Evaluation of maize inbreds by top crossing

Abstract

An experiment were conducted at the field of Crop Science Department, College of Agriculture, University of Baghdad during spring and fall seasons. The objective was to evaluate 70 inbreds in 3rd generations of selfing by top cross method with synthetic Variety (Buhoth 106), then selection best ten inbreds and continuo selfing in the future . In the spring season top crosses was carried out. While in the fall season, varietal trail for top crosses was applied in RCBD with four replications. The results showed that there are significant differences between top crosses in all the studied characters. It was found early and late top crosses in tasseling and silking .Tallest and shortest plant and ear height were revealed. The phenomena of prolificacy did not find. The average ear length 20.91-12 cm were produced from top crosses of inbreds Bk43 and Bk44, respectively. The top Cross of the inbred Bk43 produced plants with the highest number of grains/row (45 grains (, while the top cross from the inbred BK26 was produced higher number of grains /ear. The highest grain weight (103.29 gms) produced from the top cross of Bk23. The highest grain yield (183.08 and 169.23 gms/plant) produced from the plants of top crosses Bk26 and Bk43, respectively. The top crosses of inbreds Bk26, BK43 , BK25 , BK39 , BK3, BK41, BK65 , BK16 , BK55 and BK11 , were superior in yield and some agronomic characters ,so, selfing and single cross hybrids development program will conducted to those inbreds in central Iraq.