Dhurrin content and biomass yield in sorghum hybrids throughout plant growth cycle

Abstract

AbstractIn recent years, the use of sorghum [Sorghum bicolor (L.) Moench] in crop rotation as a green manure to decrease nematode infestation and promote the growth of subsequent crops has strongly increased. The reason why sorghum is effective in biofumigation against root‐knot nematodes is because it releases dhurrin, a cyanogenic glycoside found in epidermal leaf tissue. Currently, there is little information regarding dhurrin production deriving from dhurrin concentration and biomass produced. A field study was conducted in northeastern Italy to investigate the change in dhurrin content and biomass production of three commercial sorghum‐sudangrass cultivars (Hay Day, Mataco, and Ruzrok), over their entire growth cycle under seeding dates (May and July). Regardless of the growing period, Ruzrok displayed a higher dhurrin production. During the early growth stages, Ruzrok did not exhibit a higher yield compared with Mataco and Hay Day, hence its higher potential as a biofumigant is due to the higher concentration of dhurrin in plant tissues. During spring conditions, all tested cultivars showed higher dhurrin production up to a height of 100 cm, while the amount of dhurrin did not significantly change during the entire growing period in summer.