How to grow a large and healthy capsicum crop succeessfully

Capsicums or pilipili hoho are a hardy plant. All they require is a slightly warmer temperatures than tomatoes or cucumbers.

It is rarely attacked by diseases or pests though it still needs proper preventive care. Plants are retarded by cool weather as they tend to harden and seldom regain the vigorous growth necessary for high yields. In cold weather, the fruit remains small, hard and malformed because of uneven pollination. The fruit may also have numerous growth cracks.

Varieties

Most commercial varieties are hybrids. These varieties have a primary mature colour that is usually green, but may be yellow. They also have a secondary mature colour that is usually red, but may be orange or yellow or other colours. Fruit picked at this stage is much sweeter than green fruit and has more pro-vitamin A. There are also black, cream, and brown and lime coloured varieties.

New varieties are always being introduced, so check with your local seed supplier or nearest agricultural extension officer.

These varieties may be more resistant to disease, produce higher yields of fruit, produce more uniform fruit or be more suited to the latest market requirements for quality. Before planting new varieties on a large scale, compare them in small plantings to existing varieties under the same growing conditions.

Crop establishment

Planting starts from the nursery. You can make sunken or raised nurseries although most farmers prefer sunken nurseries because they retain water more than raised nurseries. Add small amounts of animal/compost manure this will ensure strong and healthy seedlings.

Ensure the distance between the rows is about 1.5 inches to give room for easy management.

After sowing the seeds, it will take about two to three weeks for them to germinate. Capsicums seedlings will be ready for transplanting within sixweeks.

Transplanting

Unprotected crops make slow early growth and harvesting is often delayed. Low plastic tunnels or cloches aid the production of early crops. Harden the capsicum seedlings by reducing frequency of watering gradually one week before transplanting, don’t do it abruptly. On the day of transplanting, wet the nursery enough to allow easy uprooting of the seedling from the nursery without damaging the roots.

Planting on the farm field is done by pressing the seedling down with your index finger deep enough – roughly one inch. The choice of spacing would depend on irrigation layout and need to access for fertiliser application, boom spraying and harvesting. A good spacing between plants is 75cm (two rows per bed) by 40 cm which gives 30 000 plants per hectare. You may space plants in a double row with plants 40cm apart between the rows and 30cm apart within the rows, with row centres at 1.5m apart. Wide spacing allow picking over a long period, while close spacing will give high yields over a short period and better pollination in hot periods. Note that the just transplanted capsicums will lose the first two to three leaves, just like kid loosing milk teeth. So it should not worry you. Phosphate fertilisers can be applied before planting on certain soils.

The rate of phosphorus should be determined from soil test results. Trace elements and magnesium should also be applied. Discuss the best options for your situation with your local advisor.

Urea and potassium fertilisers are commonly applied to the soil or by fertigation through trickle irrigation or sprinklers.

Water requirements

Capsicums need uniform soil moisture conditions for high production. Dry periods may cause shedding of flowers and young fruits, and blossom end rot on the fruit. During hot weather, water crops in sandy soil twice daily.

Trickle irrigation is recommended when combined with black plastic mulch, this results in fewer weeds and a saving in water. It is also useful for capsicums under cloches to increase soil temperatures in cooler weather.

Capsicums need frequent monitoring to produce good yields and fruit quality. Spot spraying may be needed during certain seasons to control major pests such as aphids on the whole plant, grubs on the fruits and powdery mildew and bacterial spot on the leaves.

Caterpillars and aphids are the major pest problems.

Pests and disease

Capsicums may also be affected by soil-borne diseases such as Fusarium rot, stem canker, and root knot nematode.

Crop rotation is therefore recommended, with an interval of three years between capsicum crops. In unshaded areas, exposed fruit, especially at the red stage, may be unmarketable because it is sunburnt.

Hot weather, high nitrogen and low watering may increase losses from blossom-end rot which appears as sunken brown spots on the sides or end of the fruit. A deficiency of calcium is also associated with blossom end rot and growers may spray calcium nitrate to help minimise this.

- The writer is a expert/consultant on agricultural innovations and solutions