青贮玉米生产性能对收获期的响应及收获指数的探讨

Response of Productive Qualities of Corn Silage to Harvest Time and Exploration of Harvest Index of Corn Silage

为了探讨不同收获时期青贮玉米的生产性能和青贮品质,利用收获指数对不同收获期予以评价。本研究以兼用青贮玉米品种晋单42号为试验材料,分别于籽粒形成期、乳熟期、蜡熟期和完熟期取样及青贮后测定其化学成分,并且计算青贮玉米的收获指数。结果表明,随着收获时期的延迟,原料青贮玉米干物质产量、淀粉和粗脂肪含量极显著地增加(P<0.01),而中性洗涤纤维消化率(NDFD)显著下降(P<0.05);籽粒形成期收获的玉米青贮饲料发酵品质较差(P<0.01)。利用作物收获指数、MILK 2006指数均判断蜡熟期适宜收获。从产量、品质与青贮后的产品特性综合判断以蜡熟期为适宜收获时期,可以简捷以干物质产量和含量来指导青贮玉米的收获。

The effect of different harvest times on productive qualities and silage qualities of silage corn were studied,harvest index were used to evaluate the different harvest times.The JINDAN42 corn hybrid was harvested at blister stage,milk stage,dough stage and physiological maturity.The corn were sampled and ensiled for analyzing the chemical composition and the harvest index was calculated.The results indicated that the DM production,starch and EE content increased significantly(P<0.01),while NDFD decreased(P<0.05)with the harvest time prolonged.The fermentative quality of corn silage at blister stage was worst compared that of the other stages(P<0.01).The appropriate harvest time was dough stage according to the crop harvest index or MILK 2006 index.The dough stage was suitable for corn silage on the production,quality and silage product features,in simple,the DM content and production are suitable indices for guiding silage corn harvest.