Compiled by Jayesh B. Samtani, Assistant Professor and Small Fruit Extension Specialist, School of Plant and Environmental Sciences, Hampton Roads Agricultural Research and Extension Center, Virginia Tech – Mark Hoffmann, Assistant Professor and Small Fruits Extension Specialist, Department of Horticulture, North Carolina State University – Mengjun Hu, Assistant Professor of Plant Pathology, University of Maryland
This past annual hill plasticulture season in the Southeast was quite rough, characterized by a late start to the season, high disease pressure, often lower yields and an unfavorable berry market, facing low prices due to competition. While not every grower experienced all four of those factors, we rarely found a farm which was not affected by at least one of those problems last season.
When hurricane Florence made landfall in mid-September, many growers were in the midst of preplant preparation, and many local nurseries were in the last few weeks of plug plant production. In Virginia, some growers were ready to transplant plug plants in the field, while growers in Southeast Virginia, North Carolina and South Carolina were getting ready to shape their beds. At many farms planting dates were set two or three weeks back, or field remained not fumigated. While the Piedmont regions of South and North Carolina were not as severely affected as the coastal plains by Florence, hurricane Micheal brought flooding and land-slides to growers and nurseries in the Piedmont, Mountains and many parts of Virginia.
It is fair to say that those natural disasters were the main cause for many of the problems we saw this past season. Planting material from multiple sources and of various strawberry varieties were found to be infected with Anthracnose Fruit Rot (Colletotrichum acutatum) and in some cases with Anthracnose crown rot (C. gloeosporioides). Some strawberry plug plant propagators had to throw away plants due to disease by mid-August and had to start propagation of plug plants second time over (pers. comm. Samtani). The wet after-hurricane conditions often sealed the faith of the planting material, and as a result, some of the plug plants received by the growers were smaller in size and came in at a later date than anticipated.
In many grower fields, the planting was done later than usual in the fall. Some growers did not fumigate, although it was initially planned. The cool, rainy and cloudy weather of the fall did not favor the establishment of plug plants in the field, and some growers were affected by a complex of late planting, low quality planting material and high disease pressure. Soon after strawberry transplanting in the field, there were some plants that began to die-off due to Colletotrichum spp. or other soil-borne pathogens such as Phytophthora, Pythium and Pestalotiopsis species. All of these occurrences meant a miserable start to the strawberry season. Growers who had anthracnose crown rot infected plants were advised to spray Captan tank mixed with Topsin M
or Switch at scheduled intervals among taking other precautions as outlined by the article written by Hoffmann et al. This article was emailed to Virginia Strawberry Association members in late November-early December and also appeared in the November-December 2018 edition of Strawberry Grower newsletter published by North Carolina Strawberry Association. The growers who were hoping to produce open-field unprotected fall crop with Albion were experiencing low yields, due to the unusual cold and wet fall of 2018.
The wet weather continued throughout the winter 2018/19, but the temperatures were milder than what they had been in the seasons before. Growers in Southeast Virginia and the Carolina Coastal plains did not need to cold protect as often as the winter before, and the NC State weather advisories were rarely used this winter. January was unusual warm, and some early breaking varieties already showed flowers and in some cases berries in the Carolinas. Weather fluctuations in late winter brought many plants out of dormancy pretty early.
Protecting strawberry flowers from cold damage is one of the biggest concerns in spring in the Southeast. Usually, if the crop is at more than 5-10% bloom, we recommend to protect with an integrated approach of row-covers and sprinkler systems. Fewer weather instances during spring 2019 required cold protection in the Southeast, compared to spring 2018. As the weather began to warm up in early to mid-April further losses from crown rot incidences were reported. These occurrences were traced to either infection with Phytophthora or Colletotrichum spp. Moreover, we observed green fruit infected with anthracnose in some strawberry fields in Virginia. Many growers further north in Maryland and Pennsylvania also experienced such first-ever anthracnose on green fruit. What caused the early symptoms on fruit remains to be investigated, but it may be linked with the outbreak of anthracnose in the plugs.
The strawberry harvest season started earlier than usual by a week to 10 days. Many growers in North Carolina began harvesting their spring crop in late March. With a few rainy days shortly after Mothers Day, harvest lasted in many place until the first week of June. At the research center in Virginia Beach, fruits were picked starting third week of April. At the Central Crops Research Station in Clayton, North Carolina, fruits were picked starting the first week of April. Over the 2019 harvest season, many growers in the Carolinas reported low yields, yellowing and odd shaped plants and flowers. Win Talton and Christie Almeyda from the Micropropagation and Repository Unit at NC State (Raleigh, NC) were testing some of the planting material, and we were able to trace back some of the problems to plasmodium infections of the plants. Growers with close to normal or higher yields relied on several plant sources and type of planting material (bare-root, plug plant). As a result, some growers had an above average yielding season, due to a long picking season, while others had 70% of the season average yield.
Southeastern strawberry growers in the Carolinas wholesaling berries faced competition through berries from Mexico and California. Markets were slow this year, and as of mid-May the average retail price was $2.23/lb. Consumers tend to pay more in direct marketing and for local produce. However, combined with above mentioned low yields, for many Southeastern growers the 2018/19 season was below average.
Research Trials and Observations in Virginia:
We were growing three different varieties- Ruby June, Chandler and Camino Real all started from plugs, with the majority of our acreage under Ruby June. Our experience with Ruby June has been very positive this season. We noted that it took less time for our crew to pick Ruby June than it did to pick Chandler. Chandler berries tend to peak at the same time and fruit hang too close to each other when on the plant. It takes time to evaluate each berry on the plant before berries can be detached off the plant. Ruby June fruits are much easier to sort through on the plant. Ruby June also produces larger berries than Chandler. The Camino Real yield was not as impressive as we had seen the first time we evaluated this variety in the 2014 harvest season. This season though both our Chandler and Camino Real did not get transplanted in the field until October 9 which is a delay of 8 to 10 days than our normal planting schedule. Fruits of Camino Real took fewer labor hours to pick than Chandler.
There were some growers who were disappointed with the duration of the harvest season, barely picking berries for three weeks in many parts of the state. Some had to call quits to harvest season by the third week in May due to the heavy infection with anthracnose crown and fruit rot. The warm spell towards the end of May pretty much closed the season for the majority of growers in the region. For growers in Virginia Beach, many ran out of berries on-farm for the Pungo Strawberry Festival.
On the sunny side, we heard positive experiences of the newer varieties from growers. A grower north of the Virginia Beach area talked about planting more of Camino Real for the next season as that variety performed really well at their site. A grower on the Eastern Shore of Virginia complemented Camino Real for its flavor and mentioned how the customers at his farm loved the taste of that variety. Few growers in Virginia Beach continued to stay impressed with Ruby June this year and will continue to plant that variety. A grower in northern Virginia has been impressed with the disease tolerance capacity and flavor of Flavorfest. Although the crop yields weren’t the highest this season, there were some relatively rain-free weekend days that helped growers to attract customer traffic and harvest most marketable fruits off the berry fields. Not knowing what the next season will bring to us, we continue to look forward to the next one!