Maize

Kingdom: Plantae

Order: Poales

Family: Poaceae

Subfamily: Panicoideae

Genus: Zea

Species: Z. maysa

ABOUT MAIZE

Maize (Zea mays L) is one of the most versatile emerging crops having wider adaptability under varied agro-climatic conditions. Globally, maize is known as queen of cereals because it has the highest genetic yield potential among the cereals. It is cultivated on nearly 150 m ha in about 160 countries having wider diversity of soil, climate, biodiversity and management practices that contributes 36 % (782 m t) in the global grain production. The United States of America (USA) is the largest producer of maize contributes nearly 35 % of the total production in the world and maize is the driver of the US economy. The USA has the highest productivity (> 9.6 t ha-1 ) which is double than the global average (4.92 t ha-1). Whereas, the average productivity in India is 2.43 t ha-1

In India, maize is the third most important food crops after rice and wheat. According to advance estimate its production is likely to be 22.23 M Tonnes (2012-13) mainly during Kharif season which covers 80% area. Maize in India, contributes nearly 9 % in the national food basket. In addition to staple food for human being and quality feed for animals, maize serves as a basic raw material as an ingredient to thousands of industrial products that includes starch, oil, protein, alcoholic beverages, food sweeteners, pharmaceutical, cosmetic, film, textile, gum, package and paper industries etc.

The maize is cultivated throughout the year in all states of the country for various purposes including grain, fodder, green cobs, sweet corn, baby corn, pop corn in peri-urban areas. The predominant maize growing states that contributes more than 80 % of the total maize production are Andhra Pradesh (20.9 %), Karnataka (16.5 %), Rajasthan (9.9 %), Maharashtra (9.1 %), Bihar (8.9 %), Uttar Pradesh (6.1 %), Madhya Pradesh (5.7 %), Himachal Pradesh (4.4 %). Apart from these states maize is also grown in Jammu and Kashmir and North-Eastern states. Hence, the maize has emerged as important crop in the non-traditional regions i.e. peninsular India as the state like Andhra Pradesh which ranks 5th in area (0.79 m ha) has recorded the highest production (4.14 m t) and productivity (5.26 t ha-1 ) in the country although the productivity in some of the districts of Andhra Pradesh is more or equal to the USA.

Maize can be grown successfully in variety of soils ranging from loamy sand to clay loam. However, soils with good organic matter content having high water holding capacity with neutral pH are considered good for higher productivity. Being a sensitive crop to moisture stress particularly excess soil moisture and salinity stresses; it is desirable to avoid low lying fields having poor drainage and also the field having higher salinity. Therefore, the fields having provision of proper drainage should be selected for cultivation of maize.

All India Coordinated Research Project (AICRP) on maize was launched in 1957 with the objective to develop and disseminate genetically superior cultivars and production/protection technologies. AICRP organizes interdisciplinary, interinstitutional, co-operative and systematic testing of newly developed cultivars of both public and private sectors for different agro-climatic zones of the country. The project resulted in refining efforts in varietal improvement. Since 1961, a total number of 187 cultivars including single cross hybrids, composites and multiple parent crosses have been released nationwide. In India, maize is traditionally grown in monsoon (Kharif) season, which is accompanied by high temperature (greater than 35° C) and rainfall. However, with the development of new cultivars and appropriate production technology, winter cultivation of maize has emerged as a viable alternative.

CLIMATE REQUIREMENT

Maize can be grown over a wide environmental range. It is essentially a crop of warm countries with adequate moisture. Bulk of the crop is grown in warmer parts of temperate regions and in humid subtropics. It is mainly grown from 50°N to 40°S and from sea level to 4000 m in Andes and Mexico. The lowest seasonal rainfall in maize area is 200 mm.

However, available evidence indicates that maize as purely rainfed crop may be risky in regions with mean annual rainfall of 400 mm and that even in areas receiving 600 mm rain, irrigation appears to be necessary for realising high yield. It cannot withstand frost at any stage of its growth. In India, its cultivation extends from the arid plains of Rajasthan and Gujarat to wet hills of Assam and West Bengal receiving over 4000 mm rainfall.

It can be successfully grown where the night temperature does not go below 15.6°C. The greatest intensity of maize cultivation is in the region bounded by the July isotherms of 20° and 20°C. In general, maize in temperate regions is what sorghum is in tropical areas.The latitude of maize growing in India ranges from 12° to 30°N. The range in altitude is from 49 m in Bihar to 1,250 m in Himachal Pradesh. Maximum temperature during June when maize is sown often exceed 40°C in some areas, while minimum temperature during winter is favourable for maize in several states like Bihar, Uttar Pradesh, south Rajasthan and Karnataka with moderate to low rainfall.Annual rainfall requirements vary from 513 mm at Arabhavi (Karnataka) to about 2,200 mm at Almora (Uttar Pradesh) and Kalimpong (West Bengal). Most of the rainfall is received between April and October at many locations.

SOIL

An average, good soil should contain nearly one-half mineral particles, one-fourth water, one-fourth air, and a few percent organic matter. The minerals supply and hold some nutriernt and give bulk to the soil. Water is necessary for plant growth and for the soil organisms, but not too much or too little. Air is needed by roots and beneficial soil organisms. Organic material is a storehouse of certain nutrients, holds water, gives soil a loose crumbly texture, reduces erosion, buffers and detoxifies soil, and even helps protect plants from diseases and pests because of antibiotics and inhibitors produced by beneficial bacteria and fungi. Some of these friendly microbes also produce plant growth stimulators, others help feed nutrients directly to roots, and others trap (fix) nitrogen from the air—free fertilizer.

BACTERIAL LEAF BIGHT/STRIPE

Disease Symptoms:

Water-soaked linear lesions on leaves as they emerge; lesions turn brown and may subsequently turn gray or white; lesions may have a red border; after the leaves are mature, lesions do not tend to extend any further; no new lesions tend to appear after tasseling; if corn variety is susceptible, mature leaves may shred after maturity.

BACTERIAL STALK ROT/SOFT ROOT

Disease Symptoms:

Plants suddenly beginning to lodge (bend to lie along the ground) midway through season; one or more internodes above soil line turning brown, water-soaked, soft and slimy; tissue has foul odor and mushy appearance;

GOSS BACTERIAL BLIGHT DISEASE

Disease Symptoms:

Gray or yellow stripes with irregular margins on leaf surfaces; stripes follow leaf veins and contain characteristic dark green to black water-soaked spots; if infection occurs early then plant may become wilted or withered; it is common to find a crystalline residue on leaves caused by dried bacterial exudate.