Questions From the Field (1.15.12)

— Written By

Dear Agents, Growers and Others

In late December I received a note from Mark Danieley, Agent, Alamance:
“Good Afternoon Barclay,
I am sending some pictures for your professional opinion. These were taken today at Sunset Farms in southern Alamance Co. We think the discoloration of the leaves is due to dry conditions and some possible nutrient deficiency.
The grower is also concerned about the possible virus issue. The plugs came from Aarons Creek. We can send samples to the PDIC if you think that is advisable. Thanks for your help.”
Mark Danieley
Horticulture Extension Agent
NCCES-Alamance County Center
209 N. Graham-Hopedale Rd.
Burlington, NC 27217
Strawberry Plants with discolored leavesStrawberry Plants with discolored leaves
Dear Mark,
My most sincere apologies for such a delayed reply to your note. We have begun to compile some more information related to a possible problem with virus in tips that were sourced from Nova Scotia last year. I personally sent a sample off to Dr. Martin about the time of your email (12/18), and I now have received my results back. I took a second look at your photos today and it is my impression that one of the plants in the middle of the 2nd  photo (right) has  unusually small newer leaves and these look a little suspicious. So, I have copied this to Dr. Louws for his opinion on need for further sampling for virus.
I am including my results from Dr. Martin. I tested 3 farms in NC over the period from Dec 10-16.
Here are my results from Dr. Martin (I got this on Saturday when I was down in Savannah):
Three farms sampled Dec 16th (key:  + SMoV (Strawberry Mottle Virus);  + SMYEV (Strawberry Yellow Edge Virus)). Dr. Martin did not find Strawberry Vein Banding or Strawberry Crinkle in my samples.
•NCSU  #1   Camarosa (PEI) negative for SMYEV and SMoV • <this was a PEI source Camarosa plug and no virus found>
•NCSU #2 Rudd, Benicia, Balamore (bad) had SMYEV < this is a new variety and in the smaller plant, which I called “bad”, Dr. Martin found Strawberry Yellow Edge Virus>
•Rudd #3 Rudd, Benicia, Balamore (good) had SMYEV <however, my “good” plant also had SMYEV! I was using the good/bad label to essentially describe plants that were normal looking = good, or where abnormal in appearance (unusual looking leaves), or were obviously much smaller in plant size relative to other plants in the field>
•NCSU #4 Blue, Chandler, Balamore (bad) had SMYEV <this was a sample from our Sandhills that had some confounding problems of lower pH and high salts, but SMYEV was found in the smaller plant specimens at this location…these same plants had pretty classic salt toxicity symptoms as well>
•NCSU #5 Blue, Chandler, Balamore (good) were negative for SMYEV, SMoV < in this case, the larger plants at this Sandhills location that I called “good” were indeed good! No virus>
•NCSU #6 Pope, Chandler, Balamore (Bad) had SMYEV, SMoV (in this smaller Chandler plant at David Pope’s place in Knightdale, we had both SMYEV and SMoV>
•NCSU #7, Pope Chandler, Balamore (Good) had SMYEV (in this plant sample that was from a larger, and normal looking Chandler, only SMYEV was found)
Strawberry Plants - good and bad
In this 3rd photo you can see the “bad” plants (smaller) at Pope’s compared to the “good” plants (larger) next to the white shoe at top of the photo. Again, in the “bad” plant, both SMYEV and SMoV was found. In the good plant, only SMYEV. Dr. Martin will  actually be down in FL tomorrow to further consult with their industry about this problem. So far, it can be safely said that the problem plants have Nova Scotia as a common source, and the occurrence of SMYEV by itself has been documented for Nova Scotia plants in our state, and in some instances, both viruses are present (SMYEV and SMoV).
I am not personally sure that it makes sense to keep sampling for virus at this stage (it is not inexpensive to do, and does take up to 2-3 weeks). The VA Cooperative Extension has done a very extensive sampling, and they have learned that virus presence is tightly linked to tip source (Nova Scotia and not PEI). Dr. Johnson, VA Tech, is interested in identifying any factors for the VA samples that might be tightly associated with the presence of SMoV, “as 31/35 of our samples had SMYEV, but 6/35 did not.”
In Savannah, I sent Dr. Martin an email prior to me talk about what growers may need to do at this stage, and for sure it is a good idea to scout your crop to see if you have a variable looking plant stand (like the 3rd photo), and check for strawberry aphids. Dr. Martin indicated to me in an email, ” 

Barclay,  If they have strawberry aphids, it would be a good idea to spray given all the inoculum that is present this year. If they have the black bean aphid (Aphis fabae) spraying probably is not necessary since this aphid only transmits SMoV in strawberry.

