Alternative weed control using the allelopathic effect of natural benzoxazinoids from rye mulchVincenzo Tabaglio1, Carolina Gavazzi1, Margot Schulz2 and Adriano Marocco1
1 Istituto di Agronomia Generale e Coltivazioni Erbacee, Facoltà di Agraria, Università Cattolica del Sacro Cuore, Via Emilia Parmense 84, 29100 Piacenza, Italy
2 IMBIO, University of Bonn, Karlrobert Kreiten Str. 13, 53115 Bonn, Germany
Accepted 4 January 2008 ; published online 3 June 2008
Abstract - In conventional agriculture, weed control by herbicides is an expensive practice and can also have a negative effect on the environment. Allelopathy permits sustainable weed management while reducing the impact of agriculture on the environment. We studied the content of 2,4-dihydroxy-1,4 (2H)-benzoxazin-3-one (DIBOA) and benzoxazolin-2(3H)-one (BOA), indicated as benzoxazinoids and considered effective for weed control, in 8 cultivars of rye and 1 of triticale grown in a greenhouse. We also tested the ability of mulches to inhibit the germination of four warm-season weeds. Our results show that all rye cultivars produced DIBOA, while BOA was found only in four of them. Benzoxazinoids were absent in triticale. Total benzoxazinoid content ranged from 177 to 545 g g-1 and was statistically different among cultivars. Rye mulches were not able to suppress velvetleaf and common lambsquarters seedlings, while redroot pigweed and common purslane were significantly affected. Weed suppression ranged from 40% to 52% for redroot pigweed and from 40% to 74% for common purslane. The inhibitory activity of triticale mulch was observed only for common purslane, with a suppression percentage of 33%. No correlation was found between total benzoxazinoid content and the number of weed seedlings suppressed, with R2 of 0.076 for redroot pigweed and R2 of 0.003 for common purslane, indicating that benzoxazinoids are not the only source of phytotoxicity.
Key words: allelopathy / BOA / DIBOA / integrated weed control / mulch / rye / triticale
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© INRA, EDP Sciences 2008