Mid-March Update (Noon, Tue, 3/15/16)

— Written By Barclay Poling
en Español

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Dear Agents, Agronomists and Growers,

I had an opportunity to visit a strawberry patch near Raleigh yesterday, and just wanted to share a few comments in this advisory about that visit, as well as quickly mention how this warmer weather impacting this crop’s ripening schedule.

Ripening schedule:

Yesterday, I saw Camarosa plugs with over one dozen open blooms on a farm near Wilson (Fig. 1).

jim 12 bloom camFig. 1. The growing degree day unit accumulation from Jan. 1st to March 14th (base 50 F) at a weather station near this farm is now approaching 200 hours! Hard to believe, but back on 3/7 (a week ago) it was only 75 GDDs. That’s right we picked up 125 GDD units in one week. On some Camarosa plants I counted 14 open blossoms yesterday! Most growers think about seeing berries in about 30 days from the open bloom stage! Potentially, these open blooms could be berries ready to pick by mid-April. We are hopeful to have a full crop this season, even after Camarosa plants sent out so many blossoms in late Dec and early Jan. One concern I have with the plants I saw yesterday was the concentration of so many buds that have recently emerged from the crowns.

Mid-March checklist:

1. Nitrogen – Strawberry plants need a substantial and steady supply of N during the growing season. Start weekly applications of N as soon as spring growth begins, often around March 1 (or around 45 days from the first planned harvest). This date may be earlier in the southern and eastern parts of North Carolina and later in the western parts. Apply 5.25 lb N/acre/week the first time you inject (0.75 lb N/day), and for the  remainder of the season, the weekly N application should depend on tissue testing results.

2. Tissue testing – Plant tissue samples for strawberries consist of (1) the most recently mature trifoliate leaf (MRML) and (2) the associated detached petiole. MRMLs are fully expanded and consist of one petiole (leaf stalk) with three leaflets. They are usually located three to five leaves back from the growing point.

trifoliateFig. 2. Proper leaf and petiole samples ensure reliable results

2016-03-15_11-34-39Fig. 3. Be sure to separate the petioles from leaf blades

2016-03-15_11-39-58Fig. 4. The web address:  www.ncagr.gov/agonomi, and here is the whole chapter on Fertility Mgt: SP_Chapt8 Fertility Management

3. From your tissue sample test, you will be advised about N feeding schedule to follow, as well as other nutrients that may be in “short supply.”  This first report is essential to getting a handler on micronutrients like boron. Here is some useful information about boron sources and how much to inject. For example, just 1/2 lb Solubor (20.5%) supplies 1/8th lb (0.125 lb boron)/acre. NEVER exceed 1/8th lb boron!

1 lb borax (11% B) will provide 0.125 lb B/A.
0.5 lb Solubor (20.5% B) will provide 0.125 lb B/A

4. You can still do “field sanitation” – even at this late stage!

The main problem with waiting until new leaf growth has begun for doing field sanitation, or clean-up, is that you lost the best opportunity to do this operation when the plants are still dormant, and different kinds of “brushing” techniques can be used during the late weeks of dormancy without harming the plants. Now, the plants are very succulent, and any new leaves that are “brushed” will be injured. You can still so some beneficial cleaning up now, but it will require hand removal of dead flowers and the older winter leaves. I would still recommend doing this to minimize Botrytis pressure, especially if you are getting back Profile reports (from Clemson) reporting widespread resistance issues, and you are being limited to just a few products, like captan and thiram. It is important to follow your report’s recommendations on chemical spray options! If you are limited in chemical controls, the suggestion of doing some last minute clean-up could really pay-off in a wet season with heavy gray mold pressure during bloom and harvest.

dead tissueFig. 5. Dead flower parts on Camarosa. Some Camarosa plants sent out as many as 20-30 blooms before New Year in response to over 150 GGD units that occurred on this same farm from Dec 16-Dec 31, 2015. This is an unprecedented situation where we got more than enough GGD units (base 50) in the 2nd half of December. Normally, we accumulate fewer than 10 GDD units in this period.

sprolateFig. 6. The dead leaves and winter-killed flowers from Dec/early Jan are providing  all kinds of botrytis inoculum to infect newly opened blossoms. In the last 2 days in Raleigh area, we have had near ideal conditions for botrytis infection.

inoculumFig. 7. Weather conditions have been perfect the last few days for Gray Mold.

5. Pollination

When it comes to the pollination process, the worst thing you can do is leave a row cover ON during bloom – the covers interfere with wind movement.

Early season Chandler blooms are generally not the best in structure, and stamens (male part) are frequently recessed, or even missing on some flowers. Further, the stigmas (tips of the female flower part) are receptive before the anthers on the same flower, thus there can be real benefit from cross pollination by honey-bees.

Two active honey-bee hives per acre can really help with fruit shape and berry size.

6. Frost risk in coming week?

Right now, those of you getting SkyBit can see that on both Sunday and Monday mornings next week we could be seeing some frost problems, and the crop will likely be in very heavy bloom at that time in many areas of the state of NC.


NC Min Temp Maps for Sunday and Monday:



Check your city/town for FROST risk over next 10 days, and take appropriate measures to frost protect, if needed.


