In a 6-year trial with young Delicious and Granny Smith apple trees on Merton 778 rootstock the effects were compared of trickle irrigation applied 1, 3, 4 or 5 times/week, compared with no irrigation. Water applied four times per week with trickle irrigation gave optimum growth and yields with Delicious and Granny Smith apples. Growth trends were found in the first season to be related to irrigation frequency, and these trends were reflected in later cropping
