Pod Characteristics of cocoa (Theobroma cacao L.) related to rocoa pod borer resistance.

The characteristics of cocoa (Theobroma cacao L.) pod related to cocoa pod borer resistance (CPB) had been identified in a series of study. The objective of this research is to evaluate the characteristics of cocoa pod using more diverse of genetic background to obtain selection criteria. Genetic materials for this studywere 25 cocoa clones planted in Central Sulawesi for resistance evaluation. Field evaluation of the resistance were assessed by using variable of the percentage of unextractable beans, number of larvae entry and exit holes by which the clones were grouped into 5 groups of resistance. A laboratory works were carried out to assess pod characteristics based on the number of trichomes, granules of tannin and thickness the lignified-tissue of sclerotic layer using micro-technique method at the different level of pod maturity (3.0; 3.5; 4.0 months). Correlation between groups of those variables was analyzed using canonical correlation. The result performed a positive association between the thickness of sclerotic layer at the secondary furrow with the number of entry holes and the number of entry holes through sclerotic layer. The thickness performed a higher value of the coefficient in association with the variables of canonical for pod characteristics 0.59; 0.55; 0.43 and the variables of canonical correlation for CPB resistance 0.54; 0.51; 0.39 that would presenting the characteristics of pod related to CPB resistance in 3.0, 3.5 and 4.0 months of pod maturity. Lignification at sclerotic layer was considered as genotypic expressions due to the thickness at the secondary furrow at 3.0, 3.5 and 4.0 months of pod maturity performed high value of broad-sense heritability i.e. 0.75, 0.89 and 0.92 respectively. A qualitative assessment of the lignification clearly differentiated the resistant clones of ARDACIAR 10 with the susceptible clones of ICCRI 04, KW 516, and KW 564.