SPATIAL DISTRIBUTION OF GREEN SCALE AND SOOTY MOULD IN COFFEE PLANTATIONS IN AMATEPEC, STATE OF MEXICO

Abstract

This document shows the use of geostatistical methods for constructing maps of incidence of green scale [Coccus viridis (Green); Hompoptera: Coccidae], one of the main pests of coffee (Coffea arabica); this insect, in addition to causing direct damage, produces the medium for the development of the fungus Capnodium sp. causing sooty mould. Four coffee plots were selected with varieties Typica and Caturra georeferencing plants randomly with samplings every two weeks. The objective of this study was to analyze the spatial distribution of green scale and sooty mould in coffee plantations, The presence of outbreaks of infestation and infection of green scale and sooty mould within the plots as well as the correlation between the insect and the fungus causing the disease were detected. Theoretical semivariograms adjusted to Gaussian, spherical and exponential models were obtained, with an aggregate-type distribution in several centers. The estimation of the area infested and infected by green scale and sooty mould was obtained through ordinary kriging, and it was possible to visualize the months April and May as those with the highest incidence for green scale and April for sooty mould, which coincides with the most important months for coffee flowering in the studied area. It was found by simple linear correlation analysis for arithmetic averages and Pearson correlation coefficient that the greater the presence of green scales, the higher the sooty mould concentration.