Me. Kraemer et al., EVALUATION OF VEGETABLE SOYBEAN GENOTYPES FOR RESISTANCE TO CORN-EARWORM (LEPIDOPTERA, NOCTUIDAE), Journal of entomological science, 32(1), 1997, pp. 25-36
Petri dish bioassays were used to evaluate terminal foliage from 47 fi
eld-grown genotypes of vegetable-type soybean, Glycine max (L.) Merril
l, from maturity groups III through VIII, for resistance to corn earwo
rm, Helicoverpa tea (Boddie), in 1993 and 1994. Larvae reared on ''Sat
o'', IAC 100, V89-1301, V89-1563, and V88-100 had low mean weights, no
t significantly different from resistant controls. However, larval wei
ghts ranged from moderate to high on most vegetable-type soybeans. The
most susceptible genotypes were ''Geulph'', PI 561291, and ''Rokusun'
' followed by ''Kanrich'', ''Kura'', ''Camp'', ''Wolverine'', G2246, G
4032, ''Kim, ''Hahto'', PI 561294, N2962, and D71-V89. Mortality avera
ged 2.9% in 1993 and 13.5% in 1994, but was not generally useful in ev
aluating resistance within maturity groups. High percent mortality and
low weights of larvae reared on both resistant and susceptible genoty
pes in maturity group VII/VIII in 1994 may have been related to the us
e of insect-damaged foliage. Soluble leaf sugar was determined in 1994
samples and ranged from 0.50% (PI 416868-B) to 1.04% (PI561291) of dr
y weight. A small but significant positive correlation (r=0.20, P=0.00
9) was found between sugar content and larval weight in maturity group
s III through VI. Exceptional low larval weights in maturity groups VI
I and VIII were not related to leaf sugar content.