Efficacy of Stylet-Oil® in suppressing spread of TEV infections in a Scotch Bonnet pepper (Capsicum chinense Jacquin) field in Jamaica. (54)

Abstract

The effect of Stylet-Oil® on the spread of tobacco etch virus (TEV) (Genus: Potyvirus, Family: Potyviridae) in a Scotch Bonnet pepper (Capsicum chinense Jacquin) field was investigated during 2 September 1998 through 17 March 1999. There were three treatments, each comprising 100 plants per experimental unit and replicated thrice. With the exception of the control treatment, seedlings were kept virus-free prior to transplanting by protecting them under aphid exclusion cages. Of these protected seedlings, one set was treated with JMS Stylet-Oil® after they were transplanted to the field. A backpack mist blower (low volume) was used to apply Stylet-Oil® at pressures of about 1000 kPa to pepper plants weekly, from transplant until the last harvest. Stylet-Oil ® was effective in reducing incidence of tobacco etch virus (TEV) in Scotch Bonnet pepper by about 24% and delaying its spread by seven days. The TEV incidence was based on the appearance of symptoms in naturally infected pepper plants, and was confirmed serologically. The first symptoms of TEV appeared 56 days after transplanting and were correlated with aphid flight activities. The TEV symptom appearance was most closely associated with the presence of Aphis gossypii (Glover), a known vector of TEV, and two other aphids of unknown TEV vector status, A. amaranthi (Holman) and Uroleucon ambrosiae (Thomas) complex.