Baby corn — a commercial vegetable

BABY corn, the newly developed corn, is used as a vegetable in many Asian countries. It is used as an ingredient in the preparation of many food items. Its nutritive value is similar to those of non-leguminous vegetables such as cauliflower, tomato, cucumber and cabbage.

Fresh baby corn has a crisp texture and a subtle, slightly sweet corn flavour. It has a great potential for cooking and for processing as canned product. Baby corn, in fact, is the immature ear of fully grown standard cultivars of either sweet corn or field corn.

The residual stalk and leaves of baby corn can be used as forage, livestock feed and in making silage. It is used as main source of calories in fodder and feed formulation. The corn gives the highest conversion of dry substance to meat, milk and eggs as compared to other cereals.

Baby corn is a money-making crop and farmers can boost their income in a short period by cultivating this crop. To achieve the objective, they are required to be equipped with the cultivation technology of this crop.

Production of this vegetable is an intensive task. It can be grown either as a primary crop (all ears are harvested for baby corn) or as a secondary crop (the top ear is left to mature for sweet corn or field corn while subsequent ears are harvested as baby corn). The decision whether to grow baby corn either as a primary crop or as a secondary crop will influence variety choice, planting density, and fertiliser rates. New baby corn growers can adopt secondary crop system to avoid market risks.

The first system is based on producing baby corn without dent corn production with comparatively close plant spacing. In this system the plant population should be kept 1,10,000 to 1,50,000 plants per hectare which is much higher than that of dent corn.

For commercial production the variety should have certain additional attributes. In baby corn ideal plant should bear at least three cobs with good quality, proper size and shape. Dent corn cultivars can be used for baby corn production.

Synchronisation in cob emergence reduces the cost of harvesting and storage. Therefore, for commercial cultivation of baby corn, the variety should preferably be a single cross hybrid. In addition, the ear quality should be the primary objective when selecting a variety than yield. Small kernel size, straight row kernel alignment and tapered tips are preferred characteristics for high quality baby corn. There is no taste advantage in growing a sweet corn variety over dent corn, since the ears are harvested before sugars have the opportunity to accumulate.

Another factor to be considered in variety selection is the ease in which the ears can be pulled from the stalk. Cultivars producing plants about six feet in height are generally the easiest to hand harvest.

The best soil for growing baby corn is well-drained with a texture of silt loam or loam type. It should have efficient moisture holding capacity and high amount of organic matter. The optimum pH range of soil for better corn growth is between 5.8 and 7.0. It requires a temperature of more than 10 ºC to flower. In case of moisture deficiency irrigation is necessary.

A seedbed which is deep, well pulverised yet fairly compact is excellent for growing baby corn. The soil with optimum moisture after rainfall or irrigation should be loosened 20-25 cm deep by ploughing or disking 2-3 times.

Baby corn could be sown here mainly in two seasons — spring and autumn. Spring corn can be planted between the first week of February and first week of March, while sowing time for the autumn crop starts from the last week of July and ends by mid of August. Seed rate for corn is 20-25 kg per hectare. It should be dressed with some systemic insecticide and fungicide, and should be sown at a distance of 45cm (R×R) and 20 (P×P), which may vary according to the variety under cultivation.

Fertiliser rate for baby corn is in the ratio of 150 to 100 to 100 kg nitrogen, phosphorous and potassium per hectare respectively. All phosphorus and potassium fertilisers while half dose of nitrogen fertiliser should be side dressed with sown seed rows and the remaining half N is added in two splits, first when the crop is knee high and second at tasseling. At tasseling plants should be detasselled because it is a prerequisite for good corn yield and leads not only to increase in number of cobs per plant but better cob development by avoiding the stage of fertilisation.

Weeds can cause up to 40 per cent losses therefore, it should be controlled by cultural and chemical means. Irrigation is necessary for growing baby corn where the seasonal precipitation from May through September is about 4–6 acre inches. Seasonal water requirement for corn is 12–14 inches. Due to low temperature during the spring season crop (February sown), comparatively less water is required. However, water stress must be avoided.

Corn earworm is one of the most destructive insects but as it generally attacks the plant after silking, it may be less of a problem in baby corn. Other insect pests that can cause damage include corn borers, armyworms, beetles and flea beetles. Growers producing baby corn as primary crop can avoid these problems as the crop is harvested early. Potential disease problems include wilt, leaf blights, rust and viruses.

Baby corn is hand-harvested one to two days after silk emergence, while the ears are still immature. The ideal ear size is two to four inches long and 1/3 to 2/3 inches in diameter. Because ears can quickly become too large and tough to be sold as baby corn, frequent harvest after every two to three days is necessary. Young cobs should be picked in the morning. The harvest period can last two to four weeks.

By the best production practices, a hybrid variety of baby corn can give 6-8 tones per hectare of husked cobs with 15-20 per cent recovery of de-husked tender cobs. Besides cob yield, 25-35 tones per hectare of green plant yield can also be obtained which can be used as fodder and green manuring and may result in good profit to farmers.

By Muhammad Amjad Ali and Shahid Iqbal Awan