Midwest Vegetable Trial Report for 2012

Late Blight Resistant Variety Evaluation Conducted with Organic Production Practices, New York — 2012 Margaret T. McGrath, Cornell University, Riverhead, New York Karen LaMarsh, Cornell University, Riverhead, New York Sandra Menasha, Cornell Cooperative Extension-Suffolk County, New York

Tomato is an important crop that is routinely affected by diseases. It is important for both organic and conventional diversified vegetable growers, which are common in the northeastern United States. Fresh local tomatoes are one of the most popular items during summer, therefore they are grown by many organic and conventional growers. Several foliar diseases affect tomatoes, including Septoria leaf spot, early blight, bacterial speck and spot, late blight, powdery mildew, and leaf mold. Foliar diseases are a common occurrence wherever tomatoes are grown. All plantings are affected, even those grown under protection (greenhouses and high tunnels) and in small home gardens. Resistant varieties would be a valuable tool for managing these diseases, particularly late blight because it occurs sporadically and can be difficult to control with fungicide applications started after onset. Organic growers on Long Island have identified tomato as a high priority for research. The goals of this experiment, which is part of a multi-year project, were to evaluate new tomato varieties and experimental hybrids with resistance to late blight in terms of (1) susceptibility to naturally occurring foliar diseases and (2) yield and fruit quality. Materials and Methods The experiment was conducted at the Long Island Horticultural Research and Extension Center in Riverhead, New York, in a field with Haven loam soil that has been dedicated to research on organically-produced crops since 2001. Pro-Grow 5-3-4 organic fertilizer at 2,000 lb/A (100 lb/A N) was spread over rows to be planted, then incorporated on June 29. Next, drip tape was laid as the rows were covered with black plastic mulch. Annual ryegrass was planted between rows of plastic mulch to establish a living mulch by broadcasting seed with a hand-operated spreader, and then lightly raking to incorporate. The ryegrass plus weeds that grew were mowed routinely. Some weeds were removed by hand. Tomato seed were sown in an organic seeding mix in the greenhouse on June 6. Seedlings were transplanted by hand on July 5 into holes opened in the plastic mulch by a waterwheel transplanter that also placed a starter fertilizer in the holes: Neptune’s Harvest Benefits of Fish (2-4-1 N-P-K). A completely randomized block design with four replications was used. Plots consisted of 10 in a single row with 24-inch spacing and 68-inch row spacing. A yellow cherry-type tomato plant (cv. Sungold) separated plots within rows. Plots for each of the four replications were in three adjacent rows. Following standard procedure for fresh-market tomato production on Long Island, plants were staked and trellised as they grew using the Florida weave trellising system with 4-foot stakes placed between plants. Water was provided as needed through drip tape laid beneath the plastic mulch. Insect pests were managed by applying Entrust (2 oz./A) on August 7, August 14, and September 7. Fungicides approved for organic production were applied to all plots to suppress late blight Midwest Vegetable Trial Report for 2012

after finding symptoms in the plots. The copper fungicide Badge X2 (1.75 lb./A) was applied with Actinovate AG (12 oz./A) on August 14 and 22, and with Regalia (2 qt./A) on August 17, August 31, and September 7. Sonata ASO (3 qt./A) was also applied on September 7. The onset of late blight was considered to be at a time in the growing season that left unmanaged it could adversely affect other experiments and commercial crops nearby. All applications were made using a tractor-mounted boom sprayer equipped with twinjet (TJ60-11004VS) nozzles spaced 17 inches apart that delivered 63 gal./A at 65 psi. Leaves were examined for symptoms of any foliar disease eight times from July 31 to October 12. Late blight and other diseases observed were assessed by estimating the percentage of leaves in each plot with symptoms (incidence) and the severity of symptoms on these affected leaves. Canopy severity was calculated by multiplying these values. Area Under Disease Progress Curve (AUDPC) was calculated for late blight severity from August 20 through September 19 for all entries, and also through October 12 for entries exhibiting resistance. Ripe fruit were harvested on September 11, 18, and 27, and October 3 and 12. Yield was not measured for the two entries with cherry-type fruit. Fruit quality attributes were assessed on a 1- 5 scale with 5 being excellent by project researchers as well as farmers and consumer groups. Average monthly high and low temperatures (°F) were 85/68 in July, 83/67 in August, 75/60 in September, and 66/52 in October. Rainfall (inches) was 4.35, 3.24, 3.75, and 2.17 for these months, respectively. Results and Discussion Late blight started to develop early in 2012 in Suffolk County on Long Island. First symptoms were found on May 29 in a commercial crop. Symptoms were found in this experiment on August 3. US-23 was the only genotype of the pathogen, Phytophthora infestans, found in the region, including at LIHREC. Excellent resistance was exhibited through late August by all entries with Ph2 and/or Ph3 major genes for resistance, which were Plum Regal (homozygous Ph3), JTO-545 (heterozygous Ph3), Legend OP (Ph2), Matt's Wild Cherry (undetermined resistance, possibly Ph3), Jasper (undetermined resistance), and Defiant PHR, Mountain Magic, Mountain Merit, and three experimentals from the Cornell University Department of Plant Breeding (all heterozygous Ph2 + Ph3) (Table 1). Late blight became severe in New Yorker (Ph1). Late blight did not differ significantly in severity from any of the varieties without major resistance genes, which were Mountain Fresh Plus, Juliet, and . Legend, the only entry with just the Ph2 gene, was numerically, but not significantly, more severely affected by late blight than the other resistant entries, except at the last assessment when extensive defoliation may have affected ratings. Plum Regal and JTO-545, the two entries with just the Ph3 gene, were numerically more severely affected by late blight than the other resistant entries at all assessments. The difference was significant at the last assessment (October 12), which was 35 days after the last fungicide application for late blight. In conclusion, best suppression of the US-23 genotype was achieved with tomato possessing both the Ph2 and Ph3 resistance genes. Only a few fruit with symptoms of late blight were observed on these entries. Powdery mildew and Septoria leaf spot developed to a very limited extent in this experiment. Most tomatoes evaluated produce red slicer-type fruit. Juliet, Plum Regal. and JTO-545 are plum types. Mountain Magic is a campari type. Matt's Wild Cherry and Jasper are cherry types. These Midwest Vegetable Trial Report for 2012

