Subtropical Fruit Crops Research & Education
University of California
Subtropical Fruit Crops Research & Education

Posts Tagged: irrigation

Citrus? Water? How Do They Go Together?

Advances in Citrus Water Use

                         Workshop & Field Day

Tuesday, March 26, 2019

8 Am - 3 PM

Strathmore, CA

 

Attend the Advances in Citrus Water Use Workshop & Field Day and join UC Davis Irrigation Specialist Daniele Zaccaria as well as other water experts and specialists from the University of California Cooperative Extension, the California Department of Water Resources, and the Citrus Research Board to learn about research advances in water use and irrigation for citrus production. Gain firsthand practical knowledge of the latest developments in the citrus industry and become familiar with methods and tools to measure evapotranspiration (ET) and crop coefficients (Kc), tree water status, and monitor soil moisture to inform irrigation planning and scheduling decisions for citrus. 

 

What to expect?

Session topics include:

  • Current research
  • Water management and regulation
  • Optional Field Session on irrigation technology

View a tentative agenda here.

 

 

Registration Details

 

$35 registration fee includes admission to the field day, coffee, refreshments, and lunch.

 

 

 

Register online, here. Fee will increase on March 13.

 

 

Limited to the first 150 participants

 

 

Logistics and Registration

ANR Program Support, Julia Kalika, (530) 750-1380 or Shannon Martin, (530) 750-1328

citrus cornucopia
citrus cornucopia

Posted on Friday, March 8, 2019 at 1:44 PM
Tags: citrus (302), irrigation (74), water (47)

Water is Life and Watering Citrus is Critical - Come Learn

Advances in Citrus Water Use

               Workshop & Field Day

Tuesday, March 26, 2019

8:00 AM-3:00 PM

Strathmore, California

Register NOW!!!

 https://ucanr.edu/sites/citrusfieldday/Registration/

About the Field Day

 

Attend the Advances in Citrus Water Use Workshop & Field Day and join UC Davis Irrigation Specialist Daniele Zaccaria as well as other water experts and specialists from the University of California Cooperative Extension, the California Department of Water Resources, and the Citrus Research Board to learn about research advances in water use and irrigation for citrus production. Gain firsthand practical knowledge of the latest developments in the citrus industry and become familiar with methods and tools to measure evapotranspiration (ET) and crop coefficients (Kc), tree water status, and monitor soil moisture to inform irrigation planning and scheduling decisions for citrus. 

 

What to expect?

Session topics include:

  • Current research
  • Water management and regulation
  • Optional Field Session on irrigation technology

View a tentative agenda here.

Registration Details

$35 registration fee includes admission to the field day, coffee, refreshments, and lunch.

 

Register online, here. Fee will increase on March 13.

 

Limited to the first 150 participants.

Contacts for More Information

 

Logistics and Registration

ANR Program Support, Julia Kalika, (530) 750-1380 or Shannon Martin, (530) 750-1328.

 

Course Content 

Daniele Zaccaria, UC Cooperative Extension Specialist, Agricultural Water Management

 

citrus cornucopia
citrus cornucopia

Posted on Friday, March 8, 2019 at 1:26 PM
Tags: citrus (302), field day (4), irrigation (74), water (47)

Frost and Rain?

It is that time of year and we should be alert to threat of freezing weather and damage to trees. Last winter was one of the warmest on record, but there was still a sneak cold blast around December 25 that caused some problems in some areas. Wet winters tend to have lower frost threats, and even though wet is forecast for this winter, the forecast is erratic, as usual. That still leaves January which historically is when most of our damaging frosts occur. Fox Weather on the CA Avocado Commission is forecasting some cold weather coming up, so growers need to be prepared for the worst.

http://www.californiaavocadogrowers.com/articles/30-day-weather-outlook-december-7-2015-january-7-2015

 

Here are some links to frost information, preparing for frost and managing frost damage to trees.

