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

All Vegetables Stories >All Fruits Stories >All Nuts Stories >All Citrus Stories >

The Latest

Cucurbits14 Stand-Out Melon Varieties [Slideshow]
September 15, 2014
Browse the slideshow below for information on these exceptional melon varieties from the nation’s leading seed breeders and distributors. Read More
Grower Achievement AwardView Highlights From The 2014 United Fresh Washington P…
September 15, 2014
Browse this slideshow to view photos from the 2014 United Fresh Washington Public Policy Conference, including pictures of this year’s Grower Read More
Apples & PearsCanneries Hope To Encourage Growers To Grow Pears For P…
September 15, 2014
Higher wholesale prices offered as means to boost canning pear acres. Read More
FruitsDeadline Nearing For Noninsured Crop Disaster Assistanc…
September 15, 2014
Fruit growers who suffered losses due to frost or freeze in 2012 could be eligible for assistance through USDA’S Farm Service Agency. Read More
BerriesBotrytis Gray Mold Pressure Increasing With Humid Weath…
September 15, 2014
Michigan State University researcher offers tips to reduce the spread of spores. Read More
Fruits5 Mistakes You May Be Making With Your Orchard’s …
September 15, 2014
These deadly sins may be hurting your customers’ experience — and costing you money. Read More
FruitsSuccess And The Not-Top-100 Grower [Opinion]
September 15, 2014
Innovation isn't only happening at the top. Some of the most interesting ideas in the fruit industry are being executed by small growers. Read More
Apples & PearsAmerican and Western Fruit Grower’s 2014 Top Appl…
September 13, 2014
The nations’s largest growers reflect how technology, innovations, and promotion help make their businesses run more efficiently. Read More
NutsAmerican and Western Fruit Grower’s 2014 Top Nut …
September 13, 2014
Almonds, pistachios, and walnuts grown in California make up the crops featured in this portion of the Top 100 Report. Read More
FruitsAmerican and Western Fruit Grower’s 2014 Top 100 …
September 13, 2014
The nations’s largest growers reflect how technology, innovations, and promotion help make their businesses run more efficiently. Read More
Stone FruitAmerican and Western Fruit Grower’s 2014 Top Ston…
September 13, 2014
This year’s Top 100 Report features the 25 largest stone fruit growers in the country. Read More
GrapesAmerican and Western Fruit Grower’s 2014 Top Grap…
September 13, 2014
The nations’s largest growers reflect how technology, innovations, and promotion help make their businesses run more efficiently. Read More
GrapesVintage Nurseries Welcomes New General Manager
September 12, 2014
New quality control manager also joins Wasco, CA, grapevine nursery. Read More
GrapesBrothers Continue To Grow Grapes And Produce Wine ̵…
September 12, 2014
The war has come close to their vineyard 90 miles southwest of Aleppo, with fighting only 100 yards away. Read More
GrapesMealybug Infestation Hits Michigan Vineyards
September 12, 2014
Southwestern vineyards in the state reports of grape leafroll virus which can be transmitted by mealybug. Read More
GrapesCalifornia Quarantine Partially Lifted For European Gra…
September 12, 2014
State lifts ban in Solano County and parts of Napa and Sonoma County. Read More
Crop ProtectionNimitz Nematicide Receives EPA Approval
September 12, 2014
New product from Adama has a unique mode of action and is approved for use on a variety of vegetables. Read More
Pest ControlKnock Down Nematodes In Florida Citrus
September 12, 2014
This video provides information on identifying the major nematodes threats to Florida citrus and provides management tips. Read More