Posts Tagged: strawberries
The strawberry industry ended a long good-bye to methyl bromide in 2016. The fumigant had been used for decades to kill a wide range of soil-borne pathogens, weed seeds and insects, permitting the California strawberry industry to flourish. Scientists determined it was an ozone-depleting chemical in 1991, but its phase-out was delayed for years because of lack of equally effective alternatives.
Strawberry farmers now use a combination of approaches, including fumigation with other chemicals, soil oxygen deprivation, biofumigants, and beneficial microbes that improve soil biology. A greater arsenal is needed.
“Growers have three or four chemical alternatives, some are used alone and others in various combinations,” said UC Cooperative Extension advisor Surendra Dara. “Now, certain minerals, beneficial microbes and biostimulants are becoming available to enhance plant's natural defenses and improve strawberry growth, yield and health in an era without methyl bromide.”
Dara conducts research and advises strawberry and vegetable growers in the Central Coast counties of San Luis Obispo and Santa Barbara. Each year he holds a field day that attracts nearly 200 farmers, pest control advisers and representatives of allied industries to Manzanita Berry Farms outside Santa Maria. The agenda for the May 9 event included preliminary results of trials studying a number of commercially available and soon-to-be available biological and synthetic amendments to improve strawberry plant health, berry quality and yield.
Dara was ill, so Manzanita Farm owner Dave Peck reviewed the handout prepared by Dara for the field day. Manzanita Farms is one of two sites where Dara is testing products in replicated plots. Other studies are conducted in strawberries grown at the Shafter Research Station, a privately managed agricultural research facility in Kern County.
Several products resulted in increased marketable yield of strawberries during the February 2018 to April 2018 study period. See the preliminary results here. Data collection will continue through the end of the strawberry season.
“A challenge was that many people did not have complete faith in biologicals a few years ago,” Dara said. “By conducting multiple studies year after year, we are able to generate critical data that is useful for the farmers as well as companies that produce biologicals. By using different application strategies and rates, and a combination of techniques - as appropriate for their situations - farmers can engage in sustainable strawberry production.”
A new costs and returns study for strawberries has been released by UC Agricultural Issues Center and UC Cooperative Extension to help growers make farm management decisions. The study presents sample costs to produce and harvest strawberries for fresh market in Santa Cruz andMonterey counties. The cost study is in Spanish at http://ucanr.edu/files/269041.pdf.
“The study also has an expanded section on labor, which includes information on California's new minimum wage and overtime laws,” said Laura Tourte, UC Cooperative Extension farm management advisor in Santa Cruz, Monterey and San Benito counties, who co-authored the study.
The analysis is based upon a hypothetical well-managed farming operation using practices common to the Central Coast region. The costs, materials, and practices shown in this study will not apply to all farms. Growers, UC ANR Cooperative Extension farm advisors and other agricultural associates provided input and reviewed the methods and findings of the study.
The study assumes a fairly flat farm operation of 50 contiguous acres of rented land. Strawberries are planted on 45 acres. From April through early October, the crop is harvested by hand and packed into trays containing eight 1-pound clamshells. Harvest peaks in June and July.
The authors describe the assumptions used to identify current costs for production material inputs, cash and non-cash overhead. Ranging analysis tables show net profits over a range of prices and yields. Other tables show the monthly cash costs, the costs and returns per acre, hourly equipment costs, and the whole farm annual equipment, investment and business overhead costs.
Free copies of “Sample Costs to Produce and Harvest Strawberries in the Central Coast Region-2016” and other sample cost-of-production studies for many other commodities are available. To download the cost studies, visit the UC Davis Department of Agricultural and Resource Economics website at https://coststudies.ucdavis.edu
The cost and returns studies program is funded by the UC Agricultural Issues Center and UC Cooperative Extension – both of which are part of the UC Division of Agriculture and Natural Resources – and the UC Davis Department of Agricultural and Resource Economics.
For additional information or an explanation of the calculations used in the study, contact the UC Agricultural Issues Center at (530) 752-4651, Mark Bolda, UC Cooperative Extension advisor in Santa Cruz County, at (831) 763-8025 or Tourte at (831) 763-8005.
UPDATED Sept. 13, 2017, to add link to Spanish version of cost study.
2016 is the final year for the soil fumigant to be used in California crop fields.
For many years, California growers relied on methyl bromide to kill a wide range of soil-borne pests, from fungi to insects to weeds, before planting crops. 2016 marks the last year in which the highly effective soil fumigant will be available.
