OCCURRENCE OF PESTS AND DISEASES IN CACTUS PEAR GENOTYPES / OCORRÊNCIA DE PRAGAS E DOENÇAS EM GENÓTIPOS DE PALMA FORRAGEIRA

Abstract

The objective was to evaluate the occurrence of pests, diseases and mortality rate in nine genotypes of cactus pear ( Nopalea cochenillifera ) destined for forage production. The genotypes were implanted in a complete randomized block design, with nine treatments and three replications. After 330 days of cultivation, the occurrence of pests and diseases and verification of plant mortality were carried out. Among all the pests and diseases observed in this experimental trial, the most prevalent disease regardless of the evaluated genotype was the anthracnose stain “ Colletotrichum gloeosporioides ” (49.20%) and the less frequent diseases were the resine “ Dothiorella ribis ” (6.87%) and soft rot “ Erwinia carotovora ” (2.58%). The only occurrence pest was the cochineal in scales “ Diaspis echinocacti ” (22.69%). The Texas (V13) and Negro Michoacan (F07) genotypes showed the highest occurrence of pests and diseases, from 50% of the total plants, followed by anthracnose stain and cochineal in scales. On the contrary, the genotypes Tamazunchale (V12) and California (V14) were not affected by any pest or disease. It was observed that the genotypes Nopalea Uruapan (V20) and Blanco San Pedro (V19), had a lower occurrence of pests and diseases, less than 20% of the total plants. The genotypes that presented the highest mortality rate were Texas (V13), Blanco San Pedro (V19) and Polotitlan (V09), with 80, 70 and 65% mortality rate, respectively. The genotypes Nopalea Uruapan (V20) and California (V14) had the lowest mortality rate (20 and 35%), respectively. The genotypes that were least affected by pests and diseases and had the lowest mortality rate are Tamazunchale (V12), California (V14) and Nopalea Uruapan (V20).