Invasive Species Compendium

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Abstract

Population fluctuation of pest insects and its relationship with grain yield in 16 genotypes of hard yellow corn (Zea mays L.) in the campo Verde district, Ucayali, Peru.

Abstract

The fluctuation of insect pests in 16 corn genotypes was evaluated, the relationship between the number of insects and grain yield was analyzed, and the most important pests for the conditions of the Campo Verde district in Pucallpa, Ucayali region were identified. 16 genotypes of hard yellow corn were evaluated under a randomized complete block design with three replications; each plot had 72 plants planted at a density of 62,500 plants per hectare. The experiment was carried out in the Campo Verde district, Coronel Portillo province, Ucayali department, Peru. Through the systematic sampling of pests, 15 plants were randomly taken per genotype in which the insects present in them were counted. In total, 12 evaluations were carried out at 10, 18, 26, 34, 41, 48, 54, 62, 69, 75, 84 and 96 days after sowing (dds). Six pests out of a total of seven were the most frequently obtained during the crop cycle, which were identified as: Dalbulus maidis (De Long and Wolcott) (Hemiptera: Cicadellidae), Diabrotica viridula (Fabricius) (Coleoptera: Chrysomelidae), Diatraea saccharalis (Fabricius) (Lepidoptera: Crambidae), Empoasca kraemeri (Ross and Moore) (Hemiptera: Cicadellidae), Oliarus spp. (Hemiptera: Cixiidae) and Spodoptera frugiperda (J. E. Smith) (Lepidoptera: Noctuidae). On average, of the 12 evaluations carried out on the 16 genotypes, four were the moments in which the highest number of insects per plant was recorded (26, 34, 54 and 96 dds). The regression lines turned out to be not significant; however, the negative relationship between the number of insects and grain yield is evident. Apparently, the three most important pests would be: S. frugiperda, followed by D. maidis and D. viridula, since without these pests the average yield of the 16 genotypes would rise from 2.16 t/ha to 3.1; 2.98 and 2.81 t/ha, respectively.