Grafting and Number of Polyplastic Film Layers Affect Yield of High Tunnel Tomatoes

High tunnel tomatoes play an important role in season extension in the Midwest. Farmers always request the latest information on high tunnel tomato varieties and management techniques. The objectives of our trials were to evaluate new hybrid tomato varieties and to investigate the grafting effects on heirloom tomatoes grown in 30’ x 96’ Zimmerman high tunnels covered with either single-layer or double-layer polyplastic film at Lincoln University’s Carver Farm  in Jefferson City, Missouri. In 2012, four determinate varieties (Mt. Glory, BHN-589, Charger, and Rocky Top) and seven indeterminate varieties (Arbason, Bigbeef, Bigdena, Geronimo, Panzer, Rebelski, and Trust) were tested.  Heirloom tomatoes German Pink and Ananas Noire were grafted onto rootstocks Maxifort, Beaufort, Multifort, Colosus, and RST04-106-T, with own-rooted scions as controls.  Grafting was done in a greenhouse using the Tube Grafting method. All trials in the high tunnels were conducted in a completely randomized-block design with four replications per variety and four plants per replication. Plants of indeterminate varieties and grafted heirlooms were trained to a single leader. Determinate varieties were pruned up to the first fruit cluster. All other management techniques were similar to local high tunnel tomato production standards. Data showed that yield and number of fruit were similar among determinate varieties. For indeterminate varieties, Geronimo yielded the most, while Trust yielded the least. Mt. Glory, BHN-589, Rocky Top and Geronimo yielded higher in the single-layer high tunnel than in the double-layer high tunnel. Yield was higher for grafted heirloom varieties in the double-layer high tunnel than in the single-layer high tunnel. Colosus rootstock greatly enhanced the early yield of the German Pink variety. All varieties experienced severe blossom end rot with the worst incidence occurring on Ananas Noire. Rootstocks did not reduce the incidence of blossom end rot disorder.