In A Nutshell - Second Quarter 2011

Randy S. Sanderlin, Burnham, Katherine S., Hall, Michael J., Graham, Charles J.  |  6/9/2011 7:18:21 PM

Nut Scab Control for June through July, 2011

June 8, 2011, Second Quarter Newsletter

Nut Scab Control for June through July, 2011

R. S. Sanderlin

About this time last year, in this newsletter, I tried to make the point that the lack of rainfall in the spring did not provide any assurance that the nuts would not be damaged by scab disease if rain came during the nut-sizing period of late June through early August. I can basically repeat the same sentiment for early June, 2011. Last year, because of the continuing drought throughout most of the state and the usually high temperatures, scab was generally not a problem at any point during the 2010 growing season. As I write this, the high temperature for today and the rest of the week will be in the 95-degree range with spot thundershowers as the only chance for rain. It is difficult to recommend routine fungicide applications under such conditions. Last year, no doubt, some fungicide applications were made that were never challenged by a scab infection period. You may think you wasted your money. Fungicide protection against scab disease is an insurance program, and like all insurance, you have to purchase the insurance (make the fungicide application) before it is needed. Even though it may be difficult to believe that scab disease could become a problem on the nuts given the current heat and drought, a wise pecan orchard manager will pay close attention to rain forecasts and be ready to quickly apply fungicide should conditions change during the next 7 to 9 weeks of summer. It is believed that fungicide applications are good for 2 to 3 weeks and after that period the nuts would be vulnerable to infection during a rainfall period.

This year’s recommended fungicide list follows. As always, producers are encouraged to rotate chemical activity groups at each application to try to reduce the chances of a scab pathogen strain that is resistant to one or more of the fungicide groups from becoming a problem in your orchard.


Pecan Fungicides List By Activity Group:2011

FRAC GROUP

RESISTANCE

RISK

PRODUCT

RATE / ACRE

Group 30

Organotin

Low

Agri-Tin 80WP (TPTH)

Agri-Tin 4L

Super-Tin 80WP

Super-Tin 4L

7.5 oz

12 fl oz

7.5 oz

12 fl oz

Group 3

DMIs

Moderate

Enable 2F (fenbuconazole)

Orbit 3.6F (propiconazole)

Propimax 3.6F (propiconazole

Bumper 3.6 (propiconazole

Quash 50WG (metaconazole)

Folicur 3.6F (tebuconazole)

Monsoon (tebuconazole)

Orius 3.6F (tebuconazole)

8 fl oz

6-8 fl oz

6-8 fl oz

6-8 fl oz

4 oz

6-8 fl oz

6-8 fl oz

6-8 fl oz

Group M

Guanidine Acetate (Dodine)

Moderate

Elast 400F (dodine)

51 fl oz

Group 11

Strobilurin

High

Abound 2.08F (azoxystrobin)

Sovran 50WG (kresoxim-M)

Headline 2.09F (pyraclostrobin)

9.5 fl oz

3.2 oz

7.0 fl oz

Group 3 & 30

DMI + Organotin

Same As 3 & 30

Enable/Agri-Tin

1.3 oz & 3.74 oz

Group 6: Mixture of

Groups 3 & 11

Same As 3 and 11

Stratego 1.04F (propiconazole /trifloxystrobin)

Quilt 1.04/0.62F (propiconazole/azoxystrobin)

Quilt Xcel (propiconazole/azoxystrobin)

QuadrisTop (difenoconazole/azoxystrobin)

Absolute 500SC (tebuconazole/trifloxystrobin)

10 fl oz

14 fl oz

14 fl oz

14 fl oz

7.7 fl oz

Group 33: Phosphonate

Low

Agri-fos

Fosphite

K-Phite

Phostrol

Rampart

Prophyt

1-3 qts

2-2.5 pts


New Pecan Sprayer Calibration Publication

Michael J. Hall

Common problems in controlling pecan insect pests with insecticides include the mistiming of the insecticide application, incorrect pH of the water being used for spraying, selecting the wrong insecticide, using the wrong rate of insecticide, and poorly maintained and incorrectly calibrated spray equipment.

