Cashew (Anacardium occidentale L.) breeding: A global perspective

Abstract

The cashew tree (Anacardium occidentale L.), which first originated from Brazil, is now found throughout the tropical world and in some subtropical areas with favourable climatic conditions: rainfall not so heavy and a dry period between rainy seasons. Its economic importance lies in the commercial value of the kernel extracted from the fruit, one of the tastiest and much appreciated by the nut consumers. The cashew nut producing chain provides employment and income for thousands of people and a significant turnover for agri-business dependent countries (Barros and Crisóstomo 1995). The Cashew was introduced from Brazil into India by the Portuguese during the sixteenth century. Following its introduction into southwestern India, the cashew probably diffused throughout the Indian subcontinent. Cochin served as a dispersal point for Southeast Asia as well (Johnson 1973). A look at the evolution of the world production of cashew nut gives an understanding on how the geography of the production is changing fast. From the early 1990s, a number of Asian countries have become important producers that did not appear in the statistics previously (Table 9.1). This is a clear indication that unless the traditional producers change the systems of production in utilisation through adding technologies capable of increasing production and productivity, very little will actually be achieved to improve its capability to compete with Asiatic producers in the international market. The most important nut producers are Vietnam, India, Brazil, Nigeria and Tanzania. Collectively, these countries account for 78% of the world production, according to FAO statistical data from 2004. Vietnam has seen dramatic increases in production over the last 10 years, rising from 202,000 mt in 1995 to approximately 675,000 mt in 2004. This represents 31% of the world production and means that Vietnam replaced India as the leading producer in 2002. The boost to Vietnams nut production coincided with the stagnation of the world production. This can be explained by the slow recovery of the African cashew cultivation and the stagnation of the Brazilian production leading to the change in the producers rank. Presently cashew in India is grown in 730,000 ha with a production of 460,000 mt of raw nuts (Table 9.2). It is one of the worlds largest exporters of cashew kernel. Nevertheless, its domestic production is insufficient to supply the industrial demand. This is the reason that it has imported raw material from a number of countries in Africa (Mozambique, Tanzania, Guinea-Bissau, Nigeria), Asia (Vietnam, Indonesia), Australia and South and Central America. Some of these places could aggregate value and provide jobs if the nuts are processed instead of exporting them as raw material. Mozambique has favourable ecological conditions to the development of this crop. Until the mid-1970s, it was the first cashew world producer with 210,000 mt in 1973. In 1975, the production was severely reduced to 15,000 mt due to its political problems. Due to this problem in Mozambique, the nut production in Tanzania presented a notable development until the year 1974, when it produced 140,000 mt. From this year on its production decreased. However, it increased from 2000 on, reaching 123,000 mt in 2004 (Table 9.2). In Indonesia, the cultivated area presented a substantial increase in the 1980s reaching 90,000 mt in 2004, in an area of 260,000 ha. In Nigeria, despite the increase of the cultivated area since 1999, the production remained stagnant at 186,000 mt. In Brazil, approximately 95% of the crop is produced in the three states of the Northeastern region: Cear'a, Piaui and Rio Grande do Norte, the poorest region, characterised by having more than half the area under semi-arid conditions. Cashew nut processing industry in these areas plays an important socio-economic role in the urban and rural development. Over the past few decades the cashew nut agribusiness has registered a remarkable increment. Presently, there are 700,000 ha and an industrial park capable of processing 280,000 mt of nuts annually. The importance of the cashew industry is evidenced by the export revenue to the tune of 140160 million dollars annually, along with providing thousands of direct and indirect jobs in all activities within the agro industrial chain (Barros et al. 2002; Leite and Paula Pessoa 2002). In spite of the socio-economic importance of this agri-business for a poor region, where the opportunities for reducing poverty are scarce, the cashew crop is characterised by the low usage of technology. Consequently, the productivity of the nut fell from 635 kg/ha in the early 1970s to 302 kg/ha during the 2002/2003 yield (Ibge 2004), affecting the productivity and export revenue (Paula Pessoa and Leite 1998). So it is fundamental to increase substantially the yield and productivity to make the business more profitable and attractive for new entrepreneurs. There are technologies capable of increasing production and productivity. So the crop expansion in traditional and in new potential areas as well as the approach in large stretches of unused marginal farmland should be encouraged. The most remarkable technology for the cashew crop is the selected dwarf clones because of the acceptance compared to other technologies. The main impact of these clones initially was to raise the productivity from 300 kg/ha to 1,000 kg/ha of nuts and 9,000 kg/ha of cashew apples in non-irrigated land. Later, it led to the first experiences in irrigation that resulted in as much as 3,800 kg/ha of nuts and over 34,000 kg/ha of cashew apples (Oliveira 2002). Experimentally, the last released dwarf clone produced 1,500 kg/ha of nuts in the sixth year under non-irrigated conditions (Barros et al. 2000). The use of selected clones has been changing the present situation of the cashew agri-business in Brazil. On the other hand, utilisation of cashew apple (also termed peduncle or false fruit) is gradually giving rise to an important segment of cashew agro industry with a number of industrialised products. There are over 30 products, namely, concentrated juice, sweets, soda and pure, clarified and pasteurised cashew juice called "cajuína", popular in the Cear'a State. The cashew apple represents approximately 90% of the fruit weight but only 58% of the production has been industrialised. It is necessary to increase its utilisation to aggregate value and profitability. Sales are gradually increasing and new markets are being opened for some of the apple products. In addition, the quality of apple from specific clones has resulted in a surprising increase in the consumption. Post-harvest experiments resulted in conservation of apple up to 20 days, making feasible the opening of new and important markets far from the origin of production and tradition.