SECC Fall Agricultural Outlook

Winter vegetables (tomato, green peppers)

Tomato and green peppers generally yield more during La Niña years than during Neutral or El Niño years. Dry weather generally decreases fungal and bacterial diseases and help growers reduce the number of fungicide applications, however viruses caused by thrips (Tomato Spotted Wilt [TSW]) and white fly (Tomato Yellow Leaf Curl [TYLCV]) are problems. EDIS publication: Using Seasonal Climate Variability Forecasts: Risk Management for Tomato Production in South Florida

Forestry

Warm and dry conditions associated with La Niña events may prompt managers to consider re-scheduling planting of drought vulnerable seedlings, reinforce existing control efforts of southern pine beetle, and delay the harvest of pine straw to retain soil moisture. EDIS publication: Using Seasonal Climate Variability Forecasts to Plan Forest Plantation Establishment

Pasture

The objective of ranchers for this winter is to get through with the minimum amount of grain feed, but success of winter pastures depends on rainfall. This is especially true when over seeding. The recent severe drought has created a pasture and hay shortage throughout the region, greatly impacting farm finances and profit. In central and south peninsular Florida over seeding of cool-season annuals into an established grass sod often fails due to insufficient soil moisture and this is generally not recommended unless irrigation is available since dry conditions can be exacerbated during La Niña seasons. Grazing management this fall and winter is critical especially under drought conditions that still grip the southeast. Related articles: Winter annuals make sense (UGA CAES publication), Climate-Based Management Options for North Central Florida Beef Cattle Producers (EDIS)

Fruits - temperate (peach, nectarine, apple, pear, blueberry, raspberry, strawberry)

Seasonal climate variability impacts deciduous fruit production mainly through changes in the satisfaction of dormancy that occurs by the accumulation of chilling hours (temperature at or below 45°F) and changes in the accumulation of heat units that promote flowering and fruit development. Also affected can be the extent of the threat from freeze damage during flower and fruit development, and the timing and severity of diseases and pests. La Niña conditions generally result in decreased chill accumulation in the early part of the winter (Nov. Jan.) and can increase the need for oil or other dormancy compensating sprays in peaches and blueberries. Check the chilling forecast and the regional chill maps for greater detail.

Winter annual broadleaf weeds may thrive under warm and dry conditions, and these weeds act as host plants for catfacing insects (sucking bugs) of peaches. High populations of cat-facing insects have been documented in peach orchards where winter annual broadleaf weeds are allowed to grow.

Fruits - subtropical (lychee, longan, loquat, sapodilla, mango)

As with temperate fruits, seasonal climate variability impacts fruit production through: 1) changes in the satisfaction of dormancy that occurs by the accumulation of chilling hours below 60ÁF from mid-November through January and 2) through the effect of temperatures and rainfall on maintaining trees in a non-vegetative (environmentally induced dormancy called quiescent) state from September through February. Like temperate fruits, seasonal climate also affects the timing and severity of diseases and pests.

The potential for warm weather during the fall and winter may predispose lychee, longan, and mango to continue or initiate vegetative growth during the fall/winter period. This in turn may reduce or eliminate late winter or early spring flowering of these crops. Lychee, longan, and mango producers are advised not to apply any nitrogen containing fertilizers from late summer onward and to also stop irrigating. This will decrease the potential for unwanted vegetative growth during the fall and winter months and increase the chances for flowering in the late winter or early spring for these crops. The potential for continued warm temperatures may enhance fruit production of sapodilla and loquat. Drier conditions should reduce disease pressure but may increase the incidence of some insects such as mites and scales. For more information about subtropical fruits: http://fruitscapes.ifas.ufl.edu

Fruits - tropical (mamey sapote, carambola, papaya, guava, banana)

Warm temperatures during the fall and winter may allow continued growth and increased production of carambola, guava, banana, mamey sapote, and papaya. Drier than normal conditions should decrease disease pressure but may increase insect pressure, i.e., mites on guava and papaya. Growers should be alert to the continued warm and dry conditions and irrigate during dry periods to facilitate fruit growth and development. Plant nutrients levels should be monitored closely because more nutrients may be required to maintain more vigorous fruit and vegetative growth during this time than normal. For more information about tropical fruits: http://fruitscapes.ifas.ufl.edu

Row Crops

La Niña impacts are less evident on annual summer crops since its strongest signal occurs during fall, winter and spring. Warm conditions may help certain pests and diseases. Warm, dry winter may increase flower thrips abundance. Yellow mustard and wild pansy are ideal hosts for thrips, and a warm winter may provide ideal growing conditions for these and many other host plants. Similarly, warm conditions (similar to winter of 2006) may help soybean rust over-winter on kudzu in south Georgia and throughout the Panhandle of Florida.