播期和越冬定植对洋葱生长发育及产量的影响

EFFECTS OF DIFFERENT SOWING DATES AND POST-WINTER FIELD PLANTING ON GROWTH AND YIELD OF ONION (Allinm cepa L.)

对江苏境内三个黄皮洋葱品种在南京进行了播期和越冬定植对洋葱生长发育及鳞茎商品性影响的研究。结果表明 :秋季播种越冬前定植的植株 ,越冬时生长速率随播期延迟递减 ;对鳞茎生长期无影响 ,但与品种特性有关 ,与越冬前植株大小无关 ;对洋葱抽薹率、小区产量和平均鳞茎重均有明显影响。据此认为 :在长江中下游地区高产栽培条件下 ,早熟品种“阳春黄”适宜于 9月 1 0日前后播种 ;中晚熟品种“84 5”和“986 6”适宜于 9月 2 0日前后播种。 9月 2 0日、9月 30日播种的“84 5”和“986 6” ,冬后定植比冬前定植的抽薹率明显升高 。

The effects of sowing dates and post winter field planting on the growth and the bulb yield of three onion cultivars were studied in Nanjing. Results showed that for the plants which were sown in autumn and then planted to field before winter, their growth rate decreased with later sowing date, and the sowing dates had significant effects on the mean bulb weight and the yield, however, had no effects on the period of bulb expansion, which may be relevant to the characteristic of cultivars and irrelevant to the pre winter plantlet size. It was accordingly considered that in the middle and lower area of the Yangtze River, the optimal sowing date of the early cultivar “Yangchunhuang” was about September 10, while that of the middle late cultivars“84 5”and “9866” was about September 20 to gain high yield. Compared with pre winter transplant ones, the post winter field planting plants of cultivars“84 5”and “9866” sown on September 20 and September 30 had higher premature bolting rate and sharply lower mean bulb weight and plot yield.