Agriculture

Cassava

Cassava root or Tapioca inside black plastic bag. CASSAVA (Manihot esculenta) or Tapioca also called ‘Ubi Kayu’ in Local Malay is a tropical root or tuber crop under family Euphorbiaceae.(source)

Manihot esculenta, commonly called cassava (/kəˈsɑːvə/), manioc, or yuca (among numerous regional names) is a woody shrub native to South America of the spurge family, Euphorbiaceae. Although a perennial plant, cassava is extensively cultivated as an annual crop in tropical and subtropical regions for its edible starchy tuberous root, a major source of carbohydrates. Though it is often called yuca in parts of Spanish America and in the United States, it is not related to yucca, a shrub in the family Asparagaceae. Cassava is predominantly consumed in boiled form, but substantial quantities are used to extract cassava starch, called tapioca, which is used for food, animal feed, and industrial purposes. The Brazilian farinha, and the related garri of West Africa, is an edible coarse flour obtained by grating cassava roots, pressing moisture off the obtained grated pulp, and finally drying it (and roasting in the case of farinha).

Cassava is the third-largest source of food carbohydrates in the tropics, after rice and maize. Cassava is a major staple food in the developing world, providing a basic diet for over half a billion people. It is one of the most drought-tolerant crops, capable of growing on marginal soils. Nigeria is the world’s largest producer of cassava, while Thailand is the largest exporter of cassava starch.

Cassava is classified as either sweet or bitter. Like other roots and tubers, both bitter and sweet varieties of cassava contain antinutritional factors and toxins, with the bitter varieties containing much larger amounts. It must be properly prepared before consumption, as improper preparation of cassava can leave enough residual cyanide to cause acute cyanide intoxication, goiters, and even ataxia, partial paralysis, or death. The more toxic varieties of cassava are a fall-back resource (a “food security crop”) in times of famine or food insecurity in some places. Farmers often prefer the bitter varieties because they deter pests, animals, and thieves.[source:https://en.wikipedia.org/wiki/Cassava]

Yam

A monocot related to lilies and grasses, yams are vigorous herbaceous vines providing an edible tuber. They are native to Africa, Asia, and the Americas. Some yams are also invasive plants, often considered a “noxious weed”, outside cultivated areas. Some 870 species of yams are known, and 95% of these crops are grown in Africa.

Yam plants can grow up to 15 m (49 ft) in length and 7.6 to 15.2 cm (3 to 6 in) high. The tuber may grow into the soil up to 1.5 m (4 ft 11 in) deep. The plant disperses by seed.

The edible tuber has a rough skin that is difficult to peel but readily softened by heating. The skins vary in color from dark brown to light pink. The majority of the vegetable is composed of a much softer substance known as the “meat”. This substance ranges in color from white or yellow to purple or pink in mature yams.

Cultivation

Purple yam (D. alata) freshly harvested and sliced for cross-sectional view
Yam crop begins when whole seed tubers or tuber portions are planted into mounds or ridges, at the beginning of the rainy season. The crop yield depends on how and where the sets are planted, sizes of mounds, interplant spacing, provision of stakes for the resultant plants, yam species, and tuber sizes desired at harvest. Small-scale farmers in West and Central Africa often intercrop yams with cereals and vegetables.

The seed yams are perishable and bulky to transport. Farmers who do not buy new seed yams usually set aside up to 30% of their harvest for planting the next year. Yam crops face pressure from a range of insect pests and fungal and viral diseases, as well as nematode.

Their growth and dormant phases correspond respectively to the wet season and the dry season. For maximum yield, the yams require a humid tropical environment, with an annual rainfall over 1500 mm distributed uniformly throughout the growing season. White, yellow, and water yams typically produce a single large tuber per year, generally weighing 5 to 10 kg (11 to 22 lb).

Despite the high labor requirements and production costs, consumer demand for yam is high in certain subregions of Africa, making yam cultivation quite profitable to certain farmers.

Major cultivated species
Many cultivated species of Dioscorea yams are found throughout the humid tropics. The most economically important are discussed below.

