STUDIES ON THE EFFECTS OF AGE AND CANOPY SECTIONS OF CASHEW (Anacardium occidentale L.) ON POLLEN VIABILITY AND FRUIT YIELD

Abstract

Studies on cashew pollen viability and fruit morphology, with respect to differences in plant age and canopy sections of cashew trees were carried out at two different locations (Ibadan South West and Ochaja North Central), both in Nigeria. The ages of trees were 13, 10 and 7 year-old. Pollens and fruits were harvested at the upper, middle and lower canopy sections of the trees at the appropriate time, for further studies. The experimental design was split-split plot with three factors, replicated three times. Results obtained on pollen viability and fruit characteristics from two different locations, were subjected to analysis of variance (ANOVA) and means were separated. Results showed that thirteen year-old trees had wider broad end of apple and nut at individual locations and across locations. There was no consistency in other characteristics determined with respect to the specific ages of trees studied. However, ten year-old trees had the heaviest apple, fruit and nut weights respectively at Ibadan. Upper canopy section of the trees recorded highest means in broad end of apple and length of apple at across locations and at individual location. Seven year-old trees recorded highest means in number of unstained pollen grains both at individual location and across locations. Thirteen year old cashew trees recorded highest means in number of stain pollen and total number of pollen grains respectively. Ochaja environment appeared to support better apple and nut characteristics than the Ibadan environment. This could be due to optimal climatic conditions that favour flower and cashew fruit development in Ochaja relative to Ibadan. From the results, it can be deduced that the age of cashew trees (thirteen year-old trees) and the upper canopy section of cashew trees can influence some characteristics of apple and nut studied, irrespective of the location. Further studies are suggested to be carried out on cashew trees with wide range of establishment year, to determine the effect of the traits studied.