Cheers,

Bob

I pulled this photo off a website of the black bean aphid (left) and strawberry aphid (right)

Black bean aphidStrawberry Aphids

Back to the other questions regarding (N) fertility of plants you photographed in late Dec. I would not make any attempt to fertilize these plants in January, and I would hold off doing any fertigation until at least mid-Feb in So. Alamance County (a month from now). Normally, fertigation is  not started until early March in your area, but due to this mild Jan and smaller size to these plants, I am of the view that it would not hurt to “possibly” look at some mid-Feb drip fertigation. But, if you saw yesterday’s Portal advisory, we are expecting some below average temperatures from 18 Jan – 26 Jan, and then  the OUTLOOK is for slightly below temperatures 27 – 3 Feb. We can keep re-assessing conditions after next Sunday’s extended forecast from Dr. Van Knowe.
(15 Jan – 17 Jan):  Above average temperatures
(18 Jan – 20 Jan): Below average temperatures
(21 Jan – 23 Jan) Below average temperatures
(24 Jan – 26 Jan): Below average temperatures
Day 15-22 Outlook
(27 Jan – 3 Feb): Slightly below average temperatures. Colder than normal temperatures will dominate early in the period, with with moderating temperatures late in the period. moderating temperatures late in the period.
Day 23-30 Outlook
(4 Feb – 11 Feb): Average to slightly above average temperatures.

Thanks again for your questions! For now, I would sit tight and not do any fertigation. Keep checking Dr. Van Knowes 16 day forecast (next one is this Sunday), and I would check the crop for presence of strawberry aphids. Meanwhile, I am sure we will be hearing more from various experts in our mid-South region on what they may recommend if aphids are found in plasticulture plantings at this time of year.
Also, I have a pretty good idea that most growers have pulled back row covers in recent weeks with all this very mild weather in January. I don’t see any particularly threatening weather events (on the cold side) in the near term forecast. Here is the AWIS NC 7-day max/min below:
AWIS Weather Services, Inc. 7 Day Temperature Forecast
Produced at Tue Jan 15 07:11:54 a.m. CST 2013

MIN=nighttime low (7 p.m. previous night to 8 a.m. of the indicated day, local time)
MAX=daytime high (7 a.m.-7 p.m., local time)

