Appearance, Cultivation, and Uses of Fleshy Cashew Nut Fruits

The Unique Structure and Appearance of Cashew Nut Fruits

Cashews are an incredibly popular nut, known for their sweet, buttery flavor and crunchy texture. However, many people may not realize that cashews actually grow attached to the bottom of a cashew apple, which is the fruit of the cashew tree.

The cashew apple is a fleshy, tropical fruit that is red or yellow in color when ripe. Attached to the bottom is a brown, kidney-shaped cashew nut. Together, these two components make up the cashew fruit.

Appearance of Whole Cashew Fruits

Whole, ripe cashew fruits have an oval shape and can grow over two inches long. The cashew apple portion is typically larger than the cashew nut. The skin surrounds soft, juicy flesh that can be astringent in flavor.

Cashew apples have a wrinkled appearance and thin skin that is very delicate and easily bruised. A long stem emerges from the top where the cashew apple connected to branches of the tree.

Colors and Shapes

Cashew apples exhibit a range of colors as they ripen, starting out green and developing into yellow, orange, red, or scarlet hues. Inside, the flesh is often white or yellow with a waxy appearance.

The cashew nut shells have an irregular shape, resembling a large kidney bean. They start out soft and green before hardening to a brown color as they mature.

Differences Between Caju and Anacardium Occidentale

There are two main varieties of cashew trees Anacardium occidentale and Anacardium microcarpum, also known as caju. While both produce edible cashew apples and nuts, there are some notable differences.

Caju trees produce larger cashew apples, but smaller nuts. The shells of caju nuts are also thinner. Meanwhile, common cashew or Anacardium occidentale trees yield smaller fruits with bigger nuts.

Stages of Cashew Fruit Development

Cashews go through several key stages as they grow from flowers into ripe fruits. Understanding the phases of development helps provide a deeper appreciation for how these nutritious nuts and fruits are formed.

Flowering

It all begins when cashew trees produce an abundance of reddish-yellow panicle flower clusters. These elongated flower clusters emerge directly from thick stems and trunk branches. They bloom for several weeks.

Pollination

During flowering, pollen must reach the stigma of the cashew flowers in order for fruit production to occur. Bees, wasps, and other insects serve as natural pollinators as they travel from one flower to another collecting pollen.

Fruit Set

After pollination is successful, cashew flowers fade away except for the ovary portion. The ovary begins to swell into a green, apple-like structure. Attached below it is a developing cashew nut inside a soft shell.

Maturation

Over the next two months, the cashew apples grow bigger and change from green to yellow or red shades. The nut shells harden from soft and fleshy to a firm outer layer that protects the inner cashew seed.

Ripening

By three months after the flowers first emerged, cashew fruits are heavy with ripening apples and nuts. The apples take on deeper golden and scarlet hues and may give off a sweet aroma when fully ripe in tropic climates.

Harvest

Timely harvesting by handpicking is important to enjoy perfectly ripened cashew apples, which are highly perishable. Meanwhile, the cashew nuts must be carefully removed from their toxic shells quickly after picking.

Regional Differences in Cashew Fruit Cultivation

While cashews grow well in tropical regions globally, there are some key differences depending on the country.

Vietnam

Vietnam leads the world in cashew nut exports thanks to highly productive hybrid trees. The Vietnamese growing region features a long dry season which allows farmers to harvest lots of high-quality nuts for cashew kernel production.

India

In India, cashew cultivation focuses more on enjoying the juicy and flavorful cashew apple fruit. Many farmers utilize unprocessed, organic approaches to yield very nutritious fruits valued for fresh eating, juices, wine, and vinegar.

Brazil

Brazil's humid tropical climate allows abundant flowering and fruiting from January through June. The sizable cashew apples and nuts meet extensive global demands. Mechanized production, especially for cracking nuts, contributes to significant processing for both export and domestic sale.

East Africa

Countries like Tanzania, Mozambique, and Kenya produce cashews mainly for domestic consumption rather than large-scale commercial sales. Farmers incorporate cashew trees into eco-friendly agroforestry systems mixed with other subsistence crops.

Unique Uses for Cashew Apples and Nut Shell Liquid

While most people only know about roasting and eating cashew nuts, the cashew fruits and shells also offer useful purposes.

Cashew Apple Juice

Extracting juice from fresh cashew apples results in a popular drink in tropical regions. The astringent flavor becomes sweeter as more sugar is added. Carbonating the juice produces a refreshing beverage resembling apple cider.

Cashew Apple Wine and Vinegar

Allowing cashew apple juice to ferment turns it into palm wine with around 4-5% alcohol content. Further fermentation and bottling creates flavorful fruit wines. Vinegar is also made by acetic acid fermentation of the juice or wine.

Nut Shell Liquid Extraction

Heating cashew nut shells produces a reddish-brown liquid known as cashew nut shell liquid or CNSL. This natural resin has diverse applications from brake lining adhesives to medicines, thanks to its unique chemical components.

Non-Toxic Uses for Cashew Shells

While the caustic shell oil has commercial purposes, the rest of the shell also has value, especially for non-toxic purposes. Crushed shells work well as mulch while larger pieces function as eco-friendly fuel for stoves or fruit drying.

Common Diseases and Pests

Even tropical cashew orchards face threats from various diseases and insects that can damage yields.

Powdery Mildew

Powdery mildew fungi present a nuisance in India. The telltale white, powdery spots cover emerging shoots, flowers, and young fruits causing malformed cashews. Copper fungicides provide adequate management.

Tea Mosquito Bug

In many regions, the tea mosquito bug feeds on sap from cashew shoots and apples. Feeding damage appears as brown spots that turn flowers and fruits black. Severe attacks can kill trees. Careful monitoring helps support early control applications.

Cashew Stem and Root Borer

Larvae of the longhorn beetle species called cashew stem and root borers tunnel into trunks and roots debilitating whole trees. Tiny entry holes oozing resin signal an active infestation. As a strong flier, the adult beetle easily spreads to new sites.

Implementing integrated pest management with both cultural and chemical control measures keeps cashew orchards growing strongly.

Ideal Climate Conditions for Optimal Fruiting

Cashew trees thrive best in tropical environments with specific climate needs for productive flowering and fruiting.

Minimum Temperatures

Cold winters negatively affect cashew trees, especially flowering. Areas with temperatures consistently at 50F (10C) or above prove ideal. Brief light frost only causes leaf loss while hard freezes damage entire trees.

Rainfall Needs

Cashews require at least 39 inches (1000

Disclaimer: This article is for informational purposes only and does not constitute medical advice. Always consult with a healthcare professional before starting any new treatment regimen.