The Annual UC Davis Horse Day is right around the corner!
Be sure to register before October 7th to receive the discounted rate:
If you have a group of 10 or more, please email Kathryn at firstname.lastname@example.org for further information.
First report of entomopathogenic fungi, Beauveria bassiana, Isaria fumosorosea, and Metarhizium brunneum promoting the growth and health of cabbage plants growing under water stress
Entomopathogenic fungi such as Beauveria bassiana (commercial formulations, BotaniGard and Mycotrol), Isaria fumosorosea (NoFly and Pfr-97), and Metarhizium brunneum (Met52) are primarily used for controlling arthropod pests. Research in the recent years evaluated their endophytic (colonizing plant tissues) and mycorrhiza-like (associated with roots) relationship with plants and potential benefits in improving plant growth and health. Studies conducted in California showed that B. bassiana endophytically colonized strawberry plants and persisted for up to 9 weeks in various plant tissues (Dara and Dara, 2015a); promoted strawberry plant growth (Dara, 2013); and negatively impacted green peach aphids through endophytic action (Dara, 2016). Soil application of M. brunneum appeared to have a positive impact on strawberry plants in withstanding twospotted spider mite infestations (Dara and Dara, 2015b). Similarly, M. anisopliae reduced the salt stress in soybean (Khan et al., 2012) and M. robertsii enhanced root growth and nutrient absorption in switch grass and haricot beans (Behie et al., 2012; Sasan and Bidochka, 2012). In another study, nitrogen obtained from an insect host through infection (entomopathogenic relationship) was transferred by B. bassiana and Metarrhizum spp. to a plant through an endophytic or mycorrhiza-like relationship.
Several beneficial microbe-based products are commercially available to promote plant growth under normal or stressful conditions and to boost plant defenses against pests and diseases. However, several mycorrhizae do not form a symbiotic relationship with several cruciferous hosts and mycorrhizae-based products are typically not used in cole crops. If entomopathogenic fungi, which have a great promise for pest management in IPM programs, could also promote plant growth and health through an endophytic or mycorrhiza-like relationship, they will maximize their potential for multipurpose use in crop protection and production and potentially reduce the cost of applying multiple products for multiple purposes.
A study was conducted in 2014 to evaluate the impact of B. bassiana, I. fumosorosea, and M. brunneum on potted cabbage plants growing in artificial light with reduced water.
About 3-week old cabbage (var. Supreme Vantage) transplants (obtained from Plantel Nurseries, Santa Maria, CA) were planted in Miracle-Gro® Moisture Control Potting Mix (NPKFe 0.21-0.07-0.14-0.10) in 650 ml containers. Treatments included BotaniGard ES (1 ml), Met 52 EC (1 ml), NoFly WP (2.5 mg), SumaGrow (2.3 ml), CropSignal (1 ml), Mykos Liquid (0.03 ml), and H2H (10 ml) in 100 ml of water which were added to each container in respective treatments. Miracle-Gro alone was used as the control. Each treatment had 10 plants which were grown under artificial lighting (75 W plant light in each corner). To each container, 50 ml of water was added again on 42, 50, 64, and 81 days after planting. Temperatures during the study were 56o (minimum), 71o (average), and 88o F (maximum).
Treatments used in the study
Data were collected as follows:
- Plant health rating was recorded at 40 and 70 days after planting on a scale of 0 to 5 where 0=dead, 1=weak, 2=moderate-low, 3=moderate-high, 4=good, and 5=very good.
- Plant survival was recorded at 40, 70, and 90 days after planting.
- Shoot and root length were recorded at 90 days after planting by unearthing each plant from the containers.
- Shoot-to-root ratio was calculated.
- Plants from each treatment were placed in paper bags and dried in an oven at 98oF for 8 days. Dry weight (biomass) of the plants was measured before sending them to an analytical lab for nutrient analysis.
Data were subjected to analysis of variance and significant means were separated using Least Significant Difference test. Since some treatments had fewer plants by the end of the study, biomass measurement and nutrient analysis were done together for all the remaining plants and those two parameters were not subjected to statistical analysis.
Plant survival: Beauveria bassiana was the only treatment where all the plants survived for 90 days of the observation period. There was a 10 to 80% mortality in other treatments during the observation period. Highest plant mortality was seen in SumaGrow and H2H treatments (P = 0.001 at 40 days after planting and
Plant health: Plants treated with B. bassiana were significantly and uniformly healthier (P < 0.00001) than the rest of the treatments on both observation dates with a ‘very good' rating. Health of the plants growing in Miracle-Gro with no supplements also had a ‘good' rating and was better than the health of plants in most of the remaining treatments. Plants treated with SumaGrow and H2H had poor health with a ‘weak' rating.
