Essential oil of mustard to control Rhizoctonia solani causing seedling damping off and seedling blight in nursery

Abstract

The essential oil extracted from mustard (Brassica rapa) seeds was evaluated for its effect on suppression of Rhizoctonia solani growth in vitro, and in field soils, for reducing saprophytic substrate colonization and seedling damping off and blight using snap beans as indicator plant, the in vitro growth was completely inhibited at a concentration of 50 mul/l. The saprophytic substrate colonization in soils 24 h after treatment was drastically reduced to 45% at 150 mul/kg soil concentration, in contrast to 100% colonization at concentrations of 0, 50, or 75 mul/kg. This recovery rate gradually declined to 6% and 60%, respectively, in nine days. A control of pre and post-emergence seedling damping off and blight in common beans (Phaseolus vulgaris), without any apparent phytotoxic effect was achieved by irrigating R. solani infested soils with water containing the emulsified essential oil to provide 150 mul/l soil volume ten days prior to planting, gave over 95%. The effect of the mustard essential oil was not influenced by the physical soil texture, and it appears to be a good substitute for methyl bromide fumigation in nurseries for seedling production.

Chemistry and Bioactivity of Essential Oils

“…It is these breakdown products which may be major constituents of essential oils, such as phenylacetonitrile which makes up 85.9% of the oil from Lepidium meyenii (Walp.) [101] and various isothiocyanates, which are the major constituents of mustard (Brassica rapa) seed essential oil [102][103][104]. The Brassicaceae family, with over 350 genera and 3000 species, is an important source of glucosinolates and isothiocyanates [100].…”

Effect of a Mustard Green Manure on Potato Yield and Disease Incidence in a Rainfed Environment

“…In this region, Rhizoctonia, white mold, and powdery scab are several diseases of concern to potato growers. Previous work suggests that Brassica cover crops may have some efficacy against Rhizoctonia on tubers (4). On the other hand, Brassicas are a host to white mold, and white mold sclerotia have shown some resistance to glucosinolate breakdown products (12).…”

Preparation and use of oil formulations of Beauveria bassiana and Metarhizium anisopliae against Spodoptera litura larvae

“…Compatibility levels differed significantly between the formulations of the two entomopathogens. Formulations of almond oil and Gingelly at 1, 2 and 3% were compatible with B. bassiana and to M. anisopliae (Table 2) against several species of Aspergillus, Penicillium and Eurotium (Nakahara et al, 2003), and, that mustard oil were reported (Nielsen and Rios, 2000;Dhingra et al, 2004). Barring few exceptions, all the formulations at the three concentrations and with B. bassiana as well as with M. anisopliae, germination recorded more reduction rather than the corresponding values for colony diameter.…”