With the high costs associated with making insecticide applications, it is imperative that spray equipment be well maintained and, above all, calibrated to deliver the correct amount of insecticide to the target. A new publication (Pub#2753) entitled "Sprayer Calibration for Pecan Orchards" by Roberto Barbosa and Michael Hall has recently been released. This online publication is available in the Pecan Research Station section of the LSU AgCenter website. "Sprayer Calibration for Pecan Orchards" provides growers with information on how to calibrate any type of air-blast sprayer being used for the application of insecticides and fungicides in a pecan orchard. It also provides information on how to set up the sprayer to ensure optimum coverage of the pesticide being applied.

Once the sprayer is calibrated, it is important to use the right insecticide or fungicide, at the right rate, for the insect or disease to be controlled. Listings of insecticides and fungicides suggested for use in Louisiana can be found at the Pecan Research-Extension website by going to www.lsuagcenter.com and clicking on Research Stations. Click on Pecan below the map of Louisiana, and you will be directed to the station's website. One can also find fact sheets on pecan insect pests and pecan diseases, along with information on general orchard management.

Additional tips are also provided on sprayer care and maintenance. For additional information on this publication contact Dr. Michael Hall at 318-797-8034, ext. 2320 or email.

How Is Your Pecan Crop Looking?

Charles Graham

From Texas to Georgia, the Pecan Belt has seen just about as much weather diversity as possible. Severe cold last winter, cooler or warmer temperatures this spring (depending on where you were standing), flooding, severe drought, tornadoes, wild fires, just about everything you can imagine. At this time of the year, everyone’s attention always migrates to how big the crop is going to be at the end of the growing season. A few reports are starting to trickle in from around the country, so I thought I would share some of those with you. Most of the country should be in an “on” cycle this year.

The Georgia crop is currently estimated to be in the range of 70-90 million pounds, which is a fair crop for an “on” year. The ‘Desirable’ crop started strong, but has suffered through a large June drop and a fair amount of casebearer damage in some areas. Drought may start affecting nut size soon in some areas of the state. The ‘Stuart’ crop, which makes up about 40% of the crop, is light this year. Most other cultivars, especially ‘Sumner,’ appear to have a good crop.

Following last year’s 7 million pound “off” year crop, Alabama was looking forward to a good crop in 2011; however, the late-season high temperatures and severe drought resulted in a lower return crop than many growers hoped for this spring. The lingering drought in the southern counties has contributed to a fair amount of nut drop. Currently, the crop is forecast to be similar to the 2010 crop.

You could just cut and paste the description of the crop in Alabama for Mississippi this year; just change the size of the crop. Mississippi produced a 1.5 million pound crop in 2010, and early reports suggest that the 2011 crop will be similar, perhaps approaching 2 million pounds if adequate rainfall is received.

In 2010, Oklahoma had major issues with scab and pecan weevil, but still produced a 20 million-pound crop. This large crop was followed by record cold temperatures that damaged some trees in the northern areas of Okla. The native crop appears to be a little less than average. Cultivars receiving freeze damage have a light crop, but cultivars that escaped the damage have a good-to-excellent crop. June drop was above normal in some areas, and the lingering drought will impact production. The 2011 crop is currently forecast to be similar to the 2009 crop, but with so many factors at play, the crop has been forecast to be somewhere between 10 and 16 million pounds.

Texas orchards are a mixed bag, from no crop to a heavy crop, depending on the region. The larger production areas are reporting an average crop on improved cultivars. The native crop is also highly variable, with final production probably being highly dependent on how long the severe drought continues into the season. Current estimates suggest a smaller crop than last year, probably closer to the 60 million-pound crop in 2009; however, that number will continue to decrease if many parts of the state don’t return to a normal rainfall pattern.

Louisiana growers are suffering through a variety of problems as well. Drought plagues many areas, especially the west-central parishes, while many growers in the east and southeast are struggling through record flooding. The Louisiana crop is also highly variable, ranging from almost no crop to a heavy cropload, depending on the area. The ‘Elliott’ crop was light in several orchards I visited in south La., while the crop was average to good in central and northwest orchards. I haven’t been able to get out to all areas of the state, so I would appreciate a few of you sending me an email (address at the bottom of this article) on the status of your pecan crop for this year. Thanks in advance for your help, and I look forward to seeing you next week at the TriState Pecan Conference.

Contacts: Charlie Graham at (318) 797-8034 ext. 2333 or email.

Sincerely,

Pecan Research-Extension Staff

Randy S. Sanderlin – Pathology

Mike Hall – Entomology

Charlie Graham – Horticulture

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