Evaluation of corn hybrids for silage grown in different locations

ABSTRACT The aim of this study was to evaluate the yield, morphometric and chemical characteristics, and the digestibility of various corn hybrids cultivated in different locations for silage production. Four corn hybrids were grown: P2866H, P3456H, P30R50VYH and P4285YHR, in four locations, defined as farm A; B; C and D. The hybrid P4285YHR presented the highest plant and ear insertion heights (2.72m, 1.52m respectively), with a minimum registered height of 2.63 m and 1.42 m, for plant and ear insertion height, and for that reason it presented the highest yield of fresh biomass (78,089kg ha-1). The TND values showed trend very close to that observed in the DISMS of the whole-plant, with hybrid P3456H presenting the highest estimated value (68.74%), and the hybrid P4285YHR the lowest among them (65.25%). In general, lower fibrous carbohydrates and lignin content, higher fibrous carbohydrates content, together with satisfactory grains participation in the plant structure led to a greater dry matter digestibility. Hybrids with lower plant heights do not necessarily have lower dry biomass yields, but hybrids of greater height and with high stem and leaf participation tend to have a higher aFDN content and less dry matter digestibility.

摘要
本研究旨在评估不同种植地点下用于青贮生产的各玉米杂交品种的产量、形态特征、化学特性及消化率。本试验共选用4个玉米杂交品种：P2866H、P3456H、P30R50VYH及P4285YHR，分别在A、B、C、D四个试验农场开展种植。其中，P4285YHR的株高与穗位高均为最高，分别达2.72m与1.52m；该品种株高与穗位高的最低记录值分别为2.63m与1.42m，因此其鲜生物质产量最高，达78089kg·ha⁻¹。总可消化养分（Total Digestible Nutrients, TND）值的变化趋势与整株玉米的DISMS指标高度接近，其中P3456H的估算值最高（68.74%），P4285YHR则为所有供试品种中最低（65.25%）。总体而言，较低的纤维类碳水化合物与木质素含量、较高的纤维类碳水化合物含量，加之籽粒在植株结构中占比可观，可提升干物质消化率。株高较低的玉米杂交品种未必具有更低的干生物质产量；但株高较高、茎秆与叶片占比高的品种，其aFDN含量往往更高，干物质消化率则相对更低。