SUSTAINABLE TOMATO PRODUCTION SYSTEM USING PERENNIAL GRASS ROTATION AND DISEASE RESISTANT VARIETIES

Tomato (Solanum lycopersicum, L.) production for fresh market consumption is a major agricultural enterprise in Florida. Over 16,500 ha of tomato were grown in 2006, with a production value exceeding $US 550 million. All commercial tomato growers rely upon a “raised-bed polyethylene mulch” production system to grow their crops. The use of perennial grasses in rotation with tomatoes has largely been overlooked, but has the potential to reduce soil-borne pest and weed problems. Methods for managing the growth of bahiagrass (Paspalum notatum, Flugge), sod and fertilizer application were evaluated to optimize the yield of strip-tillage tomato produced in bahiagrass pasture. Sod growth was managed by mowing, herbicides, and the width of tilled strip. Fertilizer (N, P and K) were applied at different rates and with different schedules. The highest yields were obtained using a combination of mowing and herbicides to manage sod growth. The application of N, using 1/3 at transplanting, 1/3 three weeks after transplanting and 1/3 6 weeks after transplanting gave the highest yield response. A nitrogen rate of 200 kg/ha, a typical rate in conventional growing systems, was adequate with minimum sod competition. Adequate tomato growth was obtained by mixing other nutrients and dolomite in the tilled strip according to soil test recommendations. Plant resistance is another pest and disease management practice that has been under used in conventional tomato production in Florida. Many highly productive tomato varieties now have resistance to Verticillium (race 1) and Fusarium (races 1, 2, 3) wilts, Tomato spotted wilt and root-knot disease. Proper use of disease resistant tomato in strip-tilled perennial grass rotations could eliminate soil fumigation and polyethylene mulch in most production scenarios. Plant resistance tests in bahiagrass sod containing 1,3-dichloropropene + 35% chloropicrin (1,3-D + 35%Pic) or no 1,3-D + 35% Pic were examined. No significant difference in yield or percent marketable fruit were found between 1,3-D + 35% Pic treatment or the non-treated control in either the spring or fall field trials. Soil-borne fungal diseases were not detected in tomatoes in either the spring or fall trials, and root galling caused by nematodes was not detected or at very low levels in the 1,3-D + 35% Pic or non-treated control plots. Where root-gall was found, it was present only in tomato varieties without Mi-gene resistance.