three received the highest taste ratings (4.6-4.7 out of 5). Fruit of Defiant PHR started to ripen before other non-cherry entries. It was the only one with ripe fruit at the first harvest on September 11 with an average of 2.7 fruit/plant. Numerically, but not significantly, more fruit were harvested from Defiant PHR than other entries producing red slicer type fruit (Table 2). Table 1. Severity of late blight on tomato varieties and experimental hybrids evaluated at LIHREC, 2012. z Variety or Experimental Late Blight Canopy Severity (%) y (resistance; fruit type) Aug 20 Aug 29 Sep 14 Sep 19 AUDPC x Oct 12w Mountain Fresh Plus 75.0 a 52.5 ab 67.5 ab 72.3 ab 2,294.4 a ND (none; red slicer) Brandywine 50.5 ab 47.3 ab 76.3 ab 85.0 a 2,169.2 a ND (none; red slicer) Juliet 70.0 a 37.8 abc 41.3 bcd 38.9 bcd 1,703.6 ab ND (none; small plum) New Yorker OP 74.3 a 55.6 a 88.8 a 59.5 abc 2,522.6 a ND (Ph1; red slicer) Legend OP 26.6 bc 18.9 bcd 42.8 bc 33.5 cde 906.0 bc 32.0 b (Ph2; red slicer) Plum Regal 11.3 c 12.7 cd 17.3 cd 13.5 de 428.5 c 81.3 a (Ph3; plum) JTO- 545 18.4 c 11.8 cd 22.0 cd 17.3 de 502.9 c 75.5 a (Ph3; plum) Mountain Magic 0.3 c 0.1 d 0.1 d 0.1 e 3.2 d 0.0 c (Ph2 + Ph3; campari) Jasper 1.8 c 0.2 d 1.9 cd 0.1 e 25.0 d 17.8 bc (unknown; cherry) Matt's Wild Cherry 0.2 c 0.3 d 0.1 d 0.1 e 4.6 d 5.8 bc (unknown; cherry) Mountain Merit 0.2 c 1.9 d 0.1 d 0.2 e 15.0 d 5.0 bc (Ph2 + Ph3; red slicer) Defiant PHR 0.2 c 0.2 d 0.6 d 0.0 e 8.9 d 5.5 bc (Ph2 + Ph3; red slicer) NC123S x CU-TR5 0.3 c 0.7 d 0.5 d 0.2 e 14.4 d 29.6 b (Ph2 + Ph3; red slicer) NC123S x CU-TR3 0.1 c 0.1 d 0.1 d 0.0 e 1.2 d 11.5 bc (Ph2 + Ph3; red slicer) Brandywine x CU-TR3 0.0 c 0.1 d 0.1 d 0.0 e 1.3 d 0.3 c (Ph2 + Ph3; red slicer) P-value (treatment) <0.0001 <0.0001 <0.0001 <0.0001 <0.0001 <0.0001 zNumbers in each column with a letter in common are not significantly different from each other (Tukey’s HSD, P=0.05). yEntries are organized in the table based on genetics for resistance to late blight and fruit type, which are listed under the entry name. Seed sources are in Table 2. xAUDPC values were square root transformed before analysis. Table contains de-transformed values. wND=not determined because too few leaves remained in plots to assess. Midwest Vegetable Trial Report for 2012

