MAIZE PRODUCTION GUIDE

 

MAIZE PRODUCTION GUIDE

Soils and climate

 Maize grows best on deep, well-drained, fertile soils, and where total seasonal rainfall exceeds 500 mm. Maize is reasonably tolerant to soil acidity, but if the soil is very acidic, liming will improve the soil and enhance maize yields. Maize is susceptible to both drought and waterlogging. Thus, poorly drained soils should be avoided, unless practices like ridge tillage, drainage and early planting are employed. Drought during the four week period spanning flowering (silking and tasseling) can cause serious yield losses, and therefore some form of water conservation is important (eg, pot-holing, mulching, tied-ridges), especially in the drier areas.Temperatures above 38 degrees celcius affect yield by affaceting pollen viability while temperatures below 10 retards maize growth.

Fertilization 

The fertilizer requirements of maize depends on the soil fertility and yield target. Infertile soils require more fertilizer, as does a higher yield target. The two most important nutrients for maize are nitrogen and phosphorus, but maize also requires potassium and, on some soils, Zinc in small quantities. The first consideration for fertilizing maize is manure, for it is an excellent source of nutrients and has many other benefits for soils. Bought inorganic fertilizers should be considered as a supplement to manure.

Plant spacing 

The width of rows and the spacing of plants in the row determines the plant population. The closer the spacing, the more plants there will be per unit area. The recommended number of maize plants per hectare varies from 36,000 to 60,000, depending on the environmental yield potential and hybrid. High plant populations are appropriate for early-planted crops under high rainfall or irrigated conditions where management is of a good standard. Lower plant populations should be used under dryland conditions, especially in drought prone areas, where a population of about 37,000 to 40, 000 plants per hectare is recommended. Some varieties may be susceptible to lodging under high plant populations. Generally, the taller the variety, the lower should be the plant population. Short maize varieties may be grown at higher plant populations. Whatever the case, the minimum plant population for maize is 36,000 plants per ha

Planting date 

The later maize is planted, the lower the yield, as shown in the graph below. Highest yields are obtained with October plantings, but these can usually only be sustained with irrigation (ie irrigation to establish crop). However, planting in October may be feasible on vleis or when there is good early rain (over 50mm). November planting with the onset of the first rains is the safest under dryland conditions. In order to exploit these early rains, fields need to be ready before the rains (ie in October) and seed and fertilizer must be on hand, so that as soon as the first rains fall, fields may be planted. Planting in December will produce low yields, and is very risky, because the crop may suffer from drought stress at the end of the season, while pests (eg stalk borer) and diseases (maize streak virus and HT) are more prevalent on late planted crops. Under rainfed situations, after the second week of November a farmer is encouraged to dry plant anyway at a depth of about 5 cm to ensure the seed is not reached by light showers

Varietal choice

 The choice of variety depends on the yield potential, season length, anticipated disease problems and use. The Seed Co Product Manual gives descriptions and recommendations of all the Seed Co hybrids on the market. It is best to study that manual and determine which hybrid will be best for each situation.