- Author: Ben Faber
It has been a struggle to get through the summer this year. Weird. Hot. Then fog in August. Hot. Then fog in October. It's supposed to be clear,, blue skies in October. perfect weather for avocado persea mite and citrus leaf miner. Hot times then cooler. How to irrigate? A lot of folks just decided not to irrigate. Why do it when it's so crazy? Forecast was for no rain, but it's cool. And then it rained, and suddenly that beautiful citrus that has just broken color and is an orange globe, splits. It's most common in navels, but all citrus that ripen in the fall – tight-skinned satsuma mandarins, early clementines, tangelos and blood oranges. With the hot summer, it seems that a lot of citrus fruit have accelerated their maturity and are ready, ripe and sweet right now, and maybe ready to split.
And that's the problem. Drought stress. Salt stress due to drought. Water stress due to miserly watering. A heat wave in July. And a weird fall with maybe rain and maybe no rain and is ¼ inch considered rain or just a dedusting? Irregular watering is the key to splitting this time of year. The sugar builds, the pressure to suck in water builds and the fruit has been held back by a constrained water pattern and suddenly some water comes and it goes straight to the fruit and Boom, it splits.
Years of drought, and a stressed tree are a perfect set up for a citrus splitting in fall varieties like navel and satsuma. The days have turned cooler and there's less sense on the part of the irrigator to give the tree water and suddenly out of nowhere, there is rain. That wonderful stuff comes down and all seems right with the world, but then you notice that the mandarin fruit are splitting. Rats? Nope, a dehydrated fruit that has taken on more water than its skin can take in and the fruit splits. This is called an abiotic disorder or disease. However, it's not really a disease, but a problem brought on by environmental conditions. Or poor watering practices.
Fruit that is not yet ripe, like ‘Valencias' and later maturing mandarins are fine because they haven't developed the sugar content and have a firmer skin. They then develop during the rainy season when soil moisture is more regular. Or used to be more regular. With dry, warm winters this may become more or a problem in these later varieties, as well.
Several factors contribute to fruit splitting. Studies indicate that changes in weather, including temperature, relative humidity and wind may exaggerate splitting. The amount of water in the tree changes due to the weather condition, which causes the fruit to shrink. Then with rewetting, the fruit swells and bursts. In the navel orange, it usually occurs at the weakest spot, which is the navel. In other fruit, like blood orange, it can occur as a side split, as seen in the photo below.
Proper irrigation and other cultural practices can help reduce fruit spitting. 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 the canopy beginning at least a foot from the trunk can help moderate soil moisture and soil temperature variation.
Once split, the fruit is not going to recover. It's best to get it off the tree so that it doesn't rot and encourage rodents.
(Photo by Ottillia “Toots” Bier, UCR)
- Author: Ben Faber
ACP Management for Commercial Growers - UC Ag Expert Webinar, Dec 4 @3 p.m.
Take advantage of this opportunity for an interactive web-based presentation on ACP field management from UC researcher and ACP expert Dr. Beth Grafton-Cardwell. You don't have to travel for this one, it's free, and you can earn CEUs, too! Sign up here: https://ucanr.zoom.us/webinar/register/WN_fEKM2ScPTk6WF5ilga6V7Q
HLB Update
In San Bernardino County a single residential tree tested positive for the bacterium that causes HLB. As a result, the HLB quarantine has been expanded in the Montclair area. Also of note is an adult ACP that recently tested positive for the bacterium that causes HLB near Corona, outside of the HLB quarantine. See the latest HLB map for details: maps.cdfa.ca.gov/WeeklyACPMaps/HLBWeb/HLB_Treatments.pdf. As before, all HLB detections to date have been on residential properties, the infected trees have been or are being removed, and ACP treatments are applied on a recurring basis to remaining citrus in those areas. No HLB has been found in commercial groves via PCR testing.
Regulatory responses required by the state in response to an HLB detection are described in CDFA's Action Plan for ACP and HLB.
How Close Is HLB To Your Citrus? There's a New UC App For That!
Visit ucanr.edu/hlbgrowerapp , zoom to or type in your location and it shows your proximity to HLB+ detections, recommends best practices to protect your citrus from HLB based on your current proximity to know detections, and provides a link to the Voluntary Grower Response Plan for more information. As HLB detections via PCR increase and spread, it's important to be aware of possible actions you could take to further protect your citrus should an HLB detection occur in your area.
CITRUS REMOVAL PROGRAM: Citrus trees that are neglected or abandoned may harbor ACP and HLB, increasing risk to other citrus in the area. Abandoned and neglected trees may be reported to me or the county Ag Commissioner's office. The Citrus Matters ACT NOW program may be able to assist in citrus removal. For more information contact Joel Reyes at jreyes@cacitrusmutual.com or (559) 592-3790.
Additional Useful Links:
Summaries of the latest scientific research on combating HLB: ucanr.edu/sites/scienceforcitrushealth/
Science-based analyses to guide policy decisions, logistics, and operations: www.datoc.us
General updates and information on the state ACP/HLB program and regional activities: citrusinsider.org
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Cressida Silvers
CA Citrus Pest and Disease Prevention Program
ACP/HLB Grower Liaison
Ventura, Santa Barbara and San Luis Obispo Counties
805 284-3310 (phone or text)
- Author: Bonnie Brown
Ventura County Master Gardener
A blind lemonade and orange juice taste-testing trial was incorporated into a recent citrus grower workshop in Santa Paula. The topic of the meeting was lemon rootstocks and scions and the attendees were for the most part lemon growers. This seemed like an opportune time during the refreshment portion of the workshop to see what commercial lemonade and orange juices these professional growers might prefer. This would be an unreplicated trial, since it was only this one time with a small set of tasters, but might be give a sense of what citrus farmers prefer as their juice.