The University of California's peer-reviewed journal California Agriculture examines the impact of the methyl bromide phaseout on strawberries, California's third most valuable crop, behind only almonds and grapes, with annual farmgate sales of $2.5 billion.
First identified as an ozone-depleting compound in 1991, methyl bromide was scheduled for phaseout in the United States by 2005 under the Montreal Protocol, an international agreement to protect the stratospheric ozone layer.
While methyl bromide was used for many crops, California strawberry growers found it irreplaceable, which helped the industry win exemptions that have allowed a significant, though declining, quantity of the chemical to be used through 2016. Despite years of research into alternatives, no equally effective replacement has emerged.
Berry industry grows dramatically
In the first research article, UC Cooperative Extension advisors Laura Tourte and Mark Bolda and Karen Klonsky, emeritus UC Cooperative Extension economics specialist, review economic data on the berry sector — blackberries and raspberries as well as strawberries — in Santa Cruz and Monterey counties. They look ahead to factors, including water, consumer demands, labor, invasive pests, and the full phaseout of methyl bromide, that are likely to shape future growth.
Methyl iodide controversy
In a paper chronicling events leading up to the 2012 withdrawal of methyl iodide, once promoted as a viable methyl bromide substitute, Julie Guthman, UC Santa Cruz professor in the Department of Social Sciences, reports survey findings that point to a variety of reasons why strawberry growers did not move quickly to adopt the chemical after it was approved by state regulators. Concerns about public opposition topped the list, followed by a variety of other factors, including concern about methyl iodide's toxicity, and a lack of strong incentive to switch to the new chemical because of the availability of other fumigants, including methyl bromide.
Managing soilborne pests
Three articles look at new approaches to managing soilborne pests without methyl bromide.
“It now seems likely that no single measure will suffice to meet the challenge of soilborne pathogens,” write Margaret Lloyd, UC Cooperative Extension advisor, and Tom Gordon, UC Davis professor in the Department of Plant Pathology, in this issue's Outlook. “Rather, a multi-faceted approach will be required, one that integrates advances in disease resistance through breeding with closer attention to the factors that influence the survival, activity and spread of pathogen populations in soil.” They make the case for using a suite of strategies to manage soilborne pathogens — including collective action among growers to help limit the spread of pathogens between fields.
A news item on research at the UC ANR Hansen Agricultural Research and Extension Center covers ongoing research on anaerobic soil disinfestation, a chemical-free technique that is being used in a growing number of commercial fields. Project scientist Amanda Hodson and UC Davis professor Edwin Lewis, both in the Department of Entomology and Nematology, review a variety of approaches to managing for soil health — in strawberries and other crops — as a pest suppression strategy.
Other soil fumigants
Fumigants other than methyl bromide, such as chloropicrin, remain widely used in California strawberry production. Rachael Goodhue, UC Davis professor in the Department of Agricultural and Resource Economics at UC Davis, examines how increasingly stringent buffer zone requirements for chloropicrin application have an uneven impact on growers, depending on their proximity to developed land. In another article, a group of UC Cooperative Extension and U.S. Department of Agriculture scientists report on the effectiveness of several fumigants at dosages lower than the maximum label rate.
Food safety and nutrient management on the farm
The issue also includes two research papers focused on general production practices for crops. One report discusses on-farm food safety practices based on a survey of produce growers. The researchers found that practices such as exclusion fencing and vegetation clearing, which may negatively impact wildlife, remain widespread despite a lack of clear evidence that they enhance food safety. Finally, Daniel Geisseler, UC Cooperative Extension specialist in the Department of Land, Air and Water Resources at UC Davis, and Gene Miyao, UC Cooperative Extension advisor, review the use of soil testing to guide the management of soil phosphorus and potassium in California cropping systems.
To read California Agriculture, a peer-reviewed journal of research in agricultural, human and natural resources published by UC Agriculture and Natural Resources, visit http://calag.ucanr.edu. For a free subscription, sign up on the website or write to email@example.com.
View this story in Spanish:
¿Qué hará la industria de la fresa sin el bromuro de metilo? http://ucanr.edu/sites/Spanish/noticias/?uid=6887&ds=199. Video on UCANR Spanish YouTube: California Agriculture: el bromuro de metilo en cultivos de fresa https://www.youtube.com/watch?v=5D4FwLqjaLk.
Each fall, strawberry farmers put young strawberry transplants in the ground through holes cut in plastic mulch. Beneath the mulch are drip lines that will serve to irrigate the plants as they reach maturity. But early on, farmers typically install solid-set aluminum sprinklers in the furrows to get the plants started and leach salts below the strawberry plants' root zone.
