Imtisenla Walling, Technical Officer
GKMS, ICAR Nagaland Centre
Cereals are the major source of energy and nutrition for larger part of the population and are consumed in different forms. Among cereals, wheat, rice and maize are major sources of food and feed across the world and contribute around 17%, 23% and 9% of the world calorie respectively.
Maize (Zea mays or corn) belong to the tribe Maydeae of family gramineae, is the principal cereal crop in tropical and sub tropical regions throughout the world. It is considered a promising option for diversifying agriculture in various agro climatic zones. It is one of the most versatile emerging crops having wider adaptability under varied agro – climatic conditions and has got immense yield potential and is therefore called as “miracle crop” and also “queen of cereals”. Virtually every part of maize has economic value as grains and are used for human food, fermented to produce a wide range of food and beverages, fed to livestock and industrial uses in the production of starch, oil, sugar, cellulose and ethanol and contributes to food security in most of the developing countries.
Maize is deficient in lysine. To improve lysine content, high lysine mutants called opaque-2 were generated and used in the development of Quality Protein Maize (QPM). QPM have high nutritional quality, high yields, appearance of normal maize, greater hardness than opaque-2, equal or superior pest and disease resistance. Genes for high lysine content in QPM lines have been identified and used as molecular markers in breeding.
In Nagaland, maize occupies the second place among the cereals after rice and is grown in all the districts but maximum production is from Tuensang, Zunheboto, Phek, Kiphire and Dimapur.
It is primarily grown under Jhum land and terraced area. Jhuming is a common practice followed by the farmers of Nagaland, especially in the high altitude areas. In order to get higher production and sustainable farming, multiple cropping systems has been adopted, where 20 to 40 or more items of crops are grown on the same plot of land as intercropping with paddy as the main crop. There, maize, vegetable and other crops are grown along with colocasia, ginger etc. It is also one of the key agricultural products of Nagaland under cereal crops. Different species of maize exist and consist of different colors, textures, grains, shapes and sizes. It is prepared and consumed in a multitude of ways.
Maize is a warm weather crop and is best adapted to intermediate climates to which bulk of its cultivation is confined. Moderate temperature with plentiful supply of water is most favourable. Maize can only be produced in areas that do not have extreme cold temperature, as it is a cold -intolerant crop.
It is classified as day neutral or short day requiring plant. Maize being a photo-insensitive crop has better options for adaptation and mitigation of climatic changes.
• It is a heat loving crop.
• Minimum temperature for germination is 100C and the optimum is 30 to 350C under adequate moisture (Chang, 1981). Optimum temperature for growth is around 340C.
• Temperature above 320C at reproductive phase reduces the grain yield.
• High temperature above 350C coupled with low humidity is more injurious to plants at tasseling stage.
• Improved cultivars (hybrids and composites) are mostly day neutral and can be grown throughout the year provided temperature and moisture are not limiting.
• Frost can damage maize at all growth stages and a frost free period of 120 to 140 days is required to prevent damage.
• Maize crop has high water requirement. Depending on the duration, it requires 500 to 600 mm rainfall during the season. It requires adequate moisture and warmth from sowing to end of flowering.
• It is resistant to drought and can recover from early season drought as it requires less soil moisture during the early phase of crop growth.
• Crop needs more than 50% of its total water requirements in about 30 to 35 days after tasseling and inadequate soil moisture at grain filling stage results in a poor yield of shriveled grains
• Rainfall during 3-5 weeks before silking and from silking to 3 weeks afterwards is important.
• In rainfed conditions its yield varies from 1.1 to 3.5 t grains per ha; with irrigation in kharif season its yield can be 5t/ha. In moderate to high temperature state its yield varies from 3.5 to 5 t per ha during rabi/summer.
• Water logging is hazardous for the crop at any growth stage.
• No other crop utilizes sunlight more effectively than maize, and its yield per ha is the highest of all grain crops. It needs bright sunny days for an accelerated photosynthetic activity and rapid growth of plants but this has to be associated with an abundant water supply failing which the crop will start wilting or withering.
• Prolonged cloudy period is harmful for the crop but an intermittent sunlight and cloud or rain is the most ideal for its growth.
As maize has wide adaptability and compatibility under diverse soil and climatic conditions hence it is cultivated in sequence with different crops under various agro-ecologies of the country. It is considered as one of the potential driver of crop diversification under different situation. Therefore, in view of the changing farming scenario in the country, maize has been emerging as one of the potential crops that addresses several issues like food and nutritional security, climate change, water scarcity, farming systems, bio-fuel etc
Knowledge of agro-meteorology on the impact of weather and climate on crops will greatly help to devise appropriate crop production strategies for taking advantage of favourable weather conditions and avoiding risk due to their hazards for realizing optimum and sustainable agricultural production.