2018 Evaluation of New Determinate Tomato Varieties for Backyard Garden and Small-Scale Market Production in El Paso County, TX

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1 2018 Evaluation of New Determinate Tomato Varieties for Backyard Garden and Small-Scale Market Production in El Paso County, TX Introduction Bev Clark, Marianela Milner, Evelyn Posey, Sharon Valdes El Paso County Master Gardener Association (EPCMGA), El Paso, TX Choosing plant varieties resistant to disease is key to a successful tomato crop. In 2017, the Tomato Yellow Leaf Curl Virus, TYLCV, (Begomovirus from the family Geminiviridae), vectored by several types of whitefly, Bemisia tabaci, destroyed most of the tomato plants propagated at the El Paso County Master Gardeners Association (EPCMGA) greenhouse, including a desired and high producing grape tomato variety, Juliet. This virus, unknown to most home gardeners, has been damaging crops in areas where cotton is grown because whiteflies multiply on cotton plants and disperse after cotton is harvested in the early fall (Pakkianathan et al, 2015; Black, 2018). TYLCV is contracted by immature and adult whiteflies and transmitted or vectored by adult whiteflies. One adult can infect more than one plant. This virus can also attack other hosts such as beans, peppers, petunias, and tomatoes. Symptoms that a tomato plant is infected include yellow leaf edges, leaf cupping and stunted, reduced leaf and plant size. Flower or fruit drop may also occur. Early onset of TYLCV can prevent fruit development or severely stunt the development of not only the plant, but also its tomato fruit. TYLCV can later be transmitted if in a double cropped growing situation or if it is carried to neighboring growing areas (Polston, 2018). The TYLCV generated the need to find new resistant tomato varieties that can be grown by backyard gardeners and small-scale market farmers in El Paso County to replace those tomato varieties that are not resistant to the virus. The tomato field trials were also conducted to find a replacement for the Tycoon tomato variety. Occasionally, a well-liked tomato is no longer available, either by seeds or plants. Tycoon, considered a Texas Super Star for several years and resistant to the Tomato Yellow Leaf Curl Virus, is an example of such a variety. During the summer of 2018, the EPCMGA conducted a one season, two-location tomato field trial to determine which new determinate tomato varieties, resistant to the Tomato Yellow Leaf Curl Virus, could be successfully grown in cages in El Paso County, Texas. Three test varieties and a control/check variety were grown in an in-ground garden and a raised bed garden. This provided two similar, but different growing environments, and two different growing methods comparable to what small-scale market garden growers and backyard home gardeners would use. The test varieties included: PS */ Determinate Tomato (Solanum lycopersicum PS ) a red hybrid of flattened globe shape, large to extra-large fruit, regular leaf, mid-season producer (The National Gardening Association Plants Database, 2018). Rally */ Determinate F1 hybrid salad tomato (Lycopersicon esculentum L.) red, globe, medium-early maturing salad type variety with concentrated fruit set, maintains fruit 1

