Cuttings from resistant alfalfa clone 4956 and susceptible clone 4959 were grown for 9-14 weeks in white silica sand watered with solutions that contained an excess, a medium, or a deficient amount of calcium, magnesium, nitrogen, potassium, phosphorus, or sulfur before they were infested with Therioaphis maculata (Buckton) . None of the treatments made the susceptible clone more resistant. Resistance was significantly decreased but not eliminated when the resistant clone was treated with deficient levels of calcium or potassium or excess levels of magnesium or nitrogen, but resistance was significantly increased in plants receiving deficient levels of phosphorus. Sulfur did not affect resistance.
Document Type: Research Article
Publication date: June 1, 1970
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Journal of Economic Entomology is published bimonthly in February, April, June, August, October, and December. The journal publishes articles on the economic significance of insects and is divided into the following sections: apiculture & social insects; arthropods in relation to plant disease; forum; insecticide resistance and resistance management; ecotoxicology; biological and microbial control; ecology and behavior; sampling and biostatistics; household and structural insects; medical entomology; molecular entomology; veterinary entomology; forest entomology; horticultural entomology; field and forage crops, and small grains; stored-product; commodity treatment and quarantine entomology; and plant resistance. In addition to research papers, Journal of Economic Entomology publishes Letters to the Editor, interpretive articles in a Forum section, Short Communications, Rapid Communications, and Book Reviews.