AbstractsBiology & Animal Science

The use of stylet oil to slow the spread of the whitefly- transmitted vines, lettuce infectious yellows, shows sufficient promise to plan for expanded research efforts. The main positive results were a slower buildup of virus infection and a larger number of marketable heads in the block of lettuce sprayed with oil. Weight (in grams) of individual heads could be correlated with time of infection in that the lowest weights and marketability ratings occurred in plants infected earliest in the season. Whether they were front treated or untreated plots, marketable heads weighed an average of 784 grams; unmarketable heads weighed 491 grams. The key difference is that, on the average, five marketable heads of lettuce were in the oil- treated plots for every three in the untreated plots. A follow-up experiment will be conducted in 1989 to determine if these preliminary positive results indicate that stylet oil treatment may be a practical control method for slowing the spread of L1YV.