Source: Allen Press
Researchers compared the effects of orienting rows of crops north to south or east to west to test if their exposure to sunlight decreased access to light for weeds, thereby increasing yields. The journal Weed Science reported the results of the trials, which were conducted from 2002 to 2005 in western Australia.
Situating the crop rows at a near right angle to the sunlight direction can influence the light interception. Crops can create a canopy over weed plants, giving the weeds more shade than sun, suppressing weed growth and maximizing crop yield.