Temperature regimes within which different maize (Zea mays L.) cultivars seeds germinate and seedlings grow subjected to in vitro conditions in Lesotho
Germination rate and seedling growth are essential stages in a maize plant’s life cycle, greatly influenced by temperature as well as moisture conditions. The study was conducted in Lesotho with aim of (i) determining temperature regime within which different maize cultivars seeds germinate and seedlings grow subjected to in vitro conditions. The study was conducted at the National University of Lesotho, Roma campus laboratory. The experiment was laid-out using completely randomized design with three replications, eight different temperature treatment levels, 5, 10, 15, 20, 32, 35, 38, and 40 °C and 10 different maize cultivars. After every seven days, germination data were collected on germination percentage, germination index, mean germination time, means daily germination and peak value. Concurrently seedling growth data were collected, namely; coleoptile length, plumule length, radicle length, plumule fresh weight, radicle fresh weight, plumule dry weight and radicle dry weight (growth parameters). Data collected were subjected to analysis of variance using Statistix 10 software to detect the difference among the treatments, after which least significant difference was adopted to separate the means. The results revealed that at 5, 10 and 400C no germination and seedling growth occurred in all maize cultivars. Both germination and seedlings growth took place gradually from 150C to 350C which seemed to be the peak, after which all parameters decreased and reach cessation at 400C. At 350C, the maximum germination and seedling growth was attained. It can therefore be inferred that at temperature of between 320C and 380C is ideal for good crop standability.
Keywords – Maize, germination parameters, growth parameters, lethal temperatures, sub-lethal temperatures
