In Sinaloa, water from mountain reservoirs has been extremely low since 1994, but drip irrigation has permitted tomato production to remain high. Local irrigation authorities give tomato growers first priority in water allocation. Drip tubing with regularly spaced holes are laid permanently at the center of the tomato beds, and water and liquid fertilizer are applied more efficiently than by using movable irrigation rigs and separate fertilizers. A side benefit of fertigation is reduced water pollution from leaching and runoff of agricultural chemicals. Tomatoes for export are grown according to U.S. tolerance standards for chemical residues.
Plastic mulch reduces weeds, promotes growth, and blocks pests moving from the soil to the plant.
The result is less need for herbicides, fungicides, and insecticides. Plastic mulch raises the soil temperature, reduces water evaporation, and increases total plant productivity. Stakes have replaced the traditional bark-covered sticks and branches in Sinaloa and Baja. But workers are still needed to tie the plants periodically to the stakes. The technological linchpin to the export growth of Mexico's tomato industry has been its successful adoption of the ESL varieties.