Alternative weed control using the allelopathic effect of natural benzoxazinoids from rye mulch

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 µg 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 R 2 of 0.076 for redroot pigweed and R 2 of 0.003 for common purslane, indicating that benzoxazinoids are not the only source of phytotoxicity. allelopathy / BOA / DIBOA / integrated weed control / mulch / rye / triticale

Allelopathy: driving mechanisms governing its activity in agriculture

“…Similarly, plants from the Poaceae family, such as oats (Avena strigosa Schreb. and Avena sativa L.) and rye (Secale cereale L.), are useful cover crops in the NT system because they can reduce the weed population (Tabaglio, Gavazzi, Schulz et al 2008;Gavazzi et al 2010;Bittencourt et al 2013;Schulz et al 2013). However, the straw of ryegrass (Lolium multiflorum Lam.)…”

“…NT cropping systems appear to be more likely to benefit from scientific research on the allelopathic effects of cover crops or forage mulching. The special impact of this knowledge can be foreseen on reduced weed emergence and growth and the potential decline in herbicide use (Tabaglio, Gavazzi, Schulz et al 2008;Altieri et al 2011;Pudelko et al 2015).…”

Benzoxazolinone Detoxification and Degradation – A Molecule ́s Journey

“…Investigated rye cultivars differ in the total benzoxazinoid amounts from 250 to 1800 µg g -1 dry tissue in young plants to about 100 µg g -1 or less in old plants (Reberg-Horton et al, 2005;Rice et al, 2005;Zasada et al, 2007). In rye cultivars used as mulches by Tabaglio et al (2008), the content ranges from 177 to 545 µg g -1 . High differences in the concentrations among rye cultivars are also reported by Burgos et al (1999).…”

Allelopathy, an alternative tool to improve cropping systems. A review

“…There is some consensus that a simple compound in a field situation may not be enough to affect the growth of the receiving plant and it is likely that different allelochemicals act additively or synergistically to inhibit growth (Belz, 2007;Einhellig, 1996;Kruse et al, 2000;Seigler, 1996;Tabaglio et al, 2008). The present literature review covers aspects of the current knowledge on the allelopathic interaction between crops and weeds.…”