2 size all season. Plants are vigorous, compact growth with excellent leaf cover and high yield potential (Sakata, Rally, 2018). Ruby Crush (Hybrid) Grape Tomato / Determinate (Solanum lycopersicum 'Ruby Crush') Blocky round oval, grape, red, firm, a strong compact plant height with good leaf coverage, early maturing, market and home use vine ripe, fresh. (Sakata, Ruby Crush, 2018). Celebrity */ Semi-Determinate (Solanum lycopersicum 'Celebrity') control group 1984 All American Selections winner, delicious, highly productive hybrid, widely adapted throughout the US, 7 8 oz. fruit, matures 65 days after planting, severely prone to cracking. (Bonnie Plants, 2018). *Three of the four variety specifications mention that they are resistant to the TYLCV. Although not resistant to this virus, Ruby Crush, having a different, smaller diameter stems, branches, and smaller leaves, was included in this trial. Materials and Methods The trials were conducted at the EPCMGA AgriLife Vegetable Garden on the grounds of the Texas A&M AgriLife Research Center in El Paso, as an in-ground garden of sandy loam, and at the EPCMGA Ascarate Demonstration and Teaching Garden, in raised beds with a mix of sand, topsoil and compost. The transplants were first propagated in the EPCMGA greenhouse at the Research Center, under the care of EPCMGA greenhouse Master Gardeners, using a commercial seed starting medium in growing flats that held twelve 6-packs. The seeds were propagated on February 2, 2018 and transplanted to 4 pots on March 2, EPCMGA AgriLife Vegetable Garden Trial Area Garden preparation at the EPCMGA AgriLife Vegetable Garden trial area began in late February with the application of granular fertilizer ( ), followed by of manure-based bulk compost that was tilled into the soil. Row trenches were established for better use of irrigated water. Then ¾ black, poly pipe was laid on either side of each row trench. Water was distributed to each plant via 4 ¼ feeder lines from red drippers at the poly pipe that delivered 2 gallons of water per one hour of run time, per station. Transplants were set into the ground on March 28, 2018 using the trench planting method. The trial area consisted of 20 plants, 5 of each variety and 4 additional standby plants; 5 plants and 1 standby per row. All plants were spaced 36 apart; rows were spaced 46 apart. Immediately after all plants were set into the soil, a cage wrapped with protective wind cloth was installed and anchored around each plant to protect them from high winds and cooler temperatures. The wind wraps remained in place until the first week of May. Automatic drip irrigation began in the trial area with a run time of 30 minutes per station, 3 days a week to start. On May 17 th, the watering schedule was increased to a run time of 50 minutes per station every day. With the increase of daytime temperatures to 100 F and above, 2

3 run time at each station was increased again on May 29 th to 60 minutes per station every. No mulch was used. As plants grew in height, they were tied and centered in their cages to assist with upward growth. Row trench moisture varied from damp, with just a little moisture around each of the PS plants in row 1, to wet with water standing in the row trenches after irrigation in row 3, Rally, and row 4, Celebrity. Ruby Crush plants occupied row 2. Irrigation on this row delivered enough water to keep the entire row trench damp to wet. Due to the searing 3-digit daytime weather, an additional run time of 20 minutes per station at 6:00 pm was added to the irrigation schedule in late June. The irrigation run time was lowered in early September to 40 minutes run time per station, every day in the morning and 20 minutes run time per station every day at 6:00 pm. EPCMGA Ascarate Demonstration and Teaching Garden Trial Area Raised bed preparation at the Ascarate Demonstration and Teaching Garden trial area began in late February 2018 with deep shovel bed turning and compost amending. One third of the soil in each raised bed was removed and then replaced with compost. Automatic irrigation was then installed with 2 drip lines per plant. Irrigation began in the trial beds a few days prior to planting to test the system and prepare the soil for planting. Its run schedule was 3 times a week for 30 minutes per bed. When daytime temperatures increased to 100 F and above, irrigation was increased to every day at 30 minutes per bed. No mulch was used in this trial area. Transplants were set into the Ascarate trial raised beds on March 15, 2018, using the standard hole planting method unless the transplant was very tall, then it was trench planted. The trial area at Ascarate consisted of 5 raised beds, 5 plants of one variety per bed, plus 5 standby Ruby Crush plants in bed 5. All plants were set in an evenly spaced, zigzag pattern to fit the 4 x 12 raised beds. No data was collected on the standby Ruby Crush plants unless any or all of them were needed as replacement prior to the beginning of harvesting due to mis-identification in the greenhouse phase. Immediately after all plants were set into the soil of each raised bed, a cage wrapped with protective wind cloth was installed around each plant to protect them from high winds and cooler temperatures. As plants grew in height, they were assisted in upward growth by tying to keep each plant centered in its cage. The wind wraps remained in place until the first week of May. Fertilization at Both Trial Areas Fertilizing and/or plant feeding in both trial areas was provided at the time the plants were set into the ground with 2 cups of water-soluble Miracle Grow All-Purpose Fertilizer ( ) per plant, followed with a granular application of ammonium sulfate (21-0-0) every 3 weeks, at a rate of 1 tbsp. per plant, watered in via automated irrigation. Once in May and June, an allpurpose foliar fertilizer was sprayed on all plants in the Ascarate trial area. 3

