Maize had been cultivated for grain and fodder purpose. It is used both as food for human and feed for livestock especially in poultry industries. It is the third most important cereal crop next to rice and wheat in India and also a predominant cereal in global agricultural economy. It has got immense yield potential and is therefore called as “miracle crop” and also “queen of cereals”. Maize being a C4 plant is an efficient convertor of nutrients into food.
In the recent years, baby corn maize has gained popularity as valued vegetable throughout the world including in India. Cobs removed within 3-5 days after their emergence are called baby corns. Cultivation practices of baby corn are similar to that recommended for normal corn production with only exception is the duration of the crop, which is approximate 60 days as compared as 110-120 days in case of grain crop. It can be eaten raw and included in diet in number of ways as salad, chutney, vegetables, pickles, kheer, Chinese preparation, in preparation of spicy foods, soups, pulav etc. Baby corn ears can be canned in two per cent brine solution. Pickles and canned baby corn ears have great potential for export in the western markets round the year.
Yield of grain maize is very low in the north-eastern hilly states though cultivation of grain maize in hill slopes is popular among hill tribes. Therefore production of baby corn maize instead of grain maize might be an important agronomic practice for increasing income among the hilly people of the north-east India. To popularize baby corn among hilly people, it is important to disseminate the know how of baby corn cultivation practices. India has emerged as one of the potential baby corn producing country because of the low cost of production as compared to many other countries.
Nutritional fact of baby corn
Nutritive value of baby corn is comparable with several high priced vegetables. It is rich in phosphorus (197.89 mg/100 g) in comparison to 21-57mg/ 100 g phosphorus content in other common vegetables. It is an attractive low calorie vegetable, high in fibre and without colestrol.
Climate and soil
Suitable soil for baby corn has a wide pH range, from 5.5-7.0. It can also grow in high acid soil, but cannot grow in wet land with poor drainage. As for temperature the plant prefers full sunlight necessary to its growth. Consequently, successful growth requires a minimum average temperature of 72 to 750 F. moreover, when daytime temperature exceeds 850 F, baby corn may be injured, and have to suffer slow growth.
Varieties suitable for baby corn production in North-East India
Short duration, prolific, single cross hybrid with medium height should be selected. A few varieties suitable for baby corn production are as follows: Vivek Maize Hybrid 23, Vivek Maize Hybrid 25, HM-4, Hybrid maize 5, Pusa Extra Early Hybrid maize 5, HIM 129, Prakash, DHM 109, VL Makka 42, MTH-14, RCM 1-1, RCM 1-3, Golden baby and MLY.
Plough the field with disc plough once followed by cultivator ploughing twice, after spreading FYM or compost till a fine tilth is obtained, which facilitate the sowing and provide the aeration, better seed-soil contact to improve the germination and further growth.
Crop can be grown from January to September depending upon the moisture availability in the field. However, baby corn sowing during second week of May followed by third week of April produced the highest yield particularly in hilly region of India.
Seed rate and spacing
A population of 100000-110000 sufficient for better yield of baby corn, for this quality seed should be selected and used @ 18-20 kg/ha, with an spacing of 15cm between plant to plant and 45 cm from row to row depending upon plant type.
Seed should be treated with fungicides and insecticides before sowing to protect it from seed and soil borne diseases and some insect-pests. Bavistin + Captan in 1:1 ratio @ 2g/kg seed for leaf and sheath blight, Metalaxyl or Thiram @ 2g/kg of seed for the control of downy mildew and crazy top or with carbendazim (Bavistin) @ 3g per kg seed against seed rot and seedling bligh, and Fipronil @ 4ml/kg seed for termite and shoot fly. Seeds treated with fungicides/insecticides may be treated with 3 packets of Azospirillum before sowing helps in increasing yield and quality of produce.
Method of sowing
Seed sowing is done by ridge and furrow method, generally sowing is done on southern side of the ridge by Dibbling at a depth of 4cm along the furrow in which fertilizers are placed. Seeds should be covered properly with soil. Per hole no. of seeds should be one or two.
Thinning and gap filling
If two seeds were sown, leave only one healthy and vigorous seedling per hole and remove the other after 12-15 days of sowing. Where seedlings have not germinated, dibble presoaked seeds at the rate of 2 seeds per hole and immediately irrigate.
Spread 12.5 -15 t/ha well rotten FYM or compost fifteen days before sowing and mixed well in soil. Application of inorganic fertilizers along with compost/FYM gives better results than the use of fertilizers alone. To get better response of nitrogen it is advice to apply nitrogen @ 60-80 kg/ha in four splits (25% as basal, 25% at 25days after sowing, 25% before detasseling and remaining 25% after detasseling of the crop).
Under low availability of soil phosphorus as in NEH region (mainly in acidic soils), application of 30 kg P2O5 ha-1result in an excellent crop. Basal placement of phosphorus in rows about 5-8 cm below from seed in the soil gives the best results, as it is less mobile and it does not get lost through leaching. Thus it remains available to the plants till they need it.
