- Author: Ben Faber
It ain't over yet, and this last week we had a wonderful 2 day meeting with folks who have dealt with drought in many different ways. Here are presentations made by people from Israel, Australia and California. Soon the actual videos will be available, but now see the powerpoints.
http://www.droughtmgt.com/#!presentations-and-documents/niui7
The grower panels are wonderful, but are not uploaded at this point
DAY I: UNDERSTANDING IRRIGATION WATER MANAGEMENT
Session I: California Response to Drought
9:15am // Overview of California Drought Response
9:30am // El Nino Forecast for California and Possible Impacts on Irrigated Agriculture
Session II: Technology of Water Management
9:45am // Soil Water Sensing
10:15am // ETc Estimates - Weather Stations (CIMIS), surface renewal
11:00am // Salinity Measurement
11:30am // Consideration In Selecting Water Stress Indicators
12:00pm // Precision Water and Fertility Management During Deficit Irrigation
Session III: Alternative Water Supplies
1:30pm // Irrigation With Recycled and Desalinated Water
2:00pm // Effects of Irrigation With Poor Quality Water on the Soil - California Experience
2:30pm // Effects of Irrigation With Poor Quality Water on the Soil - Israeli Experience
3:00pm // The Challenge of Sustainable Irrigation with Water High in Salts: Lessons from Dates, Olives and Grapevines
Session IV: Water Management Strategies During Drought
3:45pm // Water Management Strategies during Drought - Australian Experience
4:45pm // Cultivation Under Protective Structures to Save Water
Day II: WATER MANAGEMENT FOR INDIVIDUAL CROPS & GROWER EXPERIENCES
Session V: Technology Demonstrations​
8:00am // Irrigation Scheduling - Australian Experience - IrriSAT Approach (IrriSAT Supporting Materials)
8:30am // Using the Pressure Chamber for Drought Mangagement Decisions
9:00am // Irrigation System Evaluation
9:30am // Salinity Mapping for Water Management
Session VI: Conncurrent Breakout Groups
10:30am // Citrus - Israeli Experience: Long Term Effects of Deficit Irrigation, Salinity, and Rootstocks on Orchard Productivity
10:30am // Grapes - Table and Wine Grape Irrigation Scheduling
10:30 // Deciduous Nut Crops - Irrigation and Crop Load Interactions
10:30// Almond Irrigation, the Israeli Experience
11:15am // Olives - Israeli Experience: Cultivation Under Limited Water Availability
11:15am // Grapes - Wine Grapes Irrigation - Coastal Vineyards
11:15am // Deciduous Nut Crops - Almond Irrigation - Israeli Experience
1:00pm // Avocado - Israeli Experience
1:00pm // Grapes - Wine Grapes Irrigation: San Joaqin Valley
1:00pm // Deciduous Nut Crops - California Experience
1:30pm // Deciduous Nut Crops - Pistachios Irrigation
1:45 // Subtropical Crops - California Experience
1:45 // Grapes - Irrigation, the San Joaquin Valley
2:00pm // Deciduous Nut Crops - Walnut Irrigation
2:30pm // Grower Panels
3:15pm // Concluding Remarks
- Author: Ben Faber
I get a call.
He: My trees not doing well.
Me: What's the problem?
He: It's yellow?
Me: Have you looked at the roots? Are there roots?
He: NO
Me: I'll be out next week, but in the meantime, look at the root system.
This is a pretty common exchange and when I got out, you find out that the emitter is clogged, the ground is soggy, there's weed whack damage, there's gopher damage, there's…………………. All kinds of things that pop up and until you see the context that the poor tree is in, it's hard to diagnose the problem. Too much fertilizer, black drip tubing that had water heated in the sun and burned the roots, the trunk buried in mulch, it's hard to imagine all the possibilities. But start with the roots and then go where that leads you.
So, here's the scenario.
You get a call/email.
He: What's wrong with my young tree? It snapped off in the wind. Here's a picture of what's left. Corroded, bulbous graft union. Incompatibility? Extensive decay that indicates a problem of long standing. The leaves are green though, so it means it was hanging in there until the wind blew. Was the trunk buried at planting leading to asphyxiation and crown rot? Is it some sort of wound that started it off? Oh, and about 1% of the planting is like that.
Me: OK, I better take a look at it. I'll get some samples and send them into Akif Eskalen at UC Riverside and bring our plant pathologist Jim Downer out to look at it with me.
