How To Determine When To Add Water To Almonds

Most people know that to optimize plant growth and productivity, avoiding plant water stress is important. This is true whether you are talking about the Zinnia or tomato plants in your garden or the fruit and nut trees in your orchard. However, are there circumstances where intentional imposition of stress by withholding water may be beneficial? That depends on what the definition of beneficial is.

With almonds, the benefits of intentional deficit irrigating at the onset of hull split are well documented. Deficit irrigating at hull split is the single most effective method of managing hull rot in problematic orchards. The reduction of vigor and hydration of the hulls during that critical hull opening period can almost eliminate the problem in some situations.

The conditions leading up to the hull split susceptibility can include too much applied water, excess nitrogen, dense canopies, and even choice of rootstock. All of these issues can be addressed to a large degree by deficit irrigating.

Probably the biggest issue that growers encounter with deficit irrigating is not “When do I impose the stress?” but more importantly, “When and how do I end the stress?” For scientists and the few growers who own a pressure chamber, this is easy to determine by measuring mid-day leaf water potential. For the other 99.8% of the growers, this may be more difficult. This is particularly true considering the numerous soil types and irrigation systems used in California. Obviously a drip irrigated orchard on clay-loam in Kern County will respond differently to a flood irrigated orchard on sand in Stanislaus County.

Most growers have realized that using tensiometers, gypsum blocks, or neutron probes to try and determine when the desired -14 to -18 bars is achieved is just not possible. Without the use of or the time involved to use the pressure chamber, are there other alternatives one can use? One method that I have relied on is the visual monitoring of the terminal shoot growth on suckers and water sprouts. The accompanying photo illustrates the “terminal shoot method.” I will be the first to admit that this method is far from perfect, but it is a useful method to gauge roughly when the tree water status requires an irrigation.

This visual method is admittedly more effectual in the spring during rapid shoot growth for those trying to regulate vigor on young trees. The reduction of terminal shoot vigor in almonds due to the “summer dormancy” period can make this call more difficult at hull split. However, by watching new top growth or internal watersprouts, a rough approximation can still be made.

Scientifically, there has not been a correlation between leaf water potential and the terminal shoot method of determining water deficits, but it does put one “in the ballpark” while deciding when to re-water after a deficit. This works regardless of soil or irrigation type since the trees are the gauge of stress as with the pressure chamber. It is important to make frequent observations and to check the “weak areas” in the fields to avoid letting the orchard stress to the point of leaf drop.

Leave a Reply

Nuts Stories
Bayer company logo
Crop Protection
February 10, 2016
Bayer Contests EPA’s Decision On Insecticide  
Company seeks to stop agency’s proposed cancellation of flubendiamide. Read More
AFG state of the industry
Apples & Pears
February 9, 2016
State Of The Fruit Industry 2016 [VIDEO]
According to an national poll of fruit growers, fruit industry suppliers, and researchers, the market is poised for growth in Read More
Almonds
Nuts
February 3, 2016
Avoid Tree Nut Cargo Theft
American Fruit Grower® and Western Fruit Grower® recently reported on a rash of nut thefts, in which truckloads of nuts Read More
honey bee on almond tree
Nuts
February 3, 2016
Tips To Help Secure A Good Beekeeper Agreement
Pollination is one of the most important aspects of almond growing, and this time of year, making sure you have Read More
Varroa mites
Fruits
February 2, 2016
EPA Releases List Of Products Labeled For Use Against Varroa Mites
Agency gives recommendations on products to protect hives against parasites. Read More
Mark Jansen
Photo: Blue Diamond Growers
Nuts
January 27, 2016
Almond Industry 2016 Preview
American and Western Fruit Grower talked with Blue Diamond Growers President and CEO Mark Jansen about the health of the Read More
(Photo credit: Lindsay Turner)
Nuts
January 26, 2016
Thefts Plaguing California Tree Nut Industry
Thieves have been taking off with truckloads of tree nuts valued as much as a half million dollars, and catching Read More
The Latest
Disease Control
February 10, 2016
Broad-Spectrum Fungicide Approved For Sp…
Rhyme controls powdery mildew, brown rot blossom blight, and leaf rusts. Read More
Nuts
February 10, 2016
Almond Board Working Toward Next-Generat…
New sustainability initiatives will bring the almond industry into the 22nd century. Read More
Nuts
February 10, 2016
Incentives Available For Low-Emission Ha…
Almond and walnut growers who use lower-emission harvesting equipment may be eligible for financial incentives. Beginning this year, the USDA Read More
Crop Protection
February 10, 2016
Bayer Contests EPA’s Decision On Insecti…
Company seeks to stop agency’s proposed cancellation of flubendiamide. Read More
Apples & Pears
February 9, 2016
State Of The Fruit Industry 2016 [VIDEO]
According to an national poll of fruit growers, fruit industry suppliers, and researchers, the market is poised for growth in Read More
Nuts
February 3, 2016
Avoid Tree Nut Cargo Theft
American Fruit Grower® and Western Fruit Grower® recently reported on a rash of nut thefts, in which truckloads of nuts Read More
Nuts
February 3, 2016
Tips To Help Secure A Good Beekeeper Agr…
Pollination is one of the most important aspects of almond growing, and this time of year, making sure you have Read More
Fruits
February 2, 2016
EPA Releases List Of Products Labeled Fo…
Agency gives recommendations on products to protect hives against parasites. Read More
Nuts
January 27, 2016
Almond Industry 2016 Preview
American and Western Fruit Grower talked with Blue Diamond Growers President and CEO Mark Jansen about the health of the Read More
Nuts
January 26, 2016
Thefts Plaguing California Tree Nut Indu…
Thieves have been taking off with truckloads of tree nuts valued as much as a half million dollars, and catching Read More
Citrus
January 22, 2016
It’s Official: 2015 Was Earth’s Wa…
NASA, NOAA analyses reveal record-shattering statistics regarding global temperatures this past year. Read More
Citrus
January 21, 2016
Chance Of Profits Up For Growers Tuned I…
UF/IFAS study confirms how paying attention to the 10-day forecast can affect a farmer’s bottom line. Read More
Apples & Pears
January 20, 2016
Herbicide Flood Irrigation Application A…
Crops include stone fruit, pome fruit, grapes, tree nuts, and olives. Read More
Nuts
January 20, 2016
Regional Trials Pinpoint Almond Varietie…
Since the 1970s, the Almond Board of California has been trialing varieties regionally to determine the best and brightest trees Read More
Citrus
January 20, 2016
USDA Report: Pesticide Residues Not A Fo…
Following monthly samplings, survey finds more than 99% of products sampled fall below EPA tolerances for pesticide residues. Read More
Nuts
January 15, 2016
Researchers Crack Walnut Genome
Genetic sequencing paves the way for better breeding. Read More
Citrus
January 13, 2016
American Farm Bureau Elects New Presiden…
Georgia farmer Zippy Duvall to take leadership reins from retiring Bob Stallman. Read More
Farm Management
January 8, 2016
USDA Says China Slowing U.S. Agriculture…
International trade is a major factor in the American agricultural economy. A key player is China. In fact China’s impact Read More
[gravityform id="62" title="false" description="false"]