Grain Yield of Sorghum Midge-Resistant Sorghum Hybrids, 1997

Abstract

Abstract Resistance to sorghum midge (SM) was evaluated ir a 3-replication RCB design experiment composed of 52 sorghum hybrids at the Texas A&M University Agricultural Research and Extension Center a Corpus Christi and the Texas A&M University Agricultural Experiment Station Research Farm near College Station. Evaluated were 43 resistant X resistant experimental hybrids, 3 resistant X resistant checks, 1 resistant X susceptible check, and 5 susceptible checks. Three weeks before planting the experimental hybrids, eight rows of a susceptible hybrid were planted adjacent to the area to be used for the experiment. This sorghum provided a source of sorghum midge to infest the experimental sorghums. At Corpus Christi, seed of the experimental sorghum was planted 8 Apr in 6-m-long plots, with 97.1 cm between rows. Sorghum was planted at College Station 8 May, with 76.2 cm between rows. The sorghums were planted approximately 1 month late than normal for the region. SM were not controlled with insecticide. Performance of the experimental hybrids was compared with that of the checks (resistant X resistant, resistant X susceptible, and susceptible X susceptible) for grain yield (kg/ha) and damage caused by SM. Sorghum at physiological maturity was rated by plot for SM damage based on a scale of 1 to 9: 1 = 1-10%, 2=11-20%, to 9 = 81-100% of kernels failed to develop. Sorghun panicles in plots (0.0025 ha) were hand harvested and threshed using a stationary plot thresher. Threshed grain weight (g) was converted to kg/ha to ob tain grain yield. ANOVA and LSD0.05 were used for data analysis and mean separation, respectively.