UC ANR research on watermelon grafting helps growers produce 15-20% more watermelons while using 25-40% fewer plants than the traditional system under the same amount of water and fertilizers, contributing to economic prosperity for the agricultural sector.

The Issue

As the statewide water scarcity and rising inflation hit the California agriculture, food production with reduced inputs while maintaining productivity and controlling production cost heighten the necessity of using environmentally-sustainable farming practices. For watermelon growers, grafting, a thousand-year-old practice, has been recognized as a such practice to tackle the problems according to scientific literature. However, the adoption on grafting has been low among California watermelon growers despite the benefits being well-known. Therefore, strengthening growers' confidence with this ancient production tool is crucial.

How UC Delivers     

Extensive field visits to watermelon growers, nursery, and seed industries were conducted to understand the barrier of adopting watermelon grafting starting in 2018. Results from the interviews indicated that the increase of production cost was the biggest concern when growers considered watermelon grafting. Further investigations showed that growers pay 2.5 to 4 times more per acre for producing grafted transplants compared to non-grafted watermelons.

In addition to yielding more fruit, grafted fields should also use fewer plants to compensate for the higher cost. Since 2019, field experiments were conducted in the San Joaquin Valley to test the horticultural and economic potential of growing grafted watermelons in wider spacings. A total of eight rootstocks and four scions were grafted into 32 combinations, which were planted into the regular three feet, and wider spacings of four to five and six feet apart. The results indicated that grafted watermelons planted with the four to five feet in-row spacing balanced the best among yield enhancement, fruit quality, and control of cost. Study progress and findings were shared periodically with the cooperative growers and discussed with the watermelon industry. The information was also reported in extension articles and at various extension and scientific conferences.

The Impact

With the four to five feet in-row spacing adopted widely, the cost for grafted transplants was reduced up to $800 per acre. Furthermore, stronger confidence with grafting has led to the increase of planted acreage of grafted watermelons from less than 250 acres in 2018 to over 1,500 acres in 2021. According to the field observations, growers reported that, on average, their successfully grafted fields produced 15-20% more watermelons than non-grafted fields while using up to 40% fewer plants and the same amount of water and fertilizers. For local greenhouses, customer orders of grafted watermelon transplants increased more than 10 times in 2022 compared to 2018. These savings and increases in revenue demonstrate UC ANR's commitment to its public value of promoting economic prosperity.

Watermelons planted under 3 feet apart

Watermelons planted under 4-5 feet apart

Watermelons planted under 6 feet apart

Adapted IPM Model from former UC ANR faculty is offered in multiple languages leading to potential profit increases of $1.79 million.

The Issue

Numerous endemic and invasive pests threaten all kinds of crops, and the application of synthetic pesticides is the most common control option in many cases around the world.  Frequent application of pesticides leads to pest resistance, secondary pest outbreaks, increased risk of environmental and human health, and negatively impact sustainable crop production efforts both in the short-term and long-term. Integrated pest management (IPM) is a concept of pest management in an ecologically sustainable manner.  IPM has been promoted for decades, and many farms apply IPM practices to some extent. However, there are certain deficiencies in the understanding of IPM, its components, finding non-chemical management options, and exploiting cultural practices to improve crop health and yields.  The traditional IPM model faces challenges because of its limitations for practical applications. There is a need to improve the understanding of growers, pest control advisors, and crop advisors in developing comprehensive crop care strategies using IPM principles, as well as revise the traditional IPM model to fit the modern production trends and consumer preferences.  

How UC Delivers

Former UC ANR Cooperative Extension Advisor Dr. Surendra Dara conducted extensive research developing IPM solutions and promoting biological control options for small fruits and vegetables in California and provided advice for managing pests in nurseries, ornamental crops, urban landscapes as well. The ultimate goal is to improve IPM knowledge and implementation locally, regionally, nationally, and internationally. Based on his decades of research and extension experience in the US and other countries around the world, Dr. Dara developed the new IPM paradigm in 2019 that incorporated social and economic aspects of crop production in addition to various pest management options and other influencing factors.  He had been invited by multiple groups to speak about IPM strategies in multiple crops and the new IPM model.  Multiple symposia were organized at professional conferences, farmers, crop care professionals, and agricultural input industries updated their crop production and protection strategies based on the new IPM model. The model has been translated into multiple languages with international collaboration.

