Oilseed crops are being widely evaluated for potential biodiesel production. Seed meal (SM) remaining after extracting oil may have use as bioherbicides or organic fertilizers. Brassicaceae SM often contains glucosinolates that hydrolyze into biologically active compounds that may inhibit various pests. Jatropha curcas SM contains curcin, a phytoxin. A 14-day greenhouse study determined that Sinapis alba (white mustard), Brassica juncea (Indian mustard), Camelina sativa, and Jatropha curcas applied to soil at varying application rates [0, 0.5, 1.0, and 2.5% (w/w)] and incubation times (1, 7, and 14？d) prior to planting affected seed emergence and seedling survival of cotton [Gossypium hirsutum (L.)], sorghum [Sorghum bicolor (L.) Moench], johnsongrass (Sorghum halepense), and redroot pigweed (Amaranthus retroflexus). With each species, emergence and survival was most decreased by 2.5% SM application applied at 1？and 7？d incubations. White mustard SM incubated for 1？d applied at low and high rates had similar negative effects on johnsongrass seedlings. Redroot pigweed seedling survival was generally most decreased by all 2.5% SM applications. Based on significant effects determined by ANOVA, results suggested that the type, rate, and timing of SM application should be considered before land-applying SMs in cropping systems. 1. Introduction Research involving oilseed crops for biodiesel production has increased due to greater needs for renewable energy sources. Biodiesel is an EPA-approved renewable fuel that can be produced from oilseed crops. The oil extracted from seed is chemically reacted with an alcohol, such as methanol, to form chemical compounds known as fatty acid methyl esters, or “biodiesel.” The oil contained in the seed is most often extracted mechanically using a screw press. The residue remaining after oil extraction is referred to as either a press cake or seed meal (SM). In order for biodiesel production to be economically and environmentally sustainable, a feasible and profitable means of byproduct or SM disposal and/or usage needs to be developed. Utilization of SM in organic agricultural production systems offers a possible solution. Oilseeds have the potential to produce significant energy and renewable fuels and include such oilseeds as soybean [Glycine max (L.) Merr.], canola and rapeseed (Brassica napus), Indian mustard (Brassica juncea), white mustard (Sinapis alba), physic nut or jatropha (Jatropha curcas), camelina (Camelina sativa), and castor bean (Ricinus communis). Brassicaceae oilseeds have been reported to contain 30 to
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