GEORGIA / FLORIDA
UNIVERSITY OF GEORGIA
Department of Agronomy, Griffin, GA 30212, USA.
J.W. Johnson, R.D. Barnett, B.M. Cunfer, and G.D. Buntin. [p. 238]
The 2000 Georgia winter wheat crop was grown on about 250,000
harvested acres. The crop production resulted in a state average
yield of 52 bu/acre, which was 29 % more than in 1999. Overall,
the season was characterized by a mild, dry winter followed by
a dry, hot spring. Some cultivars had vernalization problems
because the warm autumn and winter delayed planting. Cool, dry
conditions prevailed through the grain-filling stage. Powdery
mildew and leaf rust also were a major factor in some low yields.
Hessian fly infestations reached damaging levels in some parts
of the state.
The SRWW line GA 89482 was released as an exclusively cultivar as AGS 2000. GA 89482 was selected from the cross 'Pioneer 2555/PF 84301//FL302' and carries the T1B·1R translocation. This cultivar possesses excellent resistance to powdery mildew, moderate resistance to leaf rust, and good resistance to Hessian fly. GA 89482 has excellent test weight and straw-strength and is medium in maturity.
GA 901146E15 was released as an exclusive cultivar and was selected from the cross 'GA 831127-3//79102/3* 821264'. GA 831127-3 is an experimental line from the cross 'GA 73016/3/Hunter//GA 74-23-1/C762'. GA 79102 is an early maturing line that has the leaf rust resistant gene Lr24 and the powdery mildew gene Pm17 on the T1A·1R translocation from Amigo.
GA 91426E39 was released as an exclusive cultivar and was selected
from the cross 'GA 841474/Stuckey'. GA 841474 is an experimental
line with the pedigree 'Coker 797/Oasis//Saluda/Coker 916'. Stuckey
is an early-maturing cultivar with good powdery mildew and leaf
rust.
Warmer than normal weather and the continued shift towards
reduced tillage production during the last few winters has allowed
Hessian fly populations and damage to increase in Georgia. The
biotype mix of populations from southwestern Georgia in 2000 was
88 % biotype O, 6 % biotype M, 1 % biotype L, and 12 % each
for biotypes E, F, G, and M. These data were determined by R.
Ratcliffe, USDA, Purdue University. Therefore, only 1 % of the
population (Biotype L) was virulent to H7H8, whereas 98 %, 94
%, and 92 % of the population was virulent to genes H3, H5, and
H6, respectively. The number one variety in the state last season,
Pioneer Brand 2684, is susceptible to Hessian fly. This variety
was severely damaged in some areas. Several other varieties including
AGS 2000, Roberts, Fleming, NK-Coker 9835, and Pioneer Brand 26R61
are still resistant the Hessian fly within the state.