NOT ALL MUSTARDS ARE CREATED EQUAL!
Variety selection is the first and most important step when implementing bio-fumigant green manures into your IPM system. Of the 120+ glucosinolates (GL's) produced by brassicas, only a few produce the isothiocyanates (ITC's) with the volatility and biocidal activity to be successful in commercial applications. All of our varieties have been specifically bred to contain high levels of the GL sinigrin. When the plant tissue is macerated, the sinigrin comes in contact with the enzyme, myrosinase and water to form these Alleyl ITC's (AITC's). At high enough concentrations, these very volatile AITC's are responsible for the reduction in soil-borne pest and disease levels. Mustard varieties that don't contain the proper GL's or don't have high enough concentrations of the proper GL's can act as hosts to the exact pests and/or diseases you were trying to control!
ORIENTAL MUSTARD (Brassica juncea)
Oriental mustards contain the glucosinolate, sinigrin. Whenever sinigrin-containing plant tissue is crushed or otherwise damaged, the enzyme myrosinase degrades sinigrin to a volatile gas, allyl-isothiocyanate (AITC). AITC is the organosulfur compound with the formula CH2CHCH2NCS. AITC's also serve the plant as a defense against herbivores; since it is harmful to the plant itself, it is stored in the harmless form of the glucosinolate, separate from the myrosinase enzyme. When an animal chews the plant, the AITC is released, repelling the animal. This reaction is replicated in the soil when these plant tissues are macerated and incorporated into adequate moisture. The perfect example would be dipping your pork in hot mustard at the Chinese restaurant or you sashimi in wasabi at the sushi bar! Other oriental mustard varieties on the market were bred to be edible types for humans and animals.
WHITE MUSTARD (Sinapis alba)
White mustards contain the glucosinolate, sinalbin. When the sinalbin GL comes in contact with the enzyme myrosinase, it is metabolized to form the mustard oil 4-hydroxybenzyl isothiocyanate. The less sharp taste of white mustard is because 4-hydroxybenzyl ITC is unstable and degrades to 4-hydroxybenzyl alcohol and a thiocyanate ion, which are not pungent or volatile. These white mustards were bred as mild condiment type mustards for human consumption. The perfect example of this would be squeezing French's yellow mustard on your hotdog. Although it might be tasty, it doesn't create any AITC to make your nose run. These non-volatile white mustard varieties can actually host a wide variety of pests and diseases. There are multiple cases where growers around the globe have lost their entire crops to disease damage the year following these white mustard green manure crops. Many of these varieties are advertised as having great weed suppression potential. Much research has been done to show that this suppression of weeds is caused because of extremely elevated levels of pythium, not because of any "biofumigation" occurring. CHOOSE YOUR COVER CROPS WISELY!
NEMAT/ARUGULA (Eruca sativa)
Nemat/arugula was developed as a green manure crop that contains high levels of biocidal GL's and is an effective trap crop for many Root Knot and Cyst nematode species. As the Nemat grows, the roots exude large amounts of sugar. These sugars attract the nematodes, wireworms, or other soil pests to the root zone of the growing Nemat. Females burrow into the roots to lay their eggs, but the eggs never hatch and the female dies (hence the term "Trap Crop"). Even if the female never enters the root, when the Nemat is chopped and incorporated, the volatile AITC's released have shown to be greatly effective in reducing nematode populations. The unique agronomic properties of Nemat allow good biomass production in growing conditions that most green manure crops can not tolerate. We offer straight Nemat Blends as well as multiple Nemat/Caliente Blends. The use of Nemat/Caliente Rojo Biofumigants have been widely adapted into cropping systems dealing with elevated disease and pest pressures in both organic and conventional systems.
Used in organic and conventional potato production systems across the globe.