GROWING BEETROOTS

By PENJANI NZIMA

BEETROOTS is a root vegetable that is not frequently grown by many small-scale farmers here in Zambia due to probably lack of knowledge about this crop or just maybe lack of interest in producing this kind of vegetable.

This root vegetable can be sold in its fresh form at an open market such as our famous Soweto market here in Lusaka or it can also be processed and bottled by commercial companies that have the machinery to enable value addition.

In the May edition we started looking at how farmers can venture into Beetroots production and in this edition we endeavor to continue on the same.

This edition will delve much deeper details of Beetroot production and cover the issues of fertilization, Irrigation requirements, weed control, harvesting, grading and marketing, postharvest and storage of the Beetroot.

According to information found on Starke Ayres website www.starkeayres.co.zm and obtained by this reporter in a production material known as BEETROOT PRODUCTION GUIDELINE.    

FERTILIZATION

SOIL ACIDITY AND LIMING

A soil pH range of 6.0-6.8 is adequate for beets.

FERTILIZATION GUIDELINE

It is important not to give too few or too many plant nutrients, therefore the soil must first be analyzed so that the plants will not be burned, or show poor growth.

NITROGEN

On sandy soils, apply between 110 kg – 200 kg N/ha. Broadcast 50% of the N should be applied prior planting and incorporated. The remainder of the nitrogen should be applied as a side-dressing 10, 20, 30 and 40 days after sowing. On heavy soils, apply between 40 kg 60kg N/ha.

PHOSPHORUS

No limit is normally set for the safe rate at which phosphates may be applied, however, a rate of 50 – 100kg P/ha will cover any possible shortfall.

POTASSIUM

Potassium fertilizer should be added based on a reliable soil test as it can cause plant injury if applied at an incorrect rate. Beetroot in general require a total of 150kg K/ha applied over an 8-week period.

BORON

Boron deficiency shows up as a breakdown and corky, dark discoloration of internal and external tissues. Foliar sprays have generally given faster and more effective results. Spray when the young plants are about 8 cm high.

IRRIGATION REQUIREMENTS

As with most vegetable crops it is very important to keep the soil moist until the plants emerge. In the case of very hot weather, a layer of mulch can be used to prevent the soil drying out too rapidly. Beetroot has shallow roots, with an effective depth of 300mm, and it is important to water the plants regularly and frequently.  As a guideline 300-350 mm of water is required throughout the growing cycle, an average of 4mm per day. This is dependent on the season, the varieties water requirements and soil type.

OTHER CULTIVATION PRACTICES

WEED CONTROL

Weeds compete with beetroot for space, light, water and nutritional resources in the soil, particularly during the early part of the season. They can reduce yield if left unchecked. Regular cultivating prevents weeds competing with beetroot. Applications of weed-killers (herbicides) provide control in larger-scale and commercial plantings. Perennial weeds should be eliminated prior to planting beets.

HARVESTING

Beetroot is normally ready for harvest between 75 and 90 days in summer and 100 and 120 days in winter. Due to the variable nature of beetroot and uneven spacing from multi-germ seed, harvesting generally occurs in stages. The first harvest is a thinning out process where beetroot sized between 3.0 and 4.0 cms in diameter. The majority of the beetroot can be harvested when it attains a width of 7.5cm. This can be done manually or mechanically using modified potato harvesters. The harvested yield will vary significantly as a result of climate, fertilization, disease infestation and variety planted, but average yields range between 15 and 25 tons per hectare. Some growers can achieve yields of 40 – 45 tons.

MARKETING

The large segment is the bunching market where beet, usually harvested by hand to ensure tops do not get damaged, is sold as a bunch of 4 -5 roots with the tops still attached. The quality of the tops is indicative of the freshness of the roots.

POSTHARVEST

Beetroot quality indices are based on root shape, root size, uniform and intensive colour (with minimum zoning), firmness, smoothness, cleanness, trimming of rootlets and freedom from defects. Beetroot can be stored quite successfully under certain conditions. Prior to storage, beets should be topped and sorted to remove all diseased or mechanically damaged roots. Large roots store better than smaller ones, as they shrivel relatively slower.

STORAGE

Bunched beets should be pre-cooled to below 4°C within 4 6 hours after harvest. They can be kept for around 10 – 14 days at 98% relative humidity (R.H.). Mature beetroot should be pre-cooled within 24 hours of harvest to below 5 °C. These should be topped and may be stored at 1 2 °C, at 98% R.H. for 4 6 months. Freezing injury occurs from -0.5 °C.

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