PRUNING TIME IN TWO PRODUCTION SYSTEMS IN THE GUAVA TREE BACTERIAL BLIGHT CONTROL

Celso Katsuhiro Tomita,Luiz Eduardo Bassay Blum,Marisa Alvares Da Silva Velloso Ferreira,Carlos Hidemi Uesugi

doi:10.1590/0100-29452016529

Celso Katsuhiro Tomita, Luiz Eduardo Bassay Blum + Show 2 more

Open Access

https://doi.org/10.1590/0100-29452016529

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Abstract

ABSTRACT In this work, two cultural production systems were compared [conventional (CO) and organic (OR)], and its effects in the guava trees (Psidium guajava) bacterial blight (Erwinia psidii) control. The experimental design was in radomized blocks, in split-split-plot arrangement, where it was measured the bacterial disease and the fruits production on the 2005/06, 2006/07 and 2007/08 harvests. Four pruning seasons effects were evaluated on the harvests (September, December, March and June) in both production systems. Such systems were constituted of: OR – treatment with bioactive compound (BC), liquid BC and dead coverage, and; CO – chemical fertilization, fungicide and herbicide. In 2007/08, the area under the disease progress curve (AUDPC) of all the treatments in the OR system was lower (~54-107) than the CO one(~233-298). In the 2007/08 harvest the number of fruits for each plant for all the OR treatments was higher (~146-204) than the CO ones (~57-103). In all the harvests, considering all the treatments within each system, there was a significantly lower AUDPC (~93-184) and higher fruits production (~158-188) in the OR one than the CO one (AUDPC: ~208-476; fruits ~18-104). The pruning induced a higher AUDPC and lower fruits production in both production sytems.

Highlights

The guava trees (Psidium guajava) bacterial disease, known as “bacterial blight” (Ervinia psidii) has been detected on eucalyptus (Eucalyptus spp.) in Argentina and Uruguay (COUTINHO et al, 2011) and in Brazil
The pruning may be done during dewless periods or with free water over the plants, on sick guava trees it is recommended the removal of smitten fruits or branches (FISHER et al, 2011).In areas with the bacterial disease, constant prunings on the same plant must be avoided, specially those which will induce new blooms during the humid and high temperature periods (FISHER et al, 2011)
The preparation of organic matter and compounds used in the experiment area were adaptations of the compounds production methods reported by Tomita (2010) for the guava trees disease control which presented the following compositions: bioactive compound - soil 1000 kg, forest soil 250 kg, compound 250 kg, rice bran 200 kg, castor bean bran 50 kg, bone flour 100 kg, fish residues 250 kg, ashes 50 kg, molasses 10 kg and water 45% (v/v) – liquid bioactive compound for 1000 L: 25 kg forest land, 25 kg compound, 20 kg rice bran, 5 kg castor bean bran, 10 kg bone flour, 25 kg fish residues, 25 kg ashes, 10 kg molasses, 5 kg starch, 5 kg cornmeal and 800 L of water

Summary

INTRODUCTION

The guava trees (Psidium guajava) bacterial disease, known as “bacterial blight” (Ervinia psidii) has been detected on eucalyptus (Eucalyptus spp.) in Argentina and Uruguay (COUTINHO et al, 2011) and in Brazil. The studies about the interactions between the biological control agents with the microbiological community of the enviroment are very complex, just like the quality and quantity effects of managed compounds on the soil., (HOITINK; CHANGA, 2004) and on the leaf surface (HALFELD-VIEIRA et al, 2008; 2015), these may be the plants vitality elements of success on field conditions. This works objective was to evaluate the bacterial disease control and yield on guava tree exposed to different pruning seasons in organic and conventional system

MATERIAL AND METHODS

RESULTS AND DISCUSSION

CONCLUSIONS