Banks grass mite, Oligonychus pratensis (Banks), abundance was monitored in grain sorghum (Sorghum bicolor (L.) Moench) to determine if applications of insecticides directed at greenbug, Schizaphis graminum (Rondani), induced outbreaks of Banks grass mites. Aerial applications of two commonly used insecticides, chlorpyrifos (0.28 kg [AI]/ha) and parathion (0.67 kg [AI]/ha), and an untreated check were replicated three times and repeated during each of 3 yr. In each test, mite densities were higher in insecticide-treated sorghum than in untreated sorghum. Data subjected to analysis of covariance (with pretreatment mite numbers used as the covariate) indicated that mite densities were significantly higher in insecticide-treated sorghum than in untreated sorghum, but that mite densities in chlorpyrifos- or parathion-treated sorghum, did not differ significantly. Mite predators per 1,000 mites were not significantly, lower in insecticide-treated sorghum than in untreated sorghum. Both insecticides were effective in reducing greenbug densities.

In India, sorghum (Sorghum bicolor(L.) Moench) grown during the postrainy season (rabi sorghum) accounts for nearly 40% of the total sorghum hectarage in the country. It is an important grain and fodder crop on 6.5m hectares on Vertisols in south-central India. Efforts to improve rabi sorghum yields have not resulted in any significant gain as they have for the rainy season sorghum. Continuously receding soil moisture, poor nutrient availability, and low night temperatures are some of the major reasons for the low yields. Rabi sorghum environments are diverse. They are inadequately characterized especially from the angle of recommending new genotypes. This paper reviews pertinent literature and summarizes results from the authors' studies relating the environmental factors during rabi to crop growth, development, water use, and grain yield. It also examines plant physiological traits of rabi sorghum likely to be useful for effective utilization of resources under stored soil-moisture conditions. Finally, suggestions are made on research directions for stabilization of rabi sorghum yields at higher levels. They include better characterization of environments, search for unique phenological response and root growth pattern.

This publication summarizes the proceedings of a national symposium on the current status and potential of the industrial uses of sorghum in Nigeria, held at Kano from 4 to 6 Dec 1989. The ban on the import of cereal grains and malt into Nigeria is an important factor leading to increased utilization of sorghum. The emerging principal uses of sorghum as an industrial raw material include production of lager beer, confectionery, beverages, weaning foods, and feeds. Analysis of current demand and supply situation of sorghum grain indicates considerable shortage of food grains and competition. Further in the next 10 years there will be a continued deficit of sorghum grains which calls for an increased crop productivity through use of better cultivars and production practices. Industrial milling methods of sorghum, currently used in Nigeria, were critically reviewed. The progress, problems, and prospects of using sorghum in the baking, brewing, and malting industries were evaluated. The importance of sorghum straw as a crop residue for grazing animals and of sorghum grain as a raw material for the feed industry were emphasized. Physicochemical attributes of sorghum grain and straw desired for different end uses, and which require improvement through breeding, were identified. There are abstracts of 29 papers presented in five sessions: grain economics and milling, composite flour products, malting and brewing, non alcoholic beverages and weaning foods, and forage and feeds. Summaries of the discussions following each session as well as recommendations are included.

Stochastic dominance analysis of two tillage systems, conventional tillage and no-tillage, for five crop rotations, wheat-fallow, grain sorghum-fallow, continuous wheat, continuous grain sorghum, and wheat-grain sorghum-fallow, shows that risk-averse managers prefer a conventional tillage wheat-sorghum-fallow system. Small changes in production costs or yields lead to indifference between this system and the no-tillage wheat-sorghum-fallow and no-till and conventional wheat-fallow systems. Participation in the basic government commodity program generally increases average net returns and lowers variation of returns. Government commodity program payments calculated under a variety of scenarios do not generally encourage the use of no-till practices for grain sorghum and wheat in the central Great Plains.