Maize: Planting Methods, Seed Treatment, Insect-Pest Management, and Intercropping

Maize is commonly known as corn. It is one of the world's leading crops and is a staple food in India. Maize is a versatile crop and is also referred to as the “Queen of Cereals." It belongs to the grass family (Gramineae or Poaceae) and is an annual plant.

It is an erect and tall plant that reaches up to a height of 3 meters. The stem of the plant generally acquires a thickness of 3 to 4 centimeters. The big, narrow leaves are positioned consecutively on opposite sides of the stem and have wavy borders. 

It is cultivated as a cereal grain and offers a wide range of varieties including flint, sweet, and flour. After rice and wheat, maize is India's third major food crop. Maize is cultivated primarily during the Kharif season and accounts for 80 % of the total area.

At present, maize provides approximately 9% of the food supply and more than INR 100 billion to agricultural GDP in India. In addition to this, it provides over 100 million job opportunities for people working in the fields as well as the agricultural and industrial sectors. In 2020–21, the overall maize output in India has been around 24.51 MMT, compared to a total annual demand of 25.2 MMT, including exports.  

Maize is used as a basic raw material in hundreds of industrial goods, such as oil, protein, food sweeteners, cosmetics, fodder, pharmaceuticals, packaging, paper industries, beverages, textile, etc. 

Varieties of Maize and Their Characteristics

1. Pod corn: Pod corn comprises long legumes, which enclose each kernel individually. It has leaves around each of its kernels. Pod corn is a wild variety of maize. 

2. Popcorn: Popcorns are amongst the most primitive of the maize races that have survived. The endosperm of this corn variety is exceedingly rigid and corneous and has just a little amount of soft starch. Popcorns are essential flints with little kernels. The kernels can be spherical or pointed. Some newly produced popcorn kernels have thick seed coats, but some primitive semi-popcorn kernels such as Argentine popcorns have thinner seed coatings. 

3. Dent Maize: Dent corn is mostly used as a feed for animals, but it is also utilized as a raw material in the industry and as a staple meal. It is still an essential human food and industrial commodity, with dry and wet milling industries incorporating it into a variety of specialized goods. White dent maize, on the other hand, commands a higher price in the dry milling business, where it is used for specific human food products due to its whiter starch.

Maize Producing Regions of India

Maize is grown throughout the year in many different varieties, which include fodder, popcorn, baby corn, green cobs, and sweet corn in peri-urban areas. Andhra Pradesh accounts for the highest maize yield which is 20.9 %, followed by Karnataka at 16.5 %, Rajasthan at 9.9 %, Maharashtra at 9.1 %, Bihar at 8.9 %, Uttar Pradesh at 6.1 %, Madhya Pradesh at 5.7 %, and Himachal Pradesh at 4.4 %.

These are some of the major maize-producing states and collectively account for 80 % of the total maize production in India. In addition, maize is cultivated in the north-eastern states and the state of Jammu and Kashmir. 

Soil Selection

Maize may be grown in a wide range of soil types, from loamy to sandy. However, soils with high organic matter content, high water retention, and a neutral pH, are deemed to be high yielding. Since this crop is vulnerable to water stress, notably to excessive soil wetness and salinity stress, it is advisable to avoid low-lying areas with poor drainage and fields with high salinity. Therefore, lands with adequate drainage should be chosen for maize growing.

Favorable Conditions

Maize can be planted in all four seasons—monsoon, post-monsoon, winter, and spring. To acquire a good yield during the Rabi and Kharif seasons, farmers need reliable and irrigated agricultural facilities. It is preferable to finish the sowing process 12–15 days prior to the beginning of the monsoon during the Kharif season. However, in rain-fed areas, sowing should be scheduled to coincide with the start of the monsoon.

Seed Treatment

Seed treatment with fungicides and insecticides before sowing is suggested to protect the maize crop against seed and major soil-borne diseases and insect/pests, as detailed below.

Sowing Methods

The key to getting the best plant stand, which is the main driver of crop output, is tillage and crop establishment. As crop establishment is a sequence of events comprising seeding, followed by germination, emergence, and final establishment, the method of planting is critical for enhanced crop establishment in a given growing environment. Maize seeds are directly sown using various tillage and establishment methods. 

Some of the methods that are used in planting maize are: Resource conservation technologies (RCTs), which encompass a variety of measures such as zero tillage, minimum tillage, surface seeding, and others, have recently become popular in maize-based cropping systems and are environmentally friendly and effective.

Discussed below are several possible seeding strategies for attaining a larger yield.

Raised-bed planting

During the winter and monsoon seasons, raised-bed planting is usually considered to be the ideal planting method for maize, in terms of abundant moisture, limited water availability, and rainfed circumstances.

Sowing should take place on the southern side of east-west ridges to ensure better germination. Raised-bed planting method can save 20–30% irrigation water while increasing production. Furthermore, in the event of transient excessive soil moisture or waterlogging caused by heavy rains, the furrows will operate as drainage channels, saving the crop from excessive moisture stress.

