- Author: Chris M. Webb
UC ANR’s Photographic Guide to Citrus Fruit Scarring publication is simply fantastic.
Through series of photos and brief pieces of text this publication delivers powerful information at little more than a glance.
Designed for commercial growers, home gardeners will likely benefit too. Find out how to identify the causation of early scarring damage on citrus fruit so that you can take steps to minimize injury to future crops.
Learn how to recognize damage caused by:
- Citrus thrips
- Forktailed bush katydid
- Citrus cutworm
- Fruittree leafroller
- Amorbia
- Citrus peelminer
- Potato leafhopper
- Brown garden snail
- California red scale
- Citrus red mite
- European earwig
- Chemical damage
- Physical damage caused by equipment, wind/branch rubbing, or hail
For help in controlling damage-causing insects, please visit the UC IPM Online website.
- Author: Chris M. Webb
What is happening with the Asian Citrus Psyllid (ACP) in Southern California? We are happy to report that the areas were ACP has previously been found have not expanded much.
However, two adult psyllids were recently found in San Bernardino County.
And as of late November, no huanglongbing (HLB) disease has been found in California.
It is very important growers, landscape professionals and home gardeners continue to be on the lookout for this pest. Early detection is imperative for keeping this dangerous pest/disease complex in check. For further information about ACP and HLB, including how to inspect your trees please see the USDA's Save Our Citrus website.
Our office has hard copy outreach materials for those that are interested. Please contact our office if you would like some.
- Author: Chris M. Webb
Ventura County Farm Advisor Ben Faber is currently on sabbatical in Turkey. Today Ben shares a little about his studies.
Adana, Turkey is along the Mediterranean Sea, near the middle of the country, and is where I plan to spend the next 11 months studying and doing research. I am at Cukurova (pronounced Chuckorova) University which has collections of avocados, citrus, figs, mulberries and pomegranates. I came here because as a Mediterranean climate, it grows similar crops to California.
I had not realized that a Mediterranean climate could be so hot and humid, though. What defines a Mediterranean climate is one that has winter rain and summer drought and mild winter temperatures. The temperature at 6 AM in Adana is 37 C (98.6 F) and the humidity hovers around 75%. Most businesses do not have air conditioning, but they all have heaters. Most of the ‘Hass’ avocado trees do not look good, so I guess it is going to get cold this winter.
It is hot now, though, but that’s what makes the citrus grow, and grapes and figs and wheat and plums and apricots and corn and cotton that grow all around on the Cukurova Plain, once called the Cilician Plain.
The University is the largest agricultural school in the country with 45,000 students in diverse departments, such as horticulture, soils, and engineering, but also medical, dental, biotech, letters and sciences and other schools. The town of Adana has 1.5 million people, is about 20 miles from the coast, is at about the same latitude as San Francisco and has all the modern conveniences of any California town. Plus, it has a great bus system.
I am working with faculty from different departments on different trials. Two are on citrus; evaluating different rootstocks for iron deficiency and a chemical evaluation to control leaf flush in citrus. This latter trial is to reduce the new tissue that is so attractive to Asian Citrus Psyllid. In avocado, we are looking at different girdling times and styles for their impact on fruit set and yield. They have used a double girdling technique here on various tree crops for years and found that the double ring has effects that a single ring does not have.
Another trial is looking at different fig varieties as rootstocks, again to evaluate for resistance to iron deficiency. Figs world-wide are grown from cuttings, not grafted, because they root so easily. Having a rootstock that can handle the high pH soils that we have in coastal southern California could benefit a new industry in our State.
I am also working with the curators of the pomegranate and mulberry collections to better understand how those crops are grown here and also getting out meeting local growers of these crops.
The landscape here is fresh with new plantings, as far as the eye can see. It is really a dynamic agriculture with farms that look every bit as well cared for as those in California. Many of the local growers I have met have attended this University and several have studied in Europe and the US. My English gets me by, and when I get lost, people are good at steering me straight.
Adana is famous in Turkey for its kebab, a grilled, ground lamb that is served with lemon, onion, rice, flat bread, roasted peppers, mint, and salad. And everyone asks if I have eaten Adana kebab. Yes, I have, and it is wonderfully fresh food.
Cukurova plane (photo by Ben Faber)
Cukurova University Campus (photo by Ben Faber)
- Author: Chris M. Webb
Did you know that, if planted, the seed from a delicious avocado or apple will not necessarily produce a tree with good tasting fruit? In fact the fruit might not even be edible after waiting for many years for the tree to bear fruit.
A much better way to start your own trees is by budding or grafting. The best time of year to do this is spring or fall when the bark is easily separated from the wood. It should be timed early enough so the warm weather will help ensure a good bud union, yet late enough so that the bud will not begin to grow and so that callus (hard, whitish connecting tissue of the graft) will not grow over the bud itself.
Citrus budded or grafted in the fall must be protected from frost. Avocados are best grafted in the spring when the bark is easily separated from the wood.
It is also possible to change or add varieties to mature trees with budding and grafting techniques. This process is called top working.
Detailed instruction on budding, grafting and top working can be found here.
For more information please call our Master Gardener helpline at 645-1455 or email them with your questions.
- Author: Chris M. Webb
The Asian Citrus Psyllid (ACP) has recently received a lot of media coverage and for good reason. ACP carries the deadly Huanglongbing (HLB) bacteria, the most serious citrus plant disease in the world. The disease kills all varieties of citrus trees and related plants such as orange jasmine and Indian curry leaves. The psyllid, about the size of an aphid, does not always carry HLB, but once an ACP feeds on an infected plant the psyllid will carry the disease for life to each plant on which it feeds.
What is particularly troubling about this pest-disease complex is that it can take years for the infected citrus trees to die; therefore, owners of the infected trees may not be aware they have the disease. While fruit from infected trees can be bitter, misshapen, and inedible, the tree stays up and can continue to be fed upon by psyllids, causing HLB to spread further.
People and our global economy are moving this insect. ACP has spread through Asia, parts of the Middle East, South and Central America. It has been found in Mexico, Hawaii, Texas, Louisiana, Georgia, Alabama, South Carolina, Florida and arrived in southern California in 2008. None of the ACP’s found in California have tested positive for HLB. However, it is highly likely that HLB-infected plants, brought from infected areas, are already here.
What can you do? Do not bring in plant materials from areas known to be infected with ACP. If our area becomes infected, do not move any plant materials out of our area. Purchase only certified pest- and disease-free trees from a reputable nursery. Stay informed. Check your trees regularly for signs of ACP. Report suspected ACP and/or HLB to the County Agricultural Commissioner or the California Department of Food and Agriculture (CDFA).