Use of oils in the reduction of aphid-born virus in bean (Phaseolus vulgaris L.)

Paulina Sepúlveda R.1 y Juan Francisco Navarrete G.2

Virus diseases are the main pathological problem of bean crop in Chile. Controlling the aphid vectors is one way to reduce the incidence of virus diseases. The objects of the present study were to evaluate the effects of different oil sources in reducing virus transmission, to determine the effects in yield components and to quantify and identify aphid fly populations during the season. The experiment was performed with Coscorr6n-INIA bean seed obtained from healthy and virus infected plants. Six applications of oils were performed during the crop season. The products used were: mineral and "jojoba" oil at 0.5% and milk at 2%. Water was used as control. Populations of winged aphids were established as well as the affected plants during the season. At harvest, yield components were evaluated. The results indicated thatyield increased when healthy seeds were used, as compared with infected ones, and that, regardless of the type of seed used, the yield was increased in 30% with mineral oil applications as compared with the controls. Number an weight of pods and seeds per plant, were the yield components with most increase by the oil applications. The stages of crop development that resulted most susceptible to virus infection were between prebloom and blooming. It was also established that Myzus persicae was the aphid species most frecuently detected during the crop season.

Keywords: aphid control, virus, bean, oils.
1 Centro Regional de Investigación CRI La Platina (INIA), Casilla 439, Correo 3, Santiago, Chile.
2 Walker Martinez 436, La Florida, Santiago, Chile.