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

Topics in Subtropics Blog

Biologicals in Agriculture Conference

Conference and Trade Show on Biologicals

MARCH 5, 2019

Register by 28 February, 2019 at
5.5 CCACEUs have been approved and 3.5 DPRCEUs have been requested

The purpose of the Ag Innovations Conference series is to introduce new technologies to the grower community by speakers from universities, research organizations, and the agriculture input industry.  The first event in Santa Maria (2014) covered a variety of topics while the second one in San Diego (2017) was on microbial control.  Considering the growing interest in biologicals and demand for sustainably produced food, the third conference is organized with carefully selected topics on biocontrol agents, biostimulants, and botanical and microbial pesticides and fungicides.  Early registration until February 28 is $50 per individual and $100 for onsite registration.  Registration includes lunch and refreshments.  Please contact Hiromi Peck at 805-781-5940 if you have any questions about registration or if you are interested in participating in the trade show.  Come join us for an informative day at the Veterans' Memorial Center (313 W Tunnell St, Santa Maria).


AIC 2019
AIC 2019

Posted on Wednesday, February 6, 2019 at 5:21 AM

Visit UC ANR at the World Ag Expo, Feb. 12-14

Attractions in the UC ANR tent at space 137 on I Street, just west of Pavilion A, include the opportunity to meet researchers, enjoy fresh citrus from the Lindcove Research and Extension Center, taste moringa tea, and enter to win a poster-size satellite image of one's own farm.

TULARE, Calif. — The public is invited to taste, see and learn about many UC Agriculture and Natural Resources programs offered in California at the World Ag Expo, the world's largest agricultural exposition to be held in Tulare Feb. 12-14. The Expo is at the International Agri-Center, 4500 S. Laspina St., Tulare.

Attractions in the UC ANR tent at space 137 on I Street, just west of Pavilion A, include the opportunity to meet researchers, enjoy fresh citrus from the Lindcove Research and Extension Center, taste moringa tea, and enter to win a poster-size satellite image of one's own farm.

The tent displays include leaf-footed bugs controlled by microbes, traps for managing vertebrate pests, the superior quality of soils managed with conservation techniques, and high-tech ag innovations, including a drone.

In two booths inside Pavilion A (1411 and 1412), the UC ANR programs that target the general public will be featured. The Tulare County nutrition educators will be playing nutrition Jeopardy! with visitors. The UC Master Gardeners will reach out with research-based gardening information. The 4-H Youth Development program will invite all youth to peer into virtual reality goggles to give them an idea about the fun activities that can be part of joining 4-H.

With VR goggles, viewers can be immersed in expeditions from Mount Everest to the undersea world. Expeditions explore history, science, the arts and nature. World Ag Expo visitors will have the opportunity to experience a variety of virtual experiences, from scuba diving with sea lions to flying over Greece.

Two UC ANR academics are presenting seminars during the the show.

Getting it Right: Livestock's Environmental Story
1 to 2 p.m., Feb. 12, in seminar trailer 1
Frank Mitloehner, UC Cooperative Extension specialist
Mitloehner will discuss confusion in the media about the impact livestock supposedly has on our environment. This presentation reviews how the efficiencies in livestock production and environmental emissions are related, and how our producers are leading the way to a “greener future” for California and U.S. agriculture.

Asian Citrus Psyllid and Huanglongbing – Regulatory Compliance Update and Treatment Protocols
12 to 1 p.m., Feb. 13, in seminar trailer 1
Beth Grafton-Cardwell, UC Cooperative Extension citrus entomology specialist
Victoria Hornbaker, California Department of Food and Agriculture
An update on regulatory protocols relating to Asian citrus psyllid and HLB quarantines and the proper transportation of bulk citrus to mitigate against the spread of the pest and disease. Speakers will review the University of California recommended treatment options for Asian citrus psyllid in commercial citrus groves and residential citrus trees. Continuing Education units have been requested.

UC VINE will hold a meeting with Dutch agtech professionals during World Ag Expo

The California and Dutch AgFoodTech innovation partnership is reuniting in California during the show to share their action plan and scope the projects. Contact Gabe Youtsey, UC ANR chief innovation officer, to request an invitation to the presentation and networking luncheon on Feb. 12 at the UC Cooperative Extension office across the street from the International Agri-Center in Tulare.

