Mark Hoffmann
Department of Horticultural Science
Assistant Professor / Small Fruits Extension Specialist
Kilgore Hall 258
Bio
Appointment:
70 % Extension / 30 % Research
Grape, Muscadine and Strawberry Production in North Carolina
Education
Post-Doctoral Researcher University of California Davis 2017
Post-Doctoral Researcher University of Florida 2014
Ph.D. Biology University of Mainz, Germany 2011
M.S. Biology University of Mainz, Germany 2007
B.S. Biology University of Mainz, Germany 2002
Publications
- Tolerance of muscadine grape to 2,4-D choline postemergence-directed , WEED TECHNOLOGY (2023)
- Phenology Based Variability of Tissue Nutrient Content in Mature Muscadine Vines (Vitis rotundifolia cv. Carlos) , AGRICULTURE-BASEL (2022)
- Tolerance of plasticulture strawberry to 2,4-D choline applied to row middles , WEED TECHNOLOGY (2022)
- Tolerance of southern highbush blueberry to 2,4-D choline postemergence-directed , WEED TECHNOLOGY (2022)
- First report of grapevine leafroll-associated virus 3 in Vitis vinifera in North Carolina , JOURNAL OF PLANT PATHOLOGY (2021)
- Impact of Nitrate and Ammonium Ratios on Flowering and Asexual Reproduction in the Everbearing Strawberry Cultivar Fragaria x ananassa Albion , HORTICULTURAE (2021)
- Leaf-tissue Nutrient Dynamics in Mature Muscadine Cultivars Carlos and Noble in Georgia and North Carolina , HORTTECHNOLOGY (2021)
- Market challenges for local specialty crop producers during the early phase of COVID-19 in North Carolina , JOURNAL OF AGRICULTURE FOOD SYSTEMS AND COMMUNITY DEVELOPMENT (2021)
- Microbe-dependent heterosis in maize , PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA (2021)
- Predicting Net Returns of Organic and Conventional Strawberry Following Soil Disinfestation with Steam or Steam Plus Additives , AGRONOMY-BASEL (2021)
Grants
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.
Currently the majority of strawberries in the US are produced in annual hill open-field production in California and Florida, at a farm gate value of more than $2bn annually. However, due to a variety of problems (disease, labor, weather), parts of the industry is shifting towards protected production systems. This opens up new production areas especially at the East Coast of the US. A few North Carolina growers have pivoted into soil-less strawberry production at this point of time. This amounts to approx. 25 acres of soil-less strawberry greenhouse production in NC. At the same time, an emerging indoor strawberry nursery industry began to establish in Western NC. Target harvest windows in for NC strawberry greenhouses are October to December, and February to April. Such cropping system requires plant material that is conditioned for fruit production and that can be planted in late August/early September. However, currently US and NC nurseries struggle to provide sufficiently conditioned plant material at the correct time. Growers rely on inconsistent plant supply from mostly Canadian nurseries. As a result, virtually all plants in NC greenhouses are currently planted either too late, or with lower quality, or both. This leads to insufficient returns on investment for greenhouse growers and represents one of the largest hurdles for this young industry. In this project, we propose to develop protocols and a knowledge base for optimal development of greenhouse strawberry transplants. We will evaluate strawberry rooting and conditioning protocols, as well as fruiting patters in both research and on-farm trials. We then will develop a guideline for growers and nurseries in NC. Such knowledge base has the potential to propel an emerging industry in NC at the forefront of a current trend in strawberry production nationwide.
We request funding to evaluate the performance of 20 strawberry cultivars and 130 advances selections at an on-farm trial (Cottle Farms, Faison NC). This project will yield valuable information on strawberry cultivar performance for growers. Information will be shared through a field day and newsletter articles.
We ask for funding to support the ongoing efforts of the NCSU viticulture research and extension program. These include in detail: (1) Evaluation of muscadine and PD resistant grape cultivars in NC; (2) Development of in-person and virtual workshops and field days on grape management with a focus on pruning, training and Pierce's Disease Management; (3) Evaluation of Ellagic Acid content in a variety of muscadine cultivars across NC.
The North Carolina (NC) strawberry industry is the largest in the Southeast and the third largest in the country. However, the NC strawberry experienced a significant decline in farm gate value in the past years, despite the consistent consumer demand for fresh strawberries nationwide. The reduced resilience in NC strawberry production can be explained by several factors: (1) increased labor costs; (2) increased national and international market competition; (3) frequent unfavorable weather events; (4) pest and disease problems, leading to significant losses; and (5) increasing consumer demand for organically produced strawberries. Those issues implicate a significant need for alternative strawberry production systems in NC. Here we propose to investigate the use of soilless strawberry production systems for NC, hypothesizing that soilless systems can be used to produce strawberries over an extended season, reduce pest pressure, increase yields and fruit quality. We aim to develop a scientific base on the use of substrates for strawberry production, focusing on yield and fruit quality of commonly grown strawberry cultivars in NC. The following objectives will be investigated: (a) Impact of soilless organic substrate use on disease and weed control efficacy, yield, and fruit quality in strawberry plasticulture systems; (b) Optimization of substrate types on fruit quality and yield of common strawberry cultivars. (c) Development of a strawberry greenhouse budget. (d) Development of a strawberry greenhouse production guide for North Carolina. The results of this study will be disseminated to stakeholders through online media (webinars, websites), grower meetings and field days.