Maize and Wheat: Difference in Germination Temperature - Essay Example

Maize and Wheat: Difference in Germination Temperature The study sought to investigate the previous observation from existing literature that wheat has lower germination temperatures than corn. An experimental design was used to measure germination rate, and root length, for the two plant species, at temperatures between 50C and 400C . Twenty seeds, from each species, were placed in a Petri dish, at a temperature, for a week. Results show that wheat germination occurs at lower temperatures and the germination rate for wheat are higher at lower temperatures. Wheat roots are also higher than corn roots for lower temperatures. The results are consistent with existing literature and the study concludes that wheat has lower optimal germination temperatures than corn. Introduction Temperature, as a determinant of degree of warmth, is an important factor to germination. It has indirect effects on seed germination such as regulating effects of biotic factors in a seed’s environment. According to Rodriguez-Brljevich (2008, p. 9), low temperatures favor effects of F. verticillioides, to undermine germination and growth, and possible differences in disease resistance, by plant species, could moderate the temperature effect on germination. Also, the author notes that low temperatures damages cells in maize seeds, an effect that could establish temperature as a moderator factor to germination rate between maize and other plant species. From this perspective, seeds that can withstand low temperature and its environmental effects have better survival chances, and can therefore report higher germination rate at low temperatures. Data on germination temperature for wheat, however, suggests a lower optimal temperature range. Edwards (N.D.) an assistant professor at Oklahoma State University, explains that optimal germination temperature ranges from 400F (12.220C) to 770F (250C) and wheat cannot germinate at higher temperature at which maize can germinate. Existing data, therefore, suggests a difference in optimal germination temperatures for wheat and maize. Wheat, according to the literature, germinates at lower temperatures than maize, and this study seeks to ascertain the observation. This paper attempts to examine wheat has lower germination temperature range than maize. Methods The study implemented an experimental design to compare germination rate of maize and wheat seeds at different temperatures. Eight sets of plastic Petri dishes were used, with each set containing a pair of the dishes. The dishes had a layer white “Kimpak,” with a blue indented filtered paper. The paper, in each dish, was soaked with tap water, and excess water eliminated. In each pair, 20 seeds of wheat were placed in a1 dish and 20 seeds of maize in the other dish. Each dish was labeled with the temperature for treatment. The dishes were then put in incubators, at the labeled temperatures and the set up were left for a week. Number of germinated seeds and root lengths were then noted, and average lengths determined for every dish. Results Root germination Wheat did not germinate at 50C and 100C temperatures. Germination, however occurred at 150C, at 76% and the percentage increased up to 250C, with a record of 98.9 %. The percentage germination then reduced through 300C and 350C and there was no wheat germination at 400C. Similarly, corn did not germinate at temperatures bellow 150C. Percentage germination then increased, at higher temperatures, recording the highest rate at 300C. Unlike in wheat, however, corn germinated at 400C. The following Figure shows trends in germination rates, for the two plant species, at the different temperatures. Figure1: Percentage germination of wheat and corn at different temperatures The figure further shows that germination rate is higher for wheat up to 350C, after which corn registers higher germination rate. In addition, optimal germiantion temperature for corn (300 C) was higher than that for wheat (250 C). Root length Similarly, none of the species reports roots length at 50C. Wheat, unlike corn, reports some length at 100C. This increases until a temperature of 300C, with a length of 45.4 millimeters. The root length is however just 14.67 at 350C, with no length at 400C. Corn’s mean root length also increases from 0.96 at 150C to 39.125 at 300C, before falling. Corn’s root length is however registered at 400C. Both wheat and corn have optimal root lengths at 300C. The following Figure summarizes the results. Graph 2: Mean root length of wheat and corn at different temperatures Temperatures lower than 26.450 C favored growth of wheat root than growth of corn root. Temperatures above 26.450 C, however, favored growth of corn root. Discussion Germination and growth involves cell activity and hormones. Therefore, germination rate increases with increase in temperature up to the optimal temperature, after which germination rate decreases with temperature increment. Decrease in germination rate at higher temperature is because of denaturing of cells. The study aimed at investigating difference in germination rates between corn and wheat, at different temperatures and the recorded rates is consistent with the proposed effects temperature. This means that temperature is a significant factor to germination and growth of wheat and corn. Results show that wheat germinates at temperatures that are too low for germination of corn. The study’s optimum germination temperature for wheat and for corn are consistent with data from existing literature, which identify wheat with lower germination temperature, at an optimal range that include 250C. Previous literature establishes an optimal range between 250C and 350C that is consistent with the current results. According to Yusuf, Iyanda, and Olayiwola, maize seeds do not germinate at very low temperatures such as 50C and 70C, and high temperatures such as 450C. Moreover, germination rate remains low at 210C but is high between 250C and 350C. Germination rate, based on the authors’ results, also differs across plant species. At 100 percent water application of field capacity, maize germinated at as high as 400C, while beans did not and this suggests that different plant species have different optimal ranges for germination (Yusuf, Iyanda, and Olayiwola, N.D., p. 325). Optimal temperature for corn root is also consistent with empirical results that identify 320C as the optimal temperature for growth of maize seed organs (Kurtyka, Burdach, & Karez, 2010, p. 1224). The observed consistency can be inferred to data on root length for wheat. Even though deviations exist in literature, on germination temperatures for each species, this could be due other factors to germination. In addition, there is consistency that corn has higher germination temperature. This establishes reliability of the results and builds confidence in the observed trend in root length. The study, therefore, concludes that optimal germination temperature range is lower for wheat than for corn and that temperature has same effect on root growth of germinated seeds. It achieves its aim, as it answers the research question. Further experimental studies are however, necessary to incorporate. possible effects of other environmental factors, as either independent variables or moderator variables. References Edwards, J. (n.d.). Factors affecting wheat germination and stand establishment in hot soils. Oklahoma State University. Retrieved from: http://wheat.okstate.edu/wheat-management/seeding/PSS-2256.pdf. Kurtyka, R., Burdach, Z., & Karez, W. (2010). Temperature dependence of growth in maize seedlings and excised coleoptiles segments. Polish Journal of Environmental Studies 20(5), 1221–1225. Rodriguez-Brljevich, C. (2008). Interaction of fungicide seed treatments and the fusarium-maize (Zea mays L.) pathosystem. Ann Arbor, MI: ProQuest. Yusuf, K., Iyanda, M., and Olayiwola, T. (n.d.). Determination of optimum temperature and moisture content for crop germination. University of Ilorin. Retrieved from: http://iworx5.webxtra.net/~istroorg/download/Nigeria_conf_downloads/SWE/Yusuf%20et%20al.pdf. Read More