Efficiency of a pheromone-baited trap for the sorghum stem borer, Busseola fusca

A monitoring method based on a pheromone-baited trap developed for Busseola fusca, which infests sorghum, was tested during 1998/99 wet seasons in Burkina Faso to monitor the distribution and importance of the pest both on research station and farmers' fields (at Darsalamy, Sisalia, Samangan, Bankélédaga, Sakaby and Tondogosso). Catches were observed from the 26th to the 48th conventional weeks with two distinct peaks of moth flights in both years, no moths were trapped thereafter. The number of moths caught per location ranged from 341 to 817 in 1998 and from 195 to 541 in 1991. The total number of moths caught in all locations was 4108 in 1998 and 2389 in 1999. The results confirm the efficiency of the pheromone-baited trap in monitoring adult population of B. fusca both in research station and farmers' fields

Colour variation in the African sorghum head bug

Colour variation of the head bug (Eurystylus oldi) in relation to Sorghum bicolor panicle or grain colour is reported. Results of different feeding experiments of E. oldi on sorghum of different colours are reported. Data from these research showed that the colour of the head bug changed with the colour of the food they consume. However, a few exceptions are noted, and these may be due to the changes in grain pigmentation during development that may not be apparent in the immature grain fed to the nymphs. These observations suggest that the different species of head bugs on sorghum may be colour morphs of the same species

Potential of sorghum and physic nut (Jatropha curcas) for management of plant bugs (Hemiptera: Miridae) and cotton bollworm (Helicoverpa armigera) on cotton in an assisted trap-cropping strategy

The cotton bollworm (CBW) Helicoverpa armigera and to a lesser extent plant bugs (PB) (Hemiptera: Miridae) are important pests of cotton in Africa. For sustainability reasons, it is necessary to reduce use of chemical control measures for these pests. A promising alternative to chemical control of both CBW and PB is trap cropping, assisted with botanical pesticides sprays, if needed. We report studies conducted from 1995–98 on sorghum attractiveness to PB and CBW, on the potential of physic nut (Jatropha curcas) extracts [particularly the phorbol ester (PE) fraction of the oil] for sorghum protection fromPB damage, and on the insecticidal activity of Jatropha extracts on CBW. At the ICRISAT research station (Samanko, Mali), infestation by the five main species of PB (accounting for 96% of total) was much higher on sorghum than on cotton. In the Kolokani region, CBW infestation was negligible on the Guinea loose-panicled sorghum cultivar Bibalawili, while it was significant on both compact-panicled PB susceptible ICSH 89002 and PB resistant Malisor 84-7. At Samanko, Jatropha oil application on sorghum panicles showed some effect on PB when damage level was high, better than Jatropha and neem aqueous extracts. However, it did not compete with pyrethroid protection level. PE contact toxicity on CBW larvae was too low to determine a LC 50. Aningestion insecticidal activity of PE was found on all tested larval instars. Contact toxicity LC 50 of PE on eggs was 1.66 g ml-1. Development of larvae and reproductive ability of adults derived from new-laid eggs treated with solutions of 0.35 g ml-1 PE and above were considerably affected. Prospects for using sorghum and Jatropha extracts for cotton protection against insect pests in an assisted trap-cropping strategy are discussed

Le sorgho

Denrée alimentaire de base et source importante de nourriture pour les animaux, le sorgho est cultivé dans les zones arides, semi-arides et tempérées. Totalement illustré, ce livre porte sur tous les aspects de la culture du sorgho (biologie, génétique et vulnérabilité face aux animaux nuisibles) et sur ses fonctions écologiques. Son texte révisé et mis à jour décrit également les systèmes de récolte et la transformation pour la consommation humaine