After planting, young M2 apple rootstocks were either grassed down or kept clean-cultivated, and all received irrigation to maintain minimal soil moisture stress for two complete growing seasons. The plants were grown with or without (i) a high rate of mineral nitrogen applied frequently to the soil, and (ii) frequent foliar sprays of urea. Each of the nitrogen treatments increased the growth of the plants in grass and their effects were independent of each other and additive. On the clean-cultivated plants both treatments tended to reduce growth.