Studies on sclerotic layer hardness of cocoa pods

I. Azhar

Abstract

The penetration holes of first instars and emergence holes of final instars of cocoa pod borer (CPB) were examined on cocoa pods of clones ICS 98, UIT -5 and UA 37. The sclerotic laycr (SCL) hardness was also recorded on different sites (primary furrow - PF. secondarv furrow - SF. and on ridge - R) and portions (top. middle and bottom) of the pod of these clones. The entry and emergence holes occurred near the PF in the middle portion of the pod. Generally. the entry holes occurred less than 2 mm from either the PF or SF but seldom directly on the furrows. Hardness test indicated that the SCL directly beneath the PF and SF wcrc hardcr than those from other sites of the pod. The sites around 2 mm from the PF would bc appropriate to determine SCL hardness when screening for CPB resistant clones.

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