Time of sowing affects small grain screenings in wheat in a dry season

Document Type

Conference Proceeding

Publication Date


Conference Title

Australian Society of Agronomy 11th Annual Conference 2003: Solutions for a Better Environment

Place of Publication



Small grain screenings, wheat, dockages, yield components, management


Agronomy and Crop Sciences


Based on field data from experiments over three years we conclude that time of sowing and weather conditions have a major impact on the proportion of small grain screenings. The level of screenings was greater in 2000, which experienced terminal drought, but less in 1999 with better soil moisture during grain filling, or 2001 despite dry conditions during early growth. In a time of sowing trial at Mullewa in 2000, the level of screenings with later sowing was cultivar-dependent with Westonia, Carnamah and Wyalkatchem less affected than Arrino and Brookton. Westonia adjusted number of tillers and spike size, thus adjusting grains per m2 without severe grain yield decline. Carnamah adjusted number of grains per spike, giving a more stable level of screenings. Arrino was most sensitive to screenings and this was associated with its lower tendency to adjust with later sowing for the number of grains per unit area, and per spike, than other cultivars. Correlations among screenings, kernel weight, grain yield and the amount of rainfall were significant. General linear regression analysis indicated that yield level of the trial, kernel weight, and rainfall from 14 days before mid-anthesis to maturity accounted for most of the variance of small grain screenings during the hot dry finishing season of 2000.