Improvement of growth, yield and nutritional status of maize (Zea mays L.) through X-ray bombardment of seed

Abstract

Crop improvement faces a lot of challenges ranging from genetic effects of seeds to environmental factors, among others. Therefore, certified hybrid seeds of maize (Oba super II), were exposed to three different doses of X-ray radiation: 3 MGy, 6 MGy, 9 MGy and a control, no exposure (0 MGy) to assess the effect of irradiation on growth performance, grain yield and nutritional status of maize. The field research was conducted in 2016 cropping season at Michael Okpara University of Agriculture, Umudike (latitude 05º 29'N; longitude 07º 33'E; altitude 122 masl), southeast Nigeria. The experiment was laid down in a randomized complete block design with three replications. The results indicated that X-ray irradiation significantly affected growth, yield and nutritional status of maize. The application of 6 MGy of X-ray dose gave the longest cob, highest 100-seed weight and grain yield (4,973.00 kg ha-1 ) as well as nutritional values of the crop such as b-carotene, vitamin C, protein and phosphorus relative to the other treatments suggesting a possible genetic synergy from the dosage level. Correlation showed that above ground dry matter, crop growth rate and absolute growth rate had positive and significant (P≤0.05) relationships with grain yield. The mean sequence of grain yield obtained from maize due to X-ray bombardment of the seeds before planting was in the order: 6 MGy X-ray irradiation>9 MGy X-ray irradiation>3 MGy X-ray irradiation>0 MGy X-ray irradiation. The implications of these results can lead to further improvement of maize varieties in southeast Nigeria.