Potential of some soybean varieties for resistance to lima bean pod borer (Etiella zinckenella) under field conditions

Abstract

A field experiment was carried out to evaluate the relative resistance of some soybean varieties against lima bean pod borer under field conditions in Giza Agricultural Experiments and Research Station (Lat. 30°00′30′′ N, Long. 31°12′43′′ E, 26 m a. s. l), ARC, Giza, Egypt during 2017 and 2018 summer seasons. The experiment included six soybean varieties (Giza 21, Giza 22, Giza 35, Giza 111, Crawford and Dr-101) and were distributed in randomized complete blocks design with three replications. It was observed that there was a significant difference in natural infestation of soybean varieties by lima bean pod borer. Soybean varieties Giza 35, Crawford and Giza 22 had higher infestation by the insect, meanwhile soybean variety Dr-101 showed a higher potential for resistance to lima bean pod borer where it recorded the lowest percentage of seed weight losses and the highest harvest index than the others in the two growing seasons. Seed storage proteins revealed variations among all soybean varieties under lima bean pod borer infestation. Soybean variety Dr-101 had higher resistance to lima bean pod borer where, it produced the highest number of protein bands (6 bands) for resistance to lima bean pod borer compared to the others. Soybean variety Giza 21 produced taller plants, but soybean variety Giza 35 had higher number of branches per plant, biological and straw yields per ha than the others. Although soybean variety Giza 22 was susceptible to lima bean pod borer infestation under field conditions, but this variety had higher pod pubescence length, pod and seed yields per plant, as well as, 100-seed weight than the others. Soybean varieties Giza 22 and Giza 111 gave higher seed yield per ha than the others in the two growing seasons.