Natural Crop Protection in the Tropics
Letting Information Come to Life
Methods of Storage Protection
Storage-Pest controlling Plants
Plant parts with pest-controlling properties
Mode of action
Larger grain borer
The velvet leaf is extremely bitter, therefore this treatment is suggested for application on planting seed only.
Velvet leaf controls the larger grain borer Prostephanus truncatus and the rice weevil Sitophilus oryzae more effectively when applied as slurry.
Methods of preparation and use
The slurry is made by weighing out powder and adding sufficient water to give a desired concentration (weight/weight), and stirring until a smooth paste is obtained. Then the grain is poured into the prepared slurry and stirred thoroughly to make sure that the grains are perfectly covered. Using the slurry method is more effective than plant powder only. A slurry at a 2.5% concentration reduced the weight loss of the stored goods to 7.9% compared to 68% in the control over a period of 3 months. There was no difference between the 2.5%, 5% and 10% concentration.
To control the larger grain borer effectively (< 3% weight loss, 90–100% mortality of the borer), a 10% concentration is required. The rice weevil, however, can be completely controlled with a concentration of 1% only.
© Margraf Publishers 2003