After planting of maize has been properly done, there are other farm operations that are required for a good output such as fertilizer application, weeding and harvesting.
Fertilizer application in maize farm depends on the demands of the variety as well as the conditions in the area of cultivation. Organic manure where available can be applied with low cost of buying and spreading. The introduction of inorganic fertilizers (with N, P and K mineral elements) is useful in order to produce higher yields and to avoid depleting the soil. It is recommended to combine it with organic manure to promote effective growth.
When preparing the soil, introduce 20 to 50 tonnes per hectare of well decomposed organic manure which could be compost, farm manure or other animal waste while working the field. In regions without livestock, plough in the remains of the previous harvest or the products from the fallow period; maize responds very well to organic manure. Inorganic Fertilizer can also be used at a ratio of 100 kg to 250 kg per hectare of type N P K S Mg 15-15-15-6-1, or a complete fertilizer of NPK 20.10.10.
- Begin thinning out when three to four leaves appear, around 15 days after germination. Remove surplus and weaker plants in order to obtain consistent density (one to two plants per seed hole, after thinning).
- Regular thinning is required to produce a good yield. It can be done manually or chemically, using a selective herbicide.
- Remove any weeds, especially during the vegetative phase of cultivation. Two to three hoeing sessions will be required: the first during thinning; the second when applying the urea; and the third just before the harvest. In a commercial maize farm, it is advisable to apply a pre-emergence herbicide such as Primagram Gold 660 SC (S-metolachlor 290 g/l + atrazine 370 g/l) just after sowing and before the emergence of the maize seedlings, calculating 3 l/ha. While the maize plants are developing, treat with Roundup (Glyphmosate 360 g/l), using 1 l/ha. Take care to preserve the leaf structure of the crop when using Roundup; it is non-selective and kills any kind of plant.
The first session of hoeing and banking up should take place 15 to 30 days after emergence, followed by light earthing up, because there is severe competition with weeds during this period. Repeat earthing up forty-five days after the first session.
In addition, Research Department of IITA in collaboration with Agriculture Research Service of the United State have discovered an alternative means by which farmers can produce maize free of Aflatoxin by introducing a bio-control product known as Aflasafe. 1kg/ha of Aflasafe is required in maize farm and it could be applied between 35 and 40 days after planting but before the second session of hoeing.
This can be done in two ways:
Harvesting by hands: Traditionally, when red maize cobs have dried down, the cobs are handpicked, hand shelled and dried in the sun. This is very labour intensive, which has a significant impact on the gross margin for maize. Another option is to machine harvest when moisture levels drop below 18% to
24% and then dry down to below 14% for delivery or storage.
Harvesting by machine: There are three methods of harvesting maize by machine, with the first option being the most preferable:
- The harvester picks and threshes the cobs, and the kernels are emptied into the truck
- The harvester picks the cob from the stem and de-husks the cob, which is then sent to the truck
- The machine cuts the stems, cobs and all, which are then emptied into the truck. Cobs have to be manually removed from the stalk later and threshed.
The following factors need to be considered for machine harvesting:
- plants and cobs need to be at similar heights across the field
- the stem must not be too dry or too green
- the fruit needs to be big enough for harvesting and threshing
- the plants need to have strong roots and erect stems.
Hoopen M.E and Maïga A. 2012): Maize production and processing. Pro-Agro collection. pp 9-19
Ministry of Agriculture, Animal Industry and Fisheries National Agricultural Research Organization
Oluwaranti A., Fakorede M.A.B, Menkir A. and Badu-Apraku B. (2015): Climatic conditions requirements of maize germplasm for flowering in the rainforest Agro-ecology of Nigeria. Journal of Plant Breeding and Crop Science. Vol 7 (6) pp 170-176
Tenebe V.A. and Petu-Ibikunle. A.M: Arable crop production. School of Science and Technology. National Open University