An anonymous online survey conducted between December 2021 and May 2022 received responses from California and elsewhere.  Forty-five respondents from allover California, Arizona, Florida, Georgia, Hawaii, Indiana, Illinois, Michigan, Minnesota, North Carolina, Ohio, Oregon, South Carolina, Washington, and Wisconsin states in the US, and from Argentina, Australia, Ethiopia, Honduras, India, Kenya, Mexico, Mozambique, Nigeria, Pakistan, Portugal, Tanzania, and Uganda participated in the survey.  

The new IPM model in multiple languages

The Impact

Survey results showed that 95.6% found the information from Dr. Dara's IPM program was useful, and 93.3% people would use that information or have used it to improve their farming operations. The IPM information has been or would be used on 33,703 acres with a realized or expected savings or additional returns of $1.79 million.  The respondents also indicated that they have or would share the information to 132,739 people. Survey respondents included farmers, pest control or crop advisors, private researchers, agricultural industry partners, and university faculty or researchers.  Since it was published in the Journal of Integrated Pest Management in late April 2019, the new IPM model has been read or downloaded more than 48,000 times so far. Dr. Dara's research and extension demonstrates an ongoing commitment to UC ANR's public value of protecting natural resources in California and beyond.

Testimonials

“I have been growing strawberries for more than 20 years and worked with several farm advisors. Surendra is undoubtedly the best.  He is the most productive and passionate about helping the farm industry.” Santa Maria Strawberry Grower

“IPM model is a very important tool that we can all promote to better implementation of efficient and sustianable solutions. thanks” Global Biocontrol Salesperson

“I am impressed with Dr. Dara's range and depth of trials, demonstrations, and experiments in the area of regenerative agriculture. The information he has put out is novel, useful and helpful. Sorry to see him go to Oregon.”  Pest Control Advisor in USA

“Dr. Dara research is helping growers and crop consultants navigate sustainible and environmentally safe, effective and profitable  options for pest managment in high value specialty crops.” Private Researcher, Hawaii, California, and Arizona

“Dr. Dara has a wealth of information that he distributes effectively using multiple different platforms. He is a good writer and communicator who is capable in presenting to audiences at various levels from growers to research scientists” Pest Control Advisor in the Western US

“Dr Dara is providing critical research and outreach for sustainable farming in the west and is also a linch pin in research and education on invasive pests.” Trade magazine editor

After attending UC ANR's Science for Citrus Health webinars, over 50% of participating citrus professionals say they intend to adopt actions related to psyllid management. These practices can help safeguard abundant, healthy food for all Californians.

The Issue

Huanglongbing?  Never heard of it? Why should I care? Maybe you need to learn more?

Huanglongbing, HLB, a bacterial disease of citrus also called Greening Disease, is spread by the Asian Citrus Psyllid. It causes the citrus fruits to be deformed and taste salty and bitter. HLB was first reported over a century ago in southern China. But why is it a problem for U.S. citrus? Diseases don't “respect” country borders and in 1998 the psyllid and the disease arrived in Florida in the early 2000's. Because there is no cure, damage caused in the largest orange producing state was extensive. By 2019, citrus production decreased in Florida by 74%. Despite federal bans on interstate movement of host plants, the psyllid did not abide by those rules!   

And the disease also easily spreads from state to state. The first tree with HLB in California was found in 2012 in Los Angeles County. Then the question became, even though millions of research dollars were being spent, is there progress toward a cure?  What could be done in California to slow the spread?  Much was learned in Florida's battle and much is being learned through research. But it is hard for growers, the media, and the public to understand how that information might be used in California.

