作物と雑草との竸爭第1報 : とくにオカボの除草期について
スポンサーリンク
概要
- 論文の詳細を見る
1) Dr. PAVLYCHENKO (1949) advocated the heavier seeding, cross seeding, post seeding cultivation, and so on as biological methods of weed control. Since 1949,the authors have studied methods and mechanisms increasing competing power of crops, particularly Oryza sativa L. var. terrestris MAKINO (Okabo in Japanese name). Some field experiments in 1952 testing the weeding effects to the increment of yield of Okato were reported here. 2) The field experiments were done by means of the latin square of five treatments. Treatment A is perfect weeding, B is non-weeding, C is weeding a month after seeding in May 19th, 1952,D is weeding a month and a week after seeding, and E is weeding a month and two weeks after seeding. Such treatments were based on the preliminary experiments in 1951,resulting the damage of weeds to Okabo when they were not smothered more than a month after seeding. 3) The dispersion of weeds is related to the desing of experiments and the mode of dispersion was tested by the senior author's coefficient of homogeneity (NUMATA 1949). In spite of the seedling stage (cf. CURTIS and McINTOSH 1950), they distributed considerably at random (Table 1), perhaps because of the full disturbance of the surface soil in the crop field. The dominance-subordination relationships of the weed population were represented by the relative density and the relative weight (Table 2,3). Especially in the weight, a significant difference was demonstrated between the growth of weeds of D and E. That is, the weed population grew remarkably after June 26th (D)(Table 4). The biological spectra of weed population indicate the steady increment of the grass form and R_5-type like Digitaria sanguinalis var. ciliaris in sharp contrast to the broad-leaved and R_5'-type weeds (Table 5). 4) The average yield of each treatment is different significantly with one another by the analysis of variance (Table 6), especially E is different significantly to A, C. and D (B is out of the question because of non-harvest). Then, the time after D will be in the critical condition for Okabo. The variation of the number of leaves reflects the same state of affairs (Table 8,9). The order of the average number of leaves was reversed after June 26th (D). From these data as a weed-crop population, it nessesarily follows that the weeding for Okabo should be done before D treatment, and the weeding effect after that time will become very small.
- 日本生態学会の論文
- 1953-08-20
著者
関連論文
- 植物群落と等比級數法則 : 生物集団の基本構造 第1報
- 生態学と環境科学
- 第13回アジア太平洋地域雑草学会会議について
- 雑草の生態学的研究
- 作物と雑草との竸爭第1報 : とくにオカボの除草期について
- 歸化植物の生態学的研究 I
- アメリカ生態學の自已反省
- 飯岡附近の瀕海植生 : 植物群落の構造に関する研究II
- 作物と雑草との競争III : 雑草の許容限界に及ぼすオカボの種間密度効果
- 作物と雑草との競争II : オカボの播種期と雑草害との関係
- 林床植物群落の構造(予報)
- 生物集圏を構成する種の個体数の分布