THE National Agricultural Research and Extension Institute (NAREI) is making significant strides in achieving its agriculture diversification agenda. The institute has been conducting trials to ascertain whether crops that are imported could be produced locally. This will essentially reduce the country’s food import bill.

One such crop is onion (Allium cepa). Onion is believed to have originated in the Near East. The crop can be grown under a wide range of climates from temperate to tropical. Present world production is about 46.7 million tons of bulbs from 2.7 million hectares.
NAREI through its partnership with Promotion of Regional Opportunities for Produce and Enterprises and Linkages (PROPEL) has reintroduced onions to Guyana. This time, the aim is to have onions produced for commercial purposes.
CEO of NAREI, Dr. Oudho Homenauth,, at a recent stakeholders meeting, announced that Guyana is likely to reduce the importation of onions by half by 2020. In 2015, Guyana imported US$1.4M worth in onions.

Already, farmers have shown an interest in the production of the crop. One hundred from 40 communities within Regions Two to Six and 10 were involved in trials. The varieties of onions that can be grown locally include Red Creole, Mercedes and Texas Early Grano. In addition, researchers of NAREI conducted trials at Mon Repos.
A farmer, Dexter Sultan, shared that he has seen the results of the onion cultivation in other fields. However, in his trial plot at Sandvoort, West Canje, Berbice, Region Six, some of his seedlings died while others plants were spoilt.

“When I went there to clear the area a few weeks ago I actually saw some of them, they bulb very well but not fit for human consumption due to not having consistent amounts of water,” Sultan explained.
Under normal conditions, onion forms a bulb in the first season of growth and flowers in the second season. The production of the bulb is controlled by day length and the critical day length varies from 11 to 16 hours depending on variety. The crop flourishes in mild climates without extremes in temperature and without excessive rainfall.

For the initial growth period, cool weather and adequate water are advantageous for proper crop establishment, whereas during ripening, warm, dry weather is beneficial for high yield of good quality. The optimum mean daily temperature varies between 15 and 20°C.
Proper crop variety selection is essential, particularly in relation to the day length requirements; for example, a long day temperate variety in tropical zones with short days will produce vegetative growth only without forming the bulb. The length of the growing period varies with climate but in general 130 to 175 days are required from sowing to harvest.

The crop is usually sown in the nursery and transplanted after 30 to 35 days. Direct seeding in the field is also practiced. The crop is usually planted in rows or on raised beds, with two or more rows in a bed, with a spacing of 0.3 to 0.5 x 0.05 to 0.1 m. Optimum soil temperature for germination is 15 to 25°C. For bulb production the plant should not flower since flowering adversely affects yields. Bulbs are harvested when the tops fall: For initiation of flowering, low temperatures (lower than 14 to 16°C) and low humidity are required. Flowering is, however, little affected by day length.

Onion can be grown on many soils but medium textured soils are preferred. Optimum pH is in the range of six to seven. Fertiliser requirements are normally 60 to 100 kg/ha N, 25 to 45 kg/ha P and 45 to 80 kg/ha K.
The crop is sensitive to soil salinity and yield decrease at varying levels of ECe is: 0 percent at ECe 1.2 mmhos/cm, 10 percent at 1.8, 25 percent at 2.8, 50 percent at 4.3 and 100 percent at ECe 7.5 mmhos/cm.