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February 2016

Upcoming Events

Central Florida Citrus Growers Round Table

Florida Pomegranate Association Growers Meeting

HACCP for Florida Fresh Fruit and Vegetable Packinghouses

Citrus Hall of Fame Induction Ceremonies

2015 Thermotherapy Field Day Follow-up

Temperature and Blueberry Crop Development

Citrus Bloom and PFD

Stone Fruit Field Day

CHMA Map of the Month

Central Florida

and Fruit Crops Update

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Upcoming Events

February 29—March 1 Florida Weed Science Annual Meeting at the Florida FFA

Leadership Training Facility near Haines City

March 2 Central Florida Citrus Growers Round Table Discussion at the UF/IFAS

Extension—Lake County Office in Tavares

March 4 Florida Pomegranate Growers Association Growers Meeting at the UF/

IFAS Gulf Coast Research and Education Center in Wimauma

March 8 Mature Citrus Mentors at the UF/IFAS Extension—Lake Office in Tavares

March 9-10 HACCP for Florida Fresh Fruit and Vegetable Packinghouses at the

UF/IFAS Gulf Coast Research and Education Center in Wimauma

March 11 Citrus Hall of Fame Induction Ceremonies at the Florida Southern

College Hollis Wellness Center in Lakeland

March 16 2015 Thermotherapy Field Day Follow-up at Whittaker Groves in

Grand Island

April 5 UF/IFAS Florida Citrus Growers Institute at the South Florida State College

Theater of the Preforming Arts in Avon Park

April 14 Review and Exams Ornamental/Turf/Private Applicator at the UF/IFAS

Extension Orange County Office in Orlando

April 15 Florida Citrus Mutual Districts 1-4 Area Meeting and Elections at the UF/

IFAS Extension—Lake County Office in Tavares

April 19 Stone Fruit Field Day at the UF/IFAS PSREU in Citra

asperez@ufl.edu

On-line Registration Link

On-Line Registration Link

Join us for the 54th Citrus Celebration Luncheon on Friday, March 11 as we honor the legacies of:

Dr. William S. “Bill” Castle

John C. “Jack” Norris

Victor B. “Vic” Story, Jr.

The induction luncheon ceremonies will take place on Friday, March 11, 2016 at 11:30 a.m. in the Hollis Wellness Center at Florida Southern

College, Lakeland.

To purchase tickets call Florida Citrus Mutual at (863) 682.1111 or On-Line

For more information, contact Brenda Eubanks Burnette at (561) 351-4314 or BBurne1003@aol.com

asperez@ufl.edu

Temperature and Blueberry Crop Development

There has been much discussion about the recent somewhat colder than

normal temperatures related to our current El Niño Climate Phase and its effect on development of the 2016 Florida Blueberry crop. During the past

two blueberry cropping seasons (2014 & 2015), we had Neutral and “weak” El Niño Climate Phases respectively, that also resulted in colder than

normal February and March temperatures.

Recently at the 2016 Florida Blueberry Growers Association Spring Meeting, Dr. Gerard Krewer gave an excellent presentation on recent weather trends

and their effect on crop development in both Georgia and Florida. One key factor was lack of chill that was observed in most Florida blueberry

production regions. As many farms are just now seeing significant bloom and leafing, it may be a while before the effects of the low fall/early winter

chill are completely understood.

Another factor that can affect blueberry rate of development is heat units,

commonly expressed as growing degree days (GDD). GDD is determined as a relationship of daily high and low temperatures compared to a base

high and low temperature range where increasing GDD value represents conditions favoring increased crop development in several crops, blueberry

possibly being one. There is not much research in the literature describing GDD and blueberry crop development, especially for southern highbush.

Some work conducted by Mr. John Ed Smith in Georgia indicates a base 50F low end is probably applicable to the Florida crop. The high end base

should not be of great importance to our crop but 86F is probably close. You can see an equation to calculate GDD by following the link below:

http://agron-www.agron.iastate.edu/Courses/agron212/Calculations/GDD.htm

You may ask what does all of this mean. We don’t have much, if any, published GDD research on Florida Blueberries but we do have historical

temperature and crop movement data available on the Florida Automated Weather Network (FAWN) - Report Generator and the USDA Ag Marketing

Service (AMS) - Fruit and Vegetable Market News websites respectively. Table 1 on the next page looks at GDD and the possible relationship with

March blueberry shipments over the past 5 seasons.

