Hc. Sharma et al., SOURCES AND MECHANISMS OF RESISTANCE TO SORGHUM HEAD BUG, EURYSTYLUS-IMMACULATUS ODH IN WEST-AFRICA, Insect science and its application, 15(1), 1994, pp. 39-48
Sorghum is one of the most important cereal crops in West Africa, and
the head bug, Eurystylus immaculatus Odh. (Hemiptera: Miridae) is the
key pest of grain sorghum in this region. A range of sorghum genotypes
were evaluated for resistance to sorghum head bug at Sotuba (Mali) an
d Kamboinse (Burkina Faso). Genotypes CSM 388, IS 14332, Malisor 84-7,
Sakoika. S 29 and Kamboinse local were resistant to head bugs. both u
nder natural and headcage screening. Head bug resistant genotypes had
a lower percentage of head bug damaged grain. The food quality of head
bug damaged grain was very poor and unacceptable. Cultivar non-prefer
ence was identified as a component of resistance to head bugs. and CSM
388 was nonpreferred compared to E 35-1. Panicle compactness was posi
tively associated with head bug numbers and grain damage. However, gen
otypes with loose panicles were also susceptible to bugs. Long glumes
(>5 mm), days to glume opening (>20 days after anthesis), >50% coverin
g of the grain by the glumes, and grain hardness contribute towards re
sistance to Eurystylus immaculatus. This information will be useful fo
r developing a programme to breed for resistance to this insect in Wes
t Africa.