There was “heavy frost” this morning in areas north and west of Winston Salem, and the frost pretty much followed the map posted yesterday on this site.  From the Piedmont Research Station in Salisbury, Andy Myers, wrote  this email to me last night after he turned on the irrigation.

Hi Barclay

I started the pump at 1:45 this morning. Canopy temp was 30 degrees with frost on strawberry leaves.

I think this week will be our peak picking and will be slowing down next week. This is our third week of harvest.

Thanks for all you do.

Andy

I would be concerned about the potential for frost tonight in areas in the 38-40 minimum temp range (light blue on map), or colder.  I have been very pleased with the accuracy of the AWIS minimum and maximum temperature maps this season.  This will likely be my last posting to the Portal this season on frost related issues (I hope!).

“Additional weather details, including custom weather forecasts, are available from AWIS at www.awis.com.”

Dr. E. Barclay Poling, Professor Emeritus (NC State Univ.) & Manager

StrawberryDoc, LLC, PO Box 99147, Raleigh, NC 27624

919.418.9687 cell

strawberrydoc@gmail.com

www.strawberrydoc.net

Barclay Poling, Professor Emeritus

There was a “moderate” frost in many areas of the state this morning.  In some areas, it was actually quite serious and I have heard directly from growers this morning who were very  thankful they took measures to protect.  I would definitely plan on taking measures to protect strawberry crops in areas with minimum air temperatures of 36-37 F, or lower, for tonight and tomorrow morning (4.13.12).  See the minimum temperature map below. You can see all areas of the mountains as well as the foothills will be cold enough for frost to occur.

AWIS is also anticipating widespread frost in Southeast NC, North Central NC, and South Central NC.

Good luck!

E. Barclay Poling

strawberrydoc@gmail.com

www.StrawberryDoc.net

Please be advised of the potential for frost in many areas of NC tomorrow morning.  This could be quite a bit more serious than the Easter weekend cold events. The dark blue bands are areas with a strong probability of frost Thur morning. Pink, red and gray areas will be very cold.  Measures to protect with row covers in in areas where it will be less then 35 F should be considered.  Row covers are  preferred to sprinkling in harvest season. Sprinkler irrigation may be an option with good quality water. Check with you local Extension Agent.

Crop report and unusual situation we are faced with on 4/12 and 4/13: The NC crop is now harvesting heavily in Sandhills and ENC, and the Piedmont is underway as well.  This is an unprecedented situation with needing to frost protect during harvest season.

Additional weather details, including custom weather forecasts, are available from AWIS at www.awis.com.

E. Barclay Poling, Professor Emeritus

This advisory is brought to you courtesy of my retirement business,  StrawberryDoc LLC.  You can also  email  me at strawberrydoc@gmail.com  

It is a little hard to believe that we are having to prepare AGAIN for frost starting as early as tomorrow morning in some areas of NC, and then Thursday will be the coldest morning of the week across the state (April 12) and on Friday (April 13), there is also considerable frost risk.  I am away from NC today and will not be making any additional posts to the Portal.

Good luck – B. Poling

PRECAUTIONS NEED TO BE TAKEN TO PROTECT AGAINST A POSSIBLE FROST EVENT TOMORROW MORNING.  I HAVE HAD COMMUNICATIONS THIS MORNING WITH GROWERS AND AGENTS FROM MT. OVIVE AREA IN EASTERN NC, TO AS FAR WEST AS LEXINGTON, NC.  IN EACH INSTANCE,  I HAVE EMPHASIZED THAT IT IS IMPORTANT TO MAKE PREPARATIONS TODAY FOR A FROST EVENT IN THE MORNING THAT COULD DAMAGE BLOSSOMS, AND POSSIBLY GREEN FRUIT STAGES. UNFORTUNATELY, A TV STATION STORY LAST EVENING IN RALEIGH “GOT IT COMPLETELY WRONG” AND REPRESENTED THAT I DID NOT THINK PRECAUTIONS FOR FROST THIS EASTER WEEKEND WOULD BE NEEDED!!

APPARENTLY, THE REPORTER DID NOT UNDERSTAND A CRITICAL POINT I MADE THAT:   THIS PARTICULAR COLD EVENT (4.7.12-4.8.12) SHOULD BE VERY MANAGEABLE WITH EITHER ROW COVERS OR SPRINKLING COMPARED TO EASTER WEEKEND IN 2007 WHEN WE HAD TO RESORT TO BOTH COVERS AND SPRINKLING TO BARELY SURVIVE THAT UNBELIEVABLE FREEZE 5 YEARS AGO THIS WEEKEND.    CONTRARY TO WHAT WRAL REPORTED LAST NIGHT, I DO  THINK THIS COULD BE A SERIOUS COLD EVENT, ESPECIALLY TOMORROW MORNING (SAT).  SUNDAY IS LOOKING A LITTLE BETTER.  