4 Harvesting at Both Trial Areas Harvesting was carried out in both trial areas twice a week. Harvesting at the AgriLife Vegetable Garden began on May 25 th and ran through September 18 st, with a final, non-data harvest on September 21 st. Harvesting at the Ascarate Demonstration and Teaching Garden trial area began on May 17 th and ended with a final harvest on September 13 th. Fruit was graded for home use and marketability. On each harvest day, the number of tomato fruits harvested, average weight of individual fruit and weight of harvest per plant were recorded. See Table 1 for end of season tally at the AgriLife Vegetable Garden trial area and Table 2 for the end of season tally at the Ascarate Demonstration and Teaching Garden trial area. Table 1 AgriLife Vegetable Garden Tomato Field Trial Tally Overall Yield / 5 Plants per Variety May 25 September 18, 2018 Tomato Average Average Yield # Fruit Minimum Variety # Fruit Fruit per per Specification per Plant Weight Oz. Variety Lbs. Variety Weight Oz. PS Ruby Crush Rally Celebrity Total Trial Harvest ,095 Table 2 Ascarate Garden Tomato Field Trial Tally Overall Yield / 5 Plants per Variety May 25 September 18, 2018 Tomato Average Average Yield # Fruit Minimum Variety # Fruit Fruit per per Specification per Plant Weight Oz. Variety Lbs. Variety Weight Oz. PS Ruby Crush Rally Celebrity Total Trial Harvest ,498 4

5 Blind Tomato Taste Trials (via El Paso Master Gardeners Facebook) Ruby Crush Grape Tomatoes (via El Paso Master Gardeners Facebook) 5

6 Results and Discussion EPCMGA AgriLife Vegetable Garden In-ground Tomato Field Trial Results Celebrity, the control tomato, had the highest yield with a total of lbs. for 5 plants. The test group results were as follows: Rally, with the second highest yield of lbs., for 5 plants, and PS , came in third with a total yield of lbs., for 5 plants. The grape/cherub variety, Ruby Crush, came in fourth with a total weight yield of lbs., for 5 plants. The average fruit weight of all tomato varieties fell below the minimum weight listed for specifications of each variety. See Table 1 above, on page 4. Two of the AgriLife Vegetable Gardens trial plants were replaced a few days after planting due to stem breakage. No other plants were lost during the trial period. One plant of PS had no tomato fruit, so was removed from the trial area several days prior to the end of the trial period. The roots of this plant showed no evidence of nematodes. The major portion, 80%, of the fruit quality problems seen in the trial at the EPCMGA AgriLife Vegetable Garden was the result of cloudy spots and gold flecking possibly caused by stink or squash bugs, although only one of these insects was observed within the trial area. The gold flecking observed primarily on the Ruby Crush fruit, but also on the other varieties, was possibly caused by spider mites and thrips (Brust, 2015). However, due to very thick foliage, no outstanding evidence of the presence of these were found. One infestation of Beet Armyworms was addressed with a single application of GardenSafe Bt Worm & Caterpillar Concentrate in a water spray (Kelley, 2009). The second highest quality problem, and one more devastating to marketability, was cracking with > 23% of all tomato varieties rendering some harvested fruit as cull or unusable, contributing to high spoilage. This issue was mostly seen in the control group, Celebrity, with > 92% of its harvest affected. Lesser quality problems of blossom end rot and premature fruit drop affected about 1% of the fruit on the vine. For more information, see Appendix A: AgriLife Vegetable Garden Tomato Field Trial Variety Issue Percentages. Although no percentages were taken on zippering and catfacing, these issues steadily increased near the end of the trials. Early planting, when temperatures dipped to 54 F or below at night may have caused these two issues (Brust, 2016). All varieties were consistent producers once the fruit started ripening. The primary fruit flush that heavily filled all the plants took virtually all the trial period to be harvested. A secondary flush attempt occurred, but most blooms died without setting fruit. The trial harvest season at the AgriLife Vegetable Garden Trial area was divided into three Harvest Periods (HP). Rally was the high producer of Harvest Period 1 (May 25 June 25), with lbs., followed by PS at lbs., and Celebrity at 5.28 lbs. Celebrity dominated Harvest Period 2 (June 29 August 7) weighing in at lbs., followed by Rally at a distant second at lbs. The average fruit weight of PS during this period was greater than Rally, at 4.90 oz., but produced ten pounds less than Rally, at lbs. Harvest Period 3 was once again dominated by the control variety, Celebrity, producing lbs., followed by Rally with lbs., and PS producing lbs. The first fruit harvested in this trial was from Ruby Crush, the 6

