Uso da enxertia para o controle da murcha bacteriana [Ralstonia solanacearum Smith (1896) (Yabuuchi) et al. 1996] no tomateiro

Abstract

The bacterial wilt (Ralstonia solanacearum) is a major disease of tomato (Solanum lycopersicum). The control is difficult because there are no resistant cultivars not recommended chemicals. The objective of this study was to evaluate the use of cubiu (Solanum sessiliflorum), jurubeba (Solanum viarum) and cultivar of tomato Yoshimatsu (tolerant) as rootstocks to control bacterial wilt. The experiment was conducted in a greenhouse was set up in a completely randomized design with five replicates, consisting of the treatments „Santa Cruz Kada Gigante‟/cubiu, „Santa Cruz Kada Gigante‟/jurubeba, „Santa Cruz Kada Gigante‟/‟Yoshimatsu‟, „Santa Cruz Kada Gigante‟ autograft and „Santa Cruz Kada Gigante‟ ungrafted, inoculated with 10 mL of the bacterial suspension at a concentration of 108 ufc.mL-1 race 1 (biovar 1) of Ralstonia solanacerum, the substrate around plant lap, whose roots were slightly injured with a scalpel. The witness consisted of plants treated with all combinations sterile distilled water. The experiment conducted in the field was set up in soil infested with Ralstonia solanacearum in a randomized block design with five replications, consisting of the same treatments used in the greenhouse. For both experiments, the assessment was made on a daily basis according to the incidence of the disease and the development of symptoms. It was also rated the stem diameter (mm) at the time of the colon, stem diameter 2 cm above the grafting point and plant height of the neck to the pointer (cm), these every seven days using digital calipers and tape measure, respectively . Still it was quantified the number of flowers per plant, number of flowers per inflorescence, number of fruits per plant, number of fruits per inflorescence, early flowering, early fruiting and designated rig plants above the eighth inflorescence of weeks after grafting. Data were statistically analyzed by Assistat version 7.7 program, and the averages compared by Tukey test at 5% probability. Tomato plants grafted on cubiu not developed symptoms of bacterial wilt and may be suitable for the production of seedlings and planting in areas contaminated with R. solanacearum. Cultivar yoshimatso showed the greatest growth and productivity of plants, providing partial resistance in grafted plants with this rootstock and can be used within a management program of the disease in tomato cultivation.