Threshold of treatment of the fall armyworm (Spodoptera frugiperda) in the crop of starchy corn (Zea mays L. ssp amylaceo)

Abstract

The objective of the study was to determine the treatment threshold (TU) of the fall armyworm (Spodoptera frugiperda) in the cultivation of starchy maize (Zea mays L. ssp amilaceous) in the Ccanabamba sector, Tamburco district, Abancay province, Apurímac department, Peru. A completely randomized design was used, with three chemical treatments (T1: Tifon 2.5% PS; T2: Chlorpyrifos S480; T3: Cyperklin 25) and a control. 160 larvae, Spodoptera frugiperda, in stage L3, were collected, and one larva was placed per maize plant. The evaluation was carried out every three days, from 28 days of sowing. The results indicated that the treatment threshold is 1.86%; 1.43%; 1.38% and 0.00% with T1, T2, T3 and control, respectively; T1 being the one with the highest tolerance to the presence of the pest. In addition to obtaining the highest yield and price (1,917.57 kg/ha; 5.87 S//kg), followed by T2 (1,872.63 kg/ha; 5.75 S//kg), T3 (1,823, 99 kg/ha; 5.99 S//kg) and Control (1381.35 kg/ha; 5.07 S//kg). It is recommended to use T1 in order to minimize the use of pesticides, obtain a higher yield in kg/ha, as well as a better price in S//kg of corn.