HERE IS WHY THE COLD THIS WEEKEND COULD BE VERY DANGEROUS TO FRESH OPEN BLOSSOMS:

OVER THIS SPRING I HAVE SEEN NUMEROUS SITUATIONS WHEN A 39-40 F MIN TEMP FORECAST HAS RESULTED IN FROST AND DAMAGE TO OPEN BLOSSOMS.  AND, IN LOOKING AT STATE MINIMUM TEMP MAP BELOW YOU CAN SEE THAT WE HAVE A LARGE AREA OF THE STATE WITH MINIMUMS IN THE 36-38 F BAND (TEAL).  GREEN BAND AREAS LOOK PRETTY SAFE (40-42). AREAS IN LIGHT BLUE (38-40) ARE ON THE EDGE. I DID CHECK AN AWIS HOURLY FORECAST FOR ASHEVILLE AND A FROST IS EXPECTED THERE AT 5 AM, BUT IT COULD COME SEVERAL HOURS EARLIER.  THE CRITICAL THING TO UNDERSTAND IS THAT WE DO HAVE “CLASSIC” RADIATION FROST CONDITIONS SETTING UP TODAY FOR FROST TOMORROW MORNING!  WINDS WILL BE VERY STILL TOMORROW MORNING, SKIES WILL BE CLEARING, AND DEW POINTS ARE IN THE RANGE TO MAKE IT FAIRLY EASY FOR FROST (ICE CRYSTALS) TO FORM ON PLANT SURFACES AT THE GROUND LEVEL.  WITH STRAWBERRIES BEING A GROUND LEVEL CROP, YOU CAN OFTEN GET TEMPERATURES BELOW 32 F (CANOPY LEVEL) WHEN THE AIR TEMPERATURE AT ABOUT 6.5 FT (HEIGHT OF WEATHER SHELTER) IS UP AROUND 36-37F.

CONCERNS WITH WET ROW COVERS…

I HAVE LEARNED TODAY THAT MANY AREAS IN THE CENTRAL AND WESTERN PIEDMONT DID NOT SEE MUCH RAIN LAST NIGHT, OR YESTERDAY. AND, THAT IS VERY GOOD NEWS BECAUSE THIS MEANS ROW COVERS ARE DRY ENOUGH TO BE USED FOR FROST PROTECTION IN THESE AREAS.  AFTER GROWERS FINISH PICKING THIS AFTERNOON, THE COVERS NEED TO BE RE-APPLIED (PREFERABLY BY ABOUT 2-3 PM).  BY GETTING THE COVERS BACK ON IN MID-AFTERNOON TODAY YOU CAN BUILD UP A NICE “HEAT RESERVE” FOR TONIGHT’S COLD.  MAKE SURE ALL TEARS IN ROW COVERS ARE REPAIRED.  YOU NEED AT LEAST A COVER OF 1.0 oz (weight per sq yd), and preferably a 1.2 oz cover.  A 1.5 oz cover will offer even better protection.

OF COURSE, SPRINKLER IRRIGATION WILL ALSO WORK VERY WELL.  AND SPRINKLING MAY BE THE ONLY OPTION IN AREAS IN EASTERN NC, LIKE MT OLIVE, THAT DID GET ENOUGH RAIN IN LAST 24 HRS TO MAKE THE COVERS TOO WET TO HANDLE TODAY – I KNOW THAT SOME GROWERS ARE HOPING THEY WILL DRY OUT ENOUGH TO BE USED, BUT YOU DON’T WANT TO DAMAGE THE COVERS BY HANDLING THEM IF THEY ARE TOO WET, AND SPRINKLING IS THE BEST IDEA IN THOSE SITUATIONS.

IT SHOULD NOT BE NECESSARY TO USE BOTH TOGETHER.

THIS COMPLIMENTARY ADVISORY SERVICE IS BROUGHT TO YOU BY STRAWBERRY DOC, LLC

“Additional weather details, including custom weather forecasts, are available from AWIS at www.awis.com.”.

Dr. E. Barclay Poling, Professor Emeritus (NC State Univ.) & Manager

StrawberryDoc, LLC

919.418.9687 cell

strawberrydoc@gmail.com

www.strawberrydoc.net

According to the AWIS Weather Services, Inc., North Carolina Frost/Freeze Forecast that was produced at  507 AM CDT on Wed Apr  4 2012 there is  *** No Frost And/Or Freeze Danger Tonight *** in Eastern NC, Sandhills and East Central Piedmont.

