Response of the onion (Allium cepa L.) plant to simulated pest damage

Issue Date

10-2004

Abstract

The effect of the different levels of simulated damage on each leaf at various crop growth stages on weight and size of onion bulb was investigated in farmers' fields in Bongabon and Talavera, Nueva Ecija, from December 2000 to April 2003. In 2001 and 2002, simulated damage of up to 75% at 15 days after transplanting (DAT) had no significant effect on onion bulb size and weight in both sites. The bulb formation stage (45-65 DAT) was sensitive to any level of simulated damage as shown in the measured yield components. In 2002, artificial defoliation of up to 25% at 15 DAT and 10% at 30 DAT had no effect on bulb size and weight. In 2003, the effect of cutting off 1,2 or 3 leaves or the youngest leaf at different crop ages on onion bulb size and weight was also investigated. Removal of most, if not all, the leaves (3 leaves) at 15 DAT resulted in a significant reduction in onion bulb size and weight in both locations. Similar result was recorded when the youngest leaf was removed at 60 DAT. Removal of only the oldest leaf at 15,30,45 or 60 DAT generally did not affect bulb size and weight. Results of this study suggest that onion plants can tolerate some damage caused by defoliators.

Document Type

Article

En – AGROVOC descriptors

ALLIUM CEPA; BULBS; PLANT PESTS; PLANT DAMAGE; DEFOLIATION; YIELD LOSSES

This document is currently not available here.

Share

COinS