GDD accumulation from bloom until harvest should have the greatest influence on crop development and with further refinement, could help in

estimating the beginning of harvest. In many seasons, bloom begins around February 1 and thus I have placed a column for GDD during that

(continued)

Year

10K LB. Blueberry Lots Shipped in

March

Growing Degree

Days Base 50 February 1 to April

1

Growing Degree Days Base 50 in

January

2011 0 956 297

2012* 161 1097 361

2013 161 824 485

2014 15 886 268

2015 121 946 351

*Serious freeze in mid-February

Sorted by GDD Feb. 1-April 1

2012* 161 1097 361

2011 0 956 297

2015 121 946 351

2014 15 886 268

2013 161 824 485

Sorted by GDD January

2013 161 824 485

2012* 161 1097 361

2015 121 946 351

2011 0 956 297

2014 15 886 268

Table 1. Growing Degree Days (GDD) at the Okahumpka FAWN

Station compared to USDA—Ag Marketing Service (AMS) Units Shipped in March During the previous 5 growing seasons.

time frame. You will notice the year tied for first for the highest volume of

blueberries shipped had the highest GDD in this time frame. You will also notice the other highest shipping season had the lowest GDD in this period

but also had the highest GDD during January possibly indicating that bloom was earlier that year and I believe, if memory serves me right, it was.

If you have recorded bloom and harvest dates over the past several

seasons, it may be interesting to compare with your temperature data or that of a nearby FAWN station. To improve crop forecasting, we hope to

look this relationship closely over the next few seasons.

Citrus Bloom and PFD

Postbloom Fruit Drop (PFD) has been a problem for growers of Navel, Valencia and some other varieties of citrus the last few years, especially in

central and north-central Florida. As the “strong” El Niño Climate Phase can be expected to continue bringing higher than normal rainfall, those who

have dealt with this disease in the past know that rainfall conceding with citrus bloom can lead to serious infection rates of PFD.

UF/IFAS Citrus Plant Pathologist at the CREC in Lake Alfred, Dr. Megan Dewdney, recommends that growers who anticipate dealing with PFD

familiarize themselves with the Fungicide Application Decisions System for Postbloom Fruit Drop in Citrus Model to efficiently utilize the very limited

choice of fungicides available to growers for managing this destructive pest. Utilization of the model will assist growers to make decisions when to apply

fungicides based on multiple considerations within their grove, including will the application potentially save enough of the crop to justify the cost to

make an application. Stage of bloom is a critical variable in the PFD Model. Dr. Gene Albrigo’s Citrus Flowering monitor diagram for Avalon indicates

flower bud differentiation should increase through March.

Citrus Flowering Model PFD Model

2016 UF/IFAS Stone Fruit Field Day

UF/IFAS Extension Stone Fruit Specialist, Dr. Mercy Olmstead, will be holding the annual Stone Fruit Field day at the UF/IFAS Plant Science

Research and Education Unit near Citra, FL on Tuesday, April 19, 2016. I

have placed the Agenda below and required pre-registration may be completed by following this link:

Stone Fruit Field Day Pre-registration

COOPERATIVE EXTENSION SERVICE, UNIVERSITY OF FLORIDA, INSTITUTE OF FOOD AND AGRICULTURAL SCIENCES, Dr. Nick Place, Director, in cooperation with the

United States Department of Agriculture, publishes this information to further the purpose of the May 8 and June 30, 1914 Acts of Congress; and is authorized to provide research, educational

information, and other services only to individuals and institutions that function with non-discrimination with respect to race, creed, color, religion, age, disability, sex, sexual orientation,

marital status, national origin, political opinions, or affiliations. Single copies of extension publications (excluding 4-H and youth publications) are available free to Florida residents from

county extension offices. Information about alternate formats is available from IFAS Communication Services, University of Florida, PO Box 110810, Gainesville, FL 32611-0810.

CHMA Map of the Month

The map below is for the Green Swamp CHMA through February 5. In depth

interpretation of these results can be obtained by logging in to the CHMA Sectional

Mapping Program on the CHMA Website Main Page:

http://www.crec.ifas.ufl.edu/extension/chmas/index.shtml

Central Florida Citruslines and Fruit Crops Update is published 6 times a year by the Central Florida Fruit Crops Advisory Committee and Central Florida Fruit Crops Extension Program: Gary K. England—Multi-county Extension Agent III gke@ufl.edu (352) 343-4101 Ext. 2729