直播密度对直播青菜形态特征·产量及其构成的影响

目的]探索与直播青菜栽培相配套的密植技术。方法]以青菜品种苏州青2号为供试品种，利用荷兰AL-640-SNT蔬菜气吸式精密播种机直播，在12种整地方式、播深组合的情况下设计了4种直播株距，研究直播密度对直播青菜形态特征、产量及其构成的影响。结果]在同一种整地方式和播深的情况下，随着直播密度的增加，茎秆粗度、株高、单株分枝数、单株有效角果数、千粒重、每角粒数、单株重量呈现降低趋势，但群体分枝数、群体角果数呈现增加趋势；随着播深的加深，株高、单株角果数、群体角果数呈现降低趋势，而千粒重呈现上升趋势，其余指标与整地方式、播深没有明显相关性。以旋耕2遍、覆土1档、株距为7．2cm的产量最高，产量构成较为合理：基本苗为24．02万株／hm^2，每株有效角果数为293．5个，群体角果数为7017．0万株／hm^2，每角粒数为10．01粒，千粒重为2．18g。结论]该研究可为上海农场大面积推广直播青菜机械化栽培提供技术参考。

Effects of Directly Sowing Density on Morphological Property,Yield and Its Components of Vegetables

Objective ] The aim was to explore the corresponding close planting techniques of directly sowing vegetables. Method ] Taking Suzhouqing No. 2 as tested variety, and using The Dutch AL-640-SNT Type Vegetable Precision Suction Seeder, 4 kinds of plants space were designed under 12 kinds of combinations of land preparation method and sowing depth to study the effects of directly sowing density on morpho- logical property, yield and its components of vegetables. Result ] Under the same land preparation method and sowing depth, with the in- crease of sowing density, stem diameter, plant height, branch number per plant, effective pod number per plant, 1 000-grain weight, grain number per pod and weight per plant showed the decrease tendency, while group branch number and group pod number showed the rising tend- ency ; with the increase of sowing depth, plant height, effective pod number per plant, group pod number showed the decrease tendency, while 1 000-grain weight showed rising tendency, the other indices had no significant corelation with the land preparation method and sowing depth. The combination of rotary tillage twice, covering soil 1 ]eve], and plant spacing 7.2 cm had the highest yield, and its yield components were more reasonable： basic seedling number was 24.0 ~ 104 plants per ha, effective pod number was 293.5, group pod number was 7017.0 ~ l04 per ha, grain number per pod was 10.01, 1 000-grain weight was 2.18 g. Conclnsion~ The study provides a technical reference for promoting directly sowing vegetables mechanized cultivation of Shanghai Farm in a large scale.