Sunflower varieties having plants with armored-layer seeds resulted in a high reduction of seed damage caused by larval feeding of the sunflower moth, Homoeosoma electel-lum (Hulst). Several sunflower lines were significantly more resistant to seed damage when the plants had armored-layer seeds than when the same lines had non-armored-layer seeds. The association of the armored layer with moth resistance was also shown by its significant reduction in the number of emerging adults. However, the same lines having plants with no armor still retained some resistance (compared with the check), which indicated that some chemical factors were also involved. Laboratory tests also indicated that the nature of resistance was partially chemical.

Assisting in the study were John Campbell, formerly nurseryman at U.C. Davis arid Dr. Benjamin Beard, Research Geneticist, USDA—ARS, Davis. Sunflower plants were grown for this research with the. cooperation of the Department of Agronomy and Range Science.