ピーマンの生育, 果実発育と収量に及ぼす仕立本数, 育苗日数と栽植密度の影響

Abstract

The effects of shoot number and raising period of seedlings on growth, fruiting and yield of sweet pepper were investigated. In Experiment I, 30-day or 45-day seedlings of ‘California-Wonder’, ‘Shin-sakigake’ and ‘Shishito’ were planted in the plastic house. In Experiment II, 33-day seedlings of ‘Eiko’ were used. The plants were trained with two or four shoots in Experiment I and one, two or four shoots in Experiment II. The total number of shoots in each plot (9m2) were kept in same number by changing the plant number.The more the 2-training shoot plant is in plot, the more the fruit number and yield per plot were increased. The increase in fruit number and yield in ‘California-Wonder’ and ‘Shinsakigake’ was more notable than in‘Shishito’. Except for ‘California-Wonder’, the fruit number and yield of 30-day seedlings were higher than those of 45-day seedlings.The fewer the training shoot number is, the more the top and root dry weights were increased. The total dry weight of 30-day seedlings was increased as the number of training shoots increased. The 30-day seedlings had thicker roots than the 45-day seedlings except for the 2-training shoot plants of ‘California-Wonder’. Highly signicant correlations were recognized between the yield and the number of thick roots or the total leaf area in each cultivar.The percentage of normal fruits, the mean fruit weight and fruit thickness were increased as the number of training shoots decreased. The percentage of normal fruits and the mean fruit weight in 30-day seedlings were higher than those in 45-day seedlings.Results of this study on four sweet pepper cultivars showed that with more plants, each with fewer training shoots, harvestable fruit and the total yield per plot increased. Fewer training shoots resulted in an increase in the number of thick roots, total dry weight and total leaf area per plot, thus the enhancement of photosynthesis.