Wheat Seed Insect Control

Losses in wheat seed can occur because of various reasons. These include post-harvest factors such as inadequate storage, rodent infestation and other pests. Therefore, development of a proper wheat seed insect control method and technique is an important safeguard. The main objectives of any insect control method are reducing pest incidence to economically acceptable levels, ensuring that all the control measures adopted are cost-effective and ensuring minimal negative environmental effects.

Monitoring Insect Infestations

• Needless to say, frequent monitoring of storage conditions is essential for wheat seed insect control as it helps to identify problems in a timely manner. On the other hand, rodents are not affected by physical conditions of temperature or humidity, and their only requirement is gaining access to the wheat seed. Therefore, for avoiding damage to stored wheat seed grains due to rodents, rodent-proof storage buildings should be built.

Using Synthetic Insecticides for Control of Insects

• Chemical treatment of grain and fumigation can be conducted easily because many sustainable and cost-effective techniques are available. The use of insecticides (like chlorpyrifos-methyl, malathion, or deltamethrin) through impregnation of prophylactic tarps or jute bags is common in the Asian subcontinent as a means of insect control. Disrupting mating opportunities of insects by use of synthetic sex pheromones has also been found effective. A sound mix of all the techniques can lead to effective wheat seed insect control.

Use of Inert Insect Repellents

• Use of silica-bearing ash and dust can effectively control storage insects. The ash of rice husks contains almost 90 percent silica and is extensively used as an insecticide by farmers in India and Japan. Vegetable oils like the peanut oil and palm oil are very effective against certain pests such as bruchid beetles. For areas where pesticides are expensive, vegetable oils such as groundnut, sunflower and rap-seed mixed in pirimiphos-methyl is very effective especially against S. granarius in the wheat grain.

Botanical Insect Repellents

• Certain plant products are very effective for protecting wheat seed and other stored grain from insect damage. For example, the powdered roots of Derris elliptica, dried fruits of Capsicum, and the seeds and leaves of the neem tree (Azadirachta indica) are very effective insecticides. So are the leaves from Schinese molle, Eucalyptus globulus, Lycopersicum esculentum and Phytolacca dodecandra, as they cause high rate of adult weevil mortality. Seed extracts of til (Anethum graveolens) and coriander (Coriandrum sativum) are very effective in wheat seed insect control.

Importance

• The important principle procedures for effective wheat seed insect control are:

  • Prediction and prevention of insect infestation,
  • Selection of appropriate insecticides and its dosage,
  • Effective application of insecticides,
  • Safe method of insecticide application and understanding label information.

  It is essential to follow an "integrated pest management" (IPM) regime, which essentially is the coordination between the physical, chemical and biological parameters which play an important role in wheat seed insect control.