–UC Agriculture and Natural Resources


citrus cornucopia
citrus cornucopia

Posted on Monday, February 4, 2019 at 6:56 AM
Tags: AG Fair (1), ANR (1), citrus (295), exposition (1), Tulare (1)

Tree Staking Myths

"Trees should be firmly staked at planting"

        MYTH!!!!!!!!!!!!!!! Read on:

Chalker-Scott, L. , Extension Specialist And Associate Professor, Washington State University
Downer, A.J., Farm Advisor, University of California

Nursery-grown shade trees are often rigidly staked to prevent blowdown and damage during cultivation. In some cases, trees are pruned to a long, untapered standard with a bushy top that requires a tight stake to hold it up. Nurseries often remove side branches from the young trunk and while this creates the illusion of a small tree, the practice actually inhibits the development of taper in the trunk (Harris, 1984; Neel and Harris, 1971). Trees without taper will not stand without staking. Poor culture of ornamental trees in nurseries necessitates staking once trees are planted into landscapes because they do not have the structural development in their trunks to stand on their own. Due to these cultivation errors, landscape installers frequently keep the nursery stake and add more stakes to firmly secure the tree in place and further prevent its movement in the landscape.

Staking takes three basic forms: rigid staking, guying, and anchoring. All methods of staking reduce development of taper, increase height growth, and decrease caliper of the developing tree relative to unstaked trees (Figure 7). Moreover, improper staking can result in increased tree breakage either during the staking period or after staking is removed (Figure 8a-b) (Thacker et al., 2018).

Decades ago, researchers discovered that movement of the trunk and branches is necessary for the development of trunk taper (Neel and Harris, 1971). Trees grown in a growth chamber without movement did not develop taper and instead grew taller, while trees in an identical chamber that were hand shaken each day developed significant taper and remained shorter.

Until trees are established in landscapes they may require some staking. In areas of high wind, guying (which involves cables staked to the ground) gives the greatest protection against main stem breakage or blowover (Alvey et al., 2009). Whatever system is used, any such hardware should be removed as soon as the tree can stand on its own:

  • The traditional two stakes and ties system is the least harmful to trees staked in landscapes.
  • Staking should be low and loose to allow trunk taper to develop naturally.
  • Remove all staking material as soon as possible.

If a tree is not established after a year of staking, it is unlikely to ever establish

Read on:

avocado lindcove
avocado lindcove

Posted on Friday, February 1, 2019 at 6:07 AM
Tags: avocado (266), citrus (295), planting (8), stake (1)

Herbicide Weed Resistance in California?

UCCE Agronomy and Weed Science Advisor, Merced and Madera Counties

Weeds compete with crops for light, water, and nutrients, which can result in yield reductions. Weeds can also interfere with crop production by serving as alternate hosts for pests and pathogens, providing habitat for rodents, and impeding harvest operations, among other impacts. Natural areas can also be impacted by weed species when they reduce aesthetics and disrupt ecosystem services. As a consequence, growers and land managers employ a variety of control strategies, including the application of herbicides, to manage unwanted vegetation.

Although herbicides can be effective tools for controlling undesirable plants, failures can and do occur. Weeds may escape chemical treatments for several reasons including: the selection of an ineffective herbicide or herbicide rate, improperly calibrated or malfunctioning equipment, applications made at a time when the target species is not susceptible to control, the use of herbicides under adverse environmental conditions, and the evolution of herbicide resistance.

As of 3 January 2019, there are 496 confirmed cases (species x site of action) of herbicide resistance, worldwide. Current reports provided by the International Survey of Herbicide Resistant Weeds ( indicate that 255 different species (148 dicots and 107 monocots) have evolved resistance to 163 different herbicides across 23 of 26 known sites of action. With respect to the United States, 161 unique instances of resistance have been documented. Most resistances (52 cases) are to the acetolactate synthase (ALS) inhibitors followed by the photosystem II (PS II) inhibitors (26 cases), 5-enol-pyruvyl-shikimate-3-phosphate synthase (EPSPS) inhibitors (17 cases), and the acetyl-CoA carboxylase (ACCase) inhibitors (15 cases).

Currently, in California, there are 30 confirmed occurrences of herbicide resistance. Twenty-four of those cases are to a single site of action (Table 1). The most frequently encountered resistances have been to the ALS and EPSPS inhibitors (7 each). Five weed species (late watergrass (Echinochloa oryzicola), barnyardgrass (Echinochloa crus-galli ssp. crus-galli), hairy fleabane (Conyza bonariensis), horseweed (Conyza canadensis), and Italian ryegrass (Lolium perenne ssp. multiflorum)) have populations with documented resistance to up to four herbicide sites of action (Table 2).

