Relative Incidence and Severity of Chillithrips (Scirtothrips Dorsalis) on Three Rose Cultivars in Maisirwa, Eritrea

Study was conducted in polyhouse of the rose production centre, Maisirwa with the objectives of determining the severity and incidence of chilli thrips on three rose cultivars (Avalanche, Top Secret and Upper Class). Three visual observations were taken on three stages (one on early emergence, the second after 15 days of emergence and the last after 45 days of last observation) of the three cultivars. The experiment was conducted in a Completely Randomized Block Design. The result showed that the occurrence of chilli thrips was high in all the rose cultivars at the early leaf and bud setting. In the first and second observation of severity the cultivars showed high significant difference among them at 5 % level of significance where, Avalanche and Top Secret scored the highest bud severity in the 1st and 2nd observations respectively. Chilli thrips infestation was more at early stage as compared to the later stage of the plants. In addition to that the result revealed that there was no significance difference among the three rose cultivars in leaf and overall plant severity whereas the highest incidence of the chilli thrips or highest susceptibility was observed from Avalanche and top secret. Upper Class showed the least susceptibility as it scored the lowest percentage of chilli thrips incidence. There was also a significant positive correlation between the incidence of the insect pest and the severity on the rose plants.