Forage yield potential of alfalfa plants of varying crown size from old stands

Abstract

AbstractAlfalfa (lucerne) plants can persist from one growing season to the next because of their perennial crowns. Plants with large crowns often are selected for breeding purposes. The objective of this study was to determine the forage yield potential of plants with a full range of crown sizes sampled from old stands. This was accomplished by field evaluation of clones and S1 progenies derived from plants of different crown sizes obtained from a 1 m2 of 5‐year‐old stands of cultivars ‘Agate’ and ‘Magnum III’. Significant differences (P < 0.05) in dry forage yield (DFY) were found among entries in both tests. However, there was no consistent trend in DEY with respect to the crown size of the parental plants. Although the crown of space‐planted clones dug after 16 months showed a strong association (r > 0.7, P < 0.01) with DFY, the crown size of these clones was poorly correlated with the crown size of their parental plants. These results suggest that selections based on crown size from older stands may not lead to an improvement in either crown size or forage yield. Crown health will remain an important selection criterion when plants are sampled from old stands; crown size, however, may not be as important.