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Mark Longstroth - Michigan State University. East Lansing, MI, US

Mark Longstroth

Small Fruit Extension Educator | Michigan State University


An expert in fruit production and pest management.





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How to Grow Blueberries A to Z with Mark Longstroth - Berry & Marketing Conference Interview with Mark Longstroth about how to grow blueberries - VSU College of Agriculture MSU Extension Educator Mark Longstroth on Blueberry Shock and Scorch — FGNtv Mark Longstroth from MSU Ag Extension talks what caused crop disaster in Michigan and impact



Mark has over 40 years of experience in fruit production. He has worked for MSU Extension for over 25 years. He became the District Extension Horticulture and Marketing Agent in Southwest Michigan in 1993. Mark, provided fruit production and pest management information for tree fruit, grape and berry growers in Southwest Michigan. In 2010, Mark became a Small Fruit Educator. His focuses on blueberries, grapes and other berry crops. His main education efforts are in crop production, pest management and farm financial management. Mark has a broad knowledge of all the fruits produced in Michigan and the impact of Michigan weather on fruit.

Industry Expertise (4)

Floriculture and Horticulture

Writing and Editing

Food Production


Areas of Expertise (6)



Fruit Production

Pest management



Education (2)

University of Idaho: M.S.

Boise State University: B.S.

News (5)

So Far, So Good For Many Local Fruit Crops

WMUK  online


This year’s cold, wet, late spring might yet pay off in fruit. Michigan State University Extension educator Mark Longstroth says by the time Southwest Michigan’s various fruit plants started growing in May, they’d avoided the danger of spring frost. The season looks promising for many crops. [...]

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Strawberries smaller than normal in West Michigan, but not for long

WWMT  online


Even with a late harvest, the 2018 harvest is already pointing up. Mark Longstroth, a fruit educator with Michigan State University Extension, said, despite the recent heat, the weather has been much more forgiving.

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No frozen fruit for SW Michigan

Herald Palladium  online


According to Mark Longstroth, a fruit educator with the MSU Extension in Paw Paw, each farmer he’s spoken with is happy for the delayed start to the growing season. [...]

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Parts of Michigan officially in drought as near-record heat hangs on

WWZM  online


The hot, dry conditions are a mixed bag when it comes to agriculture, said Mark Longstroth, fruit educator for Michigan State University Extension Service. [...]

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Feeling blue in Michigan

Good Fruit Grower  online


That was the message from Michigan State University small fruit educator Mark Longstroth, who gave a talk he titled “Can You Afford to Grow Blueberries? Drowning in the Blue Wave” at the Great Lakes Fruit, Vegetable, and Farm Market EXPO in Grand Rapids, Michigan, in December. [...]

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Journal Articles (7)

Worried about February warmup to fruit crops?

MSU Extension

Mark Longstroth

2017 I receive many calls about what warm weather will do to fruit in the wintertime. Often, I will say there is no need to worry, they have not completed their chilling requirement. When perennial plants go dormant in winter, they track the hours just above freezing (between 35 and 45 degrees Fahrenheit) to avoid winter cold. This is the chilling requirement. Temperatures below freezing do not matter. During winter dormancy, the trees can acclimate to very cold temperatures. Once the chilling requirement is met, then the plants can grow with warmer weather.

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Do you need to worry about early spring freezes?

MSU Extension

Mark Longstroth

2016 In early spring as fruit trees begin to grow, many people are worried that freezing temperatures will kill the buds of their fruit trees. These buds can handle very low temperatures in the winter. Just because they have begun to grow does not mean they will be killed by freezing temperatures. The swollen buds can often easily withstand cold temperatures in the teens.

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Revitalize blueberries with renovation

MSU Extension

Mark Longstroth

2015 Blueberries have a distinct growth habit. Each spring new shoots emerge from the crown at the base of the plant. These shoots grow quickly the first couple years when they are young. They then start to bear fruit. In the fall, flower buds for next year form at the tips of this year’s growth. Last year’s shoots fruit at the tips and branch below. Every year the new shoots fruit and branch again.

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What are radiation freezes?

