Influence of Tillage on Plant Populations, Disease Incidence, and Grain Yield of Two Soft Red Winter Wheat Cultivars

Abstract

No‐till soft red winter wheat (Triticum aestivum L.) production reduces soil erosion and increases the opportunity for timely planting. The purpose of this study was to determine if the elimination of tillage in winter wheat production influences plant populations, disease incidence, and grain yield response to N fertilization. A 3‐yr study was conducted on a Loradale silt loam (fine, mixed, mesic Typic Argiudolls) using two cultivars. No‐tillage (NT) was compared to more conventional (CT) systems involving either a moldboard or chisel plow. Fertilizer application rates were 0, 70, and 140 lb N/acre. Plant stands for the cultivar ‘Caldwell’, measured 3 wk after planting, were 14.7% lower in NT than in CT in 1982–1983. Plant stands for both cultivars were 12% lower in the NT system in 1983–1984. The incidence of powdery mildew (Erysiphe graminis) was higher under NT in 1982–1983, while septoria glume blotch (Septoria nodorum) infection was not affected by tillage. Powdery mildew infection was greatest for the cultivar ‘Wheeler’ while septoria glume blotch infection was greatest for Caldwell. Lodging was greater in the NT system in 1982–1983. Lodging was higher for Wheeler in NT than in the CT system in 1982–1983. Flag leaf and grain N concentrations were not influenced by tillage system in any season. Grain yields responded positively to N application 2 of the 3 yr, but were not affected by tillage system in any year. A tillage × N rate interaction for grain yield was not observed. Efficiency of fertilizer N removal by grain (corrected for controls) averaged 43% at 70 lb N/acre and 29% at 140 lb N/acre.

Nitrogen Rate Increase Not Required for No-Till Wheat in Cool and Humid Conditions

“…Thus, crop rotations with cereals followed by cereals are problematic. We also did not find an effect of tillage system on grain N content, similar to the findings of Ditsch and Grove [86] and contrary to those of Carter et al [87]. The lack of effect occurred at both studied N supply levels.…”

Effects of Disease, Nitrogen Source, and Risk on Optimal Nitrogen Fertilization Timing in Winter Wheat Production

“…Glume blotch is a late‐season grain‐head infection (Ditsch and Grove, 1991) found in all wheat‐growing areas of the world (Bowden, 2003). It is most prevalent in high‐rainfall, humid areas (Stromberg, 2003) such as the southern United States (Howard et al, 2002b).…”

“…Although N fertilization is an important determinant of wheat yield (Beuerlein et al, 1991), it can interact with glume blotch to limit yield (Boquet and Johnson, 1987). Lush vegetative growth that accompanies high N fertilization reduces air movement through the canopy, producing an environment more suited for glume blotch development (Ditsch and Grove, 1991; Wiese, 1987). Without fungicide application in the presence of glume blotch, higher N levels significantly reduced wheat yield (Kelley, 1993; Howard et al, 1994; Cox et al, 1989; Roth and Marshell, 1987; Ditsch and Grove, 1991).…”

“…Lush vegetative growth that accompanies high N fertilization reduces air movement through the canopy, producing an environment more suited for glume blotch development (Ditsch and Grove, 1991; Wiese, 1987). Without fungicide application in the presence of glume blotch, higher N levels significantly reduced wheat yield (Kelley, 1993; Howard et al, 1994; Cox et al, 1989; Roth and Marshell, 1987; Ditsch and Grove, 1991). Although these studies found that N fertilization and timing affect glume blotch severity and yield, they did not evaluate the risk effects of N timing and glume blotch severity on the N timing decision.…”

Breeding crops for reduced-tillage management in the intensive, rice–wheat systems of South Asia

“…Early studies failed to detect genotype · tillage practice interactions (Dao and Nguyen 1989;Ditsch and Grove 1991)-likely a result of the small number of genotypes tested and perhaps the fact that they were bred under conventional tillage (Trethowan and Reynolds 2005). Recently, significant genotype · tillage interaction was reported in tests involving diverse genotypes, requiring plant breeders to tailor cultivars to tillage systems (Sayre 2002;Klein 2003).…”