Submitted to: Phytologia
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/25/2018
Publication Date: 3/16/2018
Citation: Adams, R.P., Ulloa, M., Witt, T.W., Burke, J.J. 2018. Comparison of hydrocarbon yields in four cotton accessions: regular vs. limited (induced dryland) irrigation. Phytologia. 100(1):6-11.
Interpretive Summary: As water for irrigation from the Ogallala Aquifer decreases, farms on the Southern High Plains will need new sources of income. Alternative sustainable renewable sources of petrochemicals and fuels from arid and semi-arid land crops may be one source of income. Recently, it was reported that cotton presents a new possibility as a hydrocarbon source because of its growth habit as a perennial crop and adaptation to long and hot growing seasons. Scientists from ARS (Lubbock, Texas) and Baylor Univ. studied four Upland cotton cultivars grown in limited and regular irrigated field conditions to compare water stress effects on hydrocarbon (HC) production. The yields of HC were higher when grown under water stress. The results suggest that cotton grown for HC may be a supplemental income to cotton fiber production. Further research is needed to more fully understand these trends.
Technical Abstract: Four Upland accessions of cotton Gossypium hirsutum (SA-1181, 1403, 1419, and 2269) were grown in limited irrigation and regular irrigated field conditions to compare water stress effects on leaf biomass, percent yield of hydrocarbons (HC), and total HC (g HC /g leaves). Analyses revealed a significant difference between irrigations and significant interaction between entries by irrigation or genotype by environment (GxE) for percent HC yield and total HC (p < 0.05). However, when entries were examined in each irrigation, no significant differences were found among entries for percent percent yield HC, and significant differences (p = 0.03) were found for total HC under regular irrigation while high significant differences were found under limited irrigation or induced stress/dryland field conditions for these two traits (p < 0.001). The average percent HC yields and HC total were significant for SA-2269 compared to SA-1181, 1403, and 1419 under stress/dryland field conditions. The percent increase in HC yields (regular to limited irrigation) were: SA-1181 18.1 percent; SA-1403 21.5; SA-1419 30.3 and SA-2269 42.1 percent. HC yields (as g HC/leaf DW) were either barely significant (SA-1181, p=0.037*) or non-significant (SA-1403, SA-1419), except for SA-2269, that was very highly significant due to the fact that the biomass was almost as large in limited as in regular irrigated plots and percent HC yield was much greater than in regular irrigated plots. These results clearly show that the yields of HC in cotton are higher for these accessions when grown under water stress. In addition, there are some differential responses among the four accessions, with SA-2269 showing the greatest increase in HC yields in induced stress/dryland conditions.