Begomoviral disease rates and the implications to the growth and yield of chili plants (Capsicum annuum L.) at different elevations in Indonesia

The purpose of this study was to determine the effect of the pepper yellow leaf curl disease (PepYLCD) caused by begomovirus at different elevations on the percentage of growth and yield reduction in chili (Capsicum annuum L.) plants. The study was conducted in farmer’s field at Lambeugak (lowland) with the latitude of 30 meter above sea level (m asl) and Saree (middleland) with the latitude of 485 m asl of Aceh Province, Northern Sumatera, Indonesia. The samples selection was obtained using the Purpose Sampling method. Data collection were devided into 2 clusters where the first cluster samples were choosen randomly from 600 plants (300 plants for lowland and 300 plants for middleland) for the disease incident percentage and second cluster samples were choosen randomly from first cluster, each field consisted of 30 plants (15 virus-symptomatic plants and 15 non-virus symptomatic plants) for the reduction of growth and yield percentage. PepYLCD incidence in lowland reached 100 % at 120 day after transplanting (DPT), whereas in middleland it occurred at 150 DPT. At 45 DPT virus-symptomatic plants at lowland encountered higher reduction percentage of growth than the middleland plants, including height of plant (43.6 %) and stem diameter (31.1 %). The yield of virus-symptomatic plants in lowlands encountered higher loss than the middleland plants, including the number of fruits per plant (53.6 %) and productivity (72.6 %). The reduction of growth and yield was also suspected to be the impact of temperature differences that the average and maximum temperatures of lowland (27.68 and 35.53 oC) was higher than the middleland (25.36 and 30.17 oC) during the experimental period. Our present study showed that the escalation of PepYLCD incidence was affected by environmental factors which reduced the growth and yield of chili plants.