A Frost Primer

http://ceventura.ucanr.edu/Com_Ag/Subtropical/Publications/Frost/A_Frost_Primer_-_2002_/

Methods of Frost Protection

http://ceventura.ucanr.edu/Com_Ag/Subtropical/Avocado_Handbook/Frost_Control_Freeze_Damage_/Methods_of_Frost_Protection_/


Protecting Avocados from Frost

http://ceventura.ucanr.edu/Com_Ag/Subtropical/Avocado_Handbook/Frost_Control_Freeze_Damage_/Protecting_Avocados_from_Frost_/


Rehabilitation of Freeze-Damaged Citrus and Avocado Trees

http://ceventura.ucanr.edu/Com_Ag/Subtropical/Avocado_Handbook/Frost_Control_Freeze_Damage_/Rehabilitation_of_Freeze-Damaged_Citrus_and_Avocado_Trees_/

The forecast is for north winds, which often means cold, dry air and often with winds. Winds mean no inversion and no warm air that can be introduced at ground level to warm trees. If this occurs, running a wind machine can make the damage worse. Wind machines and orchard heaters work on the principle of mixing that warmer air higher up – 20-100 or so feet higher than ground level which has colder air. When temperatures drop, the air is dry (wet-bulb temp below 28 deg F) and there is no inversion, running a wind machine can just stir up cold air and cause worse conditions (freeze-drying). It's better to not run the machine. The only thing left to do is to run the microsprinklers during the day so that the water can absorb the day's heat. Then turn the water off before sunset so that evaporative cooling from the running water isn't accentuated. Then when temperatures drop near 32 at night and the dewpoint is much below that, it's time to start the water again and let it run until sunrise (when risk is less). Running water works even if the water freezes. This is due to the release of heat when water goes from liquid to frozen state. This 1-2 degrees can mean the difference between frost damage and no damage. Also, ice on fruit and leaves can insulate the fruit. As the ice melts at the surface of the plant, it releases heat, protecting the plants. If there is not sufficient water to run the whole orchard, it's best to pick out the irrigation blocks that are the coldest or the ones you definitely want to save and run the water there continuously. Running the water and turning it off during the night to irrigate another block can lead to colder temperatures in both blocks.

 

Keep warm this winter.

and check out this Wind Machine You Tube:

https://www.youtube.com/watch?v=rwTJveN8cIE

Wind Machine frost
Wind Machine frost

Posted on Wednesday, January 9, 2019 at 4:46 PM
Tags: avocado (270), citrus (302), frost (17), irrigation (74), water (47), wind (5)

Ready! Set! Split! Navel Orange Time.

These are hard days for navel oranges.  Drought stress.  Salt stress due to drought. Then a heat wave in July that messed the trees up.  And now we head into a weird fall with maybe rain. Maybe no rain. Maybe a little rain. This is ripe for navel splitting. This time of year when they are starting to build sugar, they are also ripe for splitting.

Years of drought, and a stressed tree are a perfect set up for navel oranges and fruit splitting.
The days have turned cooler and suddenly out of nowhere there is rain. That wonderful stuff comes down and all seems right with the world, but then you notice the navel fruit are splitting. Rats! No, a dehydrated fruit that has taken on more water than its skin can take in and the fruit splits. This is called an abiotic disease.  Not really a disease but a problem brought on by environmental conditions.

Fruit splitting is a long-standing problem in most areas where navel oranges are grown. In some years, the number of split fruit is high; in other years it is low. Splitting in navel oranges usually occurs on green fruit between September and November. In some years, splitting may also occur in Valencia oranges but it is less of a problem than in navel oranges.

Several factors contribute to fruit splitting. Studies indicate that changes in weather including temperature, relative humidity and wind may have more effect on fruit splitting than anything else. The amount of water in a citrus tree changes due to weather conditions and this causes the fruit to shrink and swell as water is lost or gained. If the water content changes too much or too rapidly the rind may split. In navel oranges the split usually occurs near the navel, which is a weak point in the rind.

