How to grow groundnuts

Groundnuts grow well in warm areas, below 1500 M above sea level. The best temperature requirement is about 30º C. They do not grow below 15º C. The crop does not tolerate frost and cold conditions including delay in flowering and seed formation.

For good growth, they also need 500 to 600 mm of rainfall, well-distributed throughout the growing season. The crop can survive drought or reduced rain but yields will be low. Well-drained soils are needed although the crop can also grow well in clay soils.

Land preparation and planting

Groundnut is an early season crop, which means that at the slightest sight of some rain, you need to plant. Plant when the soil is not soggy as the crop does not do well in waterlogged soils. To prevent blights caused by soil bacteria and fungi, ensure you use certified disease freeseeds. If you are using seed from the last season, ensure that the seeds for sowing are stored in their pods and only shelled a few days before planting. Shell the pods 1–2 weeks before sowing and select only good quality seed for sowing.

Plough the land and harrow to a fine tilth. Spacing depends on the variety. Small seeded types (bunch) are spaced at 30cm between rows and about 15 cm between plants. This has a plant population of 167,000 per hectare. The large seeded types (runner) are spaced at 45cm between rows and 20cm between plants, giving an optimum plant population of 89,000 per hectare. The seeds are planted in two rows on top of the ridge. Select clean and well formed seeds for planting. Sow seeds to a depth of 5-8 cm at a seed rate of 40-50kg per ha.

Use Biofix organic fertilizer when planting

Biofix is an organic nitrogen fixer for planting leguminous crops like beans, cowpeas, groundnuts and soya beans; leguminous pasture crops like Lucerne and desmodium; and leguminous trees like Sesbania and caliandra.

Being a natural product made out of nitrogen-fixing bacteria, Biofix is environmentally friendly and is not expensive to buy or apply. When applied to groundnut seeds, it helps in the formation of more root nodules (small growths on the roots). These nodules help the plant to convert nitrogen in the air into into utilizable form by the plant. Nitrogen helps in leaf development and plant growth. Ensure that when buying the Biofix inoculant, you buy the right one for the type of crop you want to grow– there is biofix for groundnuts, and different ones for other legumes.

The packet (which is available in 10g, 50g or 100g) should contain the inoculant and a sticker made of gum Arabic or sugar solution. During planting, one needs one packet of biofix (100g) for 15kg of seed, which is enough for a 1 acre farm. Follow the instructions given on the package.

Once the seeds are inoculated with biofix, crops can take up nitrogen much easier and faster, which results in more rapid growth and plentiful harvest. When using biofix ensure you plant when your soil is still moist.

Weeding

Groundnuts should be weeded promptly especially during the early stages of growth. Earthing up should be done at the time of weeding to encourage pegging, or penetration of young nuts into the soil. It is recommended that farmers use hand weeding after the start of pegging to avoid disturbing the growing nuts or damaging the flowers. Clean weeding should take place up to 6 weeks after which only hand weeding should be done.

The crop requires adequate amounts of Calcium when pods are forming, otherwise the farmer ends up with empty pods. Nitrogen fertilizers are not needed since groundnuts are leguminous plants. If soils are acidic, you can apply lime to raise the raise the pH and supply calcium. If there is no rain during flowering or pod formation, irrigate if possible to ensure the yields do not drop. For soils that are not fertile, Rock phosphate is recommended at a rate of 200kg/ha.

Dealing with pests and diseases

Like other crops, groundnuts are attacked by various pests and diseases. The table below shows how different pests and diseases can be controlled without using chemicals. The major pests and disease challenging groundnut growing are shown below:-

Harvesting and storage

Groundnuts mature from 90-130 days depending on the variety. Mature nuts should be firm and dry and brown on the outside. The inside of the pods should be grey and produce a rattling sound when shaken. To harvest, dig up nuts with great care to avoid them breaking off and remaining in the ground. Dry for 2-3 days, after which you can remove the nuts from the plants and dry them on mats for 7-10 days, to a moisture content of 10%. Shelling should be done by hand followed by sorting to remove the broken, dirty, damaged nuts which lower the quality and consequent selling price. Storage should be done in clean dry conditions to avoid growth of asperngillus spp which releases aflatoxin fungi that are poisonous to humans.