Influence Of Starter Fertilizer And Hard Red Winter Wheat Seeding Practices On Interference From Jointed Goatgrass And Cheat

Abstract

Field experiments were conducted at three sites in north central Oklahoma to determine the effects of wheat row spacing and starter fertilizer treatment on the interference of jointed goatgrass with hard red winter wheat. At two of three sites, bandi.ng fertilizer with the wheat seed decreased juvenile wheat plant density. Mean sunlight interception by the vegetative canopy in April varied from 87 to 93% at all sites. At two sites, fertilizer treatment and weed presence did not affect sunlight interception, but sunlight interception increased as row spacing decreased from 30 to 20 cm. Jointed goatgrass mean spikelet production was affected by fertilizer treatment at two sites. Wheat spike density was increased by decreasing wheat row spacing. At two sites, banding 10-34-0 fertilizer at 168 kg/ha reduced wheat yield. Averaged over other factors, reducing row spacing increased wheat yield. Field experiments were conducted at two sites for two years in north central Oklahoma to determine the effects of row spacing and starter fertilizer treatment on the interference of cheat with hard red winter wheat. Mean sunlight interception by the vegetative canopy was not increased by starter fertilizer treatments either year at one site. Averaged over cheat presence, banded fertilizer treatments increased sunlight interception at a second site one year. In 1997-98 fertHizer treatment effects on sunlight interception occurred only in the absence of cheat. Sunlight interception was less in wheat seeded in 30- than in 10- or 20-cm rows both years at one site and neither year at the other. Cheat consistently reduced wheat yield but interactions with fertilizer treatment and row spacing were abs.ent. In one of four experiments, reducing row spacing reduced dockage.