7 grape tomato variety, on May 25 th, with of 8.39 lbs. for HP 1, lbs. for HP 2, and lbs. for HP 3. Despite a very poor second bloom flush, all of the tomato plants in this trial location, the three test varieties of PS , Ruby Crush, Rally, and the control variety of Celebrity were heavy producers all through the trial period, even under harsh winds, three-digit weather, and attacks from insect and larger pests. The biggest disappointment was the Celebrity production because of cracking. See Appendix B for more AgriLife Vegetable Garden harvest period data. EPCMGA Ascarate Demonstration and Teaching Garden Tomato Field Trial Results Celebrity, the control variety, had the highest yield with a total of lbs. for 5 plants. The test group results were as follows: Ruby Crush, the grape/cherub variety of the test group, was second with a total yield of lbs., for 5 plants. PS had the third highest yield of lbs., for 5 plants, and Rally came in fourth with a total weight yield of 8.51 lbs., for 5 plants. The average fruit weight of all tomato varieties fell below the minimum specifications weight listed. See Table 2 above, on page 4. Issues observed in the Ascarate plant varieties were as follows: Celebrity experienced a lot of radial cracking, blossom end rot and some possible catfacing. PS also had problems with blossom end rot and catfacing. The bed where the Rally plants were grown had issues with ants being attracted to cracked and subsequently, rotting tomato fruit. Neem Oil was applied two times to curtail the ant problems. This Rally bed and some others were also invaded by the Small Milkweed Bug, Lygaeus kalmii. After identification, it was determined this bug posed no apparent threat to the plants or their fruit and no evidence of damage attributed to them was found. With no known milkweed growing in the garden area, Small Milkweed Bugs will feed on the pollen of herbaceous flowers and even on other insects if no milkweed is available (Mahr, 2018). Ruby Crush produced a lot of tomato fruit, but later in the season the fruit of 2 plants we observed getting smaller and smaller. Upon removal these two plants, evidence of nematode activity on the roots was discovered and confirmed. In addition to an erratic irrigation system, a very hot summer also stressed the plants. A lot of curling of leaves was observed, not contributed to curly leaf virus, but instead confirmed as a physiological response of the leaves due to the hot weather. Blind Taste Test A Blind Taste Test was conducted on July 17 for the Master Gardeners. This test included 7 varieties of tomato tasting samples, 5 garden grown tomato samples and 2 green-house grown, store-bought tomato samples. Thirty-two Master Gardener tasting volunteers participated. The judging was based on Overall Like, Overall Taste, and Texture, with responses of 1 (worst) to 5 (best). Written feedback responses were also encouraged. The tasting samples included PS , Ruby Crush, Rally, Celebrity and Tycoon, all garden grown, and Houweling s Grape and Houweling s Tomato on the Vine, both greenhouse-grown in California. 7

8 Taste winners and places were determined in three catagories: Full-Size Tomato, Grape Tomato and Best of the Tasting. See Table 3, below, for the winner results. Table 3 EPCMGA Tomato Field Trial Blind Taste Test Results July 17, 2018 Full Size Tomato Winners Grape Tomato Winners Best of the Blind Tasting Winners 1 st Place Celebrity 1 st Place Houweling s Grape 1 st Place Houweling s Grape 2 nd Place PS nd Place Ruby Crush 2 nd Place Celebrity 3 rd Place Rally 3 rd Place PS th Place Tycoon 4 th Place Ruby Crush 5 th Place Houweling s Tomato on the Vine 5 th Place - Rally 6 th Place Tycoon 7 th Place Houweling s Vine Tomato See Appendix C for more data on the blind taste test. Recommendations Although both the EPCMGA AgriLife Vegetable Garden and the Ascarate Demonstration and Teaching Garden presented some unique gardening challenges during this trial, the El Paso County Master Gardeners Association recommends that all four of the tomato varieties that were grown in this trial, i.e., PS , Ruby Crush, Rally and the control, Celebrity, are wellsuited for growing in vegetable gardens in the high desert of El Paso County, TX, using researchbased growing techniques, Integrated Pest Management (IPM) and proper water management. 8

