|BAATH, GURJINDER - Oklahoma State University
|KAKANI, VIJAYA - Oklahoma State University
|ROCATELI, ALEXANDRE - Oklahoma State University
|SINGH, HARDEEP - Oklahoma State University
Submitted to: Journal of Plant Growth Regulation
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/20/2020
Publication Date: 1/2/2021
Citation: Baath, G.S., Kakani, V.G., Northup, B.K., Gowda, P.H., Rocateli, A.C., Singh, H. 2021. Quantifying and modeling the influence of temperature on growth and reproductive development of sesame. Journal of Plant Growth Regulation. https://doi.org/10.1007/s00344-020-10278-y.
Interpretive Summary: Sesame is one of the most-important oilseed crops in the world. It has been descried as “the queen of oilseed crops”, with the seed used in many applications in food, cosmetic and drug production. It is of tropical origin, thrives under warmer conditions, and is largely cultivated in rainfed areas. The largest amounts of sesame are produced in India and Myanmar, who contribute 28% of the total global production. However, there has been increasing worldwide demand for sesame in recent decades, which has led to an increase in area planted to sesame, often in areas with growing conditions that are outside those of the original home range. We undertook a study to describe how different day/night temperature combinations affected vegetative growth and seed production by sesame, to estimate the temperature range and optimum temperature for growth by sesame. Groups of plants were grown over in growth chambers that received 6 different daytime/nighttime temperature combinations that ranged from cool to hot conditions. We found the temperature range for plant growth by sesame ranged from 61 to 113 degrees F, with an optimum temperature of 81F. We also found that seed yields declined with increasing temperatures above 77F, and that plants did not produce seeds at temperatures above 91, or below 61 degrees F. There are no reported temperatures in the scientific literature that defines the range and optimal temperature for growth by sesame. Therefore, the day/night temperature limits, and optimum temperatures, could be used to develop crop models to simulate management strategies for sesame under different climate conditions. Such models could also be used to help define areas in regions where sesame is not currently grown where this crop could be grown.
Technical Abstract: Ambient temperatures are major factors regulating the growth rates, yields and geographical distribution of crop species. The cultivation of sesame (Sesamum indicum L.) has begun increasing in regions where it is not traditionally grown, and sub-optimal yields due to extremely low or high temperatures could occur. There is currently no available information in existing literature on the temperature responses of growth by sesame. This experiment quantified the effects of different temperatures on vegetative growth and reproductive development of sesame, to estimate its cardinal temperature (Topt), and temperature limits (Tmin; Tmax), with a temperature response function, i.e. modified bilinear model. Plants (n=32) were subjected to six different day/night temperature treatments using walk-in growth chambers; 40/32, 36/28, 32/24, 28/20 and 20/12 degrees C. Vegetative growth of sesame was sensitive to low temperatures (<15C), but tolerant of high temperatures. A cardinal temperature and limits of 15.7C (Tmin), 27.3C (Topt) and 44.6C (Tmax) were observed for rate of biomass accumulation. Sesame reached the flowering stage under moderate to high temperature conditions; however, reproductive yields progressively declined above 25C, and no seed yields were obtained above 33C. The estimated temperature limits could be employed to develop crop models for simulating management and adaptation strategies of sesame under different climate scenarios, and adaptation to regions where the crop is not currently grown. Future research should focus on understanding factors controlling the temperature tolerance of reproductive development in sesame, to provide a broader geographical adaptation.