Integrated pest management

Pesticides

Under IPM, pest populations are carefully monitored. Pesticides are used only when the pest population reaches a size where economic damage is likely and nonchemical methods will not work in time.

Integrated pest management (IPM) is an effective and economical way to control crop pests. It makes use of virtually all methods of pest control, including: natural pesticides, beneficial insects, special cultivation practices, and even chemical pesticides in the right measure at the right time. Some practical techniques of IPM are described below.

Cultural methods

Cultivation

Invert the soil by deep ploughing after harvesting a crop. This buries stubble, disease-infected trash, weeds, seeds, and insect larvae and pupae. Insects hibernating in the soil are exposed to the sun's rays and birds.

Crop hygiene

Destroy unwanted crop stubble. Scrape bunds and channels regularly to keep them free of grasses which are home to insect pests.

Fallow Land

Keep some portion of the land fallow and plough it deep, especially in summer, to reduce the population of some insect pests.

Flooding

If possible, flood your fields before cultivation in the summer. This exposes hibernating army worms, cutworms, white grubs, etc., to birds.

Irrigate before sowing

Control weeds in wheat crops by irrigation. Irrigate, prepare the land, and leave it for a few days. The weeds which sprout can be destroyed by ploughing.

Crop rotation

Avoid growing the same crop, or crops of the same family, over and over again in the same field. This can lead to a build-up of certain pests. Grow sorghum or maize before a cotton crop to reduce the incidence of cutworms.

Intercropping

Intercropping can reduce pest infestation. Grow sunflower side-by-side in the same field with cotton to reduce leafhopper damage. Grow cowpeas with sorghum to reduce stem borer in sorghum. Intercropping gram with wheat reduces attack from pod borer. A castor crop grown along with cowpeas will suffer less damage from aphids.

Sunflower-cotton Reduces leafhopper damage.

Cowpea-sorghum Controls stem borer.

Wheat-gram Reduces pod borer attack.

Castor-cowpea Reduces aphid damage.

Trap crops

A "trap crop" is a crop grown as a companion to the main crop which will attract pests away from the main crop. Grow castor as a trap crop in your cotton, tobacco, and chill) crops. The castor will draw cutworm larvae away from your valuable primary crop.

Resistant varieties

Several varieties of rice, wheat, cotton, sugarcane, and other crops have been developed which are resistant to specific insect pests. Grow the insect-resistant varieties recommended for your region.

Grow varieties of proper duration

Short-duration varieties of pigeon pea escape attack from small pod borer which appears sometime in February, but long duration varieties are affected.

Seed rate

Increase normal seed rate by 20 percent. Then, uproot and destroy insect-infested and disease-infected plants. Because of the increased sowing rate, the optimum plant population can still be maintained. This is a good method for controlling sorghum shoot fly.

Healthy seeds

Treat seeds before sowing to reduce the incidence of seed-borne diseases such as smut. Soak seeds in 10-percent salt solution to treat borer-infested seeds. When sowing sugarcane, reject insectand disease-affected sets.

Time of sowing

Adjust sowing time to avoid pest damage or to ensure that the crop is sufficiently developed to better withstand attack. Maize sown at the start of the monsoon suffers less from borer infestation than maize sown earlier.

Spacing, irrigation, and fertilization

Avoid close spacing, avoid excessive use of irrigation to control insects and disease, and avoid excessive use of nitrogen fertilizers. Feed your crop a balanced mix of fertilizers which includes potash to build plant resistance.

Physical methods

- Transplant only healthy seedlings.

- Clip the tips of paddy seedlings before transplanting to reduce the carry-over of insect eggs to the field.

- Observe your crop closely at least twice a week.

- Promptly remove and bury insect-infested and diseased plants.

- Control top borer in sugarcane by cutting off the top, one inch below the last node.

- Control malformation in mango by removing and destroying affected bunches.

- Hand-pick egg masses, larvae, caterpillars, and adult beetles from crops. Immerse them in water mixed with kerosene to destroy them.

Mechanical methods

You can use several mechanical methods in conjunction with physical and cultural methods to reduce pest populations. For example, you can use a mechanical trap to combat rodents. You can pull weeds by hand, or use a hand hoe or some other simple mechanical weeding device. (See Drudgery-reducing implements for farm women.)

Light traps

Place light traps in the field to control rice leaf folder and rice stem borer.

Trenches

Dig trenches around pest-infested paddy fields to prevent migration of hairy caterpillar larvae.

Barriers

Some pests crawl up trees and attack the fruit. Smear grease around the trunk of fruit trees to prevent insects from crawling up. Smear a band of grease around the trunk of your mango trees in November to prevent mealy bug infestation.

Biological methods

Insects have natural enemies: parasites, predators, deadly microbes, birds, and other animals. These are your important allies.

Birds

Protect birds, such as the king crow, egret, cuckoo, wood pecker stork, warbler, and babbler, which feed on insects. Owls, bats, and peacocks help to control rat and mice populations.

Parasites and predators

Several agricultural universities in India mass-produce helpful parasites, and release them to farmers at the right time at low cost. Learn about the biological pest control services available in your area and use them.

Ask about:

- Trichogramma chilonis, T. japonicum, and T. achaeae.

These parasites feed on the eggs of many insects, including sorghum stem borer, sugarcane borers, paddy stem borer, cotton boll worms, tomato fruit borer, cutworms, and others.

- Chrysoperia carnea

This parasite controls aphids, white flies, mealy bugs, and young larvae of various borers, cutworms and cotton boll worms, and other soft-bodied insects.

Viruses

Some agricultural universities in India mass-produce helpful viruses (called mpv) which can be released into crops to control certain insect pests. The Tamil Nadu Agricultural University has succeeded in controlling fruit borer in gram, tomato, cotton, and other crops by this method. Contact the agricultural university in your region for more information.

Yellow-headed wagtail

Wire-tailed swallow

White stork

Cattle egret

Botanical pesticides

Use plant extracts to ward off insect pests in your fields and at home. Some plant extracts kill insects; others repel insects; still others deter insects from feeding, or inhibit their growth. These are effective and less toxic to mammals and birds than are chemical pesticides.

Powdered neem kernel (1-2 kg per 100 kg of grains) will reduce damage caused by insect pests in stored grains and pulses.

Neem oil mixed with karanj oil (ratio of 5 parts neem oil to 1 part karanj oil) is effective against aphids in cotton. Mix 3 g of the oil in 1 litre of water.

Leafhoppers, caterpillars, and army worms are less attracted to a paddy crop treated with 3 percent neem oil.

Spray neem seed kernel extract 5 percent) mixed with water to control katra worms and borers.

Apply neem cake at the rate of 150 kg per ha to control rice hoppers.

Apply karanj cake at the rate of 150 kg per ha to control beetles in tobacco.

Dature, agave (cactus), pyrethrum, annona, and other plants are also known for their effectiveness in controlling insects.

Chemical method.

Judicious use of pesticides

Apply chemical pesticides only when other effective methods are not available. Use pesticides judiciously: the right pesticide, in the right amount, at the right time, in the right place. Choose less toxic and less persistent pesticides. Choose pesticides which control the pest species, but leave beneficial species and neutral species unharmed.

Consider the cost

Only spray when the value of me threatened crop justifies the expense.

Timing

If you must spray, apply pesticide in the right amount, at the right time, in the right place. Good timing is important. For example, spray early In me growing season when the pest is active but before natural predators and parasites have built up in large numbers.

Contributors and sources: Dr. N. K. Roy, Dr. L. M. L. Mathur, Dr. Jagdish Singh, Dr. V. N. Shroff, and Dennis H. Hill