Strawberries: Covered & Uncovered. Presented by: Bronwyn Aly Extension Educator, Local Food Systems/Small Farms

Transcription

1 Strawberries: Covered & Uncovered Presented by: Bronwyn Aly Extension Educator, Local Food Systems/Small Farms

2 Objectives Covering materials Why we need to cover Timing to cover & uncover Frost protection

3 Cover materials Straw matted row production Row Cover plasticulture production Available in various weights 0.5 oz, 1.0 oz, 1.25 oz, 1.5 oz Ex. 36 x 250 roll of 1.5oz ~$400 + s/h Don t forget to secure the edges to the ground i.e. blocks or bags

4 Why we need to cover strawberries Protect plants during winter Extreme cold temperatures Prevent frost heaving Provide better picking conditions Cleaner fruit Less mud for pickers

5 Why we need to cover strawberries Mulches slow heat loss and desiccation, thus reducing injury to plants by maintaining a more uniform temperature and moisture in the crown area

6 Why we need to cover strawberries Majority of crop is made in the fall Sept, Oct, Nov, & Dec Branch crown numbers are influenced by planting date Row covers appear to increase the number of flowers per branch crown = increased yields

7 When to cover your berries for winter? (matted row) Apply straw after 2 3 consecutive days with soil temperatures at or below 40⁰ F This is usually after several frosts and the plant growth has slowed typically has been around Thanksgiving Best to apply before soil freezes solid

8 Scouting reminders before you cover! Look for problem insects aphids Look for disease problems leaf spot/scorch Runners have been pulled & rye grass under control Check your branch crown numbers

9 When to cover your berries for winter? (plasticulture) Plasticulture research at DSAC 15 yrs ago Suggested covering when you have 3 4 nights below freezing, uncover first week or so of March 1.25 to 1.5 oz row cover best investment Research from North Carolina State University Research from Ohio State University

10 When to cover your berries for winter? NCSU research Created a model for yield response as a function of fall growing degree day accumulations. Chandler ~625 GD units Camarosa ~800 GD units GD units = (Tmax + Tmin/2) 50⁰ F Start calculating at planting, place row covers on when ave. daily temp is 60⁰ F, remove covers once GD unit optimum reached.

11 When to cover your berries for winter? NCSU research Saw increased yield response, especially in cooler areas of state. This row cover management tool helps to increase the number of flowers/branch crown Once covers removed, plants still have time to acclimate to cold temperatures

12 When to cover your berries for winter? Ohio State model Depending on the fall season, start monitoring forecast at the first of November. Look for a 7 10 day pattern with average daily temperatures hitting 50 ⁰ F or less Ave. 42⁰ F

13 When to cover your berries for winter? Research at OSU has found that oz weight row cover works best For southern Ohio, preliminary results show a lighter weight cover on by the first of November, followed by an additional cover placed the first week of January showed the best results total row cover weight of oz

14 How can we compensate for a late planting date? Managing row covers in the fall can help compensate by increasing the number of flowers per crown but won t increase the number of branch crowns.

15 When to uncover your berries in spring? (matted row) When the new foliage starts to emerge from the crown Check forecast, delay a few days if cold weather predicted Try to leave about an inch of straw on the rows, plants can still grow through this layer & it offers some weed control and cleaner fruit

16 When to uncover your berries in spring? (plasticulture) Look for a 7 10 day pattern with average daily temperatures hitting 50⁰ F or more May be times when temperatures warm up for a day or two but not a consistent pattern The longer you leave the cover on into spring, the harder you are pushing the plants = earlier bloom period = double edged sword

17 Important step at time of uncovering! Remove dead leaves and plant debris! Helps cut down on over wintering disease pathogens Also remove weeds & scout for insects

18 Frost Protection Row covers are good early in spring Effective during marginal cold events depends on the stage Can cause flower or foliar damage in windy conditions Can effect pollination if left on for extended periods during bloom Have overhead irrigation system in place and ready

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20 Critical temperatures to remember

21 Critical temperatures to remember Table 3. Inches of Water/Acre/Hour to Apply for Protection at Specific Air Temperatures and Wind Speeds Wind speed (mph) at crop height Air temperature degree F at canopy Source: Martsoff and Gerber, Penn State University.

22 Frost protection considerations Dr. Barclay Poling, AHSH 2013 Hort Talks If you were counting on that few degrees of protection from row cover on a marginal night, be cautious of high humidity when enough water under the cover to trigger ice formation if temperature drops just below freezing Turn on sprinklers over row covers when wet bulb temperature is 31⁰, especially on low humidity nights Turn on drip irrigation on light frost nights added assurance along with row cover

23 Questions & Comments Bronwyn Aly University of Illinois Extension Local Food Systems & Small Farms Educator