Stomach analyses of 947 yellow pikeperch fingerlings taken from rearing ponds show that fry begin feeding on rotifers and nauplii, and that as the fish increase in size Entomostraca, insects, and fish successively become important items in the diet. Yield and management data from 185 ponds suggest that the best means of controlling cannibalism and increasing yields are: (1) fertilization to promote an early and sustained crustacean crop; (2) use of forage fish as a food and “buffer population”; and (3) harvesting at a weight of 50 to 80 fingerlings to the pound. The average yield per acre of yellow pikeperch from ponds in Minnesota for the period 1940–1943 was 48.4 pounds and 2,111 fingerlings; this output was lower than that of other game-fish ponds. The average yields in pounds per acre attained in yellow pikeperch ponds under different management methods were: neither forage nor fertilizer, 7.5; fertilizer only, 41.6; sucker fry but no fertilizer, 44.0; and minnows but no fertilizer, 95.8. Few ponds succeeded that had a game-fish or minnow population when fry were stocked. Data from 10 experimental ponds demonstrate that fertilization is usually necessary to produce an early crustacean crop and that the most effective types of fertilizer are commercial fertilizer and sheep manure. Cottonseed meal and superphosphate were found to be relatively ineffective. Water analyses on 10 experimental ponds and 71 rearing ponds suggest that a greater utilization of the natural fertility can be had in most ponds through more intensive management.