Table 2. Yield of tomato varieties and experimental hybrids grown at LIHREC, 2012. Yield (number of fruit/plant) z Variety or Seed Marketabley Totalx, y Experimental Sourcew Sep 19 Oct 12 All v Oct 12 All v Mountain Fresh Plus SW ND 0.0 b 2.5 c 2.5 bc 4.9 d Brandywine H ND 0.0 b 2.5 c 2.5 bc 5.0 d Juliet TGS ND 0.0 b 4.3 c 4.3 bc 8.5 cd New Yorker OP TT ND 0.0 b 1.6 c 1.6 c 3.3 d Legend OP TGS ND 0.3 b 2.9 c 2.6 bc 5.3 d Plum Regal BE 2.0 b 2.4 b 10.6 bc 5.4 bc 13.7 bcd JTO- 545 J 2.8 b 1.5 b 15.7 bc 7.1 b 21.3 bc Mountain Magic BE 6.2 a 13.9 a 73.6 a 16.2 a 75.8 a Jasper J ND ND ND ND ND Matt's Wild Cherry J ND ND ND ND ND Mountain Merit BE 0.3 b 1.4 b 8.4 bc 4.3 bc 11.2 bcd Defiant PHR J 2.6 b 2.0 b 21.8 b 5.0 bc 24.8 b NC123S x CU-TR5 CU 1.1 b 1.3 b 7.5 bc 3.6 bc 9.8 bcd NC123S x CU-TR3 CU 0.9 b 1.9 b 10.5 bc 5.2 bc 13.8 bcd Brandywine x CU-TR3 CU 0.4 b 2.0 b 8.2 bc 3.9 bc 10.2 bcd P-value (treatment) 0.0012 <0.0001 <0.0001 <0.0001 <0.0001 zNumbers in each column with a letter in common are not significantly different from each other (Tukey’s HSD, P=0.05). yND=not determined. w“Total” includes marketable and unmarketable fruit that were mostly diseased. wBE=Bejo Seeds, CU=Cornell University, J=Johnny’s Selected Seeds, H=Harris, TGS=Tomato Growers Supply, and TT=Totally Tomato. Experimentals developed by Cornell University Department of Plant Breeding are listed as ‘female pedigree’ X ‘male pedigree.’ vIncludes the yield from all harvest dates, which were September 11, September 19, September 27, October 3, and October12. Tomato Variety Fruit Descriptions and Assessments Mountain Fresh Plus Orange- to red-colored fruit was small and round. Some radial cracking. Flesh was bright red, juicy, but acidic and not as sweet. Taste rating of 3 and overall satisfaction 4. Mountain Merit Medium to large, round, red fruit. Flesh was sweet but very mealy and soft. Both taste and overall satisfaction rated 3.9 out of 5. Defiant PHR Round, small to medium, red fruit. Yellow shoulder on most fruit and some zippering. Flesh was light red to red in color, soft, sweet, juicy, and had good flavor. Lots of seeds. Taste rated 3.5 out of 5 and overall appearance 3.8.

Midwest Vegetable Trial Report for 2012

NC123S x CU-TR5 Medium to large, round fruit has orange- to red-colored skin. Some zippering. Flesh was bright red, sweet, and had a good flavor. Taste rating of 4.3 and overall satisfaction 4.6. NC123S x CU-TR3 Large, orange to red, round fruit. Fruit had a white core and red flesh. Slightly chewy skin. Flesh had good flavor and taste but was somewhat mealy. Taste rating of 3.4 and overall satisfaction 3.9. Brandywine x CU-TR3 Fruit were round, red, and medium in size. Slight yellow shoulder on fruit. Fruit were lacking in flavor and not sweet. Skin was thick. Taste rating of 2.5 and overall appearance 2.8. Plum Regal Plum type with orange- to red-colored skin. Fruit were medium to big in size. Flesh was mealy and lacking flavor. Taste 2.5 out of 5 and overall satisfaction 3.3 out of 5. JTO- 545 , medium in size, and red in color. Deep red flesh was meaty, slightly acidic with a slightly mealy texture. Semi-sweet. Taste rating of 3 and overall appearance rating of 3.5 out of 5. Mountain Magic Small, round, red fruit. Campari size. Some cracking of the skin. Flesh was light red, sweet, and juicy. Taste rating of 4.6 and overall satisfaction 4.8 out of 5. Jasper Very small, round, red cherry tomato. Lots of seeds. Sweet fruit with good flavor. Taste rated 4.6 and overall appearance 4.8. Matt's Wild Cherry Small red cherry tomato. Slightly chewy skin but delicious and super sweet. Taste rating of 4.7 out of 5 and overall appearance 4.8.

Acknowledgments This project was supported by the Agriculture and Food Research Initiative Competitive Grants Program Grant 2011-68004-30154 from the USDA National Institute of Food and Agriculture. Seed were donated by companies listed in Table 2. Pesticides were donated by AgraQuest, Inc., Dow AgroSciences LLC, Isagro-USA, Marrone Organic Innovations, Inc., and Natural Industries, Inc.