Herbaceous Cultivation Test of Mulberry in Sichuan Sericultural Area

With Guiteyou 2 as the test mulberry variety, mulberry herbaceous cultivation field was established at the planting densities of 60 000,90 000 and 120 000 plants/hm2, respectively. Hybrid mulberry herbaceous cultivation test was conducted, with Tongxiangqing mulberry field of mid-fist-form at conventional planting density of 4 995 plants/hm2 as the control. The results showed that the leaf yield of herbaceous cultivation mulberry was closely related to the planting density. With the increasing planting density, the leaf yield per plant was decreasing, but the leaf yield per unit area of mulberry field was increasing. The annual leaf yield per unit area in the mulberry field with the average planting density of 120 000 plants/hm2 was 37 560 kg/hm2, 2.14 times of that of the control field. The moisture content of mulberry leaf in herbaceous cultivation field was 4.74% higher than the control; the contents of crude protein, crude fat, crude fiber and crude ash were 1.264%, 0.014%, 0.744% and 0.002%lower than the control, respectively. Comparison of leaf rearing with herbaceous cultivation mulberry and control mulberry showed that there was no significant difference in growth status of silkworm. The cocoon weight, cocoon shell weight, cocoon yield per 10 000 larvae, cocoon filament length and non-broken filament length of Chuanshan × Shushui were 12.81%, 14.29%, 13.85%, 5.95% and 7.68% lower than the control, respectively; but the percentage of common cocoons was 0.16% higher than the control; the cleanness and neatness were 0.2 and 1.25 points higher than the control;the filament size was 0.196 dtex lower than the control. The cocoon weight, cocoon shell weight, cocoon yield per 10 000 larvae, cocoon filament length and non-broken filament length of Jingsong × Haoyue were 11.06%, 10.20%, 11.53%, 9.46% and 9.03% lower than the control, respectively;but the percentage of common cocoons was 1.77% higher than the control; the cleanness and neatness were 0.12 and 2.50 points higher the control;and the filament size was 0.196 dtex lower than the control.

High-grade Cocoon Filament Silkworm Chuanshan ×Shushui for Spring and Autumn Rearing

Chuanshan × Shushui is a highgrade cocoon filament silkworm variety for spring and autumn rearing bred by Nanchong Silkworm Eggs Farmthrough systematic breeding method. The characteristics of stock seed and F1 hybrid of silkworm variety Chuanshan × Shushui and their breeding technical points and precautions were introduced in the paper. Laboratory identification and rural breeding results showed that Chuanshan × Shushui wascharacterized by physical strength, high cocoon weight, good cocoon quality and superior neatness, and the cocoons produced could reel 5A6A classraw silk. The variety was suitable for breeding in silkworm areas in Sichuan, Yunnan and Shaanxi provinces. The variety was approved by Sichuansilkworm breeding committee in 2005, and more than one million boxes of silkworm eggs have been cumulatively bred in silkworm areas in Sichuan,Yunnan, Shaanxi and Hainan provinces.