Selecting tomato cultivars can be both exciting and challenging, simply because there are so many options to choose from. Some growers settle on a few favorite cultivars and focus on fine-tuning their production practices to suit them. Others prefer to explore new cultivars every year, selecting those that best fit their evolving production systems. Regardless of the approach, growers understand that no single cultivar outperforms every parameter across different production systems. The key often comes down to which traits or parameters the grower values the most.
We recently conducted a tomato cultivar trial comparing six determinate tomato cultivars. We selected these cultivars based on grower feedback—each one was mentioned as a favorite by at least one grower. Although the list of potential cultivars was much longer, space limitations allowed us to include only six: Celebrity Plus, Mountain Fresh Plus, BHN 589, Red Deuce, STM2255, and a yellow tomato cultivar, Carolina Gold.
We conducted replicated trials at the Southwest Purdue Agricultural Center, comparing performance in two distinct production systems. One was a high tunnel system with frequent irrigation and fertilization management; the other was an open-field system that depended on preplant fertilizers, and a few irrigation events that applied only during the excessive dry period. Soils were loamy sand, similar between the high tunnel and the open field.
Unsurprisingly, the same cultivars grown in high tunnels produced much higher yields (28-58 lbs/plant) and had a significantly longer harvest season than those grown in the open field (11-16 lbs/plant). The primary factors contributing to unmarketable fruit were blossom end rot (BER) in the open-field system and fruit cracking in the high tunnel system. The likely cause of BER in the open field was large fluctuations in soil moisture, while high soil moisture contents, especially during the harvest period, likely contributed to fruit cracking in the high tunnels.
Celebrity Plus had the highest incidence of BER in the open field and the most cracking in the high tunnels. In contrast, STM2255 had the lowest incidence of BER in the open field, and one of the cultivars had the fewest cracked fruits in the high tunnel. STM2255 had the highest marketable yields in the high tunnel. The same cultivar also had the highest yield in open-field, but it was not significantly different from Red Deuce, BHN589, and Carolina Gold.
Fruit quality was evaluated for high tunnel-grown tomatoes. We measured the total soluble solids of vine-ripe and counter-ripe fruit. As expected, vine-ripe tomatoes generally had a higher sugar content compared to counter-ripe fruit. Interestingly, cultivar differences in °Brix values appeared more pronounced in counter-ripe tomatoes than in vine-ripe ones. BHN589 had the highest °Brix value among the counter-ripe samples—significantly higher than those of Red Deuce, STM2255, and Mountain Fresh Plus. Notably, consumers also rated BHN589 and Celerity Plus as having the best flavor.
Internal white tissue is an undesirable trait in tomatoes. It is often associated with high temperatures and varies among cultivars. Among the six cultivars evaluated, Celebrity Plus stood out by showing the least incidence of internal white tissue.
More information about the tomato cultivar evaluation in high tunnels can be found in the published trial report Evaluation of High Tunnel Tomato Cultivars for Yield and Quality.
Figure 1. Tomato slices of six cultivars evaluated in the trial (Photo by: Wenjing Guan).