9 References Black, M. (2018). Tomato yellow leaf curl virus (TYLCV). Texas AgriLife Extension Service Uvalde Retrieved from Brust, J. (2016). Catfacing problems in tomato. University of Delaware Cooperative Extension. Retrieved from Brust, J. (2015). Gold flecking on tomatoes. University of Delaware Cooperative Extension. Retrieved from Celebrity Tomato (2018). Bonnie Plants. Retrieved from Kelley, M. (2009). Are worms eating your tomatoes? Alabama Cooperative Extension System and Auburn University. Retrieved from Mahr, Susan (2018). Common Milkweeds Insects. Master Gardener Program. University of Wisconsin-Extension. Retrieved from Pakkianathan BC, Kontsedalov S, Lebedev G, Mahadav A, Zeidan M, Czosnek H, Ghanim M. (2015). Replication of tomato yellow leaf curl virus in its whitefly vector, Bemisia tabaci. Retrieved from Tomato (Solanum lycopersicum 'PS ') (2018). The National Gardening Association Plants Database. Retrieved from Polston, J. (2018). Disease Management. Tomato Yellow Leaf Curl. Retrieved from Rally F1 Hybrid Determinate Salad Tomato (2018). Sakata. Retrieved from Ruby-Crush-Hybrid (2018). Sakata. Retrieved from 9

10 Appendix A AgriLife Vegetable Garden Tomato Field Trial Variety Issue Percentages / 5 Plants per Variety May 25 August 10, 2018* Tomato # of Fruit Blossom Premature Variety Harvested End Rot Cracking Cloudy Fruit Drop PS /282 99/ /282 6/282 7% 35% 95% 2% Ruby Crush / / / /2455 < 1% 35% 95% 2% Rally 446 7/ / /446 5/446 2% 29% 92% 1% Celebrity 648 5/ / /648 4/648 1% 92% 87% < 1% Overall / / / /3831 1% 23% 80% 1% *Note: This chart does not cover the entire harvest season but is enough to show the predominate issues. 10

11 Appendix B EPCMGA 2018 AgriLife Vegetable Garden Tomato Field Trial Individual Plant Harvest Data Harvest Period HP 1 HP 2 HP 3 Gross Harvest 5/25-6/25 6/19-8/7 8/10-9/18 As of 9/18/2018 Avg Lbs. Lbs. Lbs. Oz. Lbs. # Oz. PS PS PS PS PS PS Totals Ruby Crush RC RC RC RC RC Totals Rally R R R R R Totals Celebrity C C C C Totals HP Grand Totals Note: The HP Grand Total for Gross Harvest weight is off 0.05, due to decimal place rounding, from what is listed on Table 1. 11

12 Appendix C EPCMGA 2018 Tomato Field Trial Blind Taste Test Results/The Big Reveal A tomato blind taste test requires a "blind testing" meaning the people taking the blind taste test are unaware of the identity of the variety of tomatoes being tested. This means that any bias or preconceived ideas about a variety of tomato, whether greenhouse grown or home grown, is eliminated. The people taking the test are also unaware of any differences in appearance that were removed during the preparation of samples and no tomato fruit of any sample is on display. Thirty-two Master Gardener tasting volunteers were asked to give a number response from 1 5, 1 being the worst, 5 being the best, on response forms provided after they tasted each sample. In addition, they were also invited to give additional written responses about each sample and the blind taste experience. (See page 14 for written responses.) Samples of 7 tomato varieties were provided for this blind taste test, 5 of the varieties were grown in the EPCMGA vegetable gardens and 2 of the varieties were store bought tomatoes, grown in a greenhouse facility in California. Garden Grown Varieties PS * Rally* Ruby Crush* Celebrity* Tycoon Greenhouse, Store Bought Varieties Houweling s Grape Houweling s Tomato on the Vine * The EPCMGA Tomato Field Trial testing group, with Celebrity being the control variety. The tomato variety Tycoon will no longer be available to gardeners after All sample responses and volunteer comments shown below are presented in the order the samples of the varieties were presented in the tasting line. 12

