|Publication Type:||Journal Article|
|Year of Publication:||2010|
|Authors:||Ashikaga, K, Tamaki, H, Tanaka, T, Deguchi, K, Iida, K, Sato, K|
|Keywords:||First crop, genotypic variation, harvest time, nutritive value, Phleum, timothy|
Timothy (Phleum pratense L.) is the most important perennial forage grass grown in parts of Canada, USA, the Nordic countries of Europe and Hokkaido, Japan. Improvement of its nutritive value through breeding should result in enhanced livestock productivity. The objective of the present study was to investigate the magnitude of genotype × maturity stage interaction (G × M), genotype × harvest time on sunny day interaction (G × TS) and genotype × harvest time on cloudy day interaction (G × TC) for the nutritive value of the first crop of timothy. Fifteen early-maturing clones of timothy were used to evaluate G × M and 13 clones were used to evaluate G × TS and TC in Kunneppu, Hokkaido in 2005 by analyzing the nutritive value of the first crops using near-infrared reflectance spectroscopy. Contents of low-digestible fiber (Ob) and water-soluble carbohydrate and the ratio of Ob to organic cell wall measured at early heading significantly correlated with their measurements at full heading stage, with non-significant effects of G × M. These traits also showed a significant correlation between morning and evening in both sunny and cloudy weather conditions, with non-significant effects of G × TS and TC. We conclude that the relative ranking of genotypes at different maturity stages from early to full heading stage and at different times within a day should be consistent for the required traits, and that selection for these traits at any stage of heading and any time of day should permit effective improvement of the nutritive value of timothy only if the plants are harvested at about the same time (within 1 h).
|Short Title:||Grassland Science|
Effects of harvest time across maturity stages and within a day on the nutritive value in the first crop of timothy (Phleum pratense L.)