SYNCHRONY AND PHENOTYPIC CHARACTERIZATION OF MAIZE (Zea maysL.) INBRED LINES AND SOME SINGLE CROSSES AT BAKO, ETHIOPIA

Abstract

Maize parental lines are the basis for large-scale hybrid maize seed producers. Identification of the appropriate nicking time for maize hybrids is useful information to maximize seed production per unit area. Field trials was conducted during 2019/20 main season to evaluate flowering synchrony and seed yield performance of 13 inbred lines and 2single crosses Maize in a Randomized complete block design with three replications at Bako national maize research center. The objectives of the study were to investigate the best nicking time female and male parental lines and to identify the correct matching time between pollen shading of male parents and silking date of female parents. Besides, the flowering synchrony, seed yield performance and Growing Degree Days (GDD) for DA, DS and DM were calculated for each parents and association of the traits among parents were also calculated. Analysis of variance was done by SAS 9.3. The mean GY for inbred lines and single cross was 4.08t/ha and 10.77t/ha respectively. L10 had the highest yield (5.53t/ha), followed by L13 (5.18 t/ha) and L4 (5.13t/ha). L12, L7 and L3 had grain yield above the mean with the mean values of 5.03, 4.14, and 4.10 (t/ha). The ANOVA for Anthesis-Silking Intervals (ASI) showed highly significant differences (p< 0.01). Among inbred parents, L7, with an average of (6.66 days) had the longest ASI followed by L5, and L12 with five days of ASI. And The mean of ASI was four days for L1, L3, L4 and L10. The mean of ASI was 3.58 days, which has highly significant effect on yield. The shortest ASI was observed for L9 with (1day) followed by L6 (1.33 days), L2 (2days) and L8, L11, L13 with 3days. L10 had the highest score of Growing Degree Days (GDD) (℃) for DA and DS with 957.3 and 998, respectively. Whereas the lowest scores of GDD (℃) for DA and DS, observed on forL2, Were 815 ℃ and 835℃), respectively. GDD for single cross parents were shorter than GDD for parental lines which implies that they possess the early maturity date trait. The result indicates that to produce three-way crosses of maize, it is recommended to plant CML312BK 10days before BKL002; and plant BKL003 10 days before single cross BKL002/CML312BK. Planting of BKL001 should be 9 days before CML395/CML202and planting of the male parent 142-1-e should be 10 days before CML395/CML202. Results on two way crosses showed that the suggested planting time for the parent BKL004 should be 4 days before BKL003 to produce the hybrid BH549; and CML165should be plantedat the same time with CML161 to produce the hybrid BHQPY545, planting CML444, 1day before or on the same day with CML536 to produce the hybrid BH520w; and planting the male parent 124-b(109) 10 days before sowing BKL004 for to produce the Candidate1 are suggested to be the best combinations to maximize flowering synchrony which would result in maximum seed yield.