Effects of planting dates, corn intercropping and chemical spraying on thrips population and yield of potato
1992
Barroga, S.F.
The effects of corn intercropping, date of planting and chemical spraying on thrips population, damage and yield of potato were evaluated at the MMSU [Mariano Marcos State University] Experimental Station, Batac, Ilocos Norte [Philippines]. Potato + corn intercropping (9:1) reduced thrips population on potato. Higher population of thrips were observed in sprayed plots but with less damage both in monocrop potatoes and potato + corn intercropping system. These findings suggest that a reduction in thrips population did not necessarily reduce damage and an increase in the number of thrips did not necessarily increase damage. It appeared that thrips damage is a more significant factor in yield reduction than its population. Sprayed plots reduced population of lampylomma, a predator found prevalent in the area. The water trap method of sampling thrips was found more efficient than the dry extraction method. Early planting of potatoes produced higher marketable yield than those that were planted late. The yield obtained from each of the treatments in both early and late planting did not differ significantly from each other. Numerically, however, monocrop of potato produced higher yield than potato + corn intercropping system. In both cropping systems, sprayed plots produced higher yield than unsprayed plots. Monocrop potato with chemical spray produced the marketable highest yield. Lower net profit was realized in potato + corn intercropping system due to the reduction in potato yield.
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