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
Greg Lang of Michigan State discusses cherry tree pruning at IFTA 2016.
Fruits
February 8, 2016
Precision Fruit Growing, Business Management Top Agenda At IFTA Conference Kickoff
American Fruit Grower magazine managing editor Christina Herrick posts her updates from the 59th annual gathering. Read More
U.S. Capitol Building FEATURE
Farm Marketing
February 8, 2016
Food Policy: If You Don’t Speak, Others Will Speak For You
British Columbia’s former Minister of Agriculture, Corky Evans, spoke with attendees at 2016 North American Farmers’ Direct Marketing Association’s Convention about Read More
Winery at Krause Berry Farm FEATURE
Farm Marketing
February 8, 2016
How British Columbia And U.S. Regs Are Shaping Farm Markets [Opinion]
Laws passed decades ago to protect small farms aren't keeping up with the realities of modern farmers and their marketing efforts. Restrictions can shut down hosting weddings, but offer incentives to open wineries. Read More
Table with cut flowers at Krause Berry Farm
Farm Marketing
February 8, 2016
3 Tips On How Not To Lose Your Shirt When Adding A Restaurant To Your Farm
Chef and consultant Chuck Currie told NAFDMA Convention attendees the basic principles of what makes a farm market eatery a success or a flop. Read More
field plot
Crop Protection
February 8, 2016
7 Steps To See If Biocontrols Pencil Out For Your Operation
Have you considered adding biocontrols to your operation? If you have, there’s no doubt you’ve already weighed the potential costs, Read More
The family at the helm of Sterman Masser Potato Farms includes (from left) David, Keith, Helen, and Julie.
Photo credit: Rosemary Gordon
Potatoes
February 7, 2016
A Lesson In Marketing From Sterman Masser Potato Farms
Always looking for new product offerings and ways to expand, Sterman Masser Potato Farms caters to consumers. Read More
Thomas Björkman, the director of the Eastern Broccoli Project, discusses details on the challenges of broccoli production in the East.
Vegetables
February 7, 2016
The Eastern Broccoli Project Moves Forward
As acreage increases in the East, mid-sized growers seek channels to distribute their product and continue the search for varieties. Read More
Apples On Display
Fruits
February 6, 2016
Best Research Is Industry Driven [Opinion]
Like many of you, I’m not crazy about a lot of government programs. It’s not that their genesis isn’t noble; God Read More
RosBREED will have an impact on nearly all the major U.S. rosaceous crop production areas.
Fruits
February 6, 2016
RosBREED: A National Effort To Improve The Fruit Industry
The project focuses on improving disease resistance and fruit quality through better genetics and breeding. Read More
The Latest
Fruits
February 8, 2016
Precision Fruit Growing, Business Manage…
American Fruit Grower magazine managing editor Christina Herrick posts her updates from the 59th annual gathering. Read More
Farm Marketing
February 8, 2016
Food Policy: If You Don’t Speak, O…
British Columbia’s former Minister of Agriculture, Corky Evans, spoke with attendees at 2016 North American Farmers’ Direct Marketing Association’s Convention about Read More
Farm Marketing
February 8, 2016
How British Columbia And U.S. Regs Are S…
Laws passed decades ago to protect small farms aren't keeping up with the realities of modern farmers and their marketing efforts. Restrictions can shut down hosting weddings, but offer incentives to open wineries. Read More
Farm Marketing
February 8, 2016
3 Tips On How Not To Lose Your Shirt Whe…
Chef and consultant Chuck Currie told NAFDMA Convention attendees the basic principles of what makes a farm market eatery a success or a flop. Read More
Farm Marketing
February 8, 2016
10 Ideas You Can Steal From NAFDMA’…
We visited several farm markets, as well as poultry and cheese farms and garden shops, this past week. Here are just a few of the best ideas we spied. Read More
Crop Protection
February 8, 2016
7 Steps To See If Biocontrols Pencil Out…
Have you considered adding biocontrols to your operation? If you have, there’s no doubt you’ve already weighed the potential costs, Read More
Potatoes
February 7, 2016
A Lesson In Marketing From Sterman Masse…
Always looking for new product offerings and ways to expand, Sterman Masser Potato Farms caters to consumers. Read More
Vegetables
February 7, 2016
The Eastern Broccoli Project Moves Forwa…
As acreage increases in the East, mid-sized growers seek channels to distribute their product and continue the search for varieties. Read More
Fruits
February 6, 2016
Best Research Is Industry Driven [Opinio…
Like many of you, I’m not crazy about a lot of government programs. It’s not that their genesis isn’t noble; God Read More
Fruits
February 6, 2016
RosBREED: A National Effort To Improve T…
The project focuses on improving disease resistance and fruit quality through better genetics and breeding. Read More
Berries
February 5, 2016
Moving Beyond Methyl Bromide With Biofun…
Editor’s note: University of California Farm Advisor Mark Bolda will present much more information on this topic at the Biocontrols Read More
Grapes
February 5, 2016
Geotextiles Can Help Prevent Winter Grap…
Although Northeast and Midwest grape growing regions have so far been spared from extreme cold this year, the winters of Read More
Grapes
February 5, 2016
Researchers Test New Method To Mitigate …
The use of evaporative cooling in vineyards during hot weather isn’t a new concept, but researchers in Australia are testing Read More
Crop Protection
February 5, 2016
Register Now For Biocontrols Conference …
Space is limited, so register now to attend the first-ever Biocontrols USA 2016 Conference Field and Greenhouse Tour. Following the Read More
Grapes
February 4, 2016
Northern Grapes Project Fuels A Market F…
 There’s a burgeoning market for cold-weather grapes. The Northern Grapes Project, funded in 2011 by a USDA National Institute of Read More
Citrus
February 4, 2016
Can Olive Oil Grease Skids For Florida’s…
Researchers, interested growers help launch new industry. Read More
Citrus
February 3, 2016
Sunkist Expands Organic Portfolio
With the organic citrus sector growing three times as fast as conventional, the 123-year-old cooperative is keeping up with the times. Read More
Citrus
February 3, 2016
Syngenta OKs Buyout By ChemChina
Deal valued at more than $43 billion; Syngenta management team to stay intact. Read More
[gravityform id="62" title="false" description="false"]