Cashew

I. INTRODUCTION Cashew (Anacardium occidentale L.) is one of the important nut crops, ranking third in the international trade after hardnuts (29%) and almonds (21% ). The cashew tree is believed to be a native of Brazil, from where it is dispersed to many of the tropical areas (1). At present the major cashew-producing countries are Brazil, Mozambique, India, Indonesia, arid Tanzania (Table 1). As many as 20 species of Anacardium are known to exist within Central and South America. However, A. occidentale is the only species reported to have been introduced outside the New World. World consumption of cashew kernels has been increasing at an average annual rate of 10.9% (2). Hence, there is tremendous scope to increase cashew production by extending cashew cultivation to newer areas as well as increasing the productivity of existing plantations. The world production of cashew nuts decreased from 519,464 tonnes in 1969-1971 to 478,832 tonnes in 1990. Production in the African countries has decreased significantly during tJte last decade (3).

II. BOTANY Cashew (Anacardium occidentale L.) belongs to the family Anacardiaceae, which includes many economically important tropical and subtropical trees and shrubs. Mango and pistachio are the two most important other members of the family. Anacardium is a small genus of eight species. The chromosome number of A. occidentale is 2n = 42 (4). The cashew tree is a polygamoandromonocious plant, bearing staminate and hermaphrodite flowers. The inflorescence is a terminal, many-flowered panicle borne on the current season's growth. The percentage of hermaphrodite flowers varies from 0.5 to 36% in different types. Flowering in cashew is staggered and continues for about 90 days. Though a large number of flowers are produced, only 4-6% reach maturity, the remaining being shed away at various stages of development (1). Pollination of cashew is carried out mostly by flies, bees, and ants, as well as by wind.