Resistance induction to Pepper Golden Mosaic Virus (Capsicum annuum L.) using organic amendments and Trichoderma harzianum Rifai in nursery phase

Abstract

The research was made in the municipality of Tonacatepeque, San Salvador, El Salvador from May to October of 2015. It was evaluated the effect of three organic preparations (Bocashi, vermicompost and vermicompost tea) and a commercial formulation of Trichoderma harzianum Rifai (Excalibur Gold 5 FS ®) as inducers for PepGMV resistance in sweet pepper (variety CORTES F1) and a control. Two trials were carried out under greenhouse conditions, the first one inoculating the virus at 25 dap (days after planting) and the second one 22 dap. The virus was inoculated using whiteflies (Bemisia tabaci Genn.) reared in cages with diseased pepper plants, and then transferred to the cages with the seedlings. The trials were established following a balanced incomplete block design with five treatments and four replications. The Data were collected at 30 and 27 days after planting, respectively. The measures of final incidence, the area under the curve of disease progress, the incubation time until 10% and 50% of the plants showed symptoms, stem diameter, height and fresh weight was evaluated. In the first trial, the inoculation with Trichoderma harzianum Rifai (5x109 UFC/5 ml) showed the lowest final incidence (62%, F4,11= 4.79, p<0.05), the lowest area under the curve of disease progress (320.21 du F4,11= 6.11, p<0.05) and the highest incubation time 50 (15.39 ddi, F4,11= 6.78, p<0.01), being epidemiologically the best treatment. In the second trial, the best treatment was vermicompost, which had the lowest incidence (80.14% F4,11= 0.95, p=0.4740), the lowest area under the curve of disease progression (528.19 du, F4,11 = 1.73, p = 0.2140) and longer incubation 50 (12.23 ddi, F4,11 = 1.20, p= 0.3661). On development variables (height, diameter at the stem and fresh weight)) the organic preparations showed the best results.