Gina Fernandez

The capacity of strawberry nurseries to develop clean plant material in a timely manner is crucial to the $ 2.6 billion US strawberry production industry. However, strawberry propagation in North America is a costly multi-year and multi-location operation, leading to a multitude of challenges: (a) Dependency on methyl bromide (MB) for soil disinfestation; (b) Plants as symptomless carriers of plant pathogens; (c) Significant inefficiencies, leading to higher costs for duplicative infrastructure, equipment, labor costs and transportation; There is a critical need for the strawberry nursery industry to reduce overall costs, minimize the spread of pathogens and find alternatives to MB. We propose to address these needs through a coordinated and systematic approach in close collaboration with national and international stakeholders. We have the long-term goal to accelerate the development of optimized, clean propagation techniques, using precise indoor propagation (PIP) practices and genetic tools. Our specific objectives are (1) Development of PIP protocols to optimize strawberry propagation; (2) Determine plant propagation capacity using genetic and morphological tools; (3) Determine socio-economic structure and supply chain of the US strawberry industry; (4) Develop fully functional PIP system and transfer technology into on-farm solutions. We propsoe to develop nursery specific services, products and on-farm technology, and we will extent our research through a multitude of activities, including yield prediction tools for strawberry farmers in the US. The main outcome of this project is the development of cost-effective strawberry propagation systems, leading to reduced use of MB and the mitigation of diseases and pathogen spread.

Soilborne pests such as soil-borne fungal pathogens, nematodes, and weeds limit strawberry production in SE-USA. Among these, soilborne pathogens such as Pythium irregulare, Rhizoctonia fragariae, and Pratylenchus penetrans which cause black root rot (BRR) complex. Although soilborne pests were effectively managed in strawberry production by the application of methyl bromide (MB), a pre-plant soil fumigant, it was phased out due to health and environmental concerns. Anaerobic Soil Disinfestation (ASD)’, also known as ‘Biological Soil Disinfestation (BSD)’, is a non-chemical method used to manage soil-borne diseases, phytonematodes, and weeds in vegetable and fruit production systems. The main objective of this project is to conduct lab and greenhouse trials to examine the capacity of anaerobic soil disinfestation (ASD) with locally available labile carbon sources to advance a non-fumigant-based production system. Understanding the effects of locally available carbon sources that can initiate ASD has the promise and environmental benefits of non-chemical management of soilborne pests and continue to make this research project on this area both timely and of critical importance to improved soil conditions and agriculture sustainability in NC.

North Bay Produce has agreed to support a project to identify superior caneberry cultivars that are adapted to western NC and investigate the use of plant growth regulators to improve yield and reduce labor in blackberries. This project will last for three years and will be a collaborative research effort between NCSU Department of Horticultural Science, Mountain Horticultural Crop Research and Extension Center (MHCREC) and North Bay Produce.

The strawberry breeding program at NC State University objective is to breed strawberries that adapted to climate and cultural growing conditions in North Carolina and the southern region of the US. In order to be successful in this region, cultivars need to have a minimal chilling requirement and a fruiting period that occurs primarily in a 2 month window the spring. Our primary objectives therefore are to develop strawberry cultivars with superior yield, fruit and horticultural plant traits adapted to this region. Ideal plants would also have resistance to insect and disease pressures that are common to this region.

Production of raspberries grown in tunnels in soilless substrates offers NC growers a new niche crop. This production system known as "annual substrate grown long-cane production" involves growing plants in soilless media that is placed in pots or bags and grown in tunnels when the season is more moderate in the spring. We are investigating the use of locally produced pine bark substrates compared to imported coconut coir. The pine bark substrate system is estimated to be 1/8 the cost of the imported coconut coir. However, we have not determined the precise irrigation and fertility needs of raspberries grown in this type of substrate system compared to the more well established production protocols for growing in coconut coir. The objective of this project is to determine the fertility inputs and needs of raspberries grown in coconut coir and pine bark substrates in an on-farm research collaboration in North Carolina.

