EFFECT OF THE PEA APHID,ACYRTHOSIPHON PISUM(HEMIPTERA (HOMOPTERA): APHIDIDAE), ON YIELD AND QUALITY OF FORAGE ALFALFA

Abstract

AbstractThe pea aphid,Acyrthosiphon pisum(Harris), affected yield by significantly reducing the mean height of aphid-susceptible Grimm alfalfa in a greenhouse experiment by 45%, the height of the longest stem by 35%, the green weight by 38%, the dry weight by 44%, and the fiber by 13%. There was limited change in quality of alfalfa. The percentages of protein, fat, total sugar, reducing sugar, dry matter, and nitrogen-free extract were not significantly different in the infested and non-infested alfalfa. Potassium was significantly lower in the infested plants but they contained more calcium, magnesium, and phosphorus. With the exception of isoleucine the amino acid composition was similar in the infested and non-infested alfalfa.