Effect of Sorghum (Sorghum bicolor (L.) Moench Variety on the Severity of Head Bug (Eurystylus oldi Pop.) Damage.

ADAMU, R. S., ONU, I., DIKE, M. C.AND OGUNLANA,M. O.

ABSTRACT. Six sorghum(Sorghum bicolor (L.) Moench) varieties including a resistant and a susceptible check, were evaluated (or damage by the head bug (Eurystylus oldi Pop.) adults under natural and cage conditions using 15 and 20 pairs of E. oldi per panicle at Samaru and Minjibir during 2003 and 2004 rainy seasons. The resistant check, Malisor 86-0.41, did not differ significantly (P<0.05) from SF 85-31-1-,·1-2, 87W81O and 911W 113-2-1 in number of bugs/I 0 panicles at the soft dough, while at hard dough stage Chokwe had the highest bugs per panicle which differed significantly from S34. Similarly, Malisor 86-30-41 had the least bug population and grain damage under cage conditions; comparable values for 87W810 and 911WI1J-2 were numerically higher. The highest percentage yield loss (43,8%) was recorded on the susceptible cultivar, S34, of which 41.4% was due to E. oldi. Malisor 86-30-41 had 21% yield loss of which 185% was attributed to the bug. Loss in monetary term was highest in S34 at both locations and infestation levels W20,132.80 and N18,398.40 loss/ha, respectively, for 15 and 20 pairs per panicle. On Malisor 86-30-41, the monetary losses were N7,899.00 and N4, 158.40/ha, respectively.

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