13 Blind Taste Test Number Response Results The winner of each category was based on the responses given for #3, #4 and #5 in each category. Example: Under "Overall Like", Ruby Crush received a cumulative total of 30 responses for #3, #4 and #5 compared to Houweling's Grape total of 28. But Houweling s Grape received more responses for #4 and #5. Likewise, Houweling s outnumbered Ruby Crush on "Overall Taste" and "Texture", making it the winner of the Grape Tomato category. SAMPLE A / PS SAMPLE B / CELEBRITY SAMPLE C / RALLY SAMPLE D / TYCOON Overall Overall Overall Overall Like Response Like Response Like Response Like Response #3 14 #3 13 #3 13 #3 10 #4 7 #4 12 #4 9 #4 12 #5 4 #5 4 #5 3 #5 0 Total 25/32 Total 29/32 Total 25/32 Total 22/32 Overall Overall Overall Overall Taste Response Taste Response Taste Response Taste Response #3 12 #3 12 #3 13 #3 14 #4 8 #4 12 #4 8 #4 8 #5 3 #5 4 #5 3 #5 0 Total 23/32 Total 28/32 Total 24/32 Total 22/32 Texture Response Texture Response Texture Response Texture Response #3 9 #3 11 #3 7 #3 7 #4 11 #4 9 #4 12 #4 19 #5 8 #5 7 #5 6 #5 0 Total 28/32 Total 27/32 Total 25/32 Total 26/32 SAMPLE E / RUBY CRUSH SAMPLE F / HOUWELING S SAMPLE G / HOUWELING S GRAPE VINE TOMATO Overall Overall Overall Like Response Like Response Like Response #3 13 #3 5 #3 9 #4 9 #4 11 #4 5 #5 8 #5 12 #5 0 Total 30/32 Total 28/32 Total 14/32 Overall Overall Overall Taste Response Taste Response Taste Response #3 11 #3 6 #3 10 #4 9 #4 12 #4 4 #5 9 #5 11 #5 0 Total 29/32 Total 29/32 Total 14/32 Texture Response Texture Response Texture Response #3 9 #3 2 #3 12 #4 9 #4 14 #4 6 #5 8 #5 13 #5 2 Total 29/32 Total 29/32 Total 20/32 13

14 MG Tasting Volunteer Comments About Each Tomato Variety Sample SAMPLE A SAMPLE B SAMPLE C SAMPLE D PS CELEBRITY RALLY TYCOON 1. Mild 1. Sweeter 1. Best for burgers 1. Sweet 2. Ho-hum 2. Skin tough 2. Mushy 2. Too tart 3. Not much flavor 3. Good color 3. Not as flavorful 3. Crunchy 4. Skin stiff 4. Acidic 4. Skin very stiff 4. Little sour 5. Squishy 5. Little sweet 5. Mushy and mild 5. Skin tough 6. Very mild taste 6. Crispy texture 6. Lacks flavor 6. Mushy 7. Gross, mushy 7. Mushy 7. Skin thick 7. A bit tart at first 8. Not much taste 8. Lacks flavor 8. Meaty 8. Tangy 9. Lacks flavor 9. Very juicy 9. No flavor 10. Favorite 10. Tough skin 11. Sweet 11. Good texture 12. Very meaty SAMPLE E SAMPLE F SAMPLE G RUBY CRUSH HOUWELING S GRAPE HOUWELING S VINE TOMATO 1. Tough skin 1. Favorite overall 1. I didn t like it 2. Disliked flavor 2. Two thumbs up 2. Not good flavor 3. Hard 3. Yum 3. Ugh 4. Not much flavor 4. Great 4. Bland taste 5. Skin tough 5. Best one 5. Foul 6. Good 6. Much better 6. Tangy, but dull 7. Better 7. Mild sweet 7. No taste 8. Yummy 8. Hard 8. Juicy 9. Sweet nice flavor 9. Crunchy 9. Lemony flavor 10. Hard 10. No flavor, watery NOTE: It should be noted that it is possible that tasting results could vary depending on the order that tomato samples are placed in the tasting line. If sweeter tomato variety samples are placed early in the line, those samples that come after them may not score as well as they might have, had they been placed before the sweeter samples. 14