EVALUATION OF MAIZE VARIETIES UNDER SALT STRESS

Abstract

Two pot experiments were carried out in the laboratory of Department of Agronomy, Hajee Mohamad Danesh Science and Technology University (HSTU), during the period from 6 November, 2016 to June, 2017. In the first experiment, the seeds of seven maize varieties viz. Barnali, Shuvra, Khoi Vutta, Mohor, BARI maize 5, BARI Sweet corn-1 and BARI maize 7 were screened for salt tolerance during germination and seedling growth. The seeds of the seven maize varieties were placed in a plastic pot (25 cm x 12 cm) on sand bed irrigated with tap water (control) and NaCl (100 and 200 mM salinity levels) solutions. Data were collected on germination characters and seedling growth parameters. The experiment was laid out in a completely randomized design with three replications. The collected data were analyzed statistically and means were adjudged by DMRT at 1 and 5% level of probability. The results of the experiment clearly indicated that the salinity stress was very detrimental for reducing the maize performance significantly in all maize varieties used in the study. All the growth parameters studied were inhibited remarkably due to salinity stress and very importantly the inhibition varied among the maize varieties. The lowest inhibition in terms of germination percentage, germination rate, root length, shoot length, root and shoot fresh weight and dry weight of root and shoot was always recorded in Khoi Vutta variety while the highest inhibition was noticed in BARI sweet corn-1 variety. In the second experiment the seeds of Khoi vutta (tolerant variety) and BARI sweet corn-1 (susceptible variety) selected from the first experiment were grown in four salinity levels (0, 50, 100 and 150 mM) of NaCl to detect the degree of salt tolerability and susceptibility between these two varieties based on yield and yield contributing characters. Salt solution was prepared artificially by dissolving calculated amount of commercially available NaCl with tap water. The salt solution was applied as per treatment specification. Salinity stress treatment had also significant consequence on both maize varieties where all the studied traits showed significant decrease tendency with the increasing salinity stress as well as the higher salinity level exhibited the lower performance and without salinity showed the superior performance. The result also showed that Na+ content was increased as the salt concentration was increased but opposite results were found in K+ , Ca2+ and Mg2+ i.e. they decreased as the salinity level was increased. But Khoi Vutta was less affected than BARI sweet corn in all studied parameters. From the result it can be concluded that Khoi Vutta could be treated as salt tolerant variety whereas BARI sweet corn as salt susceptible.