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
Biocontrols 2015 Conference
CitrusGrowers Go In-Depth At Biocontrols 2015 Conference & Tradeshow
March 9, 2015
The first-of-its-kind event brought growers, researchers, regulators, and suppliers together for a two-day discussion on the latest biocontrols tools and technologies. Read More
Crop ProtectionAt Paramount Farming, Mating Disruption Pays Off
February 10, 2015
To say Brad Higbee is an expert in mating disruption, the use of pheromones to confuse target pests and reduce Read More
Crop ProtectionGrower Experienced In Biocontrols Says: Be Patient
February 4, 2015
The use of biocontrols in all aspects of agriculture is becoming more widespread. But incorporating biocontrols in a vegetable farming Read More
Food SafetyHow To Manage Food Safety Risks
March 30, 2015
You need to understand produce safety issues and what they mean to your farm. Read More
Laboratory beakers
CitrusGrowing Demand For Magnesium Nitrate Spurs TradeMark Nitrogen To Double Output
March 30, 2015
Via enhancements made to its manufacturing plant, Florida company is able to provide more of its product to various fertilizer distributors and retailers throughout the country. Read More
Apples & PearsHow Will We Sell All These Apples? [Opinion]
March 30, 2015
Apple production is reaching heights that would have been unthinkable two or three decades ago. That's great news for growers — if we can sell them all profitably, Read More
blue orchard bee
Integrated Pest ManagementBlue Orchard Bee Shows Promise As An Alternative Pollinator In Almonds
March 30, 2015
The native bee Osmia lignaria could soon be a valuable piece of the pollinator mix, especially for smaller almond growers. Read More
Richard Jones
Farm ManagementDon’t Burn Out This Spring
March 30, 2015
Finding ways to limit stress will benefit both you and your business. Read More
Apples & PearsSounding Off On GMOs: The Arctic Apple Decision
March 27, 2015
Industry leaders share their feelings on the recently approved genetically modified apples. Read More
BerriesBuilding A Better Black Raspberry
March 27, 2015
Studies focusing on consumer preference, aphid resistance, heat tolerance, and genetics aim to capitalize on an expanding market. Read More
Insect & Disease UpdateMore California Citrus Placed Under Psyllid Quarantine
March 27, 2015
Asian citrus psyllid is found in Madera County – the heart of the San Joaquin Valley. Read More
FruitsIncrease Your Knowledge By Using Tree Fruit Resources
March 27, 2015
Get educated with great resources in the tree fruit industry available at your fingertips. Read More
Apples & PearsMeet USApple’s Class of 2015 Young Apple Leaders
March 27, 2015
Young decision-makers see trip as an opportunity make sure the voice of the apple industry is heard by representatives. Read More
The Latest
Food SafetyHow To Manage Food Safety Risks
March 30, 2015
You need to understand produce safety issues and what they mean to your farm. Read More
Laboratory beakers
CitrusGrowing Demand For Magnesium Nitrate Spurs TradeMark Ni…
March 30, 2015
Via enhancements made to its manufacturing plant, Florida company is able to provide more of its product to various fertilizer distributors and retailers throughout the country. Read More
Apples & PearsHow Will We Sell All These Apples? [Opinion]
March 30, 2015
Apple production is reaching heights that would have been unthinkable two or three decades ago. That's great news for growers — if we can sell them all profitably, Read More
blue orchard bee
Integrated Pest ManagementBlue Orchard Bee Shows Promise As An Alternative Pollin…
March 30, 2015
The native bee Osmia lignaria could soon be a valuable piece of the pollinator mix, especially for smaller almond growers. Read More
Richard Jones
Farm ManagementDon’t Burn Out This Spring
March 30, 2015
Finding ways to limit stress will benefit both you and your business. Read More
Apples & PearsSounding Off On GMOs: The Arctic Apple Decision
March 27, 2015
Industry leaders share their feelings on the recently approved genetically modified apples. Read More
BerriesBuilding A Better Black Raspberry
March 27, 2015
Studies focusing on consumer preference, aphid resistance, heat tolerance, and genetics aim to capitalize on an expanding market. Read More
Insect & Disease UpdateMore California Citrus Placed Under Psyllid Quarantine
March 27, 2015
Asian citrus psyllid is found in Madera County – the heart of the San Joaquin Valley. Read More
FruitsIncrease Your Knowledge By Using Tree Fruit Resources
March 27, 2015
Get educated with great resources in the tree fruit industry available at your fingertips. Read More
Apples & PearsMeet USApple’s Class of 2015 Young Apple Leaders
March 27, 2015
Young decision-makers see trip as an opportunity make sure the voice of the apple industry is heard by representatives. Read More
GrapesGlassy-Winged Sharpshooter Found In Marin County
March 26, 2015
This pest, known to spread Pierce’s Disease, could devastate California winegrapes. Read More
GrapesFirst Raisin Grape That Dries Naturally On Vine Develop…
March 26, 2015
The new Sunpreme variety eliminates the need for growers to cut into woody canes before harvest. Read More
Fresh From Florida Strawberry Parfait recipe
BerriesNew Partnership Sends Florida Strawberries To Puerto Ri…
March 26, 2015
Latest addition extends Sunshine State’s agricultural export reach in the Caribbean. Read More
drought management; irrigation; water management
FruitsHow To Become A Soil Sleuth
March 26, 2015
To correctly apply the proper nutrients at the right rates, you need to know where your fields are deficient and how to correctly diagnose a disorder. Read More
NutsWhy You Should Use Low-Rate Applications Of Potassium
March 26, 2015
These rates provide growers a low-cost method comparable to conventional applications. Read More
Cold ProtectionWind Machine, Electric Pruners Donated To MSU Research …
March 25, 2015
New equipment to help protect research blocks from frost damage and provide center with latest technology. Read More
CitrusProposed Farm Bill Provision To Limit Payments To Non-F…
March 25, 2015
USDA has proposed a new rule which would limit payment to those who are only actively engaged in farming. Read More
Pennsylvania hard cider guild logo
Apples & PearsPennsylvania Hard Cider Producers Founded Independent T…
March 25, 2015
The Pennsylvania Cider Guild is designed to help promote and educate members and consumers. Read More