Vegetables Crops Explanation And It Examples

The range of vegetables grown in various parts of West Africa is varied since both indigenous and exotic crops are included under this general heading. Most of the local vegetables such as spinach, okra and vegetable jute are well adapted to the humid lowlands and many of the exotic or introduced temperate types can also grow under these conditions, if given good management. Many of these, however, will grow to a larger size and will mature more satisfactorily at elevations over 1,000m, due mainly to the lower temperatures and the day/night (diurnal) variation in temperature.

The main characteristics and requirements of selected vegetable crops are as follows. They are all propagated by seed, unless otherwise stated, and are mainly grown on raised beds or on ridges

Onion (Cultural and environmental requirements)
A popular crop in West Africa and, although the bulb or globe types are more difficult to grow than shallots, the area under cultivation is rapidly increasing. Many local cultivars, e.g. Gindin Tassa, are in cultivation and form seeds at higher elevations. Onions require a fertile, deep soil, with a good water-retaining capacity.

Alluvial soils are suitable if liberally treated with organic material.
Onion seeds are sown in boxes and transplanted during the early rains, when about 12-15 cm in height, to well-firmed beds. Mature bulbs are also sometimes used, the tops being cut back before planting. NPK fertiliser should be applied to the soil before planting, and later dressings with phosphate and potassium at intervals of 14-21 days are usually beneficial to
growth. Hoeing, weeding and mulching are required and irrigation may be needed in hot weather. Bulbs require a dry period for ripening, the leaves turn brown and wither when the bulbs are ripe. Pests and diseases may be checked by spraying and crop rotation.
Read More:

Shallot (Cultural and environmental requirements)
Soil preparation and general cultural operations are similar to those required by onions. Bulbs are planted during the early rains or at any time of the year if the soil can be kept moist. There are many local selections e.g. 'Bawku',  varying in size, colour of skin. Mature bulbs which are required for replanting should be well dried in the sun and stored for 6-8 weeks before being planted, up to 3 crops per year may be obtained.

Water melon or egusi (Cultural and environmental requirements)
Excessive rainfall may affect flowering and the spread of leaf diseases, but this crop is tolerant to a wide range of environmental conditions. Seeds are sown on mounds, ridges or raised beds or they may be raised in a nursery and transplanted. Soils with a good organic content and moisture retaining capacity are preferable, and a general dressing of NPK should be given before planting. Sulphate of ammonia may be applied at intervals of 14-21 days until flowering begins. Plants should be kept free of weeds until well developed, watering may be required in the dry season. Spraying with insecticides and fungicides gives reasonable crop protection.

Pumpkin, squash gourd (Cultural and environmental requirements)
High temperatures are required for rapid growth but excessively high humidity may be harmful and crops are usually sown to mature in the dry season. Soils with a high organic content are preferable and holes
60x 60x 60 cm, filled with compost or fym, are usually prepared in advance of planting. Seeds are sown in boxes or containers, or direct into the prepared holes.

The planting distances will vary, bush types requiring less space to develop than the trailing types. Young seedlings may require protection from strong winds or rain. NPK fertiliser may be applied before planting, followed by dressings of a nitrogenous fertiliser until flowering, at intervals of 14-21 days. Pests and diseases may be controlled by spraying.
Mature fruits may be stored for a considerable period after harvesting.

Tomato (Cultural and environmental requirements)
This is an increasingly important crop in West Africa and a great deal of experimentation and research has been done in selecting suitable cultivars for various areas and exploring the most efficient methods of growing the crop for both local consumption and processing. The control of various pests and diseases is important since this crop is liable to many fungal, bacterial and viral diseases, in addition to several pests, particularly when grown in high rainfall areas.

The best yields are obtained from plants grown to maturity during the dry season although very high temperatures may result in poor yields due to pollen becoming sterile. Well drained, fertile soils, with a good organic content are most suitable, the application of an fertiliser before sowing or planting is generally recommended.

Seeds may be sown direct or in containers and transplanted when about 10-15 cm in height, some protection from wind, rain or hot sun may be required and frequent watering will be needed until the plants are established. NPK fertiliser, possibly with additional potassium, may be applied at intervals of 14-21 days but the nitrogen content should be reduced after the first flowers have been produced. Regular weeding and watering, also mulching and staking are required, although some cultivars are short-stemmed and do not require the 2 m long stakes which are needed for supporting the taller growing cultivars.

Side shoots are usually removed to increase the size of fruits and a regular spraying programme should be followed to prevent serious outbreaks of pests and diseases. The most serious disease is bacterial with which may be partly controlled by sowing seeds direct into beds, growing them in containers to maturity, or treating the soil with a formalin solution. Nematodes may also be serious and regular crop rotation is
essential. Tomatoes and other plants of the same family (Solanaceae) should not be grown in the same area within a period of 4-5 years.

Fruits of the tomato vary widely in size and shape, depending on the cultivar grown.

Hot peppers: red pepper, bird's eye pepper (Cultural and environmental requirements)
This crop is popular in many parts of West Africa and is a short lived perennial which is tolerant to a wide range of rainfall and soil types. Fertile soils with a high organic content are most suitable and an NPK fertilizer application before planting, with later surface dressings, encourages high yields. Hoeing, weeding, mulching and irrigation during dry weather are necessary and fruits are harvested as they mature.

Rotational cropping is recommended to reduce losses due to diseases such as bacterial wilt and also nematodes.

Sweet peppers, bell peppers, bullnose peppers (Cultural and environmental requirements)
These are similar to those recommended for tomatoes although some cultivars may be particularly sensitive to wet soil conditions. Seeds are sown in containers and  transplanted to beds or ridges, but rarely require staking. Routine cultivations such as weeding, mulching, fertiliser application and spraying to control pests and diseases should be regularly carried out if high quality crops are required.