MSU Extension

Mark Longstroth

2015 Radiation freezes are characterized by clear skies and dry air. Often the day is warm and pleasant when the sun is out. During the day, the ground absorbs heat from the sun and gets warmer. At night, the ground radiates this heat back to the sky. A layer of clouds can help trap the heat by absorbing this radiation at night and reradiating it back down to the surface.

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Winter cold hardiness in Michigan fruit crops

MSU Extension

Mark Longstroth

2013 The perennial fruits grown in Michigan can withstand most of the conditions of a Michigan winter. They withstand several months of temperatures below freezing and generally show little injury to the winter cold. They do this by becoming dormant and cold hardy.

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Status Update on Organic Blueberries in Michigan

International Journal of Fruit Science

Mark Longstrath et al.

2012 The Great Lakes Region is an important region of blueberry production in the U.S., producing 30% of the annual U.S. production. In Michigan, blueberry acreage increased from 17,724 acres on 590 farms in 2002 to 21,758 acres on 840 farms in 2007. However, despite considerable market potential for organic blueberries, less than 1% of total Michigan blueberry acreage is organically certified. There is high interest and demand for organic blueberries from the Great Lakes Region, and the Michigan State University Blueberry Team has been working on organic production methods over the past 4 years. The establishment of the Michigan State University Organic Blueberry Research and Extension Planting on the Michigan State University campus has been one of the major accomplishments of the Michigan State Uuniversity research team. The objective of this project has been to study practices associated with soil health, nutrition, disease, and insect and weed control. Additional organic blueberry projects in Michigan have focused on studying the interaction of blueberry mulches and compost on nutrient release, and on-station and on-farm testing of OMRI-approved pesticides.

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Tree Growth and Productivity and Postharvest Fruit Quality in Various Strains of `Delicious' Apple

Journal of the American Society for Horticultural Science

Mark Longstrath et al.

1994 Twenty-six strains of `Delicious' apple (Malus domestica Borkh.) were evaluated over several years for growth, yield, and fruit quality at harvest and after 6 months of storage. `August Red', `Rose Red', and `Sharp Red' had larger trunk cross-sectional area (TCSA) 3 and 18 years after planting compared to most other strains. `August Red' and `Starking' had larger TCSA and cumulative yield. `Apex,' `Improved Ryan Spur', `Silverspur', `Starkrimson', and `Wellspur' were also among strains with high cumulative yields and yield efficiencies. `Hardi-Brite Spur' and `Red King Oregon Spur' had moderately high yields and small TCSAs, thus, high yield efficiencies. `Atwood', `Hardispur', `Imperial', `Improved Ryanred', `Starkspur Supreme', and `Topred' had low cumulative yields. `Ace' and `Improved Ryanred' had low yield efficiencies. `Ace', `Imperial', `Red King Oregon Spur', `Rose Red', `Starking', and `Wellspur' had heavier fruit, while fruit weight in `August Red', `Hardispur', and `Starkrimson' was lighter than that in most other strains. `Redspur' and `Starkspur Supreme' had the largest length to diameter (L/D) ratios. `Early Red One' had a similar red skin color rating as `Rose Red.' The red skin color rating of `Early Red One' was significantly higher than that of all other strains. `Hi-Early', `Improved Ryanred', `Redspur', and `Starking' had the poorest skin color ratings. `Hardispur', `Nured Royal', `Silverspur', and `Starkrimson' had high soluble solids concentrations (SSCs) at harvest and after storage. `Early Red One', `Imperial', `Improved Ryan Spur', and `Red King Oregon Spur' had lower SSCs at harvest and after storage. Fruit of `Apex' and `Redspur' had relatively high firmness at harvest, while `Hardispur', `Silverspur', `Starkrimson', and `Starkspur Supreme' had firm fruit at harvest and after storage. `Hardi-Brite Spur' had the softest fruit after storage, and fruit from `Rose Red' had a lower firmness than most other strains at harvest and after storage. Considering cumulative yield, yield efficiency, or some quality parameters, `Apex', `Classic Red', `Improved Ryan Spur', `Red King Oregon Spur', `Silverspur', and `Wellspur' had satisfactory overall performance. Strains are also suggested for planting depending on the market situation and the demand for a particular quality factor. `Hardispur' and `Sturdeespur' (Miller) are not recommended for planting under climatic conditions similar to those of this experiment.

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