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Hybrid, Maturity, and Cutting Height Interactions on Corn Forage Yield and Quality
Author(s) -
Lewis Andrew L.,
Cox William J.,
Cherney Jerome H.
Publication year - 2004
Publication title -
agronomy journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.752
H-Index - 131
eISSN - 1435-0645
pISSN - 0002-1962
DOI - 10.2134/agronj2004.2670
Subject(s) - hybrid , forage , dry matter , silage , neutral detergent fiber , agronomy , biology , leafy , yield (engineering) , zoology , horticulture , materials science , metallurgy
Corn ( Zea mays L.) hybrids may show different silage quality responses to harvest date and cutting height because hybrids differ in neutral detergent fiber (NDF) digestibility. A brown midrib, leafy, and dual‐purpose hybrid were harvested at early [≈280 g kg −1 dry matter (DM) content], medium (≈350 g kg −1 ), and late (≈420 g kg −1 ) harvest dates at 15‐, 30‐, and 46‐cm cutting heights in 2001 and 2002 to determine optimum harvest management for each hybrid type. Most forage quality characteristics had hybrid × harvest date interactions as indicated by the 73 g kg −1 decrease in NDF digestibility of the brown midrib compared with 20 g kg −1 decreases of the other hybrids between the early and late harvest date. Milk per megagram, a forage quality index, declined (1523, 1487, and 1417 kg Mg −1 ), but DM yields increased (13.2, 13.6, and 14.1 Mg ha −1 ), so calculated milk yields were similar (20333, 20200, and 20233 kg ha −1 ) at early, medium, and late harvest dates, respectively, suggesting a broad optimum DM content for harvest. The sharp decline in NDF digestibility, however, raises concern about harvesting the brown midrib hybrid above 350 g kg −1 DM content. Calculated milk yield had a hybrid × cutting height interaction, as indicated by no change in the leafy hybrid and a 13% decrease in the brown midrib hybrid as cutting height increased from 15 to 46 cm. This suggests that an increase in cutting height may be a good management practice for the leafy hybrid but not for the brown midrib hybrid.