THE EFFECT OF APHIS FABAE SCOP. ON THE GROWTH AND YIELD OF FIELD BEANS IN A GARDEN PLOT.

This section focuses on the effect of Aphis fabae Scop. on the growth and yield of field beans in a garden plot. By June 29, 1948, the effects of the infestation were visible and showed a statistically significant reduction in mean total stem-length per plant or 22 percent as compared with controls; there was also a significant reduction of 11 percent in the mean number of stems per plant. The yield was greatly reduced on the infested plants, the mean weight of beans per plant being 58.7 grams for controls and 33.3 grams for infested plants. A significant correlation was obtained between mean individual stem-length per plant and degree of infestation using only infested plants, as well as between yield on total stem-length per plant and yield on number of stems per plant.