It requires less water and less energy to supply the water to only the root zone. This reduces weed growth in middle rows, and it keeps leaves dry, which reduces disease and prevents washing off dusts and sprays. It also allows watering and placing soluble fertilizers under plastic mulch. You also can work in the garden while irrigating. Use traps for insect control.
Some insects spread disease and viruses to vegetables.
Many insects are attracted to yellow. The most commonly used insect trap is a bright yellow sheet of cardboard, plywood or plastic coated with a sticky compound. The color must be bright yellow to be effective. There are other traps as well. Water traps made from bright yellow pans filled with water and a small amount of liquid soap attract aphids and cabbage-root flies.