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LinkedInPosts Tagged: Tapan Pathak
Climate change may reduce frost damage to orchard crops
CalAgroClimate web tools help farmers prepare for frost events
A cold snap damaged almond blossoms across the Central Valley, resulting in more than $44 million in crop insurance claimsin late February 2018. A multi-day frost event wiped out roughly 75% of California's citrus crop and severely damaged avocados in January 2007. Frost can damage crops, impact growers' bottom lines and drive up food prices for consumers. With advance notice, farmers may be able to use heaters, wind machines, irrigation and other tactics to lessen some of the impacts of cold weather, such as damaging near-ripe citrus fruit or killing the bloom in almonds.
CalAgroClimate is a new farmer-focused website that can help growers anticipate weather-related risks and make plans for taking defensive action. Growers and crop consultants can use CalAgroClimate's crop and location-specific tools and resources to help prepare for upcoming frost events. The website's tools can also support on-farm decisions for managing heat, crop development and pests.
Future holds less frost
The risk of frost damage to crops and the need to prepare for that risk is top-of-mind for many farmers today, but will it always be so? To examine what climate change might mean for future frost risk, researchers at UC Davis, UC ANR and the USDA California Climate Hub conducted a study examining the incidence of temperatures below multiple “frost thresholds” during the months of critical development phases for three frost-sensitive California crops: almonds, avocados and navel oranges.
The researchers found that even during the coldest winters and springs, the incidence of frost exposure declined under projected mid-21st century climate conditions by more than 50% for almonds and oranges, and by more than 75% for avocados. While farmers in 2050 will not find frost risk to completely be a worry of climates past, they will not have to contend with the same frost concerns that farmers face today.
Few aspects of climate change are considered “positives,” and although the warming winters and springs that result in reduced frost temperatures could also come with increased pest pressure, reduced chill accumulation and other challenges, the reduction in frost exposure is a silver lining.
However, until this frost-free future arrives, growers still need to be prepared to protect their orchards from frost. To assess frost risk for the next seven days for your location, check out the new interactive Frost Advisory Tool at CalAgroClimate.org.
New interactive web tools help growers cope with climate change
UCCE, USDA California Climate Hub launch CalAgroClimate decision-support tool
Climate and weather variability pose increasing risks to farmers. As world leaders gather in Egypt at COP27 to address the climate crisis, University of California Cooperative Extension and the USDA California Climate Hub are launching new web-based tools to provide farmers with locally relevant and crop-specific information to make production decisions that reduce risk.
“Integrating historical weather data and forecast information with meaningful agricultural decision support information holds the potential to reduce a crop's vulnerability to such risks,” said Tapan Pathak, UC Cooperative Extension climate adaptation specialist at UC Merced.
Pathak is collaborating on building the decision support tool with partners from the U.S. Department of Agriculture, California Climate Hub, UC Cooperative Extension and UC Agriculture and Natural Resources' Informatics and Geographic Information Systems or IGIS.
“CalAgroClimate has been designed to support climate-enabled decision making for those working in the California specialty crop industry,” said Steven Ostoja, Director USDA California Climate Hub. “The USDA California Climate Hub is a proud collaborator on this important initiative to ensure the state's agricultural industry can continue to thrive in a future of climate change.”
Shane Feirer and Robert Johnson of UC ANR IGIS designed the interactive tools on the website and Lauren Parker of the USDA California Climate Hub contributed to content organization.An advisory panel composed of colleagues from UCCE and the Natural Resources Conservation Service ensure CalAgroClimate tools are relevant to stakeholder needs.
“CalAgroClimate is an amazing new tool that puts comprehensive past and forecast weather data at any grower's disposal,” said Mark Battany, UC Cooperative Extension water management and biometeorology advisor for San Luis Obispo and Santa Barbara counties.
“California's high-value crops are subject to a myriad of weather-related risk factors; this tool will allow growers to better address both near-term and long-term risks, and in the end grow more profitably, said Battany, who is a member of the CalAgroClimate advisory panel.
