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ARS Home » Southeast Area » Tifton, Georgia » Crop Genetics and Breeding Research » Research » Publications at this Location » Publication #311269
Title: Association of chlorophyll content and SPAD chlorophyll in diverse sweet sorghum cultivars under different environments

Author
item BUNPHAN, DARIKA - Khon Kaen University
item JAISIL, PRASIT - Khon Kaen University
item SANITCHON, JIRAWAT - Khon Kaen University
item Knoll, Joseph - Joe
item Anderson, William - Bill

Submitted to: Khon Kaen Agriculture Journal
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/5/2018
Publication Date: 3/15/2018
Citation: Bunphan, D., Jaisil, P., Sanitchon, J., Knoll, J.E., Anderson, W.F. 2018. Association of chlorophyll content and SPAD chlorophyll in diverse sweet sorghum cultivars under different environments. Khon Kaen Agriculture Journal. 46(1):155-162.

Interpretive Summary: Sweet sorghum is considered an excellent bio-based product and bioenergy crop. The free sugar and cellulose can both be used for producing renewal fuels and products. Chlorophyll content is directly related to productivity for many crops. Chlorophyll content can be measured directly which required collecting material from the field and performing the extraction in the lab which takes excessive time and supplies, or it can be measured indirectly through a chlorophyll meter (SPAD) which is non-destructive, can be done in the field and is very fast. It is important to know if the SPAD readings are closely associated with actual chlorophyll amounts. This study determined a correlation of the two methods at two locations for sweet sorghum in Thailand at 10 days intervals between 40 and 100 days after planting. SPAD chlorophyll meter readings (SCMR) and chlorophyll content were significantly correlated for all 7 test dates at KKU (r = 0.49 to 0.64) but only moderately correlated at 40 DAP (r = 0.48), 90 DAP (r = 0.33) and 100 DAP (r = 0.32) for the NCSRC location. The SPAD chlorophyll meter is a useful tool for indirectly measuring leaf chlorophyll content in sweet sorghum, and has several advantages over direct measurement, including reduced labor and better reproducibility.

Technical Abstract: Sweet sorghum [Sorghum bicolor (L.) Moench] can be an effective crop for bio-ethanol production due to its adaptability and high sugar yields. Like many other crops, chlorophyll content is related to high productivity and can be measured directly and indirectly. However, literature is lacking concerning non-destructive measurement of chlorophyll in sweet sorghum. The objectives of this study were to determine the most effective technique and best plant age for estimation of chlorophyll content by SPAD chlorophyll meter readings (SCMR). Chlorophyll content and SCMR were taken at 10 day intervals between 40 and 100 days after planting (DAP) at the Field Crops Research Station, Khon Kaen University (KKU) and at the National Corn and Sorghum Research Center, Nakhon Rachsima (NCSRC). SCMR and chlorophyll content were significantly correlated for all test dates at KKU (r = 0.49 to 0.64) but only moderately correlated at 40 DAP (r = 0.48), 90 DAP (r = 0.33) and 100 DAP (r = 0.32) for the NCSRC location. SCMR values had higher correlation between locations and across sample times than leaf chlorophyll content. Differences among entries were significant at all plant ages for SCMR at KKU but for only 70, 80, 90, and 100 DAP for NCSRC. Differences among entries were also observed for chlorophyll content at both locations for 80, 90 and 100 DAP. The SPAD chlorophyll meter is a useful tool for indirectly measuring leaf chlorophyll content in sweet sorghum, and has several advantages over direct measurement, including reduced labor and better reproducibility.