Survival analysis to HLB and horticultural performance of Valencia sweet orange grafted onto 16 rootstocks

Abstract

Brazil is a major producer of citrus fruits in the world. Currently the huanglongbing (HLB) is one of the most important diseases worldwide. It is devastating the world's citrus industry. Present in our country, specifically in the state of São Paulo since 2004 has caused serious damage to the São Paulo citrus industry. Caused by three species of bacteria Candidatus Liberibacter asiaticus, Ca. L. africanus and Ca. L. Americanus. In the State of São Paulo occur American and Asian species. These bacteria are transmitted by the species of psyllids, Diaphorina citri. The verification of any higher levels of survival of citrus scion/rootstock combinations to HLB in or a tolerant rootstock may contribute to significant advances in the management of HLB. This project aims to analyze the performance of citrus combinations composed of Valencia orange grafted onto 16 rootstock cultivars and their survival to HLB, in order to select combinations with greater resilience to disease. The experiment was installed in 2011 at the Experimental Station of Bebedouro. The experimental design was completely randomized with 16 treatments (rootstocks) with 30 repetitions. The evolution of HLB in each combination scion/ rootstock will be assessed through periodic inspections as well as horticultural plant performance. The results of HLB progress assessments will be submitted to the survival analysis and the horticultural variables will be analyzed using Fisher's test and the means were compared by the Scott-Knott method (P <0.05). We expected to find combinations of good horticultural and higher survival rate HLB performance. (AU)