UC Researchers Trying to Understand Roll of Green Waste and Manure

Almond Growers Are Asked to Return Survey

Researchers are trying to find out the benefit of adding green waste from animal manure and adding it to the soil of permanent crops, and they are looking for information from local growers.

A team of UC Davis and UC Merced researchers are trying to find how and why fruit and nut growers are using organic matter amended to their soils. These amendments might include green waste composted or non composted animal manure.

The goal of this survey is to help develop better approaches so the organic matter amendment can be used more safely, according to Daniel Schellenberg, postdoctoral scholar at UC Davis, who is the coordinator of the project.

“We’re hoping to find out the benefit to the orchard for using these types of materials and how they might improve environmental quality but as well as to find out are they benefit tree nutrition are they changing the biology in the soil, or they simply increasing the capacity of the soil to hold water.” said Schellenberg.

All California almond growers will be getting a survey in their mailboxes this week.

“We’re working with in partnership with the Almond Board of California we were able to have a mailing that will go out to almond growers about their practices and have also built a website that will allow all growers of trees, fruits, and nuts to be able to take the survey.” said Schellenberg

The survey can be found here.

Previously, the Almond Board of California stated that growers should not use these amendment due to food safety, but there has been no field trials to show the risk. A research goal is to find how amends can be used safely, and to determine how much nitrogen certain amendments can provide for tree and vines.

Patrick Cavanaugh2016-05-31T19:35:27-07:00June 10th, 2014|

Navel Orangeworm Pressure Imminent

Almond Growers Get Ready to Treat for Navel Orangeworm

Almond and Pistachio growers should be ready to fight back on a particular seasonal pest this year.

Joel Siegel is a research Entomologist with USDA ARS in the Fresno County Office in Parlier. He is an expert on troubling pest for Almonds and Pistachios called NavelOrangeworm. He said growers need to be ready.

“Ok the big thing this year is because of the heat. If the almonds, if the non [ prowlers?] are splitting earlier you better be prepared to be spraying earlier,” said Siegel. “Its really based on nut vulnerability in my opinion, so you have to make your plans now. Get your materials secured so that you’re ready to move.” he added.

Growers need to get ready to protect their crops. Siegel discusses how another important crop, Pistachios need to be protected from the Navel Orangeworm.

“With pistachios, its harder to predict vulnerability, but all of this heat means we have the potential for an additional generation at least. So there could be more pressure. And again there is going to be more of a need to scout, and again make your plans in advance, and make sure you have your materials lined up.

Because of the daytime heat, Siegel said we are ahead of last year, which was a bad year for NOW.

“Well what we are in terms of heat units, is depending where anywhere between four to eleven days ahead where we were last year. And again, from talking to people on the nonpareil seem to be, maybe eight to ten days earlier this year,”

Siegel said just like almonds, being prepared is the most essential.

“If everything is vulnerable earlier you have to be prepared to move earlier than you’re used to doing it. With pistachios, there might be that dragged out cluster development, and again if people are going to have to harvest late, there is going to be more pressure on the back end.” said Siegel.

Siegel was speaking at the recent Southern San Joaquin Valley Almond Symposium in Kerman California.

Patrick Cavanaugh2016-05-31T19:35:29-07:00May 30th, 2014|

Q&A Drought Management For Almonds

Source: David Doll

These questions and answers offer insightful advice for almond farmers coping with the drought.

Q. How should I plan to irrigate my trees?

A. As discussed before, this is dependent upon the amount of water that is available. If you have greater than 80-85% of the water that is typically applied to the orchard, deficits can be targeted (50% reduction in applied water) for the period after kernel fill but before hull split. If less than 80%, the water should be spread out at the relative percentage of water use. For example, if 30% of the seasons water is available, every irrigation would be 30% of normal. Keep in mind that in drought years it is often hotter than in “normal” years.

Q. When should I start irrigating?

A. Typically, irrigations should start when the trees are starting to “work” for water. Using a pressure bomb, this value is around 2 bars more negative than baseline. If baseline is -8, irrigation should begin at -10. If facing a moderate curtailment, it may be best to let the trees stress a little more, perhaps -4 bars more than baseline. If facing a severe curtailment, a scenario in which we know less about, it might be best to hold off longer before applying the water (~6-8 bars more negative than baseline, perhaps?). Basically, the idea is to stress the trees, which then triggers a physiological response which makes the tree more drought resistant (less vegetative growth, fewer stomatal openings/leaf, etc).

Q. What’s an easy way to calculate baseline?

A. To get in the ballpark, baseline can be estimated by taking one tenth of the temperature. If it is 85 degrees, baseline will be -8.5. Since it is measured as pressure applied, it is always read as a negative value. For more specific calculations, which take into account humidity and temperature, please see this UC Davis Baseline website.

Q. How much should I reduce my nitrogen if I am reducing my water?

A. Good question. Nitrogen rates should be reduced. Based upon some speculation from various trial results, our best guess is to reduce nitrogen rates by about 1/2 of the water curtailment. So, if taking a 50% water reduction, nitrogen should be reduced by a minimum of 25%. In-season estimate of crop may also determine that less N is needed. If in a second year of deficit irrigation (i.e. 2nd year of drought), the reduction of nitrogen should match the reduction in water (50% water reduction, 50% nitrogen reduction). Keep in mind that applying too much N will flush growth, increasing vegetation, which will require more water.

Q. I hear and saw stories about people pulling trees…should I?

A. If blocks were planned to be cycled out and removed within the next few years, water from these blocks should be considered to be diverted to other, younger blocks. This will help negate the effects on the developing block. Depending upon where the orchard is located, there may be some crop that is salvageable from the “dry-land” farmed block, but it will be of lower quality.

Q. Are there any other resources to help?

A. Yes – Please see UC Davis’s Drought Management Website for more drought management in multiple crops. To gain a little more help in scheduling irrigation, check out Fresno State’s Water Right Website. Farm Advisor Blake Sanden also has some good information at his Kern County Web Page. Also, feel free to contact your local farm advisor.