Submitted to: International Allelopathy Congress
Publication Type: Proceedings
Publication Acceptance Date: 7/7/2005
Publication Date: 8/22/2005
Citation: Gealy, D.R., Ottis, B., Talbert, R., Moldenhauer, K., Yan, W. 2005. Evaluation and improvement of allelopathic rice germplasm at Stuttgart, Arkansas, USA. In: Harper, J., An, M., Wu, H., Kent, J., editors. International Allelopathy Society. Proceedings and Selected Papers, Fourth World Congress on Allepathy--Establishing the Scientific Base, August 21-27, 2005, Charles Stuart, Wagga Wagga, Australia. p. 157-163. Interpretive Summary:
Technical Abstract: Effective, affordable weed control is a challenge to sustainable rice production in the U.S. In the 1980s, evaluation of the allelopathic potential of rice germplasm in drill-seeded systems was initiated in Stuttgart, AR. These efforts led to the identification of several foreign lines with allelopathic activity against aquatic weeds, and some of these lines (e.g. PI 312777) also have suppressed barnyardgrass (Echinochloa crus-galli; BYG) more effectively and economically under reduced herbicide inputs than have commercial cultivars. These suppressive rice lines appear to produce greater foot mass near the soil surface compared to non suppressive cultivars. Because plant type and grain quality of these lines have often been inadequate for the U.S. rice industry, a breeding program was initiated to combine the desirable characteristics of Katy long grain rice with several high yielding, suppressive lines. F5 or later generations from selections of the pedigree PI 338046/Katy//PI 312777 have been evaluated for several years. Some selections have produced acceptable yield and quality, but often yielded or suppressed BYG less than did parental lines or other standards. Several ‘competitive’ indica lines from Asia (e.g. 4593 from China) and commercial hybrids from the U.S. (e.g. XL8) have yielded as much or more that elite U.S. cultivars, and controlled BYG similar to the most suppressive rice lines. Thus, these germplasm lines may be useful in weed suppressive systems for U.S. rice.