Shoot and root length: Length of the shoots was significantly higher (P < 0.00001) for plants treated with B. bassiana (29 cm) and M. brunneum (27.6 cm) compared to the rest of the treatments. Plants treated with Miracle-Gro alone had a mean shoot length of 22.9 cm, but the remaining treatments had significantly shorter shoots that varied from 13-18 cm. Plants growing in Miracle-Gro alone and those supplemented with Crop Signal had significantly longer (P < 0.00001) roots.
Shoot-to-root ratio: Shoot-to-root ratio, which indicates the shoot growth in relation to the root growth, was significantly higher (P < 0.00001) for plants that were treated with B. bassiana and M. brunneum followed by those treated with I. fumosorosea and others.
Biomass and nutrient absorption: Plants treated with B. bassiana had relatively higher biomass. When the plant weight as a result of accumulated nutrients was calculated by dividing the weight with respective nutrient content, B. bassiana appeared to have relatively higher output for nitrogen, phosphorus, and potassium based on numerical values. Such an effect for iron was seen in all, except H2H, treatments compared to Miracle-Gro alone. However, these values are only indicative as they were not subjected to statistical analysis.
This is the first report of the direct impact of entomopathogenic fungi on cabbage plant growth. Beauveria bassiana and to some extent M. brunneum had a positive impact on plant growth and health even under reduced water conditions. If they could be used to promote plant growth, improve water and nutrient absorption, withstand saline or drought conditions, increase yields in addition to their typical use as biopesticides, then they can play a critical role as holistic tools in sustainable agriculture.
Acknowledgements: Thanks to Plantel Nurseries Inc. for donating cabbage transplants, and Advanced Soil Technologies, Bioworks Inc, California Safe Soil, Novozymes Biologicals, Reforestation Technologies International, and SumaGrow USA for various treatment materials used in this study.
Behie, S.W., P.M. Zelisko, and M.J. Bidochka. 2012. Endophytic insect-parasitic fungi translocate nitrogen directly from insects to plants. Science 336: 1576-1577.
Dara, S. K. 2013. Entomopathogenic fungus, Beauveria bassiana promotes strawberry plant growth and health. UCCE eNewsletter Strawberries and Vegetables, 30 September, 2013. (http://ucanr.edu/blogs/blogcore/postdetail.cfm?postnum=11624)
Dara, S. K. and S. R. Dara. 2015a. Entomopathogenic fungus, Beauveria bassiana endophytically colonizes strawberry plants. UCCE eNewsletter Strawberries and Vegetables, 17 February, 2015. (http://ucanr.edu/blogs/blogcore/postdetail.cfm?postnum=16811)
Dara, S. K. and S. R. Dara. 2015b. Soil application of the entomopathogenic fungus, Metarhizium brunneum protects strawberry plants from spider mite damage. UCCE eNewsletter Strawberries and Vegetables, 18 February, 2015. (http://ucanr.edu/blogs/blogcore/postdetail.cfm?postnum=16821)
Dara, S. K. 2016. Endophytic Beauveria bassiana negatively impacts green peach aphids on strawberries. UCCE eNewsletter Strawberries and Vegetables, 2 August, 2016. (http://ucanr.edu/blogs/blogcore/postdetail.cfm?postnum=21711)
Sasan, R.K. and M.J. Bidochka. 2012. The insect-pathogenic fungus Metarhizium robertsii (Clavicipitaceae) is also an endophyte that stimulates plant root development. Amer. J. Bot. 99:101-107./h4>
Announcement reprinted from California Wool Growers' Association newsletter. I was part of the team and it reflects input from Mendocino and Lake County ranchers as well as the rest of the state.
California has experienced five large-scale, multiyear droughts since 1960; however, the current event is considered the state's most severe drought in at least 500 years. Each year of the current drought has presented different challenges; for example, much of California received no measurable precipitation December 2013 through late January 2014. In the following year, the Sierra Nevada snowpack was just 5% of normal. As California ranching is largely dependent on rain-fed systems, as opposed to groundwater or stored water, it is very vulnerable to drought. In fact, rangeland livestock ranchers were among the first affected by the abnormally warm, dry winters at the beginning of the current multiyear drought.