Growers and crop consultants can use CalAgroClimate's crop and location-specific tools and resources to help make on-farm decisions, such as preparing for frost or untimely rain and taking advantage of expected favorable conditions.
CalAgroClimate currently includes heat advisory, frost advisory, crop phenology and pest advisory tools.
Heat advisory tool: Extreme heat poses a danger for people, animals and crops. With this tool, users can select location and temperature threshold (e.g. 90 F, 95 F 100 F) based on their crop-specific heat tolerance level and the tool will provide a customized map of heat risk for next seven days for that location, including the number of consecutive days with temperature above that threshold. Users can also assess overall heat risks across the state for a selected temperature threshold as well. Having an early warning about hot temperatures, growers can take steps to reduce risks associated with extreme heat such as providing shade, changing farm workers' schedules and applying additional irrigation.
Frost advisory tool: Frost risk is a very serious issue for many specialty crops across California. Similar to the heat advisory tool, this tool provides a customized map of frost advisory for next seven days for a user's location, and forecast of consecutive days with temperature falling below the selected temperature thresholds (e.g. 35 F, 32 F, 28 F). Similar to the heat advisory, early warning about cold temperatures can provide growers some time to protect their crops from frost damage.
Crop phenology tool: The scientists have developed a-crop specific and location-specific crop phenology tool to help users keep track of growing degree days accumulations and estimate critical growth stages. CalAgroClimate uses a high-resolution PRISM dataset to provide near real-time crop phenology information to users. This tool will inform growers about how their crop development compares to previous years, which can be helpful in planning activities specific to critical growth stages.
Pest advisory tool: Similar to crops, development of certain pests and diseases is controlled by temperature and heat unit accumulations. With the pest advisory tool, growers can keep track of estimated pest generations during the growing season to make pest management decisions.
“We are launching the website with this initial set of tools while working on adding more crop-specific information and several new tools in the near future, ” Pathak said. “We look forward to getting feedback from growers who use CalAgroClimate to make it even more useful.”
UC ANR scientists receive $1.5M NIFA grant for climate-smart agriculture
To help California farmers and ranchers adjust to uncertain weather and climate events, the USDA National Institute for Food and Agriculture has awarded $1.5 million to a team of scientists led by UC Agriculture and Natural Resources. The project is one of six projects funded by USDA NIFA's $9 million investment to expand adoption of climate-smart practices.
“The Cooperative Extension system and the USDA Climate Hubs have unmatched capacity to reach agricultural, Tribal and underserved communities, as well as educators and students, and our nation's farmers directly,” said Agriculture Secretary Tom Vilsack in a statement announcing the grant recipients. “This partnership will strengthen climate research efforts and accelerate the development, adoption and application of science-based, climate-smart practices that benefit everyone.”
California has the largest and the most diverse agricultural economy in the nation, with revenue exceeding $50 billion, which is larger than the revenues of the other 10 Western states combined. Despite its size, the state is highly vulnerable to climate change.
“California farmers and ranchers need locally relevant climate information and adaptation resources,” said Tapan Pathak, UC Cooperative Extension specialist based at UC Merced and principal investigator for the grant. “Similarly, technical service providers are often ill-equipped to assist farmers and ranchers when asked questions about climate change, weather variability and local implications to implement those decisions.”
To train the next generation of workers to be climate-ready, colleges expose students to climate science and agricultural science separately, but often lack opportunities for the students to learn about the nexus of climate and agriculture.
Pathak plans to provide classes – along with opportunities for practical learning experiences – to farmers, ranchers, agricultural service providers and students.
“An overarching goal of this project is to develop robust multifaceted pathways to climate-smart agriculture by integrating Extension and participatory education program development and delivery to enhance agricultural resilience to climate change,” he said.
“To tackle this ambitious goal, we have a large team of multidisciplinary leading scientists and experts from local, state and federal agencies, the California Climate Hub and the University of California ready to work with diverse stakeholder groups.”