Ahoskie-Tri-Cou Albemarle_AP Andrews Asheboro
Asheville_Munic Beaufort-Michae Boone_NC Burlington-Burl
Cape_Hatteras_AG Chapel_Hill-Hor Charlotte Cherry_Point
Clinton_NC Concord_NC Currituck_NC Edenton-Northea
Elizabeth_City Elizabethtown_NC Erwin-Harnett_C Fayetteville_AP
Fort_Bragg/Simm Franklin/Macon_C Gastonia-Gaston Goldsboro_AFB
Goldsboro_NC Greensboro Greenville_AP_NC Hickory
Jacksonville Jacksonville_(A Jefferson_AP_NC Kenansville-Dup
Kill_Devil_Hills Kinston_AP Lexington-David Lincolnton_AP
Louisburg_NC Lumberton_AP_NC Mackall_AAF Manteo/Dare_Co
Maxton Mcalf_Bogue_Fiel Monroe_AP_NC Morganton-Morga
Mount_Airy-Moun New_Bern North_Wilkesbor Oxford_NC
Piney_Island_Bom Pope_AFB Raleigh-Durham Reidsville_AP
Roanoke_Rap_AP Roanoke_Rapids_R Rockingham_NC Rocky_Mount-Wils
Roxboro_AP Rutherfordton Salisbury-Rowan Sanford_NC
Shelby_AP_NC Smithfield_AP Southern_Pines Southport_NC
Statesville-Sta Tarboro_AP Wadesboro_AP Washington-Warr
Whiteville_NC Wilmington_AP_NC Winston-Salem



Aberdeen Andrews_AFB Annapolis_Naval Baltimore_Sci_Ce
Baltimore/Wash Cambridge/Dorche College_Park_AP Cumberland_AP
Easton_MD Fort_Meade Frederick_MD Gaithersburg_AP
Hagerstown_AP Leonardtown Middle_River Oakland_MD_AP
Ocean_City_AP Patuxent_River Salisbury Stevensville_AP
St_Inigoes/Webst Washington_DC_AP Westminster_AP



Abingdon Ashland_VA Charlottesville Chesapeake-Ches
Culpeper Danville Dublin/New_Riv Emporia_VA
Farmville Fentress_Naval_A Fort_Belvoir/Da Fort_Eustis/Fel
Franklin/J_B_Ro Hillsville Hot_Springs/Ing Jonesville_AP
Langley_AFB Leesburg/Godfre Louisa-Louisa_C Lynchburg
Manassas_Muni(A Marion/Wythev Martinsville Mecklenburg/Bru
Melfa/Accomack Newport_News Norfolk_Hampton_ Norfolk_NAS
Norfolk_VA Oceana Orange_VA Petersburg_(AWO
Quantico Richlands_AP Richlands_VA Richmond
Richmond_Chester Roanoke Shannon_Arpt Stafford_AP_VA
Staunton-Shenan Suffolk-Suffolk Tappahannock_AP Virginia_Tech_A
Wakefield_AP Wallops_Island Warrenton_Fauqui Washington_Dulle
West_Point_VA Williamsburg_VA Winchester_Rgnl Wise/Lonesome_P



Aiken_AP Anderson_Co_Air Barnwell_AP Beaufort_Cnty_AP
Beaufort_SC Bennettsville_Je Camden_AP Charleston_Exec_
Charleston_Muni Cheraw_AP Chester_AP Clemson-Clemson
Columbia-Columb Columbia/McEnti Columbia_Metro Conway_AP
Darlington Florence_SC Georgetown_AP_SC Greenville_Donal
Greenville_Down Greenville-Spart Greenwood-Green Hartsville_AP
Hilton_Head_AP Kingstree_AP Lancaster-McWhir Laurens_AP
Manning_AP Marion_AP_SC Moncks_Corner_AP Mount_Pleasant_A
Myrtle_Beach Newberry_AP North_Myrtle_Be Orangeburg-Oran
Pickens_AP Rock_Hill Spartanburg_Down Summerville_AP
Sumter_AP Sumter_SC Walterboro_AP Winnsboro_AP



Albany_Municipa Alma/Bacon_Co Americus_AP Athens_Municipa
Atlanta/DeKalb Atlanta/Fulton Atlanta_Intl_Ar Atlanta_Paulding
Augusta/Bush_Fi Augusta_Daniel_F Bainbridge_GA Blakely_AP
Brunswick_GA Brunswick/Glync Canton_GA Carrollton_AP
Cartersville_AP Claxton_AP Columbus_GA Covington_GA_AP
Dalton-Dalton_M Douglas_Muni Dublin/WHBarron Fitzgerald_AP
Fort_Benning Ft_Stewart/Wrig Gainesville_AP_G Greensboro_GA
Homerville_AP Hunter_(AAF) Jesup_AP La_Grange
Lakeland Lawrenceville_AP Macon_AP Marietta
Marietta/Cobb Milledgeville_AP Moultrie_Muni_AP Newnan-Newnan_C
Peachtree_City Rome_GA Savannah Statesboro_GA
Swainsboro_AP Sylvania_AP_GA Thomaston_AP Thomasville_AP
Thomson_GA Tifton_AP Valdosta Valdosta/Moody
Vidalia Warner_Robins_A Washington_GA Washington_GA
Waycross_AP Winder_AP