Effect of Wheat Vernalization on Rhopalosiphum padi L. Survival

Abstract

Four wheats, three Triticum aestivum L. em. Thell. and one T. turgidum L., vernalized and nonvernalized, were evaluated for response by the bird-cherry oat aphid, Rhopalosiphum padi L. Results showed that aphids on both vernalized and nonvernalized ‘Abe’ seedlings had better survival rates, higher fecundity, and more nymphs molting to adults than those of ‘Caldwell’ wheat seedlings. Abe was susceptible to R. padi and Caldwell had moderate resistance. Resistance rankings of these two cultivars were not affected by vernalization, whereas the rankings of‘Elmo’ and CI 17647 changed. Because the aphid performance on Elmo and CI 17647 seedlings was not consistent, these two wheats could not easily be classified as resistant or susceptible to R. padi.