UC Cooperative Extension specialists Leslie Roche, Vikram Koundinya and Daniele Zaccaria at UC Davis; Mark Cooper, UC Davis professor; and Steven Ostoja of the USDA California Climate Hub, are co-principal investigators with Pathak.
They will begin with a needs assessment for all of their stakeholders, including socially disadvantaged farmers and ranchers. Through three components, the project team will work to understand growers' perception of climate change-related threats, build capacity for technical assistance providers to advance climate-smart agriculture research and delivery of science-based information, and educate community college and undergraduate university students.
Engaging with farmers and ranchers
With the help of community partners including the Community Alliance of Family Farmers and the California Association of Resource Conservation Districts, the team will reach out to socially disadvantaged and limited-resource producers, including beginning and first-generation farmers and ranchers to attend regional workshops, led by instructors who are fluent in Spanish and Hmong.
Workshop content will address a broad range of topics including climate change trends and local impacts, drought planning strategies, optimization of agricultural productivity with limited resources and farm and ranch economic sustainability.
“California has so much diversity in terms of scale, crops, geography, micro-climates, market conditions and natural resource considerations that a one-size-fits-all approach will not work,” wrote Renata Brillinger, CalCAN executive director, in her letter supporting the project. “We support your plans to address the needs of producers though region-specific workshops.”
Five county-based UC Cooperative Extension academics will serve as regional leads for the farming workshops across broad geographic regions:
- Andre Biscaro, UCCE irrigation and water resources advisor serving Ventura County
- Ruth Dahlquist-Willard, UCCE small farms advisor for Fresno and Tulare counties
- Surendra Dara, UCCE entomology and biologicals advisor serving San Luis Obispo and Ventura counties
- Jairo Diaz, director of the UC Desert Research and Extension Center in Southern California
- Jhalendra Rijal, UCCE integrated pest management advisor serving San Joaquin and Merced counties
Workshops for ranchers and rangeland managers will be coordinated by UCCE rangeland and livestock advisors in their respective regions:
- Dan Macon, UCCE livestock and natural resources advisor for Plumas, Nevada, Sutter and Yuba counties, will organize workshops for the Sierra Nevada mountains and foothill region
- Grace Woodmansee, UCCE livestock and natural resources advisor for Siskiyou County, will organize workshops in Northern California
- Rebecca Ozeran, UCCE livestock and natural resources advisor for Fresno and Madera counties, will organize workshops in Central California
- Devii Rao, UCCE livestock and natural resources advisor for Monterey, San Benito and Santa Cruz counties, will organize workshops in the coastal region
- Brooke Latack, UCCE livestock advisor for Imperial, Riverside and San Bernardino counties, will organize workshops in Southern California
Training technical service providers
The team will offer climate-smart agriculture trainings for technical service providers on how to prepare for key stressors in California agriculture such as floods, droughts, wildfires and heatwaves; effective climate communications; invasive pests and disease management under future climate; and weather and climate resources and decision support tools for managing risks.
One of the aims of this component is to encourage more coordinated efforts among different agencies to deliver climate change resources to their respective stakeholders, Pathak said.
California Cattlemen's Association has expressed its support for the project.
“Given ranchers' strong relationships with and reliance upon technical services providers – particularly those housed within the USDA and University of California – CCA also sees great value in the project's goal of building capacity within those organizations to assist ranchers in addressing the challenges of climate change,” wrote Kirk Wilbur, CCA vice president of government affairs.
Nurturing future generations
For college students, there will be the UC Merced Summer Institute on Climate and Agriculture certificate course organized by Karina Diaz Rios, UC Cooperative Extension specialist based at UC Merced; the UC Davis credit-based course “Science and Society: Climate Change and Agriculture;”and a certificate course for community college students, which will be overseen by the Bay Area Community College Consortium of 28 colleges.
“We will join you in this exciting work and shared vision towards inclusive education in climate resilient agriculture,” wrote Nancy Gutierrez, statewide director of the Agriculture, Water, Environmental Tech sector of the California Community College System.
Students from the three courses will be selected for paid summer internships to engage in Cooperative Extension projects.
