AG OUTLOOKLA NIÑA WINTER 2010Clyde Fraisse
Agricultural and Biological Engineering
University of Florida
November 18, 2010
Albany, GA
Potential Impacts on AgricultureLa Niña 2010-2011
• Winter vegetables• Winter pasture• Temperate fruits• Forestry• Row crops
Major Freezes in Florida CitrusFreeze Event ENSO Phase
December 1894 Neutral
February 1899 Neutral
December 1934 Neutral
January 1940 Neutral
December 1962 Neutral
January 1977 El Niño
January 1981 Neutral
January 1982 Neutral
December 1983 Neutral
January 1985 Neutral
December 1989 Neutral
January 1997 Neutral
Adapted from: John Attaway, “A History of Florida Citrus Freezes
Winter Vegetables
• Tomato and green peppers generally yield more during La Niña years than during Neutral or El Niño years.
• Dry weather associated with La Niña generally decreases fungal and bacterial diseases. Increased solar radiation is also a factor. Source: Hansen, J.W., Hodges, A.W., Jones,
J.W., 1998. ENSO influences on agriculture in the southeastern US. J. Climate 11 (3), 404–411.
Winter Pasture• Success of winter pastures
depends on rainfall. This is especially true when overseeding.
• In central and south peninsular Florida, overseeding of cool-season annuals into an established grass sod often fails due to insufficient soil moisture
Winter Pasture• Based on the current dry conditions across parts of the
Southeast and the probability of a dry winter, the following considerations should be made in regard to winter pasture:• Soil moisture at planting will be an important factor for success,
postpone planting If the soil is dry;• Prioritize planting in prepared seedbeds where chances of success
are higher, avoid overseeding;• Plant in best fields that typically hold moisture in the winter;• Don’t invest only in winter forage, save some dollars for feed
purchase;• Be prepared to reduce stocking rates and number of grazing days
with the expected reduced rainfall.
Temperate Fruits• Seasonal climate
variability impacts deciduous fruit production mainly because of a decrease in the satisfaction of dormancy that occurs by the accumulation of chilling hours (temperature at or below 45°F)
Chill Accumulation Variability• Chill hours variability in:
• Alachua• Hendry• Hernando• Marion• Pasco• Polk• Sumter
• Chill Hours (32°F ≤ T < 45°F)• From Oct 1st to Feb 28th • Entire period of records 1948-2007• Different ENSO phases:
• Neutral• El Niño• La Niña
C. W. Fraisse, Agricultural & Biological Engineering
Chill Accumulation Averages Entire Period of Records
C. W. Fraisse, Agricultural & Biological Engineering
Alachua Marion Sumter Hernando Pasco Polk Hendry0
100
200
300
400
500
600
522
354 348
262232
204174
Average Chill AccumulationChill Hours (32F ≤ T < 45F)
El Niño - Southern OscillationMarion County 1948-2007
El Niño La Niña Neutral All Years
Average 405 284 362 354
Minimum 222 146 110 110
Maximum 598 500 593 598
Temperate Fruits - Diseases• The dry weather during La
Niña years is usually not conducive to fungal diseases such as Anthracnose and Botrytis fruit rots.
• Regular applications of fungicides may not be needed as often to suppress these diseases.
Seasonal Forecast of Disease PressurePlant City, Florida – 1892 to 2009
C. W. Fraisse, Agricultural & Biological Engineering
Forestry• Managers could consider:
• Re-scheduling planting of drought vulnerable seedlings
• Reinforce existing control efforts of southern pine beetle
• Delay the harvest of pine straw to retain soil moisture
• La Niña also brings the potential for a very active wildfire season.
Row Crops• Warmer and/or drier conditions
may help certain pests and diseases:• Warm, dry winter may increase flower
thrips abundance• Warm conditions may also help
soybean rust over-winter on kudzu in South Georgia and throughout the Panhandle of Florida
If conditions are dry during the spring it may be best to kill cover crops earlier in order to preserve more moisture in the soil
Drought Monitoring and Forecasting
Agricultural Reference Index for DroughtNOAA-Sector Applications Research Program
Survey
& Prototype
Workshops in FL & GA
Refinement of the tool
Release of final version
on AgroClimate
Training Workshops
AgroClimate Cycle
Objective: Develop a decision support system on AgroClimate specifically designed to help forage producers cope and adapt to drought conditions in the southeastern USA
Drought Workshops w/ Forage ProducersFanning Springs, FL October 14, 2010
Tifton, GA October 15, 2010
Extension Newsletters and Ag Press
Extension Newsletters and Ag Press