                     Tue   Wed     Thu     Fri     Sat     Sun     Mon     Tue
                   01/15  01/16   01/17   01/18   01/19   01/20   01/21   01/22
STATION              MAX MIN MAX MIN MAX MIN MAX MIN MAX MIN MAX MIN MAX MIN MAX
-------------------- --- ------- ------- ------- ------- ------- ------- -------
Western North_Carolina
Andrews               53  39  54  32  47  22  53  20  57  24  49  21  47  20  40
Asheville_Munic       52  45  56  36  45  25  54  22  56  28  47  23  44  24  35
Banner_Elk            46  38  50  31  44  21  48  21  52  23  41  18  39  18  33
Beech_Mountain        40  37  44  30  38  20  42  19  46  22  35  17  33  17  27
Bent_Creek            53  41  54  34  47  24  53  23  56  27  48  23  46  22  39
Black_Mountain        54  42  55  34  48  24  54  23  57  27  49  23  48  22  41
Blowing_Rock          43  38  47  31  41  21  45  21  49  24  38  19  36  19  30
Brevard               55  41  57  34  50  24  56  23  59  27  51  23  49  22  42
Burnsville            50  37  54  30  48  20  52  20  56  23  45  18  43  18  37
Canton                52  40  53  33  46  23  52  22  55  26  47  22  45  21  39
Celo                  51  36  52  29  45  19  51  18  54  22  46  18  44  17  37
Charlotte             63  47  61  44  52  30  53  27  56  31  54  25  52  28  46
Concord               59  43  59  40  50  27  55  26  58  30  53  25  51  26  46
Coweeta               54  39  55  32  48  22  54  21  57  25  49  21  47  20  40
Cullowhee             54  41  55  34  48  24  55  23  58  27  50  23  48  22  41
Enka                  50  40  51  33  44  23  50  22  53  26  45  22  43  22  36
Fletcher              51  37  52  30  45  20  52  19  55  23  47  19  45  18  38
Forest_City           56  45  58  38  51  28  57  27  60  31  52  27  50  26  43
Franklin_AG           55  41  56  34  49  24  55  23  58  27  50  23  48  22  42
Gastonia-Gaston       65  54  71  47  53  31  56  28  58  32  53  27  51  29  47
Gastonia_AG           60  45  60  42  51  29  55  28  58  32  53  27  51  28  46
Grandfather_MTN       40  37  44  30  38  20  42  19  46  22  35  17  33  17  27
Hayesville            56  46  57  39  51  29  57  28  60  32  52  28  50  27  43
Hendersonville        53  42  54  35  47  25  53  24  56  28  48  24  46  23  39
Hickory               54  43  57  38  46  28  53  25  58  32  49  26  47  25  43
Highlands             47  39  49  32  42  22  48  21  51  25  43  21  41  20  34
Hot_Springs           52  44  53  37  46  26  52  25  55  29  47  25  46  25  39
Jefferson_AG          47  40  51  33  45  22  49  22  53  25  42  20  40  20  34
Jefferson_AP_NC       44  43  59  38  45  25  49  30  54  31  40  23  35  20  31
Lenoir                54  44  59  37  53  27  57  27  61  30  50  25  48  25  42
Lincolnton            60  44  60  41  51  28  55  27  58  31  53  26  51  27  46
Long_Valley           52  41  53  34  46  24  52  23  55  27  47  24  45  23  38
Marion                55  44  56  37  49  27  55  26  58  30  50  26  48  25  41
Marshall              50  39  51  32  44  22  50  21  53  25  45  21  43  20  37
Mocksville            52  41  60  38  50  28  53  24  58  30  51  23  47  24  45
Morganton             56  43  57  36  50  26  56  25  59  29  51  25  50  24  43
Mount_Airy            52  43  56  36  50  26  54  26  58  28  47  24  45  24  39
Murphy                53  41  54  34  47  24  54  23  57  27  49  23  47  22  40
North_Wilkesboro      51  40  55  33  50  22  54  22  58  25  47  21  45  21  39
Oconaluftee           53  37  54  30  47  20  53  19  56  23  48  19  46  18  39
Old_Fort              51  39  52  32  45  22  51  21  54  25  46  21  44  20  38
Pisgah_Forest         53  39  54  32  47  22  53  21  56  25  48  21  46  20  39
Rosman                55  41  57  34  50  24  56  23  59  27  51  23  49  22  42
Salisbury             53  45  61  42  51  32  55  28  60  34  53  27  49  28  47
Shelby                60  44  61  41  52  28  56  27  59  31  54  26  52  27  47
Statesville           53  42  61  39  51  28  54  24  59  30  52  24  48  25  46
Tapoco                55  45  56  38  49  28  55  27  58  31  50  26  48  26  41
Transou               47  38  51  31  45  21  49  21  53  24  42  19  40  19  34
Tryon                 57  47  58  40  52  30  58  28  61  32  53  28  51  27  44
Vale                  60  45  60  42  51  29  55  28  58  32  53  27  51  28  46
W_Kerr_Scott_Reservo  51  40  55  33  50  22  54  22  58  25  47  21  45  21  39
Waterville            53  43  54  36  47  26  53  25  56  29  48  25  46  24  39
Waynesville           53  40  54  33  47  23  53  22  56  26  48  22  46  21  39
West_Jefferson        47  40  51  33  45  22  49  22  53  25  42  20  40  20  34
Yadkinville           53  44  57  37  51  27  55  27  60  30  49  25  47  25  41

