Effect of concentration and soakingduration with gibberellic acid on emergence properties and seedling growth of maize

Abstract

An experiment was carried out in shadow that belong to Agriculture College, University of Baghdad during fall and spring seasons 2012-2013 in order to determine the best treatment of seeds soaking with different concentration of GA3 0, 100, 200, 300, 400 and 500 mg L-1, and duration 12, 24 and 36 h, through its impact on emergence properties and seedling growth of Zea mays L. cv. 5018. Factorial experiment with two factors according to randomize complete block design (RCBD) was carried out with four replications. The results showed significant superiority of treatment of soaking with concentration 300 mg L-1 of GA3 to give the best values for each of attributes of first day of emergence, last day of emergence, time it takes for the emergence, mean of emergence time, percentage of emergence in first count, percentage of emergence in final count, coefficient velocity of emergence, emergence rate index, seedling length, and seedling dry weight during both seasons. As well as results showed significant superiority of treatment of soaking in GA3 for 24 hours to give the best values for the same attributes above except first day of emergence and time it takes for the emergence during both seasons. Also results showed significant superiority of interaction treatment, soaking with concentration 300 mg L-1 of GA3 for 24 hours to give the best values for each of attributes of percentage of emergence in first count 88.0 and 93.0%, coefficient velocity of emergence 46.3 and 32.4 % day-1, emergence rate index 41.7 and 30.4 % day-1, seedling length 14.9 and 12.1 cm, and seedling dry weight 0.0431 and 0.0500 mg, during both seasons, respectively. Significant correlation positive or negative was found between most attributes. It can be conclude that soaking of seeds in GA3 reduced soaking duration, improve emergence properties and seedling growth. We recommend soaking seeds of maize in 300 mg L-1 concentration of GA3 for 24 hours before planting.