Feed The Leaves

Feed The Leaves

Foliar feeding is not intended to completely replace soil-applied fertilization of the macronutrients (nitrogen, potassium, and phosphorous). However, macronutrients can be foliarly applied in sufficient quantities to influence both fruit yield and quality. Some crops, like citrus, can have a large part of the nitrogen, potassium, and phosphorous requirements met through foliar applications.

Foliar applications of other plant nutrients (calcium, magnesium, and sulfur) and micronutrients (zinc, manganese, copper, boron, and molybdenum) have proven for many crops to be an excellent means for supplying the plants’ requirements. Soil application of magnesium, manganese, zinc, boron, and molybdenum is not as economical and not as effective as foliar application to supply those nutrients to citrus trees. Applications made to the soil can be subject to leaching, volatilization, and/or being tied up by soil particles in unavailable forms to plants.

Foliar Flexibility

Foliar feeding should be used as an integral part of the annual nutritional program. It can be used in other situations to help plants through short, but critical periods of nutrient demand, such as fruit set and bud differentiation. Foliar nutrition also may prove to be useful at times of soil or environmentally induced nutritional shortages. Leaf application of nutrients is of significant importance when the root system is unable to keep up with crop demand or when the soil has a history of problems that inhibit normal growth.

Foliar feeding is proven to be useful under prolonged spells of wet soil conditions, dry soil conditions, calcareous soil, cold weather, or any other condition that decreases the tree’s ability to take up nutrients when there is a demand. It also may be utilized effectively when a nutritional deficiency is diagnosed. A foliar application is the quickest method of getting the most nutrients into plants. However, if the deficiency can be seen, the crop might have already lost some potential yield.

Several Florida citrus growers and production managers are using foliar nutritional sprays, mainly micronutrients, to slow down decline and maintain adequate fruit productivity of citrus greening-infected trees. Supplemental, balanced foliar nutrition has positive effects on plant diseases by inducing naturally occurring plant resistance mechanisms. It is always important to maintain the balance between nutrients because having one nutrient significantly out of balance can be as bad as a deficiency.

Burn Notice

While foliar feeding has many advantages, it can burn plants at certain rates under certain environmental conditions. It is important to follow the established guidelines for applications. There are a number of conditions that can increase the chances of causing foliar burn. A plant under stress is more susceptible to damage. Stressful conditions include drying winds, disease infestations, and poor soil conditions. The environmental conditions at the time of application also are important factors. Applications when the weather is warm (above 80°F) should be avoided. This means that during warm seasons, applications should be made in the morning or evening.

Additionally, applications should not be at less than two-week intervals to give the plant sufficient time to metabolize the nutrients and deal with the added osmotic stress.

Another important factor when applying nutrients foliarly is to ensure that the pH of the material is in the proper range. The pH range of the spray solution should be between six and seven. Attention should be paid to the pH of the final spray solution. This is significant in areas where water quality is poor.

Post-bloom foliar applications (applied in April when the spring flush leaves are about fully expanded) of potassium nitrate or mono-potassium phosphate have been found to increase fruit yield and size (8 lb. K2O per acre per application).

