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close this bookBiodiversity in the Western Ghats: An Information Kit (IIRR, 1994, 224 p.)
close this folder5. Agriculture
View the document5.1 Rice diversity and conservation in the Konkan
View the document5.2 Conservation of traditional vegetables in the backyard
View the document5.3 Genetic diversity in mango and cashew
View the document5.4 Floriculture and arboriculture
View the document5.5 Enriched biodiversity by plant introductions
View the document5.6 Impact of introduced plants
View the document5.7 Effects of pesticides on biodiversity
View the document5.8 Khazan (saline) lands

5.3 Genetic diversity in mango and cashew

Though they look very different, mango and cashew are relatives. Both belong to the botanical family Anacardiaceae.

Both are economically very important in all the Western Ghat states from Gujarat to Kerala.

Though they are related, mango and cashew come from opposite ends of the globe. Mango is native to Assam in the Indo-Malayan realm, which stretches from Pakistan to western Indonesia. Cashew originates from Brazil in the western hemisphere.

But both have become naturalized in the Western Ghats, and most people in the region think of them as natives. The two tree species and their produce form part of the religion and culture as well as the diet of local people.


Mango


Cashew

Cashew (Anacardium occidentale)

Cashew seeds were brought to India by the Portuguese in the 16th century to prevent soil erosion and mud-slides during the heavy monsoon rains. It was only in 1926 that local people discovered that the kernel was edible.

The cashew has been naturalized in the Western Ghats to such an extent that scientists refer to centuries-old varieties as "indigenous". These varieties have adapted to local soil, climatic and biotic conditions. Natural selection has ensured that the best adapted varieties could survive and multiply.

Cashew kernels are rich in protein (21%) and fat (47%). They contain 22% carbohydrate. They are high in iron (5 mg/100 g), vitamin B1 (630 mg/100 g) and B2 (190 mg/100 g), but low in vitamin A (100 I.U./100 g).

Cashew kernels, or "nuts", are a much sought-after and healthy snack food. The germinating nuts, called godavlim, can also be eaten.

In the northern Western Ghats, cashew juice is drunk fresh or is fermented into fenny, wines and vinegar.

Cashew nut shell liquid is used to treat wood against termites, and is used to make paints, varnishes, and other chemicals.

A major problem in cashew cultivation is fungal pink disease. The most serious pest is the tea mosquito bug, which can cause complete crop loss. The stem boring beetle, though less important economically, can kill the trees.

Conservation

Attempts to boost cashew production have meant that a few high-yielding varieties are now multiplied by the million. They are sold to farmers with government subsidies. These varieties have low tolerance to the tea mosquito bug. Planting a single variety exposes entire plantations to being wiped out by this or other pests.

The National Research Centre for Cashew, at Puttur in the central Western Ghats, has collected more than 300 varieties of cashew. Universities and research stations maintain plants in Vengurla (Maharashtra, 161 varieties), Chintamani (Karnataka, 172 varieties), and Madakkathara (Kerala, 115 varieties). Research stations at Ullal and Vittal (Karnataka) also have cashew collections.

Not a nut

Cashew "nuts" are not really nuts: botanically they are fruit because they contain a kernel and pericarp (an outer hard coating).
The cashew "apple" is not a fruit: it is a swollen fruit stalk.


Development of the cashew "nut" and "apple"

Mango (Mangifera indica)

India has more than 1000 named varieties of mango. Forty species of Mangifera are known, but only three are found wild in India: the cultivated Mangifera indica, and two others. In Goa, 77 varieties of mango have been reported.

Mango has five genomes (sets of chromosomes). This is unusual because most plants have an even number of genomes: two, four, six or eight. This complicates the breeding of new mango varieties.

Because seedlings are genetically different from the parent plants, true varieties can be maintained only through grafting.

Some varieties common in northern parts of the Western Ghats, such as Alphonso and Malcurada, have delicious fruits but bear fruit only every other year. Varieties further south produce fruit every year, but the fruit is of poorer quality. Plant breeders have crossed varieties from the north and south to get trees that produce good quality fruits every year. Some of these hybrids are Anmol, Ratna and Sindhu.

Popular mango varieties

- Early season Malcurada, Malgueso, Bemcurada, Pairi
- Mid-season Xavier, Colaco, Alphonso, Chimud, Udgo, Bispo, Secretina
- Late season Fernandina, Hilario, Monserata

Endangered or extinct varieties

Brindao, Mogri, Mirio, Don Filipe, Don Bernado


Mango fruit shapes

Mango fruit

Different mango varieties produce fruit of various sizes, taste and colour. They bear fruit at different times of the year, meaning that the mango season is getting longer. Some varieties are resistant to powdery mildew disease and pests such as mango hopper and fruit fly.

Mangoes are sweet because they contain a lot of sugar: between 10 and 18% of their weight. They are also high in vitamin C (25 to 175 mg/100 g) and vitamin A (0.8 to 13 mg/100 g).

Summer, from March to June, is mango season in the Western Ghats. Although it is a seasonal fruit, Indians eat a large number of mangoes: an average of 4 kg a year. They consume only 9 kg of bananas a year, even though bananas are available all year round.

The fruit can be eaten in many forms: fresh, canned, as juice or jam, sun-dried, or pickled in brine or spices.

Conservation

A new technique of grafting the very young shoots of newly germinated seedlings has made it easier to propagate and conserve rare varieties. Universities and research institutes are establishing germplasm banks to conserve important varieties.


Conservation

Mango trees symbolize goodness, and mango leaves are strung across doors on auspicious occasions.

Prepared by Miguel Braganza

Information kit produced by
WWF-India, Goa division and the
International Institute of Rural
Reconstruction.