Friday, December 9, 2011

Cashew trees

Cashew trees are attractive, fast growing trees with pink flowers. They are known for the nuts they produce. But this nut is produced outside of the fruit, which is known as the cashew apple. The nut is attached to the lower portion of the cashew apple. Botanically speaking the apple is actually the swollen stem of the fruit.

Cashew apples and cashew nuts are excellent sources of nutrition. The cashew apple contains five times more vitamin C than an orange and more calcium, iron and vitamin B1 than citrus, avocados and bananas.

The best soils for growing cashews are sandy soils, but the trees grow well even in marginal ground. You can grow cashew trees from seed, but they will not be true to type – they will not be identical to the parent. Seedling trees flower in the third year after planting. Grafted or air layer cashew trees can fruit within 18 months, and the fruit (and other tree characteristics) will be identical to the ‘mother’ tree.

Cashew apples and nuts are ripe about two months after fruiting. The apple will be pink, red or yellow, and the shell of the nut will turn a dull grey. When the fruit falls to the ground, it's definitely ready. The nut develops first while the apple develops and enlarges only 2 weeks before the fruit falls. In Brazil, fresh cashew apples are packed in trays and marketed in retail fresh produce outlets.

As with mangos, rain during the flowering season will cause flowers to drop due to the anthracnose fungus. There are more than 200 registered patents for different uses of the oil contained in the shell of the nut. One of the most important uses is in the manufacture of brake linings.  There is also a caustic liquid that causes severe burns inside the shell of the nut. Be careful when handling it.