W.B. Evans. Ohio State University/Ohio Agricultural Research

and Development Center Muck Crops Branch, Willard, OH.

Three lettuce plantings were evaluated as observational trials in 1998. Ratings were focused on potential for marketing through wholesale channels as unprocessed, full sized plants. The season was marked by periodic flooding rains that resulted in poor quality and significant bolting. Regional favorites performing well included New Red Fire red leaf, Full Heart 65 escarole, Slobolt green leaf, and Esmerelda Boston. Each class produced some other named and numbered entries worthy of further testing. Several other entries showed good potential for niche markets.

Ohio’s muck crop growers raise more than one dozen salad crops including more than half a dozen types of lettuce, escarole, and endive. Most lettuce is marketed to grocers and others through wholesale channels. Growers need uniform, high quality leaf goods that withstand each step in the market channel and provide buyers and consumers with appealing, high quality product. This set of trials was designed to evaluate the growth and market traits of named and numbered entries grown under Ohio conditions.

Entries for these trials were solicited from more than a dozen seed producers and resellers. No restrictions were placed on the number of entries or their classifications, except than iceberg-types, not grown locally, were not requested. More than 130 entries were tested, with an effort being made to include local standards.

The spring crop was transplanted 10 inches apart in rows 19 inches apart on May 20 and 21. The summer crop of escarole, endive, and romaine was direct-seeded on June 10. The Boston, red leaf, green leaf, and Batavian entries were seeded June 21. The fall trial was sown August 6 and 10. The seeded crops were thinned to stand 10 inches apart at the 2-3 leaf stage. Pronamide (12 lb./acre) was watered in at each planting for weed control. Additional hand cultivation was used. Minimal insect and disease control was employed so that observations on the relative susceptibility of each entry to yellows and other diseases could be recorded.

Initially, several cultivars in each class were planted in replicated trials. Flooding damaged some replicates. Thus, no statistical analyses were conducted. The results are reported instead as the means and summaries of observations from one to four plots across all listed seasons of evaluation. Important differences seen within an entry, among the seasons, are noted.

Entries were evaluated mainly for potential in wholesale/shipping markets. Evaluations were not focused on potential in the home garden, baby, whole-leaf blend, or lightly processed markets. Field evaluations were made to assess crop uniformity, maturity, color, habit, and disease/stress incidence. Ten heads were removed from each mature plot, weighed, trimmed, and reweighed. Additional observations on head characteristics and quality were made prior to washing and photographing. Head size comments refer to the general size of the trimmed plants, whether or not they formed a true head. Lettuces that looked good stacked on their sides, leaf tips out and butts away as they would be displayed at retail, were deemed to "present well". If significant petiole cracking occurred as the lettuces were trimmed and brought together, they were deemed to "fold poorly". Cross sections were made to evaluate cores for hollow stems and possible bolting.

An overall, subjective rating was given to each entry based on all of the observations listed above, averaged across all seasons in which the entry was evaluated. These ratings are against others of the same class and relate relative quality within the class.

These results reflect the great stresses each planting went through before harvest. Each planting was subject to at least one flooding rain in the first half of growth. The water had the most affect on romaines. No romaines reached harvestable stage in any season. The spring and summer crops bolted due to flooding stress. The fall romaines did not mature before frost. Bolting was significant in all the spring and summer classes. Entries that did well in these trials will likely prove quite tolerant of a wide range of growing conditions and environmental stresses. Almost all entries were planted spring, summer, and fall. Only entries that approached or reached harvestable size were evaluated and discussed in the tables. An entry with comments from two or three plantings was likely more tolerant of the year’s stresses than one with comments from only one plantings.

Not all seed entries for this trial were primed. This led to stand establishment difficulties for some entries. The fall crop emerged better than the summer crop.

Overall, the results of this trial should be used in context with previous trials (discussed below) and grower experience. While the severe conditions encountered this season allowed versatile entries to stand out, they might have masked the potential of others. Additional trials, under less stressful, will be needed to make stronger recommendations.

Batavians (Table 1):

Nevada performed admirably, especially in the fall. It is a lime-green, semi-heading lettuce which might do very well for a niche marketer. Cardinale, entered by three vendors, did not do well in this trial. It bolted and produced ununiform plants. The Batavian class produced diverse types, most with somewhat sturdy leaves. Leafy and semi-heading types were seen. Lettuces in this European class are said to have a longer shelf life than standard leaf lettuces. This class is not currently grown locally.

Boston/bibb (Table 2):

Esmerelda performed best. This class was quite susceptible to the stresses of the growing seasons. Most spring entries were wiped out by flooding, the fall ones by frost. A common defect was yellow leaf margins.

Green leaf (Table 3):

Greenday showed potential for fall crops in this area as a darker green alternative to Slobolt, which also grew well. Crisp ‘N Green was indeed somewhat brittle, as were most other entries. Green Vision was entered by three vendors. Each ended up with a different numerical rating indicating possible questions of uniformity within the cultivar or among the plots in the trials. The spring trial was damaged the most by flooding rains.

Red leaf (Table 4):

New Red Fire performed well in all three seasons. PS68292, PSR 7509, HMX 2267, and HMX 7554 showed some promise. For specialty markets, the oak-leafed Brunia proved adaptable to our growing conditions, especially for fall.

Romaines: Ratings and comments on the romaines are excluded from this report as most entries failed to produce marketable heads due to water stress. Flooding rains impacted all three plantings. Romaines were the most severely affected class. No romaines reached harvestable size before bolting in the spring and summer trials, nor before frost in the fall trial. Darkland and Sweet Valentine, a red leafed cultivar, stood out in the fall as those with the most potential for late season production.

Endive (Table 5):

Cosma, Enza 18504, and Tasos were the best of several good entries. They were uniform and produced large, high quality heads. Monaco, Neos, Frisan RS, Salad King, and Enza 18503 were also worthy entries. Monaco and Neos were less uniform. Frisan RS yielded some hollow butts. Salad King required significant trimming of rotten and yellowed leaves. The fine-leafed Stratego would do well if blanched for specialty markets.

Escarole (Table 6):

Coral, Full Heart 65, and Twinkle were the highest rated entries. Coral was uniform in one set of plots but produced more variable heads in another. Full Heart 65 was somewhat non-uniform but produced large, good looking heads. Twinkle did well in the spring and fall but bolted somewhat in summer.

Of the cultivars described above as performing well, the following also performed well for Hassell and Wallace¹ in 1997: Esmerelda Boston; Crisp ‘N Green and Slobolt green leaf; New Red Fire, and PS69292 red leaf; Tasos, Markant, Salad King, and Cosma endive; along with NR65 and Stratego escarole. Those doing well in 1998, but not in 1997 include Bossa and Twinkle escarole, and Wallone and Monaco Endive. Those doing well in 1997 but not in 1998 included: Optima and Ermosa Bostons, Red Line red leaf, Eros escarole, and Oxalie endive. Those recommended in either 1997 or 1998, but not evaluated in the other included: Balisto Boston; Tiara, SVR 64289, and Green Day green leaf; PSR 7509, HMX 2267, HMX 7554, and Brunia red leaf; Elisa escarole; all recommended Batavians; and all recommended romaines.