Forage yield and profitability of grain‐type intermediate wheatgrass under different harvest schedules

Abstract

Intermediate wheatgrass [Thinopyrum intermedium (Host) Barkworth & Dewey] (IWG) is a perennial forage grass being domesticated to function as a perennial grain crop. Grain yield of improved, grain-type IWG cultivars decline by the third year of production and managing aging stands for forage production presents economic opportunities. Limited research is available on the response of second-and thirdyear grain-type IWG to different forage harvest schedules. We measured forage yield and nutritive value of grain-type IWG in the second and third year of production under nine forage harvest schedules varying in the timing of the first harvest (at boot, anthesis, or soft dough stage) and the number of fall harvests (none, one [Sept.], or two [Sept. and Nov.]). As timing of the first harvest was delayed and IWG maturity increased from boot to soft dough, yield increased from 2.4 to 3.7 Mg ha -1 and relative feed value decreased from 113 to 82. Yield at subsequent September and November harvests averaged 30% and 12% of the initial harvest yield, respectively. Total annual forage yield was not affected by the timing of the first harvest but was predictably greater for two or three harvests compared with one harvest; however, additional harvests in September and November decreased net returns. Grain-type IWG stands harvested in the third year after peak grain production have potential to provide forage similar to common perennial cool season forage grasses. Tradeoffs between forage yield and nutritive value should be considered when selecting the timing of the initial spring forage harvest. INTRODUCTIONIntermediate wheatgrass [Thinopyrum intermedium (Host) Barkworth & D.R. Dewey] (IWG) is an introduced, coolseason perennial grass used as a forage crop in the U.S. Great Plains (Asay & Jensen, 1996

Forage harvest management impacts “Kernza” intermediate wheatgrass productivity across North America

“…This stability of forage mass and nutritive value of IWG over time persists in stands older than those studied here. This suggests that a shift in management from grain to forage can be economical for producers after IWG grain yields decline (Puka-Beals et al, 2022) Seasonal trends in forage nutritive values are well established and our values align with those previously reported in the literature (Coleman et al, 2010;Favre et al, 2019;Karn et al, 2006;Nelson et al, 1989). This suggests that breeding efforts with IWG to increase the reproductive effort in grain has not detectably impacted forage nutritive values and the role it could play as a dual-use crop.…”

“…This stability of forage mass and nutritive value of IWG over time persists in stands older than those studied here. This suggests that a shift in management from grain to forage can be economical for producers after IWG grain yields decline (Puka‐Beals et al., 2022)…”

Effect of Defoliation Time on Rye Yield and Its Quality under Dual-Purpose Cultivation for Roughage and Concentrate Production

“…After the onset of reproductive growth, grass plants generally show improved regrowth when their foliage is harvested at an earlier stage. During this stage, a substantial amount of the nutrients are retained in the stubble and roots [46][47][48], while the relationship between the time of defoliation and the vigor of regrowth is obscure in winter cereals during the tillering stage [14,49,50]. In this study, defoliation was applied during the reproductive growth stage, and the plants that were mowed earlier exhibited vigorous regrowth.…”