Chapter Four - Efficacy of Stylet-oil in Suppressing the of Spread of Tev Infections in a ‘scotch Bonnet’ Pepper (capsicum Chinensis Jacquin) Field in Jamaica

Stylet-Oil was effective in reducing incidence of tobacco etch virus (TEV) (Genus: Potyvirus, Family: Potyviridae) in ‘Scotch Bonnet’ pepper (Capsicum chinense Jacquin) plots by about 24% and delaying its spread by 7 days. A backpack mist blower (low volume) was used to apply JMS Stylet-Oil at pressures of about 1000 kPa to pepper plants weekly, from transplant until the end of the crop. Seedlings were kept virus free prior to transplanting by protecting them under aphid exclusion cages. TEV incidence was based on the appearance of symptoms in naturally infected pepper plants, and confirmed serologically. The first symptoms of TEV appeared 56 days after transplanting (DAT) and were correlated with aphid flight activities. 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). Stylet-Oil did not affect the growth of healthy pepper plants but the total number of fruit produced by plants of the Stylet-Oil treatment was less than plants of the two control treatments. Stylet-Oil treated plants in the absence of TEV were also less affected by the broad mite, Polyphagotarsonemus latus (Banks) and so produced a greater proportion of marketable fruit than untreated plants.