In this article, we highlight lessons learned so far from past droughts, as well as California's unprecedented and ongoing multiyear drought. We draw on ranchers' perspectives and experiences, including research results from a statewide mail survey of 507 ranchers and semistructured interviews of 102 ranchers, as well as our own experiences. The mail survey (the California Rangeland Decision-Making Survey) included questions on operator and operation demographics, goals and practices, information resources, and rancher perspectives. Semistructured interviews are part of a larger ongoing project (the California Ranch Stewardship Project) examining rangeland management for multiple ecosystem services.
The publication is available at the following link - http://www.sciencedirect.com/science/article/pii/S019005281630027X
Twospotted spider mite (TSSM) is a global pest infesting a wide variety of crops. TSSM adapts to new hosts very quickly compared to other arthropods and this ability is attributed to the groups or families of genes that detoxify poisonous plant compounds (Grbić et al., 2011). In just nine generations, TSSM was adapted to a resistant cucumber variety (Gould 1978) and this adaptation allowed them to use potato and tobacco as hosts (Gould, 1979) and imparted cross resistance to three organophosphate pesticides (Gould et al., 1982).
Genetic makeup of TSSM also helps to develop resistance to miticides and it has the highest incidence of resistance to pesticides among arthropods (Van Leeuwen et al., 2010; Grbić et al., 2011). Head and Savinelli (2008) reported that TSSM tops the list of arthropods with pesticide resistance by having resistance to 79 active ingredients in 325 cases based on the arthropod resistance database from Michigan State University by Whalon et al. (2006). However, in the current database, the number of resistance cases for TSSM went up to 498 (Table 1).
Multiple factors that contribute to the success of TSSM, rapid development of pesticide resistance, and the ability to feed on a large number of plant species include the following:
i) Short life cycle and high fecundity that lead to multiple generations in a short time.
ii) Haplo-diploid sex determination system, where males develop from unfertilized eggs and females from fertilized eggs. As a results unfavorable recessive alleles will be removed from mite populations.
iii) Spinning of a strong, but very thin webbing that provide protection against natural enemies
iv) Multiple families of detoxification genes that allow digestion, detoxification, and transportation of toxic metabolites.
v) Lateral transfer of genes from bacteria, fungi, and other organisms through lateral gene transfer which facilitated digestion and detoxification of xenobiotics.
vi) Large number (39) of multidrug resistance proteins compared to a smaller number (9-14) in vertebrates or invertebrates.
Since TSSM is a global pest on multiple hosts, the chances of exposure to pesticides is high, which creates a high selection pressure for resistance. Repeated use of effective pesticides renders them ineffective due to resistance development. Gould et al. (1991) reported slower adaptation of TSSM when a lower level of host plant resistance was combined with natural enemies rather than high host plant resistance alone. Monitoring resistance and adopting integrated pest management (IPM) practices is critical in managing TSSM.
General recommendations for managing TSSM:
- Regularly monitor several parts of the field for mite infestations and make appropriate treatment decision depending on the level and distribution of mite populations and environmental conditions.
- Consider an IPM approach by using biological control options (release of predatory mites), modifying cultural practices (avoiding water stress and excessive nitrogen fertilization), and applying botanical (rosemary oil or other similar products), microbial (BotaniGard, Pfr-97, Met 52, Grandevo, and Venerate), or chemical (Table 2) pesticides.
- Provide refuges that support susceptible mite populations to delay resistance development.
- When applying chemical miticides rotate those among different mode of action (MoA) groups. Use softer chemicals when predatory mites are used.
Periodically monitor miticide efficacy and signs of resistance development. If resistance is suspected, conduct a simple bioassay to confirm before field application of the miticide. Collect several leaves samples from different parts of the field with TSSM suspected to have resistance to a particular miticide. Prepare a small quantity of the spray liquid in a container following field application rates. Dip the leaves in the spray liquid and keep them in a covered container (not airtight) in a cool, dry place. Check 48 hours after the exposure to determine the efficacy of or resistance to the miticide based on TSSM mortality.
Bioassay to determine miticide resistance in twospotted spider mites.