Permanent beds, where sowing can be accomplished in a single process without any preparatory tillage, are recommended for acquiring the full potential of bed planting technology. In excess soil moisture situations, permanent beds are more useful since the infiltration rate is substantially higher and the crop can be saved from temporary waterlogging harm.

Zero-till Planting

In a no-till setting, maize can be grown successfully without any initial tillage, resulting in lower cultivation costs, improved farm profitability, and efficient resource use. A substantial number of farmers in peninsular and eastern India have used the technology, particularly in rice–maize and maize–wheat systems.

The adoption of an adequate planter, along with a compatible furrow opener and seed metering system, is the key to the no-till technology's success. 

Conventional till flat planting

Flat planting can be done with seed-cum-fertilizer planters in high weed infestations where herbicidal and chemical weed management is economically unviable in no-till and also for rainfed areas where crop survival depends on conserved soil moisture.

Furrow Planting

During the spring season, evaporative losses of water from the soil under flat, along with raised-bed planting, are higher, and the crop suffers as an outcome of moisture stress. It is recommended to plant maize in furrows in such circumstances for optimum growth, seed set, and increased production.

Maize Sowing: Water Management

Since over 80 % of maize is grown during the monsoon season, particularly under rainfed circumstances, irrigation water management is seasonal. However, in regions where adequate irrigation facilities are available, irrigation should be implemented as or when the crop requires it, depending on the rainfall events and soil retaining capacity and first irrigation should be practiced very carefully so that water does not overflow on the ridges/beds.

Insect/Pest Management

Stem Borer (Chilo partellus)

The Stalk borer is the most common maize pest in India. Chilo partellus, often known as the stalk borer, is an insect threat all across the country during the monsoon season. Stem borer lays its eggs on the lower half of the leaves 10–25 days after germination. The Stem Borer larvae penetrate the leaves and cause harm to them. 

Prevention and Management of Stem Borer

About 10 days after germination, 8 Trichocards (Trichogramma chilonis) per hectare can be released to control the stem borer. Intercropping maize with suitable cowpea cultivars is an environmentally beneficial way of reducing the occurrence of stem borer on maize. 

Shoot Fly (Atherigona sp.)

It is a major pest in South India, but it also arises in the springtime and summertime maize crops in North India. It primarily attacks the crop at the seedling stage. The tiny maggots burrow beneath the leaf sheaths until they reach the seedlings' base. They then cut the growing tip or center branch, resulting in the dead heart of the plant. 

Prevention and Management of Shoot Fly

To prevent the infestation of shoot fly, farmers are advised to complete the sowing before the first of February. Along with timely sowing, farmers can treat the seeds with Imidacloprid at 6 ml per kg. 

Termites (Odontotermes obesus)

Termites are also a major pest issue in many regions. Termites are prone to attacking the maize plants during their entire life cycle. They can cause damage to the crop even after storage. Usually, the plants are entirely destroyed after termite infestation which makes their control and management more important.

Prevention and Management of Termites

For control and prevention of termite infestations, fipronil should be incorporated in the fields along with light irrigation. 

Intercropping in Maize

Intercropping allows for the simultaneous planting of two or more crops on the same piece of land, resulting in increased productivity per unit area. Maize is planted in wide rows, hence giving scope for intercropping. The selection of crops, their maturity, intensity, and sowing time—all have a part in the effectiveness of the maize intercropping system. The advantages of a maize intercropping system include higher yield, better resource usage, weed, insect, and disease management. It also helps in the nitrogen fixation of the soil. 

Crop Selection

Intercropping requires careful crop selection, Due to intense competition, mixed cultures may not be advantageous for the crop and may even be potentially dangerous if the wrong plant species are used. If the available resources are utilized carefully, it can result in a reduction in plant competition. The intercropping of cereal with legumes is thought to be the optimum choice. Legume species such as black gram, cowpea, groundnut, and green gram have less of an impact on maize and are more tolerant. 

Crop Maturity

Another crucial factor to consider while intercropping is crop maturity. Crops produced in intercropping should, in general, have different peak periods of growth, otherwise, crop species will compete for available resources. When the individual species in the cropping system have separate growing periods for large demands on available resources, the complementary impacts benefit the system and are represented in yield advantage. 

For instance, in an intercropping system of maize and green gram, maize grows slowly at first, reaching knee height after 6–7 weeks.

Peak light demand begins 55 to 60 days after sowing, and green grams sown at the same time will be in the reproductive stage or close to harvest by this time. Green gram completes its major growth stage at the same time as maize begins, resulting in a high level of complementarity.

Time of Planting

Maize is widely identified as a major crop in intercropping systems where legumes are easily cultivated. For example, maize has a slow initial growth rate. If short-duration legumes are planted alongside maize, they can reach their reproductive stage and begin their reproductive period even before maize, thus avoiding the competition for common natural resources.