Impact of Delayed Planting on Yield and Nutritive Value of Cool-Season Annual Forage Mixtures

Abstract

Late-fall drought can delay establishment of cool-season annual forages in the southeastern United States. This study evaluated delayed planting effects on yield, chemical composition, and in vitro true digestibility of four forage mixtures containing rye or wheat, oat, and crimson clover, with or without annual ryegrass. A randomized complete block design was used at the Gulf Coast Research and Extension Center (Fairhope, AL). Five planting dates, from October 15 to January 5, represented 30 to 112 days after the recommended September 15 date. Forage was harvested monthly from January through May. Each day of planting delay reduced cumulative dry matter yield through January and February by 19.0 and 22.8 kg DM/ha, respectively (P < 0.001), but delay did not affect yield through March, April, or May (P ≥ 0.104) or final seasonal yield (P = 0.708). Planting delay and harvest date affected fiber, crude protein, and digestibility (P < 0.05), whereas mixture did not consistently affect yield. Delayed planting reduced early-season forage availability, but spring growth partially compensated by season’s end, indicating that producers may experience a narrower forage availability window despite similar total seasonal production.