Research On Developmental Characteristics And Key Planting Technology Of Cabbage Cv. Qingan 80

Cabbage is one important vegetable in the world and China with great planting areas. Chose as one of the first batch varieties founded by the National Agricultural Sci-Tech Production Transform Project, Qingan 80 is demonstrated in middle and west China. Planting cabbage in springtime occurs bolting premature frequently and leads to low output. So the conditions of vernalization and sowing date need to be studied to avoid bolting premature. Moreover, cabbage had high biological yield need great fertilizers and accumulate nitrate easily.This experiment wants to research the development and planting technology for the new cabbage verity Qingan 80. This experiment utilized Qingan80 as the material, treated the seedling with the natural low temperature, analyzed the change of biological matters and conditions of vernalization, and studied the effect of seedtime on growth, bolting, and yield.Through experiment of general spinning regressive design, the comprehensive effect of planting density, N,P,K on cabbage yield and nitrate were studied and set up regressive model.The main results were as follows: (1) Seedling with 12～13 leaves and stem width 1.1cm could accept vernalization in 70d,more bigger seedling, more less time needed. During vernalization with 14～15 leaves and stem width 1.3cm, soluble protein content in seedling leaves and stem point changed with a wave crest, soluble sugar increase as a line. (2) Sowed in Aug.27th,9% plants bolted. Sowed from Sep.26th to Oct.26th got rather high yield. The heading time was Apr.29th,with little effect from sowing date, as well as harvest time. Seeding in suitable time helped to increase the edible rate, compactness, and weight per head. Plant extent and area of the biggest functional leaves increased in the growth period, the changes of leaves shape of different seedtime were almost identical, the broad were equal to the length in Apr.9th, later, leaves broad increased fast than length. (3) Established mathematical model between yield and density, N, P, K. it showed the yield increasing effect was N>density>K>P, the relationship between N and density, N and K had significant effect on yield. The optimal combination for yield above 70000 ㎏/hm² was density 36491～37028 plant/hm²,N 307.1～317.5 ㎏/hm²,P₂O₅ 104.6～111.7 ㎏/hm²,K₂O 237.2～252.2 ㎏/hm²ã€‚(4) Established mathematical model between nitrate and density, N, P, K. it showed N had plus effect on cabbage nitrate, density ,P and K had minus effect. The four factors effect in degressive order was N> K> density> P.