DEFOLIATION ASSESSMENT BY Cerotoma fascialis THROUGH TWO SAMPLING METHODS IN TWO VARIETIES OF SOY (Glycine max) SALITRE-GUAYAS

Abstract

This work was carried out in canton Salitre, province of Guayas, for the purpose of evaluating the defoliations by Cerotoma fascialis by means of two sampling methods in two varieties of soy (Glycine max). The used methodology was a completely random block design (CRBD) with 2x2 factorial arrangement where Factor A represented the varieties: INIAP 308 and FAENA; and Factor B represented the types of sampling: Systematic and Random, assigned in 4 treatments and 5 repetitions: T1 (INIAP 308*systematic sampling), T2 (INIAP 308*random sampling), T3 (FAENA*systematic sampling), T4 (FAENA*random sampling). For the comparison of the means between the treatments, the Tukey multiple-range test was implemented at 5% of probability. Results: Random sampling was the lowest accurate method for counting defoliations reflecting the lowest mean with 11.27 perforations; on the other hand, the systematic sampling as more accurate and significant obtaining the highest average with 13.55 perforations. Drilling count, T4 (FAENA*random sampling) presented lower average with 8.57 perforations; on the contrary, T1 (INIAP 308*systematic sampling) was significant with a higher average of 17.90 perforations. These results affect the percentage of affectation where the lowest average had T4 (FAENA*random sampling) with 30.46%; whereas, the highest average was t1 (INIAP 308*systematic sampling) with 56.94% of affectation. The FAENA variety had lower defoliation intensity with 8.88 perforations; however, the INIAP 308 variety was significant, presenting susceptibility with 15.93 perforations.