Things to consider before starting onion farming

Transplanting

It’s always wise to do a soil test before planting to know the status of nutrients in the soil, which will guide you on nutrient application for onions production.

A serious farmer should prepare the land to a fine tilth and add well decomposed manure. Depending on the soil test, one can consider using DAP during planting and top-dress using CAN at week four. Frequent scouting for crop nutrition is paramount and mitigation measures should be taken immediately.

To prevent the transplanting shock, do the exercise early morning, late in evening or when the weather is cloudy.

It’s ideal to trim the shoot and root (3 inches for shoots and 0.5 inch for roots) before seedling placement to minimize moisture loss and seedling shock during and after transplanting.

The ideal spacing is 8-10cm between the seedlings and 15cm for inter row distance to allow better bulb development. Spacing is also determined by the variety planted and soil fertility.

Onion production can be done in the greenhouse and open field depending on the location with the latter being more preferred.

Rains or excess watering

Too much rains or excess watering can water log the crop. If the rain in your area is too much, focus on growing the crop during the short rains. You can also raise the beds to ensure the water flows out of the field. Avoid excessive watering of your onions. The best type of irrigation on onions is drip irrigation. Overhead irrigation should be avoided as it causes fungal diseases.

Pests and diseases

Common diseases that affect onions include Downy Mildew, Bacterial Soft Rots, Pink/White Root, Botrytis, and Rusts. Use herbicides to get rid of the diseases. Common pests that attack onions include maggots, thrips, onion flies, red spider mites, nematodes and the leaf miner. Use pesticides from accredited brands to get rid of the pests. Frequent scouting for pest and diseases is important for early detection, prevention and control.

Weeds

The land should be free of weeds, which compete for nutrients, light and space and harbour pest and diseases. Weeds should be removed occasionally either physically or through the use of herbicides. In one season, there should be at least 2 – 3 weeding sessions.

Harvesting

Once transplanting is done, one should prepare to harvest after 4-5 months depending on the variety. Top leaves will yellow and begin to fall over, an indication they are ready for harvesting, which should coincide with dry and hot weather.

Curing of the onions is done by uprooting every single stem and leaving it to dry after which leaves and roots are cut off with a sharp knife. A good harvest offers 20-25 tonnes per acre depending with the variety.