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
Grapes
February 18, 2017
Sustainability Is a Growing Factor in Wine Purchasing
California Sustainable Winegrowing Alliance updates certification program, shows sustainability is important part of wine trade. Read More
citrus psyllid closeup
Insect & Disease Update
February 18, 2017
The War on Citrus Psyllids Still Raging
Despite control challenges, keeping the pest in check remains the best approach to managing HLB. Read More
IMPAC.org screenshot
Citrus
February 17, 2017
How Precision Agriculture Is Helping Farmers Win Over Consumers
New Florida-based organization is seeking to break down barriers between farmers and shoppers by providing a platform to not only show what it is grown, but how it's grown. Read More
Grapes
February 17, 2017
Washington Organization Rebrands Itself
Washington Association of Wine Grape Growers unveils new identity at convention, now known as Washington Winegrowers Association. Read More
Registration area at the 2017 Florida Blueberry Growers Association Spring Meeting
Berries
February 17, 2017
Florida Blueberry Growers Counting on a Comeback
With last season's disaster in the rear view, all eyes are searching for bluer skies. Read More
Agras MG-1 agriculture drone
Equipment
February 17, 2017
Wanted: Tech Innovators for Drone Challenge
Land O'Lakes Prize offers up $150,000 to help make drones more useable for farmers Read More
Fruits
February 17, 2017
Are Drones the Future of Pollination?
Researchers in Japan have turned drones into robot bees as artificial pollinators. Read More
GenNext Growers
February 16, 2017
Young Start-Up Hort Tech Companies Honored
Western Growers Center for Innovation & Technology Scholarships promote sustainability. Read More
GenNext Growers
February 16, 2017
Young Farmer Success Act Reintroduced to Congress
Bill to add young growers to Public Service Loan Forgiveness Program. Read More
Fruits
February 16, 2017
New App Helps Fruit Growers Calculate Chill Hours
App helps growers calculate chill hours based on locations and models and assess physiological needs of fruit crops. Read More
The Latest
Grapes
February 18, 2017
Sustainability Is a Growing Factor in Wi…
California Sustainable Winegrowing Alliance updates certification program, shows sustainability is important part of wine trade. Read More
Insect & Disease Update
February 18, 2017
The War on Citrus Psyllids Still Raging
Despite control challenges, keeping the pest in check remains the best approach to managing HLB. Read More
Citrus
February 17, 2017
How Precision Agriculture Is Helping Far…
New Florida-based organization is seeking to break down barriers between farmers and shoppers by providing a platform to not only show what it is grown, but how it's grown. Read More
Grapes
February 17, 2017
Washington Organization Rebrands Itself
Washington Association of Wine Grape Growers unveils new identity at convention, now known as Washington Winegrowers Association. Read More
Berries
February 17, 2017
Florida Blueberry Growers Counting on a …
With last season's disaster in the rear view, all eyes are searching for bluer skies. Read More
Equipment
February 17, 2017
Wanted: Tech Innovators for Drone Challe…
Land O'Lakes Prize offers up $150,000 to help make drones more useable for farmers Read More
Fruits
February 17, 2017
Are Drones the Future of Pollination?
Researchers in Japan have turned drones into robot bees as artificial pollinators. Read More
GenNext Growers
February 16, 2017
Young Start-Up Hort Tech Companies Honor…
Western Growers Center for Innovation & Technology Scholarships promote sustainability. Read More
GenNext Growers
February 16, 2017
Young Farmer Success Act Reintroduced to…
Bill to add young growers to Public Service Loan Forgiveness Program. Read More
Fruits
February 16, 2017
New App Helps Fruit Growers Calculate Ch…
App helps growers calculate chill hours based on locations and models and assess physiological needs of fruit crops. Read More
Citrus
February 16, 2017
Food Trends Driving Growth Opportunities…
More niche markets emerging for growers to give consumers what they want and need. Read More
Vegetables
February 15, 2017
Tanimura & Antle Will Now Be Partial…
The third-generation farming company takes employee commitment to the next level Read More
Business Planning
February 15, 2017
Are Retailers Your New Competition?
Target will be following a trend that is already under way in Germany and China: offering shoppers greens that are grown right there in the store. Read More
Citrus
February 15, 2017
Florida Citrus Community Loses Longtime …
John Merritt, known as an innovative grower and staunch industry advocate, was 60. Read More
Farm Management
February 14, 2017
Californians Holding Breath as More Stor…
Nearly 200,000 people evacuated below nation’s tallest dam; even growers have had enough for now. Read More
Stone Fruit
February 14, 2017
Georgia Peach Growers Brace for Low Chil…
Last year trees netted almost 700 chill hours; however, Extension agent expects that figure to drop to 600 hours this year. Read More
Grapes
February 14, 2017
2016 California Winegrape Crush Up 9%
Prices were up 12%, and red wine grapes continue to gain on white wine grapes in popularity, though ‘Chardonnay’ remained king. Read More
Berries
February 14, 2017
Wish Farms Shows Love With Super-Sized S…
More than 4,000 pounds of locally grown produce from Central Florida farming operation goes to help feed needy families in the Tampa area. Read More