Fruiting and abscission patterns in cashew

Abstract

SUMMARYThe variation in setting fruit and immature fruit abscission at successive nodes of an individual panicle, and in panicles at different directions of the canopy in an individual tree, were studied in cashew (Anacardium occidentale L.). The numbers of perfect flowers and fruits set increased from the proximal to the distal end with the maximum yield at the fifth or sixth nodes in a panicle of 8–10 branches. The productivity of an entire inflorescence or a whole fruiting branch was related to its orientation with respect to the sun. The numbers of nodes and fruits set and the percentage of fruit retained were maximal in panicles located on the western and southern sides of the canopy. Tea mosquito damage was also less on these sides of the canopy but the physiological disorder of ‘apple’ cracking was higher here than on the eastern and northern sides. These variations are discussed in relation to the differences in the incident photosynthetically active radiation on these sides.

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

“…Fruit set from all crosses involving the eleven parental clones as both paternal and maternal parents indicates absence of strong compatibility barrier among the selected clones (Leonardi et al 1994;Aliyu 2007). Hybrid nuts obtained from both crosses were normal and viable with well-developed embryos and cotyledons, indicating that incidence of fruit drop and abnormal fruit development may probably be due to nutritional, physiological or environmental factors (Subbaiah 1983;Nawale et al 1984;Ghosh 1989). Leonardi et al (1994) opined that high rate of fruit abscission during the early stage of development is probably an indication of post-fertilization incompatibility, but should not be considered as only reason for fruit abscission because resource allocation might also play a vital role.…”

“…Although, this study show direct relationship between pollination/compatibility and fruit set, however, other limiting factors such, pollinator eYciency/abundance and resource allocation, must be taken into consideration to achieve optimum fruit set under natural conditions in cashew farms. Subbaiah (1983), Nawale et al (1984), and Ghosh (1989) remarked that, rather than by the number of fertile ovules, fruit set in cashew appears to be limited by maternal resources. Nutritional state of the cacao tree has been reported as one of the critical factors limiting fruit set in cacao (Lachenaud 1991).…”

“…Foltan and Ludders (1995) uphold the same view with studies in Australia. Subbaiah (1983), Nawale et al (1984), and Ghosh (1989) emphasized eVect of resources or inadequate pollination (Heard et al 1990) on fruit yield. Cashew has hitherto been described as out-crossing plant, but studies have shown some degree of self-pollination (Westergaard and Kayumo 1970;Foltan and Ludders 1995) and self-incompatibility .…”

Foliar application of the exogenous plant hormones at pre-blooming stage improves flowering and fruiting in cashew (Anacardium occidentale L.)

“…And trees with low yield were also characterized by poor production of hermaphrodite flowers (Aliyu 2006;Parameswaran et al 1984). Other authors had emphasized nutritional deficiency (Ghosh 1989;Subbaiah 1983), inefficient pollination (Heard et al 1990), and irregular and prolong flowering (Aliyu 2006;Aliyu and Awopetu 2003;Masawe et al 1996) as among other factors limiting cashew tree yield. Unfortunately, crop improvement programs to address the problem of declining yield in most major producing countries are at infancy (Topper et al 2001) and the widely recommended recurrent selection method ideal for improving tropical tree crops, like cashew, also requires a long gestation.…”

Influência da irrigação e da localização da inflorescência sobre a expressão do sexo em cajueiro-anão precoce

“…Contudo, tais diferenças, bem como a distribuição dos tipos de flores entre os diferentes lados (por exemplo, lado sombreado e lado exposto ao sol) apresentam resultados contraditórios. Para alguns autores, existem diferenças numéricas entre as panículas quanto ao número de flores, conforme suas orientações em relação aos pontos cardeais (Chakraborty et al, 1981;Subbaiah, 1983;Frota, 1988;Masawe et al, 1996). Outros, como Oliveira (1992) e Bueno (1997), observaram que o número de flores estaminadas e perfeitas e o número de frutos maduros não foram influenciados pela localização em relação aos pontos cardeais.…”