Farmers' bulletin (United States. Dept. of Agriculture) ; no. 1863

"The turnip aphid is one of the most destructive and widely distributed pests of turnip, mustard, radish, and related crops in the United States. It causes heavy losses to growers of these crops every year, especially in the Southern States. Dust mixtures containing derris, cube, or nicotine, and sprays containing derris or cube, will control the turnip aphid when applied properly. The first application of insecticides should be made when the plants are very small, and additional applications should be made at intervals of 7 to 14 days up to the time of harvest. To provide for effective application of insecticides, the seed of susceptible crops should be planted in drills, with the rows spaced uniformly apart. The following cultural practices aid in the successful production of crops exposed to turnip aphid attack: (1) A well-prepared, fertile seedbed to produce thrifty and rapidly growing plants, (2) planting the seed in drills to permit cultivation, (3) harvesting early to shorten the period of exposure to infestation, (4) destroying crop remnants to eliminate a common sources of infestation to succeeding crops, and (5) applying a nitrogenous fertilizer to stimulate plant growth." -- p. i