We did have a surprise yesterday morning though, and many growers in Virginia had a major early morning frost on 4/3.  Luckily, growers had their frost alarms set at 35-36, and they were able to get sprinkling underway to avoid any damage.

I am seeing a “cooling off” trend  that could actually be a factor in getting crowds out to pick on this Easter weekend in locations that are opening up.  The cooling is very desirable though from the standpoint of “slowing down” this crop.  As it is, we have a huge volume of fruit that will start coming off in the 3rd week of April.  Cooler temps are always better for flavor development and also these cooler nights and mornings will hopefully stimulate the Chandler and Camarosa varieties to “kick out” some more flower buds from the crowns.  I would like to see that happen towards the middle of this month (new blossoms), as we need these blooms for Mother’s Day weekend in May.  Agents, please check in with your local strawberry growers (if not done already) and check on crop ripening and when they expect picking to start as well as when they think they are really going to need the crowds (I am thinking that a major campaign to get people out for the weekends of April 21-22 and April 28-29 could really payoff this year – we are definitely 10 days early, at least).  Here are the AWIS minimum temp maps for this Saturday morning, and it will also be cool Sunday morning (Easter).

Have a good week!

E. Barclay Poling, Professor Emeritus

AWIS Weather Services, Inc.

Please find below a 20 point grower checklist for April/May 2012 (appreciation is expressed to the NC Strawberry Growers Association, Inc. for their encouragement of me to produce these grower checklists that appear in their monthly newsletters – you may find more information about becoming a member of the NCSA at this web location: www.ncstrawberry.com/ )

1. Leave overhead irrigation in field for evaporative cooling of blossoms in the first half of April & monitor daily forecasts closely in April and early May for high temperatures that can damage to open blossoms – consider sprinkler irrigation for evaporative cooling to protect fresh blossoms from temperatures above 87/88 F.  Hot weather in early to mid-April can kill blooms needed for fruit production on Mother’s Day Weekend (May 12-13, 2012)

2. For growers who do not have sprinkler irrigation, it is critical to drip irrigate for a few hours in the early morning on warm-hot days to minimize blossom and fruit damage from warm-hot temperatures.

3. A critical equipment requirement for evaporative cooling of blossoms is a digital thermometer with a   thermocouple that is inserted into the open blossom – learn more about this equipment and how to use it on the Portal  website:   http://ncsu.edu/enterprises/strawberries/2009/12/26/mauris-sed-leo-aliquam-aliquam/

4. A less expensive Infrared Thermometer costing around $30 may also be used measuring strawberry blossom temperatures.  A Centech digital laser thermometer (item 96451) is available thru Harbor Freight Stores with a coupon for about $27 each.

5. Never allow strawberry plants to wilt. Provide drip irrigation on a daily basis in warm/hot weather; in milder conditions, every other day is fine. Strawberries need an average of 1 inch of water per week in order to grow vigorously;  in warmer conditions (e.g. late March 2012), 1.5 inch of water per week per acre is needed. One inch of water equals 27,154 gallons/acre per week, or 3,879 gallons/acre per day.  Don’t let the shoulders of the beds become dry.

6. If you get hail damage in April/May, be sure to use a fungicide afterwards to reduce growth of fungi that take advantage of the wounded tissue to colonize the berry (so-called opportunistic and secondary pathogens). Warm, dry weather is best to allow the wounds on green berries to heal. Switch is a more broad spectrum fungicide with 12 hr REI and 0 day PHI. If Switch cannot be used, a broad spectrum product like captan would also work well.

7. Try to keep pest problems under control with pre-harvest sprays. Customers don’t like to see sprayers in the field when they are picking.

8. Scout fields for mites, insects, and diseases, especially botrytis, anthracnose, powdery mildew, mites, aphids, thrips, and clippers.

9. Bloom sprays are the most important for managing botrytis because 90% of the infection occurs through the blossom. Recent research suggests bloom sprays are also critical for anthracnose ripe fruit rot control (Source:  2012 Southeast Regional Strawberry Integrated Pest Management Guide (http://www.smallfruits.org/SmallFruitsRegGuide/Guides/2012/2012_strawberry.pdf)

10.  Botrytis has acquired resistance to several fungicides in some grower fields. Tests can be secured through Clemson University in 2012 to help determine farm specific recommendations. To have a test made, go to the advisory, Collecting and Mailing Gray Mold Samples for Fungicide Resistance Testing: http://ncsu.edu/enterprises/strawberries/wp-admin/post.php?post=2195&action=edit

11. Send suspicious-looking plants to the NC Plant Disease and Insect Clinic. Manage pesticides carefully. Avoid making more than two consecutive sprays of Elevate for botrytis. Rinse out spray tank thoroughly after each chemical use and read and follow pesticide labels carefully.

