptile had grown rather vainly and the appearance of roots and leaves were repressed in comparison with that of shallow watering conditions.
2) Morphological characteristics of Indica varieties on its growth of coleoptile and the appearance of leaves and roots at the initial growth period under the deep watering conditions showed very wide range of variations from varieties which were similar to Japonica type to varieties of which germination and growth of coleoptile showed same aspect as that of shallow watering conditions, that is, elongation of coleptile stoped and bended at the early stage, then the appearance and growth of leaves and roots were rapid and vigorous.
3) Amount of consumption of oxgen in the water during the germination and initial growth period was much more both in Japonica varieties and Indica varieties of which coleoptile had grown rather vainly, and was less in Indica varieties of which leaves and roots had grown fast.

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1) With seven strains selected from the four strain groups classified in the preceding studies, investigations were carried out to clear up the relation between the leaf portion and oil, citral and myrcene content and its varietal differences. In these studies, each of leaves which were gained from greenhouse cultivation was divided into four parts, the upper and lower halves of leaf-blade and leaf-sheath, respectively.
2) All the strains showed wide variation of oil content due to the leaf portion, at the same time remarkable varietal differences were recognized in this respect. First of all, strain 14 of group 1 which is considered to be the East Indian lemon-grass, Cymbopogon flexuosus Stapf, differs conspicuously from the strains of group 2 to 4 which belong to the West Indian lemon-grass, C. citratus Stapf; the former is characterized by the high level and smaller variation of oil content throughout the whole leaf.
3) In strains of groups 2 to 4, the oil content was highest in always in the upper part of leaf-blade, and decreased towards the upper part of leaf-sheath, and finally increased a little again in the basal part of leaf-sheath. In detail of the variation of oil content, however, remarkable differences were observed among strains.
4) The variation of citral content of oil due to the leaf portion is considerably smaller than that of oil content on the whole, but varietal differences were also recognized regarding this matter. Above all, strain 14 was most distinguished by the highest level and smaller variation of citral content through the whole leaf.
5) The myrcene content of oil from the leaf-blade was much higher than that from the leaf-sheath in each strain, but the difference between the upper and lower parts was not clear in both the blade and sheath.The myrcene content was confirmed, however, to vary considerably according to the strain and to be especially low in strain 14.
6) The relation between the leaf portion and oil, citral and myrcene content mentioned above, is considered to be an important factor in the practical production of lemon-grass oil, and from this point of view, selection of the superior strains was made.

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