Non-Dioscorea tubers that were historically important in Africa include Plectranthus rotundifolius (the Hausa potato) and Plectranthus esculentus (the Livingstone potato); these two tuber crops have now been largely displaced by the introduction of cassava.[source:https://en.wikipedia.org/wiki/Yam_(vegetable)]

CocoYam

Cocoyam is a common name for more than one tropical root crop and vegetable crop belonging to the Arum family (also known as Aroids and by the family name Araceae) and may refer to:

• Taro (Colocasia esculenta) – old cocoyam
• Malanga (Xanthosoma spp.) – new cocoyam

Cocoyams are herbaceous perennial plants belonging to the family Araceae and are grown primarily for their edible roots, although all parts of the plant are edible. Cocoyams that are cultivated as food crops belong to either the genus Colocasia or the genus Xanthosoma and are generally composed of a large spherical corm (swollen underground storage stem), from which a few large leaves emerge.

The petioles of the leaves (leaf stems) stand erect and can reach lengths in excess of 1 m (3.3 ft). The leaf blades are large and heart-shaped and can reach 50 cm (15.8 in) in length. The corm produces lateral buds that give rise to side-corms (cormels, suckers) or stolons (long runners, creeping rhizomes) depending on the species and variety.

Cocoyams commonly reach in excess of 1 m (3.3 ft) in height and although they are perennials, they are often grown as annuals, harvested after one season. Colocasia species may also be referred to as taro, old cocoyam, arrowroot, eddoe, macabo or dasheen and originate from the region of Southeast Asia. Xanthosoma species may be referred to as tannia, yautia, new cocoyam or Chinese taro and originate from Central and South America.[source:https://en.wikipedia.org/wiki/Cocoyam]

Cashew

Cashews as a snack
Culinary uses for cashew seeds in snacking and cooking are similar to those for all tree seeds called nuts.

Cashews are commonly used in South Asian cuisine, whole for garnishing sweets or curries, or ground into a paste that forms a base of sauces for curries (e.g., korma), or some sweets (e.g., kaju barfi). It is also used in powdered form in the preparation of several Indian sweets and desserts. In Goan cuisine, both roasted and raw kernels are used whole for making curries and sweets. Cashews are also used in Thai and Chinese cuisines, generally in whole form. In the Philippines, cashew is a known product of Antipolo, and is eaten with suman. The province of Pampanga also has a sweet dessert called turrones de casuy, which is cashew marzipan wrapped in white wafers. In Indonesia, roasted and salted cashews are called kacang mete or kacang mede, while the cashew apple is called jambu monyet (lit. ‘monkey rose apple’).

In the 21st century, cashew cultivation increased in several African countries to meet the demands for manufacturing cashew milk, a plant milk alternative to dairy milk. In Mozambique, bolo polana is a cake prepared using powdered cashews and mashed potatoes as the main ingredients. This dessert is popular in South Africa.

In Brazil, cashew fruit juice and the fruit pulp are used in the production of sweets, juice, alcoholic beverages, such as cachaça, and as a flour, milk or cheese.In Panama, the cashew fruit is cooked with water and sugar for a prolonged time to make a sweet, brown, paste-like dessert called dulce de marañón (marañón being a Spanish name for cashew).

The shell of the cashew nut contains oil compounds that can cause contact dermatitis similar to poison ivy, primarily resulting from the phenolic lipids, anacardic acid, and cardanol. Due to the possible dermatitis, cashews are typically not sold in the shell to consumers. Readily and inexpensively extracted from the waste shells, cardanol is under research for its potential applications in nanomaterials and biotechnology.[source:https://en.wikipedia.org/wiki/Cashew]

Timber

Lumber, also known as timber, is a type of wood that has been processed into beams and planks, a stage in the process of wood production. Lumber is mainly used for structural purposes but has many other uses as well.

There are two main types of lumber. It may be supplied either rough-sawn, or surfaced on one or more of its faces. Besides pulpwood, rough lumber is the raw material for furniture-making and other items requiring additional cutting and shaping. It is available in many species, usually hardwoods; but it is also readily available in softwoods, such as white pine and red pine, because of their low cost.^[1]

Finished lumber is supplied in standard sizes, mostly for the construction industry – primarily softwood, from coniferous species, including pine, fir and spruce (collectively spruce-pine-fir), cedar, and hemlock, but also some hardwood, for high-grade flooring. It is more commonly made from softwood than hardwoods, and 80% of lumber comes from softwood.[source:https://en.wikipedia.org/wiki/Lumber]