Study Results on Pest Insects and Diseases and Integrated Crop Management Application for Corn in Chieng Pan Commune, Yen Chau District, Son La Province

Abstract

The study was carried out at Chiengpan commune of Yenchau district, Sonla province in 2007 -
2008. Fourteen insect pest species and six pathogenic pest species were identified in corn fields of
the Chiengpan commune. Of the identified pests, stem borer (Strain francolins Gurnee), banded leaf  
(Rhizoctonia solani) and common rust (Puccinia sorghi) were more prevalent than others. Stem borer
ocurred with high density and caused remarkable damage from flowering to milk maturing stages. The
density of stem borer and the incidence of banded leaf and common rust disease in the Intergrated
Crop Management (ICM) fields were lower than those in the fields where farmers applied
conventiobnal cutivation practice (FP). In two comparisions, the economic efficacy of the ICM1 model
was 27.9% higher than that of the FP1 model (control). The same figure was also obtained for the ICM2
and FP2 models (28.3%).
Seeds stored with herbal leaves showed lower weevil (Zoophiles zamias Mitch) density and lower
percentage of damaged seeds at  30, 60 and 120 days after storing than those without leaves as
control.  Among the herbs tested, China-tree (Melia azedarach ), lemon grass (Cymbopogon citrates )
and common sagebrush (Artemisia vulgarism L.) leaves gave high efficiency of control. At 120 days
after storing with China-tree leaves, the density of weevil was 8.1 weevils/kg of seeds (level a) and
percentage of damaged seeds was 1.2% (level a). The figures for the common sagebrush and lemon
grass treatments were 9.4 weevils/kg (level a), 1.8% (level ab) and 10.7 weevil/kg, 1.6% (level ab),
respectively.