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
NutsWhy You Should Use Low-Rate Applications Of Potassium
March 26, 2015
These rates provide growers a low-cost method comparable to conventional applications. Read More
Disease ControlBacterial Spot Can Make Almonds Unmarketable
March 24, 2015
Management strategies can help you mitigate losses from this nasty almond disease. Read More
CitrusFarm Bureau Says WOTUS Rule Would Ignore Exemptions
March 24, 2015
Common farming practices may be vulnerable to Clean Water Act enforcement under the rule. Read More
NutsIndustry Update: American Pistachio Growers 2015 Conference
March 23, 2015
Industry flying high as a billion-pound crop looms at the end of the decade. Read More
CitrusCalifornia Unveils $1 Billion Drought Package
March 23, 2015
Governor, legislative leaders, announce $1 billion emergency drought legislation. Read More
CitrusFeed A Bee Campaign Aims To Plant 50 Million Flowers
March 23, 2015
Bayer CropScience announces program to increase forage opportunities for critical pollinators. Read More
FruitsBe On High Alert For Leaffooted Bug
March 18, 2015
Now is the time to start scouting for leaffooted bug in almond orchards. Read More
The Latest
CitrusMake Every Day Ag Day
March 31, 2015
Another National Ag Day came and went on March 18. Did you do anything to promote it this year? Even Read More
Laboratory beakers
CitrusGrowing Demand For Magnesium Nitrate Spurs TradeMark Ni…
March 30, 2015
Via enhancements made to its manufacturing plant, Florida company is able to provide more of its product to various fertilizer distributors and retailers throughout the country. Read More
blue orchard bee
Integrated Pest ManagementBlue Orchard Bee Shows Promise As An Alternative Pollin…
March 30, 2015
The native bee Osmia lignaria could soon be a valuable piece of the pollinator mix, especially for smaller almond growers. Read More
NutsWhy You Should Use Low-Rate Applications Of Potassium
March 26, 2015
These rates provide growers a low-cost method comparable to conventional applications. Read More
Disease ControlBacterial Spot Can Make Almonds Unmarketable
March 24, 2015
Management strategies can help you mitigate losses from this nasty almond disease. Read More
CitrusFarm Bureau Says WOTUS Rule Would Ignore Exemptions
March 24, 2015
Common farming practices may be vulnerable to Clean Water Act enforcement under the rule. Read More
NutsIndustry Update: American Pistachio Growers 2015 Confer…
March 23, 2015
Industry flying high as a billion-pound crop looms at the end of the decade. Read More
CitrusCalifornia Unveils $1 Billion Drought Package
March 23, 2015
Governor, legislative leaders, announce $1 billion emergency drought legislation. Read More
CitrusFeed A Bee Campaign Aims To Plant 50 Million Flowers
March 23, 2015
Bayer CropScience announces program to increase forage opportunities for critical pollinators. Read More
FruitsBe On High Alert For Leaffooted Bug
March 18, 2015
Now is the time to start scouting for leaffooted bug in almond orchards. Read More
NutsHoneybee Forage Program Helps Bees And Growers
March 10, 2015
Project Apis m. is targeted at improving bee health with the help of California almond growers. Read More
FruitsNo Federal Water For California’s Central Valley Grower…
February 27, 2015
Skimpy snowpack leads Bureau of Reclamation to make unprecedented announcement that there will be a zero initial allocation for the second year in a row. Read More
FruitsMaximize Produce Profits By Focusing On Soil Health
February 27, 2015
Cover crops are just one of the ways you can help boost your trees’ and vines’ performance and your bottom line. Read More
FNV logo
CitrusPMA Announces Funding For Major Produce Marketing Progr…
February 26, 2015
The produce industry is getting into brand marketing in a big way. The Produce Marketing Association (PMA) has announced the launch of a new promotional campaign - FNV - designed to take a page from the marketing strategies of big-money consumer brands like Nike and Apple. Read More
CitrusFDA, Federal Partners Develop New Method For Attributin…
February 25, 2015
Data was analyzed from nearly 1,000 outbreaks to assess which categories of foods were most responsible for making people sick. Read More
CitrusBiocontrols 2015: Exhibition Sneak Preview
February 25, 2015
We take a look inside the exhibit hall at the Biocontrols 2015 Conference & Tradeshow. Read More
NutsA Better Way To Gauge Chilling Hours
February 24, 2015
Using a new system, the chill portions model, can improve growers’ accuracy. Read More
CitrusNew App Helps Identify Insects, Diseases, And Nutrient …
February 24, 2015
Spensa Technologies launches app that helps growers take control of pests and improve soil nutrients. Read More