Genetically modified corn on Spodoptera frugiperda and Helicoverpa zea control in Sinaloa, Mexico

Genetically modified corn on Spodoptera frugiperda and Helicoverpa zea control in Sinaloa, Mex 

Corn hybids Agrisure Viptera 3111 and Agrisure 3000 GT with the Cry 1Ab, and Vip3Aa20 and mCry3A proteins of Bacillus thuringiensis (Bt) provided by Syngenta Agro were tested for fall armyworm and corn earworm cotrol at El Dorado and Navolato ,Sinaloa using a complete randomized block design with 8 treatments with 3 replicates.  Davis scale (1= no damage to 9= severe damage) was used to evaluate armyworm and length (cm) of damaged corncobs for corn earworm evaluation. Spodoptera frugiperda. At El Dorado, Agrisure Viptera 3111 and Agrisure Viptera 3111 with Crop Protection (CP), had an average of 1 on Davis scale and are considered to be highly resistant to the pest whereas the isoline presented damages of  3.53 and 2.89 with and without chemical control respectivelly; on the other hand, the isolines had 64.4 and 56.7 % of damaged plants with and without insecticide treatment  respectivelly. A high armyworm population was found at Navolato; Agisure 3000GT and Agrisure 3000GT+CP showed damage of  1.34 and 1.13 respectivelly on Davis scale and 13.3 and 7.8% damaged plants that are also resistant to the pest if compared with their isolines that had 3.87 and 4.97 damage on Davis scale and 66.7 and 76% affected plants for the same hybrids  respectivelly. Helicoverpa zea. AgrisureViptera 3111 and Agrisure Viptera 3111 + CP at El Dorado had 40 and 46.7% damaged cobs with small  galeries of 0.33 and 0.45 cm long respectivelly, whereas the isolines had 93.3 damaged cobs with galeries averageing 2.1 and 2.2 cm long without and with insecticide treatment respectivelly finding galeries up to 7 cm long. At Navolato, Agrisure 3000 GT with and without chemical control had low infestation levels of corn earworm with average galeries of  0.27cm and 0.45cm long with a 36.7 and 56.75% of corncobs with damage; on the other hand, the isolines had galeries of 4.37cm with insecticide tratment and 5.5cm without treatment and up to 12 cm  long in the last one with a high 96.7 and 100% cobs with damage for the same materials respectivelly. BtAgrisure Viptera 3111 and Agisure 3000GT probe to be resistant to both pests , damage found is due that the insects must feed to be affected by the bacteria endotoxin.