Tillage and Weed Management Affects Winter Wheat Yield in an Integrated Pest Management System

Abstract

Adoption of conservation practices by U.S. Pacific Northwest growers to meet farm bill legislation for erosion control is limited by the inability to control weeds and other pests in cereal and pulse crops. A 6-yr, 16-ha integrated pest management field study was conducted in the sub humid wheat area of the Pacific Northwest from 1985 through 1991 to develop a crop production system that controls weeds effectively and reduces soil erosion. Farm-size machinery were used to till, plant, and harvest crops grown in either a continuous wheat (Triticum aestivum L.) sequence or a 3-yr rotation of winter wheat-spring barley (Hordeum vulgare L.)-spring pea (Pisum sativum L.) in conservation and conventional tillage systems. Minimum, moderate, and maximum weed management levels were superimposed over each cropping by tillage system. Position of winter wheat within a cropping system influenced yield so that wheat produced more grain following spring pea > spring wheat >> winter wheat. Insects and root diseases were not yield-limiting factors in either conventionally tilled monoculture wheat or no-till wheat in the 3-yr cropping system. Yield of winter wheat in the conventionally tilled, continuous wheat system was similar for all three weed management levels. Yield of winter wheat in conservation tillage systems increased at both the moderate and maximum level of weed management compared with the minimum level. No-till winter wheat planted after either pea or spring wheat at the moderate and maximum weed management levels yielded a minimum of 605 kg ha-• more than conventionally tilled wheat at the same management levels.

Study of Integrate Methods Chemical and Cultural Control of Weeds to Wheat (Triticum aestivum L.)

“…Weeds also increase harvesting costs, require costly cleaning of seeds, clog water ways, and increase fire hazards (Arnon, 1972;Ashrafi et al, 2009;Rahnavard et al, 2009). Young et al, (1994) reported that weeds reduced the wheat yield from 9.50 to 16.03% depending on the intensity of weeds. It is therefore, essential to control weeds in order to obtain maximum yield of wheat having good quality grains.…”

Effects of Tillage Methods on Wheat Yield and Yield Components in Continuous Wheat Cropping

“…Maintaining residues on the soil surface protects the soil from wind and water erosion, provides a source of plant nutrients, improves organic matter levels in the soil and increases soil water content (Chastain et al, 1995). Winter wheat (Triticum aestivum) usually provides suf®cient residues for these purposes (Crutch®eld et al, 1985;Young et al, 1994). Wheat residues provide more shade to suppress weed growth when lyinḡ at.…”

Case studies of integrated/whole farm system designs: Field-scale replicated IPM trials

“…(Pisum sativum L.); and minimum, moderate or maximum weed management levels (Young, F.L., et al, 1994). Winter wheat in the conservation tillage system (a combination of no-till and reduced tillage) was planted no-till following spring pea and spring wheat.…”

“…We chose the 3-yr rotation because it greatly reduces root diseases of wheat (Cook and Veseth, 1991). However, the population dynamics of insects and weeds and the economics and productivity of barley and peas in this system have not been examined (Young, F.L., et al, 1994).…”

“…Three weed management levels were provided by different combinations of tillage and rates and kinds of herbicides (Young, F.L., et al, 1994). Minimum weed management was a short-term, low input system; moderate was the management recommended by weed extension specialists; maximum was a high input system, although it never had the economically unfeasible objective of 100% weed control.…”