Compatibility and fruit-set in cashew (Anacardium occidentale L.)

Abstract

Understanding complex factors controlling yield is very crucial to the improvement of cashew in major producing countries currently experiencing very low yield and consequently making cashew farming unprofitable and the whole industry unsustainable. Eleven cashew clones were evaluated for their compatibility and fruit set between 2000 and 2002 seasons, in a diallel cross using randomized complete block design with three replications. Data collected on number of fruit set at 6 weeks after pollination were statistically analyzed. Significant differences between the parents at the 1% level, revealed the existence of variability for compatibility and fruit set, with 34% cross-compatibility, 51% partial cross-compatibility and 15% cross-incompatibility recorded, while 37% of the parents were self-compatible. Parents sharing the same apples colors tend to be highly cross-compatible, while some clones showed evidence of unilateral compatibility. Maximum value of 55% fruit set obtained from cross-pollination probably indicates upper limit for fruit set in cashew. Significant correlation between compatibility and variation in fruit yield suggests the important role of parental compatibility in selection of planting materials for the establishment of cashew plantation.