Central North_Carolina
                     Tue   Wed     Thu     Fri     Sat     Sun     Mon     Tue
Albemarle             61  45  61  42  52  29  56  28  59  32  54  27  52  28  47
Apex                  52  46  60  43  50  33  53  28  58  34  52  27  48  28  46
Arcola                50  44  60  43  52  33  53  29  59  34  51  26  48  29  45
Asheboro              53  46  61  43  51  33  54  29  59  35  52  28  48  29  47
Badin_Ag              61  45  61  42  52  29  56  28  59  32  54  27  52  28  47
Burlington-Burl       53  44  67  43  53  31  54  25  57  29  53  23  48  28  48
Burlington_AG         49  43  60  42  52  32  53  28  59  33  51  25  48  28  45
Carrboro              50  41  60  40  52  30  53  26  59  31  51  23  48  26  46
Carthage              59  45  59  42  50  29  54  28  57  32  52  27  50  28  45
Chapel_Hill           50  41  60  40  52  30  53  26  59  31  51  23  48  26  46
Clayton               62  47  67  46  57  32  51  29  56  33  55  29  50  26  48
Clinton               67  53  71  49  58  35  53  31  58  36  57  31  53  30  50
Danbury               48  39  58  38  50  28  51  24  57  29  49  21  46  24  43
Durham_AG             51  41  61  40  53  30  54  26  60  31  52  23  49  26  46
Eden                  47  42  57  41  49  31  50  27  56  31  48  23  45  27  43
Ellerbe               66  52  70  48  57  34  53  30  58  35  57  30  53  29  50
Erwin                 64  49  68  45  55  31  50  27  55  32  54  27  50  26  47
Fayetteville_AG       65  51  69  47  56  33  51  29  56  34  55  29  51  28  48
Fayetteville_AP       68  52  74  49  56  35  55  31  56  34  58  30  52  31  47
Goldsboro_AFB         62  53  73  53  61  36  52  31  56  37  56  30  50  27  50
Goldsboro_AG          63  48  68  47  57  33  51  30  56  34  55  30  50  27  48
Graham_AG             49  43  60  42  52  32  53  28  59  33  51  25  48  28  45
Greensboro            48  41  55  39  48  32  52  28  58  33  51  24  46  26  43
Hamlet                61  43  61  40  53  27  57  26  60  30  55  25  53  27  48
Henderson             49  40  59  39  51  28  53  24  59  29  51  21  48  25  45
High_Point            50  45  60  44  52  34  53  30  60  34  52  26  49  30  46
Jackson_Springs       59  45  59  42  50  29  54  28  57  32  52  27  50  28  45
King                  50  42  60  41  52  31  53  27  60  32  52  24  49  27  46
Laurinburg            66  52  70  48  57  34  53  30  58  35  57  30  53  29  50
Lexington             53  45  61  42  51  32  54  28  59  34  52  27  48  28  46
Louisburg             50  39  60  38  52  28  53  23  60  28  52  20  49  24  46
Lumberton_AG          66  50  70  46  57  32  52  28  57  34  56  29  52  28  49
Lumberton_AP_NC       74  55  74  51  61  35  51  32  56  33  57  31  53  29  50
Maxton                70  54  74  54  60  34  53  29  55  32  57  28  53  28  49
Mcleansville          48  42  58  41  50  31  51  27  57  32  50  24  47  27  44
Monroe                61  46  61  43  52  30  56  29  59  33  54  28  52  29  47
Monroe_AP_NC          67  56  69  49  56  32  53  28  55  32  52  26  50  29  47
Nashville             53  41  60  40  52  31  49  27  55  31  54  26  48  26  46
Oxford                50  43  59  42  51  32  52  28  59  33  51  25  48  28  45
Oxford_AG             50  43  59  42  51  32  52  28  59  33  51  25  48  28  45
Pittsboro             52  41  60  38  50  28  53  24  58  30  51  23  47  24  46
Raeford               65  49  69  45  57  31  52  27  57  32  56  27  52  27  49
Raleigh               54  47  62  44  52  34  56  30  61  36  54  29  50  30  48
Raleigh-Durham        53  45  62  45  50  33  55  28  59  33  55  26  49  29  49
Raleigh_State_Univ    52  46  60  43  50  33  53  28  58  34  52  27  48  28  46
Randleman             53  46  61  43  51  33  54  29  59  35  52  28  48  29  47
Reidsville            47  42  57  41  49  31  50  27  56  31  48  23  45  27  43
Rocky_Mount-Wilson    53  46  64  45  52  34  52  26  55  33  53  25  49  27  47
Roxboro               49  41  59  40  51  30  52  26  58  31  50  23  47  26  44
Siler_City            52  41  60  38  50  28  53  24  58  30  51  23  47  24  46
Smithfield            63  46  68  45  57  31  51  28  56  32  55  28  50  25  48
Swann                 54  44  62  41  52  31  55  27  60  33  53  26  49  27  47
Wadesboro             60  46  60  43  51  30  55  29  58  33  53  28  52  29  47
Wilson_AG             62  46  67  45  56  31  50  28  55  32  54  28  49  25  47
Winston-Salem         52  47  66  44  54  31  52  29  57  33  51  25  47  29  43

