Influence of Cultural Treatments on Seed Production of Intermediate Wheatgrass (Agropyron intermedium (Host) Beauv.)¹

Abstract

Synopsis Burning of the straw and stubble after harvest was beneficial in maintaining high seed yields of intermediate wheatgrass. Mechanical removal of every other foot of vegetation in the row produced seed yields equal to burning. The effects of burning and mechanical thinning appeared to be additive. Increasing the rate of nitrogen was not effective in maintaining seed production as the stands became older.

Effects of defoliation and row spacing on intermediate wheatgrass I: Grain production

“…As expected based on previous reports (Canode, 1964; Hampton & Fairey, 1997; Hebblethwaite & Ivins, 1977; Young et al., 1996), TKW was only minimally responsive to management. The decrease in TKW in the 15‐cm row spacing following Sp defoliation in 2015 was surprising, given that all of the preceding yield components in that treatment combination also tended to be low.…”

“…Seed number per fertile tiller is typically the YC with the strongest effect on total yield (Hampton & Fairey, 1997; Hebblethwaite & Clemence, 1981; Hebblethwaite & Ivins, 1977). In contrast, seed size is relatively invariant and therefore is not commonly a main determinant of seed yield (Canode, 1964; Hampton & Fairey, 1997; Hebblethwaite & Ivins, 1977; Young et al., 1996; but see Hare, 1993 and Koeritz et al., 2015).…”

“…Planting in wider row spacings can also increase in‐row tillering and reduce lodging by increasing both light intensity and R/FR ratio (Canode, 1964; Han et al., 2013). In addition, widening the row spacings gives each row greater access to edaphic resources (water, nutrients).…”

“…Crowle (1966) reported ∼20% higher seed yield over 5 yr when IWG was planted in wider rows (91 vs. 30 cm). Black and Reitz (1969) found that seed yields were higher in wider row spacings in dry years and at narrow row spacings in wet years, with little overall effect across 5 yr. Canode (1964) found that thinning stands of IWG by removing every other 30 cm length of row reduced lodging and increased yields in the third, fourth, and fifth harvest years. These early reports indicate that IWG may benefit from planting at wide row spacings, especially in long‐term stands.…”

Crop Residue Removal and Nitrogen Fertilization Affects Seed Production in Meadow Bromegrass

“…As a result, it has become Law, 1978). Two important management practices to improve Removing crop residue after seed harvest has been grass seed production include N fertilization and crop shown to increase seed production in several perennial grass crops (Canode, 1965;Canode and Law, 1978;Nordestgaard, 1980;Upton, 1983 try and Willis (1988) and Hamm et al (1972), respectively. Based eas of the Canadian Prairies that receive between 350 on soil mineral N, response to N fertilizer rate has been to 500 mm of annual precipitation (Kruger, 1997).…”