Root plant to fuel the process. In return, the plant takes nitrogen compounds produced from ammonia by the bacteria. The term root crops refers to any edible underground plant structure, but many root crops are actually stems, such as potato tubers. Edible roots include cassava, sweet potato, beet, carrot, rutabaga, turnip, parsnip, radish, yam and horseradish. Spices obtained from roots include sassafras, angelica, sarsaparilla and licorice. Sugar beet is an important source of sugar. Yam roots are a source of estrogen compounds used in birth control pills. The fish poison and insecticide rotenone is obtained from roots of "Lonchocarpus" spp. Important
Sweet potato feathery mottle virus as well as strain of virus, and can vary between geographical locations. Many infections are localized, mild, and often asymptomatic, and can go untreated without causing significant damage to the plant. The most common symptom of SPFMV is a feathery, purple pattern in the leaves. However, more virulent strains such as the russet crack strain (RC) have been known to cause root necrosis and leaf chlorosis, and some strains have been shown to cause root discoloration. However, due to SPFMV’s significant contribution to sweet potato viral disease, many studies are directed toward creating immunity to SPFMV in susceptible plants. One