How Do Farmers Grow Seedless Grapes and watermelon?

Two weeks before flowers appear on the vines the buds are dipped in a special liquid. The liquid contains a special substance that comes from a fungus. Ten days after the flowers bloom they are dipped again. That is what causes the grapes to be seedless. Gibberellin's acts like a plant hormone to cause grapes to ripen without fertilisation and without seeds. A chemical called colchicines is applied to a normal watermelon, which has two chromosomes, to produce one with four chromosomes. This is crossed with a normal melon to make one with three chromosomes When this is crossed with a normal melon a seedless one results.