Proper irrigation and other cultural practices can help reduce fruit splitting. Maintaining adequate but not excessive soil moisture is very important. A large area of soil around a tree should be watered since roots normally grow somewhat beyond the edge of the canopy. Wet the soil to a depth of at least 2 feet then allow it to become somewhat dry in the top few inches before irrigating again. Applying a layer of coarse organic mulch under a tree beginning at least a foot from the trunk can help conserve soil moisture and encourage feeder roots to grow closer to the surface.  

If trees are fertilized, apply the correct amount of plant food and water thoroughly after it is applied.  If the soil is dry, first irrigate, then apply fertilizer and irrigate again.

navel split
navel split

Posted on Friday, November 2, 2018 at 4:55 AM
Tags: citrus (302), irrigation (74), navel orange (2), rain (17), water (47), weather (8)

Irrigating with an Atmometer?

Say what? Atmosphere meters can be used to assess irrigation requirement. Here's a great little report from Mark Battany, our advisor in Santa Barbara and San Luis Obispo Counties.

 

ATMOMETERS FOR IRRIGATION MANAGEMENT

  • Author: Mark Battany

Efficient and precise irrigation management is becoming increasingly important inCaliforniaagriculture, both for maximizing crop quality and for conserving water. The most advanced irrigation scheduling strategy is based on local measurements of reference evapotranspiration (ETo), which is converted to crop evapotranspiration (ETc) with an appropriate crop coefficient (kc).

To be able to use this method, an irrigation manager needs to have locally accurate ETo values throughout the growing season. However, the highly variable microclimates that characterize many farming areas often make it difficult to use data from distant weather stations; therefore an accurate local measurement may often be preferable to relying on a regional value.

One inexpensive option for measuring ETo locally is to use a simple atmometer. Atmometers are water-filled devices, in which the actual evaporation of water is measured over time. In their simplest form, the atmometer is outfitted with a graduated sight glass on the water supply tank which allows the user to easily measure the evaporation that occurred over a given period. In practice, this type of atmometer is most suited for making readings at multiple day intervals, for example once per week, or on days when irrigation is applied.

The performance of atmometers versus more expensive weather stations was evaluated on the CentralCoastin 2003. In this study, atmometers were placed adjacent to seven weather stations throughout the area, and weekly values for both methods were compared. The results indicate that the atmometers and weather stations have very comparable ETo readings, with the atmometers indicating somewhat lower ETo values under conditions of lower evapotranspiration.

Like any technique, using atmometers has advantages and disadvantages. Advantages include their very low cost and ease of operation, with no computer or power required. Disadvantages include the potential for damage by freezing weather, the need to refill the water supply (every three to six weeks), and the need to read the gauge manually. Also, if they are installed in a large open area, birds may tend to perch on the evaporating surface and foul it with their droppings; for this reason several wires are installed on top of the device to discourage birds from perching there. In general, atmometers function quite reliably with few problems.

Converting atmometer ETo readings to the amount of irrigation run time required to replenish the soil moisture lost to evapotranspiration is fairly straightforward. A relatively simple example for a sprinkler-irrigated field is presented below in Table 1.

Table 1. Example conversion of ETo to irrigation run times   for a sprinkler irrigated field

 

 

 

A.  Measured atmometer ETo for one week

2

inches

B.  Crop coefficient (kc)

0.8

 

C.  Calculated ETc for the week (=AxB)

1.6

inches

D.  Sprinkler application rate

0.13

in/hr

E.  Hours of irrigation required (=C/D)

12.3

hours

 

(Note: To convert Gallons to Inches: Gallons ÷ Area (square feet) ÷ 0.6234 = Inches. To convert Inches to Gallons: Inches * Area (square feet) ÷ 1.604 = Gallons)

 Regression table showing relationshiop between CIMIS weather station and atmometer

Atmometer in

                       

 Atmometer in the field

atmometer grapes
atmometer grapes

Posted on Friday, June 15, 2018 at 6:28 AM
Tags: atmometer (2), avocdo (1), citrus (302), irrigation (74), scheduling (10)

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