Eastern North_Carolina
                     Tue   Wed     Thu     Fri     Sat     Sun     Mon     Tue
Aurora                63  49  68  48  57  34  51  31  56  35  55  31  50  28  48
Burgaw                69  54  73  50  60  36  55  32  60  37  59  32  55  31  52
Cape_Fear             68  52  72  48  59  34  54  30  59  35  58  30  54  29  51
Cape_Hatteras         56  51  63  50  55  40  52  36  58  40  56  35  50  35  48
Cape_Hatteras_AG      61  51  62  48  56  41  49  39  56  41  54  36  49  35  46
Cedar_Island          64  53  69  52  58  38  52  35  57  38  56  34  51  31  49
Cherry_Point          66  52  72  54  60  38  51  34  58  36  58  32  52  27  50
Columbia              56  46  63  45  55  36  52  31  58  35  56  30  50  30  48
Edenton               55  46  62  45  54  36  51  32  57  36  55  31  49  31  47
Elizabeth_City        54  46  64  45  54  35  49  32  56  35  55  29  47  27  45
Elizabethtown         68  52  72  48  59  34  54  30  59  35  58  30  54  29  51
Greenville_AG         63  47  68  46  57  32  51  29  56  33  55  29  50  26  48
Greenville_AP_NC      57  47  68  44  53  37  52  31  58  35  55  29  50  29  48
Halifax_AG            52  41  59  40  51  31  48  26  54  30  52  25  46  25  44
Hatteras              57  52  64  51  56  41  53  37  59  41  57  36  51  36  49
Hofmann_Forest        69  53  73  49  61  35  56  31  61  36  60  31  56  30  53
Jackson               52  41  59  40  51  31  48  26  54  30  52  25  46  25  44
Jacksonville          71  56  74  48  61  35  50  31  58  37  57  32  53  28  50
Kinston_AG            63  47  68  46  57  32  51  29  56  33  55  29  50  26  49
Kinston_AP            63  53  74  54  61  37  52  32  57  34  54  30  50  28  46
Lewiston              54  41  61  40  53  31  50  27  56  31  54  26  48  26  46
Manteo                56  48  63  47  55  38  52  34  57  38  55  33  50  32  48
Milwaukee             54  41  61  40  53  31  50  27  56  31  54  26  48  26  46
Morehead_City         66  53  71  52  60  38  54  35  59  39  58  35  53  32  51
Mount_Olive_6SE       67  50  72  49  61  35  55  32  60  36  59  32  54  29  52
New_Bern              65  51  73  47  59  33  51  31  59  35  57  31  52  29  48
New_Holland           66  51  71  50  60  36  54  33  59  37  58  33  53  30  51
Newport_NC            66  53  71  52  60  38  54  35  59  39  58  35  53  32  51
Plymouth              57  44  64  43  56  34  53  30  59  34  57  29  51  29  49
Roanoke_Rap_AG        52  41  59  40  51  31  48  26  54  30  52  25  46  25  44
Roanoke_Rap_AP        49  44  66  47  60  35  53  29  59  35  53  27  48  27  44
Rocky_Mount           54  43  61  42  53  33  50  29  56  33  54  28  48  28  46
Shallotte             68  54  72  50  59  36  54  32  59  37  58  32  54  31  51
Snow_Hill             63  48  68  47  57  33  51  30  56  34  55  30  50  27  48
Southport             68  54  72  50  59  36  54  32  59  37  58  32  54  31  51
Tarboro               55  40  61  39  53  30  50  26  56  30  54  25  48  25  46
Warsaw                67  53  71  49  58  35  53  31  58  36  57  31  53  30  50
Whiteville            67  52  71  48  58  34  53  30  58  35  57  29  53  28  50
Willard               69  54  73  50  60  36  55  32  60  37  59  32  55  31  52
Williamston           55  44  62  43  54  33  51  29  57  33  55  28  49  28  47
Wilmington_AG         69  54  73  50  60  36  55  32  60  37  59  32  55  31  52
Wilmington_AP_NC      76  57  73  53  63  37  53  32  58  38  59  35  54  30  50

Copyright 2013: AWIS Weather Services, Inc. All rights reserved.