“In some areas, overhead aluminum sprinkler irrigation is considered very important to prevent dry conditions which could result from Santa Ana winds,” Dara said. “However, the aluminum sprinkler irrigation requires a significant amount of water and can be inefficient.”
During the 2014-15 strawberry season, Dara worked with farmer Dave Peck of Manzanita Berry Farms in Santa Maria to compare micro-sprinklers with the more commonly used aluminum sprinkler systems. The experimental plots were planted in early November and carefully monitored throughout the growing and harvest season, which ended in June. The two types of sprinkler irrigation were used for about one month, then the grower switched to using exclusively the drip irrigation installed underneath the mulch.
Dara found that micro-sprinkler irrigation cut water use by 32 percent compared to the area where aluminum sprinklers were used, and resulted in no significant difference in total marketable yield.
Strawberry plant vigor was measured each month during the study. At first, the plants in the micro-sprinkler treatment area were significantly smaller, but they caught up with the rest by March. Sprinkler irrigation is also thought to help control twospotted spider mites and predatory mites. In Dara's experiment, however, the pests' sparse numbers did not allow for useful data to be collected.
The sprinkler comparison did offer insight on powdery mildew, a serious disease problem, particularly for organic strawberry growers. Sampling for powdery mildew in the plots showed that its severity was significantly less in the micro-sprinkler treatment. Another common strawberry production problem, botrytis fruit rot, was also eased with the micro-sprinkler treatment.
RDO Water and Netafim were partial funders of the project.
The full research report is posted on Dara's eNewsletter.
An initiative to improve California water quality, quantity and security is part of the UC Division of Agriculture and Natural Resources Strategic Vision 2025.
Author: Jeannette Warnert
Each analysis is based upon a hypothetical farm operation using practices common to the region. Input and reviews were provided by growers, UC Cooperative Extension farm advisors and other agricultural associates. The authors describe the assumptions used to identify current costs for individual crops, material inputs and cash and non-cash overhead. A ranging analysis table shows profits over a range of prices and yields. Other tables show the monthly cash costs, the costs and returns per acre, hourly equipment costs, and the whole farm annual equipment, investment and business overhead costs.
The studies for establishing orchards to produce lemons and oranges estimate costs for growing in Kern and Tulare counties. Revenue for the citrus is based on estimated sales to the fresh packaging market.
The study for organic strawberries takes into consideration growing conditions on the Central Coast of California and complying with the National Organic Program. In particular, it focuses on growing organic strawberries in Santa Cruz and San Benito counties for the fresh packaging market.
The study for producing paddy rice in the Sacramento Valley focuses on the costs of growing medium-grain rice, under a rice-only rotation in Butte, Colusa, Glenn and Yolo counties.
The field corn study focuses on the production costs of a full-season corn crop in the Sacramento Valley and the northern San Joaquin Valley. This region would include Colusa, Glenn, Sacramento, Sutter and Yolo counties. The study based costs on a farm using furrow irrigation and Roundup Ready-GMO seed.
The study on silage corn, double cropped under conservation tillage methods, focuses on production costs of corn silage using minimum tillage operations in the northern San Joaquin Valley. The corn is planted in the spring after a winter forage crop is harvested. The study is based its costs on a farm using border/flood irrigation and Roundup Ready-GMO seed.
- “Sample Costs to Establish an Orchard and Produce Lemons in the San Joaquin Valley-South-2015”
- “Sample Costs to Establish an Orchard and Produce Oranges in the San Joaquin Valley-South-2015”
- “Sample Costs to Produce Organic Strawberries in the Central Coast Region-2014”
- “Sample Costs to Produce Rice in the Sacramento Valley-2015”
- “Sample Costs to Produce Field Corn in the Sacramento Valley and Northern San Joaquin Valley-2015”
- “Sample Costs to Produce Silage Corn-Conservation Tillage Practices in the Northern San Joaquin Valley-2015”
These cost-of-production studies can be downloaded for free from the UC Davis Department of Agriculture and Resource Economics website http://coststudies.ucdavis.edu. Sample costs are also available for many other commodities. Many earlier production cost studies for agricultural commodities are also available at http://coststudies.ucdavis.edu/archived.php.
For additional information or an explanation of the calculations used in the studies, contact Don Stewart, staff research associate in the Department of Agriculture and Resource Economics at UC Davis at (530) 752-4651, firstname.lastname@example.org.