The numbers of Aphis gossypii Glover, Helicoverpa armigera Hiibner,cotton mites and their main enemies in the upper,middle and lower parts of plants of spring planted cotton in different developmental periods were investigated.

Studies on correlation between spring sowing and autumn sowing characters of spring soybeans. Journal of Zhejiang Agricultural University;

The results of experiments for breeding Chosenia arbutifolia show that: sowing along with collecting seed and overshadowing above the seedbed can increase emerging rate about 15 per cent, and the seedlings quality is better than spring sowing apparently; using No.

The growing period, the earbearing number of tiller, the characters of ear and the yield of wheat have been studied in the dryland in Xining area in Qinghai under the treatments of autumn sowing, spring sowing and film mulch after autumn sowing.

【Method】 19 cross-bred spring cotton varieties were gathered in 17 test points in the Yellow River zone in 2005,and 8 norms were examined such as fiber length,strength,micronaire,elongation,reflecting rate,the yellow degree of fiber,uniformation and spinning consistence index.