High Tunnel Tomato Variety Results

• Gary Shafer, ISP Research

As with the greenhouse tomato variety data given in the Autumn issue of this newsletter, the owner of the farm where the trail was located grows “pesticide free” produce, so we were limited as to the materials we could use to offset disease and insect pressures.  Diseases identified included; early blight, septoria leaf spot, botrytis (leaf mold), random anthracnose, and late blight.  Insect pests included some early thrip, very intense aphid pressure, spider mite, brown marmorated stink bug, tomato hornworm, corn ear worm, and grasshoppers.  There was also the secondary disease issues stemming from other disease or insect damage.

There was an early application of Pyganic applied once aphids were noticeable.  This application did little to reduce the populations, or the spread throughout all the tomatoes.  It had been used in the past so there was probably resistance to this chemistry.  Aside from that, the primary methods of fighting aphids was introducing predator species.  The primary problem with the predators was that they can consume only so many aphids in a day, and we were well above those limits.

In addition, the weight of the plants caused portions of the row to fall three different times through the season.  One time almost the entire row was down.  In each instance, the row was forced back upright and additional stakes were used to strengthen the support.  All other management procedures were consistent across all varieties.  Applied nutrient included dry fertilizer applied preplant, fertigation through drip lines and foliar applications.

Each plot had five tomato plants, which were planted on May 11.  The project was terminated on October 29^th due to frost.  All plants still had a large number of fruit, most of which were not harvestable.  One other observation during production was the use of straw as mulch, rather than the usual plastic row cover.  Weed control was quite good, as good, and perhaps slightly better than the plastic used in the greenhouse trails.