ARS | Publication request: The Relationship of Temperature to Plant Morphology of Lesquerella

Submitted to: Crop Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: April 4, 2011
Publication Date: September 1, 2011
Citation: Dierig, D.A., Crafts-Brandner, S.J. 2011. The Relationship of Temperature to Plant Morphology of Lesquerella. Crop Science. 51:2165-2173.

Interpretive Summary: A key challenge for developing a new crop such as lesquerella is that it be sustainable by having enough production regions to keep up with market demands. These growing regions need to be defined so industry can contract farmers in appropriate areas. Our objective was to better define what temperatures are required to obtain optimum yields. We grew plants at the Agricultural Research Service (ARS), Arid-Land Agricultural Research Center (ALARC) at four different temperature ranges and measured and counted dry weight, number of branches, and reproductive parts. Temperature of 21.1 – 29.4°C caused faster growth but temperatures of 12.8 – 21.1°C were more efficient by using less units of heat to grow the same plant quantity. This treatment also produced more buds and flowers resulting in more seed. Growth was greatly suppressed by the coldest and warmest treatments. It is apparent that temperatures of 12.8 to 21.1°C promoted both plant vegetative and reproductive growth the best. This information will provide guidance industry looking to expand lesquerella production and should help other researchers trying to improve this potential new crop.

Technical Abstract: There is a lack of information regarding the impact of temperature on yield-related traits for lesquerella [Physaria fendleri (Gray)], a new crop with potential as a biofuel or bioproduct due to the high content of seed hydroxyl fatty acids. Here we determined the effect of four temperature regimes on plant branching, dry matter production, and reproductive growth in two controlled environment experiments. The night:day temperature treatments were 1) 4.4-12.8°C, 2) 12.8-21.1°C, 3) 21.1-29.4°C, and 4) 29.4-37.8°C. Plant branch number, biomass, and reproductive development were greatly suppressed by the coolest and warmest temperature treatments. Biomass and branch production were similar for treatments 2 and 3, but reproductive development and was increased in treatment 2. Treatment 2 led to more branches with reproductive structures, and more buds and flowers compared with treatment 3. Plants moved from the coolest treatment (1) to treatment 2 temperature at 45 DAP exhibited accelerated branching and production of dry matter, buds, and flowers, whereas, transfer from treatment 1 to treatment 3 led to enhanced silique production. These results suggest that moving from a cold to a warmer temperature enhanced both biomass production and reproductive development. In addition to documenting the temperature impact on growth and reproductive development of lesquerella, the results provide evidence pertinent to defining growing regions suitable for cultivation of this new crop.