Comparisons of F1 and F2 Grain Sorghums for Yield and Other Agronomic Characteristics1

Abstract

AbstractA 2‐year study was conducted under irrigation in Lebanon comparing F1 and F2 grain sorghums.Average grain yields of F2 hybrids were 13.5 and 20.8% less than those of F1 hybrids for the 2 years. Stover yields and test weights, however, were not influenced by planting either F1 or F2 generation seed. Average date of flowering of the F2 sorghum plants was delayed a few days, and the F2 heads were a few grams lighter than F1 heads. In some hybrids the F1 plants were taller and their heads were longer than the F2 plants and heads. However, kernel weights from F2 sorghum plants were heavier than from F1 plants.Less variation was observed between plants in each F1 population than between plants of the corresponding F2 population for the following characteristics of six sorghum hybrids: days to flowering, plant height, head length, head weight, and 100‐kernel weight. The study revealed that F2 grain sorghum hybrids were inferior in yield to F1 hybrids. In addition, the F2 produced plants that varied widely in maturity, height and other agronomic characteristics, which made sorghum harvesting and processing more difficult.