Additional information on TSSM and its management in strawberries can be found at:
- Managing spider mites in California strawberries (http://ucanr.edu/blogs/blogcore/postdetail.cfm?postnum=13943)
- Efficacy of botanical, chemical, and microbial pesticides on twospotted spider mites and their impact on predatory mites (http://ucanr.edu/blogs/blogcore/postdetail.cfm?postnum=18553)
- Predatory mites for managing spider mites on strawberries (http://ucanr.edu/blogs/blogcore/postdetail.cfm?postnum=14065)
- Response of predatory mites to chemical, botanical, and microbial miticides in strawberries (http://ucanr.edu/blogs/blogcore/postdetail.cfm?postnum=14428)
- Spider mite damage causes unique foliar discoloration in Benicia variety (http://ucanr.edu/blogs/blogcore/postdetail.cfm?postnum=11600)
- Multiple handouts on spider mites in strawberries (http://ucanr.edu/meetinghandouts)
- UC IPM Pest Management Guidelines for spider mites in strawberry (http://ipm.ucanr.edu/PMG/r734400111.html)
Gould, F. 1978. Predicting the future rresistance of crop varieties to pest populations: a case study of mites and cucumbers. Environ. Entomol. 7: 622-626.
Gould, F. 1979. Rapid host range evolution in a population of the phytophagous mite Tetranychus urticae Koch. Evolution 33: 791-802.
Gould, F. Carroll, C. R., and Futuyma, D. J. 1982. Cross-resistance to pesticides and plant defenses: a study of the two-spotted spider mite. Entomol. Exp. Appl. 31:175-180.
Grbić, M., Van Leeuwen, T., Clark, R.M., Rombauts, S., Rouzé, P., Grbić, V., Osborne, E.J., Dermauw, W., Ngoc, P.C.T., Ortego, F. and Hernández-Crespo, P. 2011. The genome of Tetranychus urticae reveals herbivorous pest adaptations. Nature, 479: 487-492. DOI: 10.1038/nature10640
Head, G. and C. Savinelli. 2008. Adapting insect resistance management programs to local needs. In: Onstad, D. W. (Ed.) Insect Resistance Management: Biology, Economics, and Prediction, Academic Press, United Kingdom, pp. 89-106.
Van Leeuwen, T., Vontas, J., Tsagkarakou, A., Dermauw, W. and Tirry, L. 2010. Acaricide resistance mechanisms in the two-spotted spider mite Tetranychus urticae and other important Acari: a review. Insect Biochem. Mol. Biol. 40: 563–572.
Whalon, M. E., Mota-Sanchez, D., Hollingworth, R. M., and Duynslager, L. 2006. Michigan State University Arthropod Resistance Database. http://www.pesticideresistance.org/search.php
The following is a repost from ASAS Taking Stock.
By Jan Suszkiw, Agricultural Research Service, USDA
USDA's Agricultural Research Service (ARS) has launched a new smartphone application (“app”) that forecasts conditions triggering heat stress in cattle. The app is available at both Google Play and the App Store.
Compatible with Android and Apple mobile phone, the app issues forecasts one to seven days in advance of extreme heat conditions, along with recommended actions that can protect animals before and during a heat-stress event.
In some cattle, distress and discomfort from prolonged exposure to extreme heat cause diminished appetite, reduced growth or weight gain, greater susceptibility to disease and, in some cases, even death. Cattle housed in confined feedlot pens are especially vulnerable to heat-stress events, notes Tami Brown-Brandl, an ARS agricultural engineer at the Roman L. Hruska U.S. Meat Animal Research Center (USMARC) in Clay Center, Nebraska.
In addition to high temperatures, weather-related factors like humidity, wind speed, and solar radiation can contribute to heat stress, adds Brown-Brandl.
Until the early 1990s, the National Weather Service (NWS) issued livestock safety warnings that helped feedlot producers preempt losses or diminished productivity resulting from heat-stress events. Starting in the mid-2000s, USMARC researchers filled the void with a Web page, which is still available today, offering similar forecasts.
Recent increases in smartphone usage prompted ARS to design and launch a mobile-app that allows producers to access forecasts while they're in the field.
The resulting “Heat Stress” app, which was beta-tested last year, is based on several years of field research conducted by Brown-Brandl, fellow ag engineer Roger Eigenberg and others at USMARC—including Randy Bradley. Bradley, an information technology specialist, is responsible for a color-coded heat-index map of the entire continental United States.
In addition to feedlot producers, animal caretakers and extension personnel, the Heat Stress app may also prove useful to professors, students and others with an interest in livestock welfare. The app has been added to Federal Mobile Apps Registry.
A list of ARS Mobile Apps can be found on the ARS Web page under “Quick Links.”
ARS is USDA's principal intramural scientific research agency.
Tami Brown-Brandl, Roman L. Hruska U.S. Meat Animal Research Center, Clay Center, Nebr., (402) 762-4279(402) 762-4279,email@example.com.
For further reading:
Temperament Plays Key Role in Cattle Health
Keeping Cattle Cool and Stress-Free Is Goal of ARS Study