Effects On Yield And Quality Of Different Types Of Silage Maize Because Of Sowing Dates In Areas Along Huai River

This experiment selects two representatives of maize varieties:Early-maturity, silage special, Zheng silage No.l and middle-late maturity, grain-feeding dual-purpose type ND108 as the research materials, consisting of spring, summer and autumn sowing dates, totally 18. The essay systematically researches on the effects on growth and development, growth period and yield indicators of different types of silage maize in the area along Huai River because of sowing dates. Besides, focus on the effects on quality indicators of silage maize during the 4 autumn sowing dates (after July 15). The results show that:1. Within the scope of setting sowing dates, varieties of silage maize and sowing dates make significant effect on growth period. Dividing the growth period into two parts according to tasseling stage, with the delaying of sowing date, the sowing and seedling stages significantly reduced, both the dates between seedling stage and tasseling stage and the dates between tasseling stage and the end of maturity shorten and then increase. The whole growth period of silage maize presents gradually shortens and then gradually extends; The type of middle-late maturity silage maize is more sensitive to early maturity silage maize; The sowing of early maturity silage maize (after August 19) and middle-late maturity silage maize(after August 14) are almost empty bar.2. Effects on plant height and weight of thousand seed of silage maize because of sowing dates, generally presents wave trend that firstly reduce, secondly increase and then reduce, during the period, the middle of May is the high-incidence season of Maize Rough Dwarf Disease, which seriously affects the plant height, and the reduce of plant height of Zheng silage No.1 because of Maize Rough Dwarf Disease is more sensitive than ND108; during the whole growth period, maize sowed on the date of July 15 bears the highest weight of thousand seed; Maize Rough Dwarf Disease in the middle of May makes great effect on both dry and fresh weight, and the overall trend of effect on fresh weight of overground part because of sowing dates is that with the delaying of sowing dates, the change takes on a broken line which firstly reduces, secondly rises and at last reduces again. The fresh weight of middle-late maturity type sowed in spring is higher than early-maturity type ZQZ1, and early-maturity type sowed in autumn is more favourable than middle-late maturity type ND108; Effect on accumulation of dry matters because of sowing dates generally presents that with the delaying of sowing dates, content of dry matter decreases, accumulation of dry matters is the biggest in spring sowing (except Maize Rough Dwarf Disease in the middle of May), the second is summer sowing, and the low temperature in autumn sowing is unfavourable for accumulation of dry matters afterwards.3. This experiment only focuses on the effect on the quality of silage maize because of sowing dates in autumn (after July 15). On the whole, with the delaying of sowing dates， Crude protein, Neutral detergent fiber and Ether Extra Fat take a trend of downward, the content of Crude protein has a significant difference between silage maize sowed after August 4 and before; The content Netarl Deetrgnet Fiber has a no significant difference between silage maize sowed during July 25 and August 4; The content of Crude Fat of ND108 is higher than that of ZQZ1 sowed on July 25, but the content is lower sowed after August 4.In sum, through the study on effects on yield and quality of different types silage maize because of sowing date, we think, in the area along Huai River, the date of August 4 is the lower limit date of sowing and the dates in the middle of April are the best sowing dates, the better dates are the middle of July, and the last dates are June. In addition, the better choice is early maturity types because of sowing delaying, reseeding after autumn or reseeding because of natural disasters.