Grafting Influences on Fruit Yield of Tomatoes Grown in a High Tunnel

There has been a large increase in the use of high tunnels for vegetable production in the United States.  While high tunnels offer well-defined benefits, growers have difficulty practicing crop rotation.  This increases risks of soil-borne disease.  Past studies have shown that grafting tomatoes onto disease resistant rootstocks can protect plants from soil borne disease, and improve plant growth and yield. A two-year study was conducted in research high tunnels at the Rutgers Agricultural Research & Extension Center, Bridgeton, NJ, to determine if grafting affected tomato yield and quality independent of disease pressure using a bag culture system.  The trial compared four tomato cultivars (BHN589, Primo Red, Red Deuce, and Scarlet Red) grafted onto ‘Multifort’ rootstock in 2011 and ‘Maxifort’ rootstock in 2012 with ungrafted plants.  Plant height and total yield was greater for all four cultivars from grafted plants than ungrafted plants in both years.  There was a significant interaction between cultivar and grafting treatment for total yield in 2012 (P = 0.0022) but not in 2011 (P =0.1202).  Average fruit size was significantly increased by grafting in 2012 but not in 2011.  Grafting tomato plants is a useful tool for high tunnel growers when unable to rotate crops subject to disease pressure, and for increased productivity in the absence of disease pressure.