You will get some dispute on this, but generally on flat ground they should run close to North-South. Some will set the rows to be in line with the sun at about 2:00 pm to shade the fruit from the hottest sun, but in fact the sun's maximum radiation intensity is when it is highest in the sky, very close to noon, even though the hottest temperature of the day may be later in the early afternoon. I have seen other published opinion/research stating that it makes very little difference. Ralph