Determination of resistance of experimental soybeans to the lima bean pod borer etiella zinckenella treitschke and the whitefly bemisia tabaci gennadius at dakhla oases, New Valley, Egypt

Abstract EN

Three soybean varieties and two cultivars have been planted in an isolated and closed agro-desert ecosystem in Dakhla Oases, New Valley Governorate.

The resistance status of the selected soybeans against the lima bean pod borer Etiella zinckenella and the whitefly Bemisia tabaci has been determined.

In respect to E.

zinckenella the obtained results indicated that the tested soybean varieties Clark, Giza22 and Tono equipped higher infestation by this insect pest with an average 4.30, 3.54 and 9.13 % respectively, than the tested cultivars Hagen32 and S5 by 2.38 and 3.21 %, respectively.

Similar results were obtained by calculating the damaged soybean seeds.

The highest damage percentage appeared on Tono variety by 9.30 % while, the lowest one appeared on Hagon32 cultivar by 1.97 %.

Also, results showed no variations between the influences of the analyzed soybean seed components on the yield consumption by E.

zinckenella, whereas (r) values were nonsignificant.

High compatibility is recorded between the resistance status of the tested soybeans and the mean numbers of E.

zinckenella individuals attacking the developing pods.

The newly produced cultivars Hagen32 and S5 presented some sort of resistance and appeared as moderately resistant cultivars.

However, the soybean varieties Clark, Giza22 and Tono appeared as relatively resistant, susceptible and highly susceptible varieties, respectively.

Concerning the whitefly B.

tabaci, results indicated a distinct compatibility between the nymphal incidence and the degree of resistance.

Although, the tested varieties and cultivars exist different degrees of resistance, the newly produced cultivar S5 appeared as a resistant cultivar against B.

tabaci infestation.

Consequently, plant breeders must be select soybean cultivars that have a desirable resistance levels for breeding purpose with serious trials to transfer gene(s) responsible for these phenomenon to the newly produced soybean varieties.