Seeds and seedlings

Aspects to consider when deciding what to plant

Environment

• Make sure the soil is suitable for the proposed crops. Take into account soil depth, texture, acidity and salinity.
• Study the rainfall and temperature pattern over the various seasons when deciding which crop can be grown successfully at different times of the year.

Planting dates

• Make sure of the correct planting dates of each crops and for each region.

Cultivar

• Ensure that the cultivar to be planted is adaptable to the prevailing conditions. Consider yield potential, tolerance to drought and acidity, length of growing season, disease and insect resistance, lodging, sprouting or prolificacy (multiple cobs) and intended use. However, in some instances, rotation of cultivars can be used to spread the risk of entire crop loss from infestation and to maintain a high biological diversity.

Note: The use of certified seed is highly recommended. Consult an expert, a seed merchant, or the local co-operative to obtain information on cultivars recommended for a specific area.

Seedbed preparation

• A plough or tined implement can be used for primary cultivation. Ploughing is, however, not recommended for sandy soils that are susceptible to erosion.
• Wind erosion is an important factor that should always be taken into account. In areas where wind is a problem, conservation tillage (zero or minimum cultivation and use of stubble or mulch) is recommended.
• The seedbed should be firm and weed free. In cases where wind erosion is a problem, the seedbed should not be too fine.

Planting spacing and depth

• Planting depth is determined by the moisture status of the soil, as well as clay fraction and the soil type.
• Generally bigger seeds can be planted deep and smaller seeds shallow.
• The spacing between plants is wider in low rainfall areas.

Planting method

• Most crops can be planted mechanically or by hand. In the latter case, a hand hoe or spade can be used.
• Do not compact the soil, but firm it down to ensure good soil/seed contact.

Fertilisation

• Make sure that the soil has sufficient nutrient content for crop growth by using fertiliser before planting and/or top dressing. Compost or organic matter (manure) should be applied three to four weeks before planting.
• Fertiliser can be applied when the results from soil analysis will tell you what nutrients are required in the soil, with the type of fertiliser to use recommended. To have soil analysed, contact the Department of Agriculture or ARC in your area, an extension officer, or one of the role players from the “Soils” page. The type of fertiliser best suited often depends on the expected yield and the previous crop (in the case of crop rotation).
• The optimum pH for most crops is 4,5 to 5,5 (KCI). Lime should be applied in the case of soils with a pH of below 4,5. Poultry manure also alleviates low pH problems.

Economy

• Before planting, note the inputs required and estimate the costs. Don’t look at the cost of individual products in isolation, but at the combination of them all. At times, you might need to invest more at the beginning of the season but will find you need to spend much less towards the end of the season.
• Consider product marketability before planting. Compare the input costs to the crop income.

Diseases and insect pests

• Crops belonging to the same family are often attacked by the same group of pests and diseases. Related crops should therefore not be included in successive plantings or even in the same three-year rotation programme (e.g. cowpeas, groundnuts, bambara groundnuts, soy beans).
• Pesticides should be used as recommended to prevent yield loss.
• Fields should be inspected on a regular basis to spot pests at an early stage, especially in the case of maize and cotton.
• Pesticides can be applied manually or mechanically.

Weeds

• A weed free environment during seedling emergence time is highly recommended because by the time the weeds germinate the crop will be well established and have a competitive advantage. Weeds can be controlled by hand, mechanically, or by the use of herbicides (especially when using conservation tillage), or a combination of the three methods.
• In the case of chemical control, particular attention must be given to herbicides’ residual periods, during which the remedy is active in the soil.If a system of crop rotation is followed, the herbicide applied may damage follow-up crops.
• Bear in mind that the clay fraction of the soil has an influence on the quality and quantity of the herbicide needed – refer to the product guidelines.

Remember: When using chemicals, you need to use protective clothing for your eyes, face and skin. You also need to ensure that all chemicals are stored separate from food, feed and seed and locked away from children. Remember too that it is important to read and follow instructions on labels.

Harvesting

• Most crops can be harvested mechanically or by hand. These methods can also be combined. If harvesting is done by hand, threshing can be either mechanical or by hand.
• Watch out for seed damage during harvesting (especially to legumes).

Gradual growth

• Do as much as possible in the first season. Spend as much as you can afford in the first season for inputs and increase expenditure in the second season (e.g. work on 1ha or less first and make enough money and gain enough experience to expand to 2ha or more in the second season).

Source: www.sansor.org – A Crop Guide for Emerging Farmers.