Potassium is essential for translocation of water and photosynthates, the crop may be fertilized with 20 kg K2O ha-1 for remunerative return. Application of half of potassium along with phosphorus as basal and the rest at 25 days after sowing along with 25% nitrogen produced higher baby corn yield as compared to the 100% potassium applied as basal dose.
In zinc deficient plants chlorotic spots are seen at the base of the leaves become white, symptoms called ‘white bud of maize’, it is advisable to apply 10-20 kg zinc sulphate ha-1 before sowing. The deficiency of zinc in plants at later stages of growth, however, corrected by foliar application of zinc sulphate (5% ZnSO4+ 2.5 % hydrated lime) dissolve in water.
When long dry spells occur at the tasseling to silking stage of the crop then crop may be irrigated by stored water harvesting practices for better baby corn production. Young seedlings, knee height stage, tasseling and silking are for the most sensitive stages for water stress for crops and irrigation should be ensured at these stages. Excess water and water stress is equally or even more harmful as the crop cannot tolerate stagnant water and is very sensitive to water logging. Water stagnation in baby corn fields for continuous three days almost spoils the whole crop. Therefore an efficient drainage is of greater significance than the irrigation particularly in NEH region.
Two manual weeding would be sufficient for weed management in baby corn. While mechanical weeding is good for soil aeration and root respiration. But continuous rain during kharif season pose serious problem in which the soil becomes wet and any agricultural operation cannot be done, under such situation Atrazine or Simazine either of these herbicides may be applied immediately after sowing of the crop. The rate of application varies from 1.0 to 1.25 kg a.i. ha-1 in light soils and 1.25 to 1.50 kg ha-1 of a.i. per hectare in heavy soils with 500-600 litre of water. Herbicide application should be done only when soil having sufficient soil moisture, a field should not be disturbed for initial 3-4 days.
Baby corn is very remunerative, if it is grown with intercrop. There is no any adverse affect of intercrop on baby corn and vice-versa, rather some of intercrop help in improving soil fertility. In general, short duration varieties of intercrops are preferred for intercropping with baby corn. Recommended dose of fertilizers of intercrops should be applied in addition to the recommended dose of fertilizers of baby corn. Crops like potato, garden pea, palak, sugarbeet, radish, carrot, turnip, lettuce, onion, garlic, methi, coriander, broccoli, gladiolus, knoll-khol etc. are best suited intercrops with baby corn.
Apply bleaching powder to prevent the attack of mole cricket to optimize the plant population per hectare. Apply phorate 10 G @ 40 kg ha-1 at the time of sowing or spray neem seed kernel extract 5% or neemazal 1% as a precautionary measure when the crop is 20-25 days old. Stem borer, pink borer and shoot fly are serious pest of corn. It can be controlled by spraying of carbaryl @ 500-750g/ha in 500-700 litre water in the central whorl of plant.
Baby corn is an immature part of the female flower, removing the male flower (tassel) is essential to maintain the quality of baby corn. Remove the tassel of the plant as soon as it emerges from the flag leaf prior to pollen grains shedding in the plant to avoid pollination. The removed tassel should not be thrown in the field as it is nutrient rich and should be fed to the cattle.
Harvesting of cob
Small cobs are to be harvested at 3-5 days after their emergence without damaging the plant. Harvesting should be done when baby corn silk comes out 2-3cm from the top of ears. In special varieties meant for baby corn like VL Makka 42, Golden Baby and early composite first cob will be ready for harvest at about 47 to 50 days after sowing. After 8 or 10 days of first harvest, second and third cobs will be ready for harvesting. The cobs are 8-10 cm long with golden yellow colour.
When crop is grown with improved agronomic practices then crop produce tender cob (baby corn with husk) about 5550- 6660 kg ha-1 and 32 – 35 tones green fodder ha-1.
Marketing and processing
Baby corn can be marketed as fresh husked/ de-husked young cobs, canned products and pickles. It can be processed to improve its self life. Main processing methods which can be used to improve the self life are: Canning, Dehydration and Freezing. Baby corn can be canned in a solution of brine (3%), sugar (2%) and citric acid (0.4%) and can be stored for months together and transport to far off places. Baby corn candy and pickle are in great demand in USA and some European countries, India could be an important country for export of baby corn in future.
Constraints in baby corn production
Despite of its better economic return and increasing demand in international market, the cultivation for baby corn has not become popular in India due to:
i) Less availability of quality seed
ii) Lack of processing facility iii) Lack of marketing facility in rural areas.
Technology regarding cultivation and uses of baby corn are available, therefore its awareness among farmers should be provided through training programs, demonstrations etc.
DINESH SAH1 AND VISHRAM RAM2
1. Assistant Professor, Agronomy and Meteorology, College of Horticulture and Forestry, CAU, Pasighat
2. Asssociate Professor, Agronomy, College of Post Graduate Studies,CAU, Barapani, Meghalaya