Wheat and barley were introduced into watermelon production systems to control weeds and save labor in Japan. Mature seeds then germinate after mowing and new leaves develop into a living mulch. Watermelons are grown on this straw and living mulch the following year.
Watermelons coil their leaves around the straw and new leaves to fix their vines to the ground.
This system decreases working hours for laying of straw and weeding and consequently leads to labor savings overall. Wheat and barley thus support the growth of watermelon even without producing grain. This cropping system has two merits from the ecological and social point of view. One is weed suppression by organic mulch, and the other is decreasing working hours for laying of straw and weeding. Mowers are needed in large-scale fields because mowing with bush cutters is too labor intensive.