“Through climate-smart agriculture education, the workforce will be prepared to advance climate science and research efforts for future generations,” Pathak said.
A hike in navel orangeworm pressure expected later this century due to climate change
Outsized wildfires, rising sea levels and disappearing glaciers are dramatic signs of climate change, but not the only ones. New UC Agriculture and Natural Resources research provides forewarning of a change that will be economically and environmentally costly to California – a fifth generation of navel orangeworm, the most destructive pest of almonds, walnuts and pistachios.
Navel orangeworm (NOW) will be more problematic in the future because of warming temperatures, UC Cooperative Extension scientists report in Science of the Total Environment.
Like most insects,NOW's development rate, physiology, behavior and reproduction are highly dependent on the ambient temperature. When the weather warms in the spring, NOW moths emerge from the nuts left in the tree or on the ground during the winter. After mating, females then recycle those last year's nuts to lay eggs and complete one generation. Adults emerged from that first and subsequent generations then lay eggs on in-season hull-splitalmondnuts, where larvae feeding damages the crop. Typically the pests fly three to four times per year – with more flights in areas with warmer weather.
“Warmer temperatures can result in early activity of the pests in the spring and increased activity during the season,” said Tapan Pathak, the UC Cooperative Extension climate change specialist and the study's principle investigator.
The scientists looked at 10 climate models to determine what nut farmers can expect to face over the next 80 years and applied NOW developmental models to the changing climate. Daily maximum and minimum temperature data were obtained for 1950 to 2005, and future projections stretched to 2100.
“The fifth generation can happen in the next few decades,” said Jhalendra Rijal, UC integrated pest management advisor and co-author of the research. “The climate models suggest that spring will begin earlier. That causes insect activity to start earlier. With increased temperatures through the season, the number of days to complete a generation is less. At the end of 2050 or so, we'll see an extra generation.”
The study focused on 23 counties in the Central Valley, from Shasta County in the north to Kern County in the south, where 1.78 million bearing acres of nut crops are planted. About two-thirds of that acreage is planted to almonds, 20% in walnuts and 16% in pistachios. The tree nut crops were valued at more than $8 billion combined in 2018, according to the California Department of Food and Agriculture.
The completion of the NOW life cycle is faster in pistachio compared to almonds and walnuts, so the potential risk of crop damage and economic loss is higher in pistachio, according to the research report. There are only a few years historically in which the models detected the fifth generation of NOW in Kern County pistachios. The occurrence of the fifth generation in almonds and walnuts was historically nonexistent, but it starts appearing in three southern counties by 2040 and eleven counties by 2100.
“In order to alleviate some of the risks related to navel orangeworm damage to nut crops, it is important to implement integrated pest management practices,” Pathak said.
IPM preventative and control measures include sanitizing the orchard during the winter by removing all the nuts on the ground and in the trees, applying synthetic reproductive hormones to limit the pests' ability to find mates, encouraging natural enemies, judicious of least-toxic pesticides if necessary and harvesting the crop early to avoid a new generation of the pest.
“A better understanding of future navel orangeworm pressure on California's major nut crops can help facilitate and strategize integrated pest management practices in order to minimize production risks,” Pathak said.
The results of the research can also inform growers and pest control advisers about the potential increased threat from other pests as the climate changes.
Climate-change research provides tools for farmers to adapt
This is one of a series of stories featuring a sampling of UC ANR academics whose work exemplifies the public value UC ANR brings to California.
Farmers are already seeing the effects of warmer winter nights and hotter summer days on their crops. Climate change is gradual, but increasing overall temperatures affect many aspects of farming, including where and how crops are grown. Tapan Pathak, University of California Cooperative Extension specialist based at UC Merced, is doing applied research that farmers and ranchers can use to adapt to new conditions created by a variable and changing climate.
“You don't have to shift your practice tomorrow, but if you are thinking of making a 30-year investment, it's important to know what risks there are for planting different crops,” said Pathak, who is based in the Sierra Nevada Research Institute at UC Merced.