Four different orange juice brands and four different lemonade brands were chosen based on a range of prices. Two tables, one with lemonades and the other with orange juices, were divided into four sections labeled with Roman numerals, 1-4. A small amount of each juice was provided to the tasters in unmarked cups. The testers ranked their preferences on a grid with an 'A' though 'D' ranking beneath the corresponding Roman numeral label. “A” being the preferred juice and “D” being the least preferred. A paper label on the juice container temporarily concealed the juice's actual identity.
In this small,unreplicated trial, the most expensive juices did not have the greatest number of taster votes. None of the tasters expressed negative opinions about any of the juices, but there were definite preferences as can be seen by the tally. There's no accounting for growers' tastes, maybe.
ORANGE JUICE RESULTS, in order of preference:
Trader Joe's fresh squeezed orange juice; 16 votes; 8.6 cents/oz.
Walmart store brand; 6 votes; 3.5 cents/oz.
Tropicana Original; 5 votes; 5.5 cents/oz.
Simply Orange with pulp; 3 votes; 9.0 cents/oz.
LEMONADE RESULTS:
Simply Lemonade; 12 votes; 5.8 cents/oz.
Tropicana Lemonade; 10 votes; 6.8 cents/oz.
Minute Maid Lemonade; 5 votes; 2.3 cents/oz.
Newman's Own Virgin Lemonade; 3 votes; 5.6 cents/oz.
We thank all who were involved in this survey and to the five Master Gardeners who have been involved in not only the organization of this tasting, but also the grower meeting and help in harvesting some of the lemon trials that were reported on at this meeting.
- Author: Ben Faber
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- Author: Ben Faber
On behalf of the International Society of Citriculture (ISC) and the Organizing Committee of the 14th International Citrus Congress (ICC 2020), we are very pleased to invite participants from public and private research and institutions, and from the production and commercial sector to attend the ICC 2020 that will be held in Mersin, Turkey, from 8-13 November 2020, under the theme “Reframing Citriculture: Better Connections for Future”. The Congress is being organized by the Mediterranean Exporters' Association (MEA), Çukurova University (ÇU) and National Citrus Council (NCC). These three institutions will cooperate with universities, research institutes, associations, companies, growers, exporters and sponsors. The Congress that will be realized with attendance of all stakeholders concerning whole citrus industry attracts attention with all activities including a number of workshop, plenary, oral presentation and poster sessions which cover policies, comments, approaches under the theme “Reframing Citriculture: Better Connections for Future”. So citrus will be reframe for better connection in future
Historians believe that the ancestor of the citrus trees, Citrus medica L., was introduced from India into Anatolia (Turkey) in the late 4th century BC. Today, Turkey is the 8th largest citrus producer in the World. Total citrus production of Turkey was 4.902.052 t. Oranges are the main citrus fruit grown in Turkey, accounting for about 43% of total production (1.900.000 t). Orange production is followed by mandarins (1.650.000 t), lemons (1.100.000 t), grapefruit (250.000 t) and others (2.052 t). Citrus area has expanded rapidly and reached 135.643 ha. This expansion is driven by domestic and export demands. It is believed that Turkey has a production potential at least three times of the present level. (TUIK, 2018)
The major citrus producing areas are located along Turkey's southern Mediterranean (88%) and Aegean coastal plains (12%), where typical mild or cool Mediterranean subtropical climate prevails. The most producer provinces are Adana (1.142.686 t), Mersin (1.052.992 t) and Hatay (906.392 t) in the Eastern Mediterranean. The Mediterranean climate is more suitable for high quality citrus; continue to shift to citrus from field crops (cotton and grains) because of its more attractive returns. In these regions, high quality citrus fruit production is oriented particularly towards fresh fruit markets and consumption.
Most of Turkey's citrus production is used for the local fresh fruit market and for export. Turkey has a significant place in international citrus trade, particularly in fresh citrus fruit exports. In the total global fresh citrus fruit export, Turkey was the second in the world. In recent years, exports of citrus, especially mandarin, have steadily increased.
The first settlement in Mersin, the host city of ICC 2020, which is known as Cilicia in ancient times, dates as far back as to the New Stone Age. It is one of the important ports of the Mediterranean and the center of maritime commerce just as it was during ancient times. As a settlement of dominant powers since Neolithic Period, Mersin hosts many archaeological and historical monuments remaining from Chalcolithic, Hittite, Roman, Byzantine and Ottoman civilizations. Therefore, many important figures in the history of civilization, such as Alexander the Great, Saint Paul, Cleopatra, Aya Thecla, Prophet Daniel, lived in this area and changed the course of history.
During the congress, a great many scientific activities such as plenary and ordinary sessions, workshops and poster display to establish new links and collaborations among participants will be carried out by well-appointed scientists who will come from all of the world. Furthermore, participants will find opportunities to see both Turkish citrus industries and historical background by technic and social pre, mid and post Congress tours.
We look forward to meeting you in Turkey.
Website: https://www.icc2020.org/
