Herbicides for Weed Control in Blessed Thistle (Silybum Marianum)

Abstract

Blessed thistle is an important medicinal crop in Europe and recently has become more significant in North America. A limiting factor in blessed thistle production is weed interference. Field experiments were conducted near Plovdiv, Bulgaria, to study the effect of selected herbicides on weed control, crop productivity, and crop quality. Seed yields of blessed thistle were increased with metribuzin alone at 0.5 kg ai/ha, pendimethalin alone 1.32 kg ai/ha, pendimethalin at 1.32 kg ai/ha plus metribuzin at 0.5 kg ai/ha, trifluralin at 0.84 kg ai/ha plus linuron at 1.0 kg ai/ha, and in the hand-weeded control compared to the nonweeded control (nontreated check). Pendimethalin and metribuzin were safe both alone and in combination for weed control in blessed thistle. Bentazon at 0.96 kg ai/ha inhibited blessed thistle development and reduced seed yields compared to the untreated check. Generally, weed control increased the content of silymarin and decreased the amount of seed oil. Overall, seeds contained 0.26 to 0.36% taxifolin, 0.69 to 0.99% silydianin plus silycristin, 1.31 to 1.78% silybin, and 0.27 to 0.39 % isosilybin.

Biology of milk thistle (Silybum marianum) and the management options for growers in north‐western Pakistan

“…Milk thistle, also known as blessed thistle, has become one of the most widely grown and economically viable medicinal plants in parts of Europe, including Bulgaria (Zheljazkov et al. 1996), and is being evaluated as a crop in Canada (Omidbaigi & Nobakht 2001; Zheljazkov et al. 2006).…”

“…(2007) reported that milk thistle control in wheat ranged from 90–94% with chlorsulfuron at 10.5 g ai ha −1 , metsulfuron plus sulfosulfuron at 36 g ai ha −1 , or bromoxynil plus MCPA at 560 g ai ha −1 . Zheljazkov et al. (2006) reported that bentazon at 0.96 kg ai ha −1 suppressed milk thistle growth and seed production.…”

Changes in the sterol compositions of milk thistle oil (<em>Silybium marianum</em> L.) during seed maturation

“…Milk thistle is an important medicinal crop in Europe and has recently become more significant in North America (Zheljazkov et al, 2006). The medicinal compounds of value are found in the seeds of the plant.…”

Nonchemical weeding of medicinal and aromatic plants

“…), fennel (F. vulgare Mill. ), sage (Salvia officinalis L.), savory (Satureja officinalis L.), and thyme (Thymus officinalis L.) (Kothari et al 1989;Pank 1992;Zheljazkov et al 1996;Zheljazkov et al 2006). Following these authors, if phytotoxic effects were avoided, the use of pendimethalin, fluchloralin, and other chemicals did not affect seed or oil yields or oil quality.…”