So tune in to find out what we diagnose as the problem. In the meantime, if you have an unknown avocado or citrus problem that looks of root origin. You can contact Akif and send him a sample after following the “Sample Submission Form” at: http://eskalenlab.ucr.edu/
- Author: Ben Faber
There have been so many calls recently with the same problem, thinning canopy with dieback. Thiscan be caused by several problems, but the most common this time of year is lack of good water management over the year, accentuated by lack of rain and salt damage. The rain will often leach salts accumulated from the root zone over these many years of water from only irrigation. I thought as everyone else did that we would be having some gushers in S. California and some of these problems would be relieved. With rain, the cankers from black streak, bacterial canker and Botryosphaeria canker (Dothiorella) staining are washed away, and often times, so are the tree's problems. Well that hasn't happened. Or rather the rain hasn't happened to resolve this problem - Botryosphaeria or Bot Rot.
This problem has been ongoing and growers are still calling in about avocados with thinning canopies, fruit drop and sunburn and leaf death. Coastal avocados are always difficult to irrigate. Mild weather followed by dry windy conditions means growers have to scramble to get water on. If the trees are on some sort of calendar schedule, it usually means the trees get stressed. If trees are on a slope where pressure is not properly regulated, some of the trees are going to get stressed. If emitter clogging is not addressed, then more trees get stressed. And lack of rains to leach salts from the root zone, and more trees are stressed.
This stress sets up the trees for disease and a very common one in an avocado orchard that is filled with lots of leaves where decay fungi are working is stem and leaf blight. The disease causes defoliation and exposed fruit sun burn and drop. In an orchard, it's possible to see healthy trees and sick ones at the same time. This may be due to the differences in soil type from tree to tree or the fruit load on trees - more fruit, more stress. Looking out over the orchard there may be a polka dot of sick trees. And it might all happen at once in a week or gradually.
So, this is a problem that is out there, if the irrigation issue is corrected, the trees usually recover. It might require white washing and pruning out dead tissue. If it is a young tree under two years, it might actually kill the little tree, but the disease is not usually fatal, just loosing the fruit.
This is a disease that goes to many different tree species - redwoods, eucalyptus, pine, Brazilian pepper, CITRUS. The cause is the same, water or salinity stress. To read more about this disease, go to:
http://www.ipm.ucdavis.edu/PMG/r8101311.html
Thinning canopy, dieback and shriveled fruit in avocado and dieback and gumming in citrus
- Author: Ben Faber
Lots of seeds; thick, coarse skin; not big, not small; thorns; sour; but fragrant, cold tolerant and selling for good prices. A cross between one of the original citrus parents – papeda – and a mandarin. It's got some pretty ancestral properties with something of a lemony flavor and a grapefruit odor. Yuzu is a citrus fruit esteemed by Japanese and Korean chefs just for the qualities of the juice and peel. At this point it cannot be imported fresh, so must be grown in California if it is used as a fresh ingredient. And prices at a recent farmers market made me shake my head at what was being charged. I would hate to think what would happen to prices if suddenly we had 500 acres of the fruit.
For more on yuzu, check out the UC Citrus Variety Collection at:
http://www.citrusvariety.ucr.edu/citrus/yuzu1.html
Check out the seeds in this fruit
And the productivity
- Author: Ben Faber
It seems the world is attacked on all sides, including the iconic citrus and avocado industries in California. Aside from the other agricultural issues all growers have of water, labor, costs, weather, family, you name it, citrus and avocado growers have particular problems. There is Asian Citrus Psyllid/Huanglongbing for citrus and the Shot Hole Borers for Avocado. The latter is a beast that is going to lay waste to many other tree species besides avocado, like sycamore, coast live oak, native maple and many other tree species.
Citrus and avocado are still strong industries in California and will remain so as solutions to these pest invasions are dealt with. But we are coming up to the time when maybe other tree crops should be considered. These alternative tree crops come with new promise, but they also come with problems. You have to figure out how to market them. The California industry knows what to do with an avocado and a grower knows where to go with a ‘Gold Nugget' mandarin, but what do you do with a longan or cherimoya. You figure out how to market it, through direct marketing at farmers markets or the internet, some specialty marketer like Frieda's Finest or Melissa's or your regular packer who has taken an interest in your product.
I've spoken with growers who say they have grown such and such for four generations and they are not adjusted physically or psychologically to grow anything else. Well, it is good to stick with what you know best and refine it for current conditions, but it's also good to keep options open. Stick to what is best for your situation and support the studies needed to make citrus and avocado strong industries, but also think about maybe something else.
Here's links to tree crops that do well in Southern California and for that matter can be adjusted to much of California. Just watch out, it gets cold north of the Grapevine and San Luis Obispo and options are more limited with subtropicals, but think deciduous.
Subtropicals
http://ceventura.ucanr.edu/Com_Ag/Subtropical/Fruit_and_Nut_Varieties/Citrus_and_Other_Subtropicals/
Deciduous
http://ceventura.ucanr.edu/Com_Ag/Subtropical/Fruit_and_Nut_Varieties/Deciduous/