12. Send in leaf samples every 14 days and adjust fertility accordingly. The NCDA & CS has recently sent out a news release about strawberry tissue samples and included a statement about fees for out-of-state growers. It is at this link http://ncagr.gov/agronomi/release/3-12sberry.htm

13.  Estimate when crop will ripen so you can anticipate yields and schedule sales, promotions, and labor accordingly. Schedule and train picking/sales ­labor.

14.  It will take about 28–30 days from open blossom to a fully red-ripe fruit. Cooler temperatures will increase this time by a few days and warmer temperatures will decrease this time. Check with your buyers to make sure they are ready for your berries.

15.  The NC strawberry crop is up to 10-14 days earlier in 2012 than 2011 – many farms in the Southeastern CP, the Sandhills and East Central NC,  will begin picking Easter Weekend.  The crop is quite concentrated this year. It will not be uncommon for some fields to be potentially be picking 3-4 thousands pounds of fruit per acre (in a single picking) in the 2nd half of April 2012.  The NC Strawberry Association, NCDA & CS – Marketing Division, and the NC Cooperative Extension Service, are all working very closely with the state’s strawberry growers to get the word out about this extra early strawberry season in 2012.

16.  Have porta-potty delivered and emphasize proper sanitation for farm laborers and customers.

17.  Fire up refrigeration systems (walk-in cooler, etc.). For pre-pick berries, rapidly forced-air cool late season fruit in properly ventilated containers. High humidity condensate on prechilled fruit must be VENTILATED uniformly or it will cause a quality disaster.

18.  Put out signs on roadsides to direct customers to your fields when berries are ready.

19.  Figure out a system to collect customer names, addresses, and emails for your mailing list.

20.  Be sure to post a good message on your telephone answering machine (mention the early crop). Keep fields picked every 2-3 days. Keep records, even when you get busy!

Dr. E. Barclay Poling, Professor Emeritus (NC State Univ.) & Manager of StrawberryDoc, LLC

strawberrydoc@gmail.com

www.strawberrydoc.net

Sampling Procedure

1. You need cotton swabs and an envelope for sending the samples:

• Can Standard drug store cotton swabs be used?  yes

• you can also buy these online (http://www.vitalitymedical.com/puritan-cotton-tipped-applicators-medical-swabs.html?utm_source=google&utm_medium=base&utm_campaign=products&gclid=CPuuhpSD8a4CFcIFRQodR0M08w)
• Return the swab to its package once sample has been collected

Sample 10 individual berries with fresh gray mold lesions (Fig. 1) randomly from the site.

Do not sample from badly rotted or dried berries (Figure  2).

Use a fresh cotton swab for each berry.  Return the swab to its package once sample has been collected.

When sampling the lesion, use only enough force to collect the fungal mycelium and spores; do not rub the fruit hard enough to collect fruit tissue (Figure 3).  Hint:  if the cotton swab is pink, discard and take another sample.

Place all 10 swabs/individual packages in the postage paid mailing envelope.  Please include your name, address, and email address.  Ship to:

Guido Schnabel

Clemson University

School of Agricultural, Forest, and Environmental Sciences

114 Long Hall (230 Parkway Drive)

Clemson, SC 29634

You can expect results in form of an electronic e-mail report 4 days after Dr. Schnabel has received the samples

• Additional Grower Questions to Dr. Schnablel from VA grower
• Que.  Can I ship via standard UPS, etc. or next day shipping?  (SE VA to Clemson would be two days via standard UPS, I think.)

REPLY:  ship with any method. The faster I get the samples, the faster you will have your answer

Another grower question…

• We don’t have botrytis-infected fruit (yet), just little green berries. We can probably find some botrytis-infested petioles on “old” senescent leaves (that were missed in sanitation efforts).  Would swabs from petiole lesions work?

REPLY:  I take dead flowers and cotton swabs containing spores. Leaves are too messy and often do not provide the target fungus.

Final Grower Question:  ”Usually UPS wants a street address.   Is the address shown (above), which appears to be a postal mail address, indeed the best to use for samples?

REPLY:  Good point. We never use the street address, but some companies require that. The street address for my building is: 230 Parkway Drive.