Study on the Severity of Damage by Sap Sucking Pests to Different Off-Season Sweet Pepper Varieties

Abstract

The Study was conducted to evaluate the feeding effect of various sap sucking pests such as the chilli trip (Scirtothrip dosalis), the cotton aphid (Aphis gossypii) and the broad mite (Polyphagotarsonemus latus) on eight swet pepper varieties under field conditions at Pichit horticultural Research Centre. Resuts indicated that the attack of these sap sucking pests to both Dayongkok and No. 9198 was moderately severe with damage levels of 5.6 and 5.8, respectively, but the severity was significantly lower than other varieties namely No.1. No.3, No.6, No.3 TMV, Big Jim and California which were heavily infested with damage scales ranging from 7.3 to 8.5. Stunted symptom was obvious in many varieties eg. No.3 TMV, No. 1 and No. 6 (48.0, 53.8 and 55.9 cm height, respectively) while Dayongkak and No.9198 were slightly affected on plant height (69.9 and 67.2 cm, respectively). In considering yield and yield quality, Dayongkak gave significantly greater marketable and total yields (225.5 and 257.2 kg/rai). No.3 TMV, california, No.6, No.1, Big Jim, No.3 and No. 9198 produced marketable yields of 51.8, 56.3, 75.0 , 77.1 , 79.7, 80.4 and 86.8 kg/rai, respectively.