Leave a Reply

Featured Stories
Berries
May 26, 2017
Jury Sides with University in Strawberry Breeding Lawsuit
Decision says former breeders infringed on UC patents to develop material for corporate breeding firm. Read More
Managed bee hive boxes around a blueberry field
Nuts
May 25, 2017
Stolen Hives Recovered in Nearly $1M Heist
Man likely stole hives from across the state of California in the last three years. Read More
Panama Canal Expansion opening celebration
Farm Management
May 25, 2017
Plight of Trade Policy Grounding Many U.S. Growers
Much-needed investments in labor-saving technology could be key to long-term survival. Read More
Cannabis plant closeup
Farm Management
May 25, 2017
Florida Farm Winning Case for Medicinal Cannabis License
Judge rules in favor of 3 Boys Farm in the quest to expand its crop/business portfolio. Read More
hands holding a globe
Citrus
May 25, 2017
Are We Overstating the World’s Overpopulation Problem?
If growers can’t achieve a fair return on investment and stay in business, it won’t matter what the population is in 2050. We all will be trouble. Read More
Falcon-takes-flight-at-Duncan-Family-Farms
Citrus
May 24, 2017
Falcons Scare off Other Birds at Duncan Family Farms
It collaborates with a firm that uses trained falcons to intimidate and scare off nuisance birds such as the horned larks and pigeons that frequent the area. Read More
Organic
May 24, 2017
Organic Growers in Turmoil (Opinion)
Although consumers are demanding, and getting more organic produce options, growers are grappling with fundamental questions. Read More
Corn leaf aphids on sweet corn
Sweet Corn
May 24, 2017
Stay on Your A Game to Conquer Corn Leaf Aphid
Learn how to identify, the survival and spread, as well as management methods for this vegetable pest. Read More
Florida Ag Hall of Famer William Cook
Citrus
May 23, 2017
Search is on For Next Crop of Florida Agriculture Hall of Famers
Nomination period now open for longtime industry honor. Read More
Apples & Pears
May 23, 2017
Grower Shares Personal Impact of Labor Shortage
USApple leader Phil Glaize of Virginia stresses need for reform with current labor regulations, programs at Congressional briefing on agriculture labor crisis. Read More
Stone Fruit
May 23, 2017
Northeast Peach Crop Rebounds
After a mild winter and relatively uneventful bloom time, the crop is setting up nicely for the region. Read More
Berries
May 23, 2017
Researchers Examining Potential for Longer Berry Season in Northeast
Team at Penn State University using low and high tunnels and plastic coverings to extend raspberry and strawberry seasons. Read More
honeybees
Citrus
May 23, 2017
Webinar Series Highlights New Research on Honeybee Health
National Pollinator Week webinar showcases research to improve honeybee colony health by 2020. Read More
stack of lemons
Citrus
May 23, 2017
California Lemon Growers Sue USDA
Lemon industry files suit against rule allowing importation of Argentine lemons. Read More
Bee Vectoring Technologies experimental hives
Citrus
May 23, 2017
Insects (Bad and Good) Make for Interesting Field Trips
Disease-fighting bees and the deadly citrus psyllid were at the center of two recent, research-fueled out-of-office adventures. Read More
The Latest
Berries
May 26, 2017
Jury Sides with University in Strawberry…
Decision says former breeders infringed on UC patents to develop material for corporate breeding firm. Read More
Nuts
May 25, 2017
Stolen Hives Recovered in Nearly $1M Hei…
Man likely stole hives from across the state of California in the last three years. Read More
Farm Management
May 25, 2017
Plight of Trade Policy Grounding Many U.…
Much-needed investments in labor-saving technology could be key to long-term survival. Read More
Farm Management
May 25, 2017
Florida Farm Winning Case for Medicinal …
Judge rules in favor of 3 Boys Farm in the quest to expand its crop/business portfolio. Read More
Citrus
May 25, 2017
Are We Overstating the World’s Ove…
If growers can’t achieve a fair return on investment and stay in business, it won’t matter what the population is in 2050. We all will be trouble. Read More
Citrus
May 24, 2017
Falcons Scare off Other Birds at Duncan …
It collaborates with a firm that uses trained falcons to intimidate and scare off nuisance birds such as the horned larks and pigeons that frequent the area. Read More
Organic
May 24, 2017
Organic Growers in Turmoil (Opinion)
Although consumers are demanding, and getting more organic produce options, growers are grappling with fundamental questions. Read More
Sweet Corn
May 24, 2017
Stay on Your A Game to Conquer Corn Leaf…
Learn how to identify, the survival and spread, as well as management methods for this vegetable pest. Read More
Citrus
May 23, 2017
Search is on For Next Crop of Florida Ag…
Nomination period now open for longtime industry honor. Read More
Apples & Pears
May 23, 2017
Grower Shares Personal Impact of Labor S…
USApple leader Phil Glaize of Virginia stresses need for reform with current labor regulations, programs at Congressional briefing on agriculture labor crisis. Read More
Stone Fruit
May 23, 2017
Northeast Peach Crop Rebounds
After a mild winter and relatively uneventful bloom time, the crop is setting up nicely for the region. Read More
Berries
May 23, 2017
Researchers Examining Potential for Long…
Team at Penn State University using low and high tunnels and plastic coverings to extend raspberry and strawberry seasons. Read More
Citrus
May 23, 2017
Webinar Series Highlights New Research o…
National Pollinator Week webinar showcases research to improve honeybee colony health by 2020. Read More
Citrus
May 23, 2017
California Lemon Growers Sue USDA
Lemon industry files suit against rule allowing importation of Argentine lemons. Read More
Citrus
May 23, 2017
Insects (Bad and Good) Make for Interest…
Disease-fighting bees and the deadly citrus psyllid were at the center of two recent, research-fueled out-of-office adventures. Read More
Crop Protection
May 23, 2017
Valent Grants Organic Farming Scholarshi…
University of Florida Doctor of Plant Medicine student receives $1,500 toward the development of training materials. Read More
Varieties & Rootstocks
May 23, 2017
In Quest for Low-Seeded Citrus, It Takes…
Momentum for viable mandarin hybrids for Florida reaching a peak in the land down under. Read More
GenNext Growers
May 22, 2017
How to Make Dollars and Sense of Today&#…
Despite current challenges impacting the future of the North American fruit and vegetable industry, there are opportunities to be had. Read More