Carrots (Cultural and environmental requirements)
This crop is not widely grown, but is becoming popular in some areas. The short rooted cultivars are normally considered to give the best results but elevations over 1 000 m are necessary for the production of high yields since high temperatures affect both the quality and size of the swollen roots.

Well drained, sandy soils, with a good content of organic material are most suitable and fertiliser should be applied before sowing, and at intervals until the roots begin to swell. Seeds are sown broadcast or in drills and seedlings thinned to 5-8 cm apart; they may be earthed up when the roots begin to develop, to protect them from excessive sun. Pests and diseases may be controlled by spraying. The roots are lifted when mature and may be stored for several weeks if kept in cool conditions.

Okra, okro (Cultural and environmental requirements)
This popular vegetable is grown either on flat land or on beds and thrives well at low elevations although some cultivars are sensitive to wet soils. Both short and long duration types are grown, pods on both types may begin to mature in 8-10 weeks, but the long duration ones will continue to fruit for several months Tonger than the short season cultivars. Fertile soils promote rapid growth, the seeds are sown direct on beds or on the flat, 2-3 seeds per stand, later thinning to single plants. Crop rotation will reduce damage due to nematodes and the use of good quality seed will prevent the spread of mosaic virus.

African spinach, amaranth, bush greens
(Cultural and environmental requirements)
The various species of Amaranthus which are included under the general heading of 'spinach' include:
Amaranthus hybridus var. cruentus, A. gangeticus, and A. viridis.

African spinach is grown throughout West Africa and in many tropical regions, it has a high nutritional value and, due to the rapid growth rate, several crops per year can be grown. It is a lowland crop, rarely successful at elevations over 5-600 m. Well drained soils, of a high organic content are suitable for this crop, additions of NPK fertiliser and particularly potassium, stimulate rapid and vigorous growth.

Seeds are generally sown broadcast and thinned and some of the thinned plants used for transplanting. The crop is rarely attacked by diseases and occasional pests may be controlled by spraying, although the value of  the crop rarely justifies this. The removal of flower heads before they mature promotes the development
of leaves and lateral branches which also develop after the first harvest, giving a second crop.

Vegetable jute, long-fruited jute, bush okra (Cultural and environmental requirements)
In some areas, this vegetable is also known as African sorrel and is widely grown in most parts of West Africa. It is closely related to the jute (Corchorus capsularis) which is used in the  production of fibres for produce bags. A lowland crop, yields may be reduced if grown at elevations of more than 800 m. Soils with a good moisture retaining capacity and high organic content give early production of the leaves and young shoots which are used as a spinach.

Fertilisers also promote vigorous growth, particular nitrogenous fertilisers used as a dressing every 14-21 days until flowering. The seeds are sown on raised beds or ridges at the beginning or the end of the wet season, usually broadcast and thinned to one per stand, the thinning are often used as transplants.

Late sown crops may require irrigation in the early stages. Weeds should be controlled until the plants are well established. Nematode damage can be reduced by regular rotation.

Lettuce (Cultural and environmental requirements)
This exotic vegetable is gaining in popularity in West Africa and is generally grown by market gardeners for sale. Many cultivars have been found to be well adapted to low elevations and high temperatures, but larger plants are produced in hilly areas or at elevations over 500 m where plants have less tendency to run to seed. There are two main groups: the 'cabbage" and the 'cos' lettuce, the latter have long crisp leaves
which are sometimes tied to encourage blanching.

Fertile soils with good reserves of organic material are essential for rapid and vigorous growth which is also
promoted by fertiliser applications, particularly nitrogen.

Seeds may be sown direct but are generally sown in containers in a nursery and transplanted to raised beds or on flat land. Young transplanted seedlings require protection from excessive rain and sun until well established; weeds should be controlled until the plants are mature. Irrigation will be necessary for dry
season crops. Pests and diseases may be controlled by spraying and crop rotation will reduce nematode infestation.

Cabbage (Cultural and environmental requirements)
This crop is normally grown for market and large heads may be obtained if cultivars suitable to the locality are grown. At low elevations, heads are slow to develop, but at elevations over 500 m, growth is more rapid and higher yields are obtained. Soils should be moisture retaining and have a good reserve of organic material. Fertilisers applied before and after transplanting will promote growth and nitrogenous fertilisers are particularly required by this crop.

Seeds are raised in containers in nursery conditions and transplanted to raised beds, ridges or flat land when 10-15 cm high; protection from wind, sun and heavy rainfall should be provided until they are well established. Diseases and pests may become serious if not controlled early, the use of sprays is normally justified due to the market value of the crop. Irrigation is required for crops grown in the dry season.

Cauliflower (Cultural and environmental requirements)
This is also an exotic crop which can be grown in West Africa if cultivars adapted to the local environment are selected. The edible part is the enlarged flower head which may grow to 15 cm in diameter, particularly if grown at elevations over 800m.

Lowland cultivation is rarely successful. As for cabbage, the soil requirements are fairly demanding, soils of high fertility and good moisture retaining capacity producing the higher yields. Fertilisers, particularly nitrogen, are required for most soils and irrigation during the dry season should be regular.

Seeds are sown in containers and transplanted to beds, ridges or on flat land; they should be shaded and watered carefully until established. Weeds should be removed until the crop is mature and irrigation will be required until the heads are formed. Excessive sun may scorch the developing heads and leaves are often
bent over the flowers or curds, as a protection against heavy rain or sun scorch. Spraying will protect the plants from diseases and pests, and rotation will reduce nematode infestation.

Vegetables Crops Explanation And It Examples Vegetables Crops Explanation And It Examples Reviewed by Legit Mentor on November 20, 2021 Rating: 5

1 comment:

Powered by Blogger.