How UC Delivers

To address this information gap, Cooperative Extension Specialist Beth Grafton Cardwell and I started Science for Citrus Health (SCH) in 2015. It is designed to spread in lay language information about research aimed at understanding and combating HLB. SCH is now a cooperative effort with individuals from California, Florida and Texas, involving many activities.

These included developing Snapshots, short, two-page pieces on HLB research, written in lay language, posted on the SCH website, on Instagram, and disseminated at citrus meetings. In total, 45 Snapshots have been written, focusing on five themes related to detection, disease and psyllid management and the tools being used. Another resource for educational efforts is a large PowerPoint slide set, covering genetics, as well as regulatory and consumer issues. Recently efforts expanded, owing to grad students and postdocs, to include a YouTube channel on HLB and a popular podcast series that focuses on HLB researchers, their approaches and their career stories. Another effort involves translating citrus information and Snapshots into Spanish to reach Hispanic growers and workers in the citrus industry. In 2021, five informational webinars were convened on topics, such as ACP and HLB Management, the use of particle films to manage HLB, and citrus thrips. A recent webinar on the biology and management of ACP was presented in Spanish. These webinars attracted international audiences of up to 300 people.

The Impact

Post-meeting polls from UC ANR's Science for Citrus Health webinars indicated that more than 50% of attendees would implement at least one new practice they learned at the session. Research from the University of Florida has shown that the application of particle film screens, for example, has the potential to reduce ACP populations by more than 80% compared to monthly insecticide treatments, thereby contributing to UC ANR's public value of safeguarding abundant, healthy food for all Californians. Creation and proliferation of SCH efforts, providing information on research efforts focused on HLB, is an important educational resource for citrus growers, the media and industry. Another resource provides slides and educational materials to be used by educators for presentations to these groups, and the public. These newly created educational resources, some in Spanish, are unparalleled on other citrus sites.

Huanglongbing Illustration. Credit: Barbara Alonso

Agricultural clientele utilize Extension information to inform irrigation management decisions, potentially improving water use efficiency and protecting California's water resources.

The Issue

For farmers to grow high-yielding and good quality crops and be good stewards of our finite water resources, they need to know how much water is used by their crop and how much to refill the soil with irrigation. Weather conditions and the crop's life stage determine the water use, also known as crop evapotranspiration (ET). When farmers have accurate crop ET information available, they can more closely apply the appropriate amount of water at the right time and grow more and better quality food and fiber with each unit of water.

How UC Delivers

Since 1995, UC ANR has collaborated with the Department of Water Resources (DWR) to deliver weekly crop ET estimates to growers for the major crops grown in California. These ET estimates integrate real-time, on-the-ground weather measurements taken by DWR and decades of research by UC ANR on crop water use. These reports provide growers with representative estimates of crop ET each week and a running total of crop water use as each crop develops. The weekly rates of ET can be related to the water application rate of an irrigation system to help determine how frequently to irrigate and how long to run a system. Comparing cumulative ET early in the season to the available soil moisture can help decide when to apply the first irrigation of the season. At the end of the season, a comparison of the seasonal ET to total applied irrigation water provides a yardstick to assess irrigation efficiency. Beginning in 2000, methods of delivering these weekly reports expanded to include email and blogs. In 2015, these reports expanded to UC ANR offices throughout the Central Valley to serve more than 1,200 clientele throughout California.

The Impact

In 2019, a one-time survey was sent to about 1,200 clientele throughout California, including growers, agricultural land managers, and crop advisors to understand how the weekly ET reports were being used, quantify the impact of use of the emails, and assess the needs of irrigation education. The survey findings indicated that 70% of clientele use these weekly ET reports in irrigation management decisions. Of that 70%, 75% use the information to inform how long to irrigate, 73% how frequently to irrigate, 53% when to begin the irrigation season, and 39% when to end the irrigation season.

Research has shown that scheduling irrigation based on ET can improve plant health and yields, translating to more crop per drop. Previous UC ANR research has demonstrated that California growers save approximately $64.7 million per year by using CIMIS weather station data. In this way, UC ANR contributes to improved water use efficiency, demonstrating UC ANR's commitment to the public value of protecting California's natural resources.