Growers and land managers can take several actions to thwart the evolution and spread of herbicide resistant weeds. First and foremost is scouting fields following herbicide applications and keeping careful records of herbicide performance to quickly identify repeated instances of weed control failure. Pesticide applicators should ensure that their equipment is properly calibrated and that they are applying effective herbicides at appropriate rates to manage the target species. Whenever possible, diversify herbicides to reduce chemical selection pressure. If appropriate, incorporate physical and cultural weed control practices into a vegetation management plan. Be sure to control unwanted plants when they are small and never allow escapes to set seed. Clean equipment to prevent seeds of herbicide-resistant weed species from moving between infested and non-infested sites and don't forget that unmanaged roadsides, canal banks, fence lines, and field margins, etc., can serve as a source of propagules.



Table 1. A summary of herbicide resistance in California to single sites of action.




Table 2. Weed species in California with confirmed resistance to multiple herbicide sites of action



horseweed bolting
horseweed bolting

Posted on Tuesday, January 29, 2019 at 7:42 PM
  • Author: Lynn M. Sosnoskie, PhD
Tags: resistance (11), weeds (29)

Mycorrhizal Inoculants

"Mycorrhizal inoculants should be added to planting holes when installing woody ornamentals in landscapes"           MYTH!!!!!!  Read on:

Chalker-Scott, L. , Extension Specialist And Associate Professor, Washington State University
Downer, A.J., Farm Advisor, University of California

Beneficial fungi called mycorrhizae associate with roots of woody plants in a mutualistic relationship that benefits each partner. Decades of research have shown how plants inoculated with mycorrhizae grow faster and larger than those without these fungal partners (Carpio et al., 2005). This knowledge has prompted entrepreneurs to market mycorrhizal inoculant products as planting amendments, claiming they will ensure establishment of landscape plants. Mycorrhizal inoculants are often seen in container (potting) media, organic fertilizers, or sold separately as growth promoting products, but their efficacy is often unproven, especially in landscape situations (Chalker-Scott, 2017).

Misconceptions about mycorrhizal products are common:

  • My soil is “poor” so I have to add the mycorrhizae to my garden. Most soils are already inoculated with mycorrhizal fungi, so they do not need to be added. Plants will form mycorrhizal associations in most soils without additional inoculant. Soils where mycorrhizal inoculants have been effective in promoting plant growth responses are extremely disturbed or toxic, such as mine spoils or severely “cut” sites where all surface soil is removed and plants are being grown in subsoils.
  • Mycorrhizal inoculants will support my aging or dying tree. While research shows that mycorrhizae play a role in plant defense from pathogens (Linderman, 1988), there is no evidence to suggest that inoculants can provide additional benefit to previously inoculated plants.
  • Mycorrhizae will promote growth of my established trees. There is no published work to indicate inoculation of established trees will promote their growth; Appleton et al. (2003) reported no effect from this application.
  • The mycorrhizal inoculant contains viable spores. Biological products have limited shelf life. Research on commonly available inoculants showed that over 50% of the products available to consumers were not viable (Corkidi et al., 2003). Mycorrhizal fungi have naturally low viability of their spores so if a product does not have hyphal fragments included, it may not be viable.
  • If I inoculate with mycorrhizae I don't need to fertilize my plants. Mycorrhizae aid in nutrient uptake (especially phosphorus), but they do not cure nutrient deficiencies, especially when the soil is deficient in those minerals. Research indicates that mycorrhizae can enhance uptake of normally available soil nutrients, but the soil has to contain them in the first place (Corkidi et al., 2005).

If I add mycorrhizae I will bring life to my soil. If a soil is devoid of microbial activity, it is likely an unsuitable soil for mycorrhizae to grow in. Just like plants, mycorrhizal fungi need good soil conditions in which to grow. Compacted, flooded, or contaminated soils are also harmful to these fungi, so they will not cure a toxic or otherwise non-arable soil.

Read on:


mycorrhizal inoculation
mycorrhizal inoculation

Posted on Monday, January 28, 2019 at 6:07 AM
Tags: inoculation (1), mycorrhizae (3)

First storyPrevious 5 stories  |  Next 5 stories | Last story

Webmaster Email: