Temperature Effect on Maize Germination and Root Elongation.

Corn is a versatile crop grown over a range of agro climatic zones. If producers adopt early planting to avoid high temperature and drought under rain fed systems, cold temperatures may negatively affect corn yield. Experiments were conducted by imposing low temperatures during seed germination. 20 commercially available corn hybrids were evaluated for seed germination and root elongation. Seeds for these trials were obtained from two industry leading seed companies in 2015 and 2016. Standard germination assays confirmed all seed germinated at or near 100 percent under optimal conditions. Each temperature x hybrid treatment was replicated four times in a completely randomized design with 50 seed per replicate. Seed were placed on a moistened seed germination paper, rolled, and secured with rubber bands. The samples were monitored daily to ensure that the filter paper remained moist. Replicates for each hybrid were completely randomized within the germination chamber for each temperature. Because we hope to plant earlier into potentially wet and cold soil, we evaluated seed germination at different temperatures with the following objectives: 1. Do some hybrids germinate better at cooler temperatures than others? 2. Is there variation for root elongation at cold temps among commercially available hybrids? 3. From among the best and worst hybrids from objective 1 and conduct extensive and intensive germ time series trials across decreasing temps. We measured germination rate as well as % germination across increasing cooler temperature. Corn hybrids varied significantly for seed germination and root traits under cold temperatures. So that the hybrids of (Company 1) have significantly surpassed (Company 2) in seed germination traits, and they germinated earlier as well as the radicle length. There were significant differences among temperatures for all traits. Also, most of the hybrids gave significant differences among them for all traits in both experiments.