Baby Those Babies

Baby Those Babies

Nitrogen is the most important element we can apply to our tree fruit crops. Almond growth and productivity depend on the availability and uptake of nitrogen. Most fertilizer recommendations are based on making nitrogen available to our trees so that a nitrogen shortage does not limit tree growth or productivity.

However, it’s important for growers to keep in mind that young almond trees don’t require as much nitrogen as older trees. I like my fellow farm adviser Wilbur Reil’s rule of “1 ounce of actual nitrogen per year of age of tree.” That rate can be applied several times per season, but never more than that at any one application. Thus, a first leaf (first year in your orchard) almond tree should not receive more than 1 ounce of actual nitrogen per any application. A five-year-old almond tree should not receive more than 5 ounces of actual nitrogen per one single application.

The University of California only recommends 1 ounce of actual nitrogen per one-year-old tree over the course of the entire season, but I have been told by many growers and pest control advisers that this rate is not enough for the growth they desire. So, if you want to put out 5 ounces of actual nitrogen per one-year-old tree, do so in five applications and not all at once!

I have seen many trees burned by nitrogen, espe-cially if liquid fertilizers like UN-32 (urea ammonium nitrate 32%) or CAN 17 (a clear solution of calcium nitrate and ammonium nitrate) are used in single applications. These liquid fertilizers are very effective and easy to use, but it doesn’t take much to burn young trees. In fact, I do not recommend using these liquid fertilizers on first leaf trees — I prefer to see triple 15-15-15 (15% nitrogen; 15% phosphorous; 15% potassium) fertilizers used on first leaf trees. I like to see these granular fertilizers placed at least 18 inches from the trunk.

Can The Liquids

With micro-sprinkler and drip irrigation systems, liquid nitrogen fertilizers can be used very efficiently and easily by growers. But be careful; I know several farm managers that will not allow more than 10 gallons of UN-32 per acre per application on mature almond trees. UN-32 contains 3.54 pounds of actual nitrogen per gallon. If you put out 10 gallons of UN-32 per acre, you added 35.4 pounds of nitrogen per acre. If you have 120 trees per acre and do the math you come up with 4.72 ounces of actual nitrogen per tree — almost 5 ounces! I recommend not applying higher rates than this per application.

Also, growers should pay close attention during the summer months. I have seen nitrogen burn occur more often during hot summer days when trees have elevated transpiration rates and obviously faster nitrogen uptake rates than what would have occurred at a cooler time of the year.

Spoon Feed If Possible

If you plan on applying a total of 200 pounds of nitrogen per year per acre to your orchard, I would prefer to see you add 10 pounds of actual nitrogen in 20 irrigations over the course of the season, rather than applying it all at once or even in two split applications of 100 pounds each. I know many growers who “spoon feed” their trees with injections of nitrogen and other liquid fertilizers into their irrigation systems, and they seem quite pleased with the fertilizer efficiency.

Another factor is that mature trees need more nitrogen in early spring so you may want to emphasize applying more nitrogen earlier in the season than later. Nitrogen uptake has been shown to be correlated with leaf activity and photosynthesis. Thus, dormant winter applications of nitrogen should be avoided!  

Leave a Reply

Featured Stories

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

The Latest

BerriesReal Estate Firm, Wish Farms Strike Large Land Deal
October 1, 2014
$13.8 million transaction includes more than 800 acres acquired from longtime Central Florida produce operation. Read More
VegetablesFind The Right Market For Your Crops
October 1, 2014
Getting to know the demographics of your market is key to maximizing your return on investment. Read More
Insect ControlBagrada Bug And Brown Marmorated Stink Bug Posing Threa…
October 1, 2014
Two species of stink bugs are now posing a serious threat to agricultural production in the Western U.S.: the brown Read More
OrganicResearchers Breeding Organic Tomato Varieties Receive $…
October 1, 2014
Purdue University accepts funding to lead multi-institution research to breed organic varieties that will resist foliar diseases. Read More
Vegetables14 Quality Cabbage Varieties [Slideshow]
October 1, 2014
Browse the slideshow below for information on cabbage varieties from the nation’s leading seed breeders and distributors. Read More
FruitsOrganic And Local Food Economies Receive More Than $52 …
October 1, 2014
Most of the grants were authorized through the 2014 Farm Bill. Read More
Insect ControlMore Than 600,000 Acres Removed From Golden Nematode Re…
October 1, 2014
The potato acreage was taken off the Animal and Plant Health Inspection Service’s list; under 6,000 acres in New York are still considered to be infested. Read More
Crop ProtectionTool Helps Track Insects On The Move At Night
October 1, 2014
Signals collected by the National Weather Service’s Doppler radar network may serve as an early warning system to track corn earworm, a major pest in sweet corn. Read More
NutsNew Walnut Budding, Grafting, and Planting Video Releas…
October 1, 2014
Lake County nurseryman Alex Suchan, who has been grafting trees for two-thirds of a century, is the star. Read More
GenNext GrowersGrowers Need To Be Mindful When Dealing With The Media
October 1, 2014
When being interviewed for a story, preparation is the foundation to help you successfully get your point across. Read More
Citrus Achievement AwardSharing Is Caring When It Comes To Curing Citrus Greeni…
October 1, 2014
Mike Sparks, 2014 Citrus Achievement Award winner, says being open with peers about what's working and not working is crucial in managing HLB. Read More
Florida Ag ExpoKnow How To Knock Back Nematodes
October 1, 2014
The 2014 Florida Ag Expo will provide critical tips in soilborne pest management. Read More
CEU SeriesCEU Series: Vow To Vanquish Weeds Among Vegetables
October 1, 2014
Herbicidal neglect can and will kill your crops. Read More
Insect & Disease UpdateUF Names Interim Director For Citrus Research And Educa…
September 30, 2014
Michael Rogers has been a central figure in Florida’s battle to survive greening. Read More
BerriesPractice Persistence When Battling Botrytis In Blueberr…
September 30, 2014
Cognizance of resistance is key to managing formidable fungus. Read More
CitrusFarming Is Quite The Scary Prospect For Some [Opinion]
September 30, 2014
Florida Grower managing editor Paul Rusnak says economic realities might frighten off future leaders from noble professions. Read More
FruitsNew Suppress Herbicide Gets Green Light From EPA
September 30, 2014
Approval gives organic growers new weed management tool. Read More
BerriesNew Fill-By-Weight Clamshell Filler For Blueberries
September 30, 2014
Lakewood Process Machinery's equipment offers a simplified user interface, minimized drop heights, a new dribble-gate system designed for an increased level of accuracy. Read More