Plasticulture Strawberry Variety Trial Report
Posted: March 31, 2016
Back in December, Kathy Demchak reported on a matted-row strawberry variety trial at the Russell E. Larson Agricultural Research Center at Rock Springs. This is a report on the performance of many of these same varieties in a plasticulture planting at the Penn State Southeast Agricultural Research and Extension Center in Manheim, PA.
The Rutgers selections were specifically bred for plasticulture and were planted one month later than all others. Rows were on 6’ centers and each plot was a double row of plants on a 12” x 12” spacing. Not all cultivars or selections were available as plug plants so those only available as dormant plants (Cornell selections, ‘Daroyal’, ‘Donna’, ‘Galletta’, ‘Rubicon’, and ‘Sonata’) were “plugged” by trimming the root system and growing them in 32-cell trays until planting time. The harvest season started dry with average temperatures and ended wet and with above-average temperatures. Minimal fungicides and no insecticides were applied during harvest.
Summary of the characteristics of each variety
‘Sweet Charlie’ performed as expected with low yields and good fruit quality. There was also some powdery mildew in the variety. ‘ Chandler’ had disappointing yields that were lower than usually reported. This was a result of variable plant vigor as well as plant loss to Phytophthora root rot. In addition, this variety had the worst rating for angular leaf spot in the fall which also probably impacted yields.
Order of Ripening
As with the matted row planting, it was somewhat difficult to clearly list the order of ripening as many early varieties ripened simultaneously but there was evidence of cold-damaged flowers throughout the planting.
‘Florida Radiance’ (aka ‘Radiance’)
‘Radiance’ is from the University of Florida breeding program and was developed for winter production on plastic. In our planting these plants were weak and were susceptible to leaf scorch. Total yields were low (7,182 lb/A) but berry size and appearance were very good. Flavor was poor.
These varieties were bred for plasticulture and flavor was the main breeding objective. In our planting these varieties were planted one month after the other varieties because of propagation issues. We did carry the planting over for a second harvest so we should get a better idea of performance this season.
All three of these selections had low yields. This is likely a combination of late planting and bird damage. However - these selections had the highest brix readings in the trial and as a result were rated the highest for flavor. Shape was somewhat unusual in two of the selections – berries were long and narrow – which may or may not be a marketing problem. Yields from the 3 selections were 3,292, 3,882, and 4,069 lb/A with excellent size and flavor.
As in matted row culture, ‘Earliglow’ had excellent flavor but berry size dropped off quickly. The plants also had some powdery mildew in this planting. Total yield was 10,966 lb/A with 68% marketable and the brix was highest of all named varieties. Plant vigor was good and runner production in the fall was low.
‘AC Wendy’ is from the Agriculture and Agri-Food Canada-Nova Scotia breeding program. It had low runner production in the fall and was susceptible to leaf scorch and angular leaf spot. It was the highest yielding variety in the trial (15,535 lb/A with 60% marketable) but fruit quality was poor, especially during the heaviest harvest period. Fruit size also dropped quickly but was not as bad as with ‘Earliglow’.
‘Galletta’ is from the breeding program at NC State and was bred for plasticulture. Plants were vigorous but susceptible to powdery mildew and scorch. Yields were good at 10,565 lb/A with 64% marketable and very good berry size and flavor.
‘Flavorfest’ is from the USDA breeding program at Beltsville, MD and was bred for both matted row and plasticulture. In our trial the plants had moderate vigor and low runner production. Some plants died from Phytophthora root rot. Yields were disappointing at 5,970 lb/A (63% marketable) but berry size and flavor were very good.
‘Daroyal’ is from the Darbonne/Inotalis (France/Spain) breeding program. The plants were vigorous in our trial – perhaps lower N fertility should be used with this variety - and were susceptible to powdery mildew. Yields were good at 13,572 lb/A with 59% marketable. Berry size and flavor were good.
‘Donna’ is from the same breeding programs a ‘Daroyal’. It was also a vigorous plant and produced many runners in the fall. The foliage showed no signs of disease. Yields were moderate at 10,186 lb/A with 63% marketable. Fruit size was good and flavor was average.
‘Sonata’ is from Plant Research International (PRI) in the Netherlands and was selected for growing in the cool areas of western Europe. Under warm harvest seasons the fruit can be soft and we did see this trait in our trial. This plant is susceptible to many of our strawberry diseases. In our trial the plants were very vigorous with many branch crowns. Yields were very good at 15,337 lb/A with 52% marketable. Berry size was very good and quality was average. Harvest season was long and berries were soft in the heat of later harvests.
‘Rubicon’ was selected at the Connecticut Agricultural Experiment Station for resistance to black root rot and black vine weevil. This variety was extremely vigorous in our planting. Yields were very good at 14,843 lbs/A and 68% marketable. Berry size was very good and flavor was average. We had problems with soft berries during the warmer late harvest season.
Cornell Advanced Selections
The three Cornell selections did better in the matted row trial than they did in the plasticulture trial. Yield in two of the selections were average (8,826 lb/A, 63% marketable and 7,511 lb/A, 45% marketable) with very good berry size and average to poor fruit quality. The third selection had poor yields (4,558 lb/A, 50% marketable) with average berry size and quality. All three selections were soft during the warm late harvest season; we do not think these will be selections for growing in warm weather areas.
Plans for 2016
This planting was carried-over for a second season of harvest. To examine the need/effect of renovation on yields and quality, half of the planting had 50% of the branch crowns on the plants removed by hand after harvest. Another benefit of carryover is that it will allow us to continue to observe susceptibility to Phytophthora root rot which is found throughout the planting. Several plots in the trial are completely dead while others have minimal or no plant loss.