Blackberries are an emerging and economically important commodity in NC with approximately 600 acres of commercial blackberries that are managed by approximately 25 commercial growers. Primocane-fruiting blackberry cultivars are a relatively new cropping system in the US and are especially prone to inadequate lateral branching. Inadequate lateral branch development can have negative consequences on blackberry productivity and profitability, since yield is positively correlated with lateral branch number. Additionally, disease management programs for primocane-fruiting blackberry are limited. Growers have concerns regarding development of fungicide resistance with current management strategies. We seek to conduct a comprehensive evaluation of factors that enhance lateral branching and develop new disease management programs to reduce risk of fungicide resistance of primocane-fruiting blackberry.

Americans consume on average eight pounds of strawberries annually, making them the most popular berry crop. In 2014, there were 59,895 acres planted in the United States (US), valued at $2,865,432,000. In the southern states of North Carolina, Arkansas, Georgia, South Carolina, Tennessee and Virginia, 2,342 planted acres were valued of $47,158,000. Three cultivars, ’Chandler,’ ‘Camarosa,’ and ‘Sweet Charlie’ have been the backbone of the southern industry for 30 years as they are best adapted to our climate, require moderate to high amounts of chilling, and produce fruit in the spring prior to summer heat. However, they have poor shelf-life, produce inconsistent yields, and have poor flavor respectively. All three cultivars are susceptible to a number of diseases including anthracnose. University of Florida’s (UFL) strawberry breeding program develops cultivars with no chilling requirement, designed for winter production from December-March. The University of California-Davis (UCD) breeding program develops day neutral (perpetual flowering) strawberries, designed to produce fruit through the mild California summers and short day types that are adapted to the cooler California climates . Neither UFL nor UCD breeding programs focus on southern climactic requirements or developing cultivars specifically adapted to the southern region which are necessary to meet growing local and regional demands. The short term goal of the North Carolina State University (NCSU) breeding program is to release strawberry cultivars currently in the program that are adapted to the southern US. The long term goal is to develop spring bearing strawberry cultivars adapted to the southern US with high yields, superior flavor, and improved disease resistance (especially anthracnose) and improved post-harvest quality.

Objective: To compare the effects of sod and reflective groundcovers on canopy microclimate, bud phenology, yield, fruit quality, SWD infestation, disease incidence, and vegetative growth of ‘Osage’ and ‘Prime-Ark Traveler’ blackberry.

The Crop Profile (CP) and the Pest Management Strategic Plans (PMSP) for fresh market blackberry are required to be within five years old; this crop an emerging crop therefore there are no CP or PMSP in the database. Production practices need to reflect current practices and issues. It is proposed that a group of Contributors (i.e., faculty, Extension Specialists, Industry) representing the states involved will develop a CP for their state commodity. The CP will be used as the backbone of the PMSP and will allow for specialists and stakeholders to set priorities and update current production practices.

Summary. Strawberry nurseries must provide a high level of sanitation to ensure heathy plant production and avoid spreading pests and pathogens through planting material. The Montreal Protocol allows strawberry nurseries to continue to use methyl bromide (MB) for soil disinfestation for control of soilborne pests and pathogens under the quarantine and preshipment exemption (QPS). However, there is concern in the strawberry nursery industry about long-term availability of MB and lack of a suitable alternative as well as increasing demands for organically produced nursery stock. Therefore, reliable fumigant and non-fumigant MB alternatives are urgently needed for the U.S. strawberry nursery industry. Steam is a dependable non-fumigant method of soil disinfestation and is proven to control soilborne pathogens and weeds effectively in strawberry production fields in conventional and organic plantings. Recent USDA NIFA MBT funded research led to the finding that the fumigant allyl isothiocyanate (AITC, Dominus) co-applied with steam leads to enhanced pathogen control. Based on those results, we propose to investigate an integrated soil disinfestation system designed for strawberry nurseries. We request funds: (1) to modify an existing steam applicator to make it compatible with commercial industry requirements; (2) to evaluate and demonstrate the new steam applicator; (3) to integrate steam with AITC and exothermic additives for soil disinfestation in strawberry nurseries; (4) To perform economic analyses of proposed treatments and (5) to deliver results to industry, growers and the public. The project will be performed at strawberry nurseries in California and North Carolina where much of the U.S strawberry nursery industry is centered. We expect to develop an integrated soil disinfestation system based on steam and fumigants for strawberry nurseries in the United States and to transfer our findings to interested parties.