Pathak co-chairs the UC Cooperative Extension Climate Change Program Team, whose mission is to increase the capacity among UCCE academics to address climate change concerns with science-based information. Pathak also collaborates with extension professionals from across the western U.S. to do extension events related to climate change adaptation. He works closely with state and federal agencies statewide and growers to identify changes occurring as a result of climate change that affect agriculture. Pathak's research will inform growers' decisions, such as crop variety, planting and harvest dates, extreme heat and frost protection and pest management.
“We are seeing impacts of climate change, that's evident. We have some solutions that are available, but we also need to do more locally relevant crop specific research to make agriculture resilient to climate risks,” Pathak said.
The UCCE scientist was the lead author on an important paper that synthesized the impacts of climate change on California agriculture and offers directions for future research and implementation. The authors concluded that almost all of California's crops, collectively valued at more than $50 billion a year, will be endangered to some degree by rising temperatures and variable weather patterns. The study “Climate Change Trends and Impacts on California Agriculture” was published in Agronomy in 2018.
“I think there's a lot of solutions available and there is also a clear need for adaptation research that include growers' perspectives,” said Pathak, who received a Climate Leadership Award for research from the California Climate & Agriculture Network.
Pathak is also collaborating very closely with UC Davis-based UCCE specialist Daniele Zaccaria, who is leading an international project on evaluating bioclimatic indices and developing the index that is more relevant to irrigated agriculture, which includes scientists from the U.S., Italy, Brazil and Chile.
“A bioclimatic index specific to irrigated agriculture can provide more accurate and valuable agricultural drought information that could be helpful for water resources planning and management decisions,” Pathak said.
Cal AgroClimate
Pathak is developing a web-based decision support system called Cal AgroClimate to help growers make decisions, in partnership with the USDA California Climate Hub director Steven Ostoja. It is being built on the same platform as AgroClimate, which is popular with growers in the Southeast.
Cal AgroClimate translates historical climate data and future projections into a useful decision support system for growers. For example, growers can get extreme heat and frost advisories for the next 10 to 14 days in their region and relevant resources to mitigate risks for their selected crop. It is in the early phase of development and will include a suite of tools based on the needs and priorities identified by UCCE colleagues, growers and the agricultural community in general.
In addition to his work on Cal AgroClimate, Pathak has been conducting research on specific crops.
Tomatoes
In a study looking at processing tomato production in the Central Valley, Pathak and UCCE advisor Scott Stoddard found that changing temperatures will likely change the tomato growing season. The scientists looked at processing tomato data starting from 1950 and projections for 2030-2040 to see how the time to maturity is changing.
“In general, the time from emergence to maturity, the timeframe for processing tomatoes in that region is going to shrink by two to three weeks,” said Pathak. “A lot of processors have their timeline for when they need the tomatoes for processing and so when you have this shift in the phenology, that alters the timeframe for when they mature and are ready for the processors. So, there's a whole shift in the management that growers might have to think about in the future.”
Almonds
To identify the climate information almond growers need to take adaptation action, UC Berkeley postdoctoral researcher Kripa Jagannathan, former UCCE advisor David Doll and Pathak interviewed almond growers in the Central Valley. During their conversations with farmers, the researchers clarified that long-term climate projections are not seasonal forecasts or weather forecasts for the next 20 to 30 years. The projections provide information on trends or potential of shifts from historical conditions for making long-term planning decisions.
Pest control is one area where growers will need to make changes. Research by UCCE advisor Jhalendra Rijal and Pathak shows the almond pest navel orangeworm is already extending its life to a fifth generation during a season.
Strawberries
For strawberries, Pathak, UCCE entomology and biologicals advisor Surendra Dara and postdoctoral researcher Mahesh Maskey have developed a model to forecast weekly crop yields based on weather data. “The model was pretty accurate for the Santa Maria region,” Pathak said. “A crop-specific model can be used for labor management not just crop management.”
Because California produces more than 400 agricultural products, adapting to climate change will be more complex than in other states.
