Pod husk thickness and percentage moisture content were evaluated for their influence on Phytophthora palmivora infection of resistant, moderately resistant and susceptible selections of cocoa. The aim of this work was to elucidate if thickness of the pod husk and its moisture content are resistance factors to Phytophthora pod rot in cocoa genotypes. Twelve cocoa genotypes were inoculated with Phytophthora palmivora using detached pod test at penetration and post-penetration stages of inoculation. Cocoa genotypes resistant to Phytophthora palmivora in the field and in the laboratory inoculation (SCA 6, GU225V, T85/799 and LAF 1) had the thickest pod husk and lowest moisture content in the current study suggesting that pod husk thickness and moisture content factors were involved. Susceptible cocoa clones had the thinnest pod husk and highest percentage moisture content of pod husk, suggesting that thinner pod husk with high moisture content favours Phytophthora pod rot infection. A significant negative correlation was obtained between pod husk thickness and lesion number and size on pods indicating that as thickness of the pod husk increases, lesion number and size decreases. Correlation between moisture content of pod husk and lesion number and size on pod was positive and significant suggesting that as moisture content increases, lesion number and lesion size also increases. These results suggest pod husk thickness and moisture content as resistance factors in cocoa. Nevertheless, other pod husk factors could not be excluded.
D. Nyadanu, M.K. Assuah, B. Adomako, Y.O. Asiama and Y. Adu-Ampomah, 2011. Thickness of the Cocoa Pod Husk and its Moisture Content as Resistance Factors to Phytophthora Pod Rot. International Journal of Agricultural Research, 6: 310-322.