A crop is a plant which is cultivated by man for some beneficial purposes. Therefore all crops are plant but not all plant are crops.
These are crops that look like grasses having long and flat leaves. They are monocotyledonous crops. The crops are grown because of their seeds which are rich in carbohydrate and are used mainly ass food by both man and animals. Examples are Maize, Rice, Guinea corn, Millet, Wheat, Barley, Oats, Rye and Acha.
1. Maize (zea mays)
Maize is said to have originated in America and has become one of the main food crops in West Africa. It is used in Various forms as food by man and is also used as livestock feeds.
Maize is monotonous grass belonging to the family of gramineae. It is a monocotyledonous annual plant which reaches a height of about 1m – 3m. The stem is soft and divided into several inter-nodes by the nodes. The leaves which are long and flat with conspicuous midribs and parallel veins arise from the nodes.
The plant is shallow rooted and has adventitious roots underground. Some of the adventitious roots also develop at the lower inter-node of the stem above the ground. These are called the prop roots.
Maize has both the male and female flowers on the same plant. The male (tassels) are borne in a terminal panicle, while the female flowers are borne in the cobs or ears. The fruit is one seeded and has fused pericarp when dry (caryopsis). Some varieties of maize are flint, floury, dent, yellow maize (TZRS) white maize (Ferz 27) and hybrid maize such as 8434-11.
a) Method of Maize Propagation
Maize is propagated by seeds.
b) Climatic and Soil Requirement of Maize
Maize is sun loving crop. It requires a minimum temperature of about 10 degree Celsius and a maximum of about 46 degree Celsius. The crop requires much rainfall at the beginning of it growing period with an annual rainfall requirement of 750 mm to 1500 mm.
Deep, permeable, fertile soil, preferably loamy soil which is neutral or alkaline is best suited for maize cultivation. However, maize will grow in all soil except pure sand.
c) Land Preparation and Planting of Maize
In the forest or heavy grass areas, clearing and burning of bush are necessary. The land maybe ploughed and harrowed under mechanized farming. At times low ridges, mound or beds are prepared. Experience has however shown that fine seed bed is not essential for maize. Zero or minimum tillage gives good yields while using herbicides to control weeds.
Planting on flat land will produce good results if there is less danger of erosion in the area.
Maize is best planted in the south in late February to April for early maize, and in August for late maize. In the north it is planted in June.
Plant only the high yielding varieties such as TZSR (Yellow), Ferz 27(white), hybrid 8434-11. Sow 2-3 weeks after planting, supplying should be done to fill un-germinated stands. spacing is 30 cm along rows and 90 cm between rows. About 25kg of maize grains will be needed to plant one hectare of farm land. This is considered as an appropriate seed rate if maize is planted as a sole crops.
d) Manure, Fertilizer Requirement and Application of Maize
Planting in freshly cleared forest soils may not require fertilizer application. But on used farm land, apply 15-15-15 (NPK) fertilizer at planting and sulphate of ammonia four weeks after planting. It is advisable to consult the Ministry of Agriculture in this regard.
Apply in channels 5 cm deep and 5 cm away from the stands in row and cover the trench. Theuse of fertilizer for late maize has been found not be profitable.
d) Weed Control
The maize plot is weeded clean within the first five weeks of planting, weeding can be done using a small hoe or cutlass. Selective herbicide can be used on large farms.
e) Harvesting, Processing and Storage of Maize
The maize cobs are ready for harvesting when the silks begin to dry. This is green harvesting in which case the cobs are meant for immediate consumption. On the alternative, the maize plants maybe allowed to dry so that the sheaths of the cobs are thoroughly dried out. This is dry harvesting, in which case the grains or cobs can be stored after proper drying.
Harvesting can be done by plucking the cobs with hands or by first cutting the stalks with a cutlass and then removing the cobs or by the use of combine harvester for maize if on a large scale. After harvesting, the dry maize cobs can be stored in three ways –
- They may be stored along with the husk or sheaths by hanging over a fire place for heating and drying.
- The husk maybe removed, the cobs thoroughly dried in the sun and then stored in bags or cribs.
- the dehusked maize cobs may be shelled . The grains thoroughly dried and then stored in bags, plastic drums or in silos, if on commercial quantity.
The major problem in the storage of maize is the maze weevils which eat into the cotyledons and render the grains useless. They can be controlled by proper drying. The use of actellic dust, which is sprinkled on the grains is very effective. Silos, large containers and stores can be fumigated before grains are stored in them.
The maize grains are used for different purpose. They are eaten fresh either roasted or boiled or fried when dry. The grains are also used to prepare pap and other human food. Maize grains form the bulk of livestock feeds.
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