Tomato Cultivar Evaluation: Marketable Yield

Methods: How We Conducted the Experiment

The study occurred in central Pennsylvania at Pennsylvania State University's Russell E. Larson Research Center in Pennsylvania Furnace and in southeastern Pennsylvania at Pennsylvania State University's Southeast Agricultural Research and Extension Center in Manheim. We evaluated 11 tomato cultivars and selections in 2022 and 13 in 2023 at the central site and 19 at the southeastern site in both years. 'Red Deuce' was used as the standard.

We used plasticulture systems at both sites with raised beds, a single line of drip tape per bed, and black plastic mulch. Five- to seven-week-old transplants were planted in mid-May to late June. We planted six plants of each cultivar in a single row with 18-inch in-row spacing and 10 ft between rows. Plants were suckered about three weeks after planting. Plants were provided with 1 – 1.5 acre-inches of water each week. Irrigation water was acidified to pH 6.3 in 2023 at the southeastern site. Pests and fertility were managed following recommendations in the 2022-23 Mid-Atlantic Commercial Vegetable Production Recommendations guide. We planted annual ryegrass between rows primarily to suppress weeds. 

We harvested tomatoes when they reached the ripe red stage. At the center site, we harvested weekly from July 21 to September 27, 2022, and August 2 to September 27, 2023. At the southeastern site, we harvested twice weekly from July 21 to August 18, 2022, and August 1 to September 25, 2023. Once harvested, fruit were categorized as marketable or unmarketable, counted, and weighed.

 The experiment used a randomized complete block design, with each cultivar replicated four times. Data were collected from six plants per cultivar and replication and analyzed using SAS's mixed procedure. Means were separated using pdiff.

Results: What We Saw 

Center Site

Overall, yields were lower in 2023 compared to 2022, likely because we experienced a cooler growing season. In 2022 and 2023, the total and marketable yield, measured as tomato fruit weight and number, of every cultivar in the experiment, was not different from 'Red Deuce' (see Tables 1 and 2). In 2023, the number of tomato culls was higher from FTM9743 than 'Red Deuce'. The total yields we saw were what we expected for 'Red Deuce' based on our experiences and other experiments (for example, 2005 Seedless Watermelon Variety Trial: Varieties by Average Melon Weight (University of Delaware). However, the marketable yield was lower. This is likely due to moisture and heat stress the plants experienced. You can find more information about these issues here: Blossom End Rot, Internal Whitening, and Rain Check of Tomatoes (Penn State).

*Values are means of six plants per replication and four replications; 'Red Deuce' (bolded) is the standard to which all other cultivars were compared; Values followed by different letters within a column are statistically different at P ≤ 0.05. Please read this article for more information on reading tables like this: Science, Tomatoes, and How to Read a Table (Penn State). 

*Values are means of six plants per replication and four replications; 'Red Deuce' (bolded) is the standard to which all other cultivars were compared; Values followed by different letters within a column are statistically different at P ≤ 0.05. Values in the blue text within a column are significantly larger than 'Red Deuce'. 

The results indicate that growing any cultivar we evaluated using the same growing methods in similar environments will produce yields that are not different from 'Red Deuce' most of the time and are good options for Pennsylvania farms. We also want to mention that in 2023, we observed that FTM 9743, FTM 9744, and FTM 9745 produced many fruit with a pointed blossom end, as shown in the following photos.

Southeastern Site

In 2022, bacterial canker destroyed the planting. It was abandoned on August 18, well before the growing season ended. 

In 2023, marketable tomato fruit by weight was higher from 'Patsy', 'Carrie', and PSFH 18-3 than 'Red Deuce' (see Table 3). The number of marketable tomatoes was higher from 'Patsy', PSFH 16-90, 'Carrie', STM 2255, PSFH 18-3, and PSFH 18-13. All other cultivars were not different from 'Red Deuce' in terms of either marketable tomato fruit weight or number. 

In 2023, tomato cull weight was lower from 'Carrie', 'Rambler', 'Patsy', PSFH 18-3, and PSFH 18-13 than 'Red Deuce' (see Table 3). All other cultivars were not different than 'Red Deuce’. The number of culls was higher from FTM 9744 and FTM 9743 than 'Red Deuce'. All other cultivars were not different than 'Red Deuce'. The main factor resulting in culled tomatoes was cracking – mostly small cracks, ¼ - ½ inch, at the stem end of the fruit. While acceptable in some markets, these fruit are sold as canners in local produce auctions and thus were considered culls. Markets with less stringent standards would have more marketable fruit than we had in this trial. During the mid and latter part of September, rains started (the season was dry until then), and most culled fruits had rain damage (long radial cracks, concentric cracks, and general fruit damage from excessive moisture).

*Values are means for individual plants; 'Red Deuce' (bolded) is the standard to which all other cultivars were compared; Values in the blue text within a column are significantly larger than 'Red Deuce,' values in the purple text within a column are significantly smaller than 'Red Deuce’. 

The high incidence of bacterial canker in 2022 makes it difficult to draw conclusions over both years of the trial at this site. However, all the cultivars we evaluated produced yields that were either higher or not different than 'Red Deuce’. This finding and the results from the central site suggest that all the cultivars evaluated are good options for Pennsylvania farms in similar environments using the same growing methods.