- First, the full potential of higher-resolution spatial data and new data products on environmental conditions should be explored. Many possibilities exist to wring more value from satellite data for index insurance—such as pairing data from multiple sensors and or with crop models—and examining those possibilities is a promising opportunity to improve the match between observation and experience on the ground.
- Second, several opportunities exist to help improve loss detection. For example, this can be done with better crop modeling and new data products enabled by remote sensing, such as higher resolution soil moisture indicators of 100-meter resolution. Additional data sources such as drones and smartphones can be incorporated. Insurers should focus on metrics of farmer welfare as the key objective in insurance design.
- Third, better on-the-ground data will help bolster the usefulness and quality of insurance programs. Ground-referenced data is essential to evaluate how well a given index relates to a farmer's reality, and strategically collected data on environmental conditions, crop types, and yields for the areas considered by insurance would help diagnose and improve insurance quality.
- Fourth, insurance zones can be optimized to better reflect the geographic, microclimatic, and crop-management conditions that influence the productivity of specific landscapes. Within large administrative boundaries, considerable variation can occur due to mountains, rivers and different social customs.
- Finally, contracts can be designed to accommodate a variety of needs and the inevitability of index failure. Farmers have different needs and a rigid insurance contract window may not always reflect the times of the year a farmer is most concerned about risk as it relates to their production strategies and location. In addition, secondary mechanisms—liked audits—can be put into place to minimize uncompensated losses that can be missed by index errors.
Africa - Advances in modeling and sensors can help farmers and insurers manage risk22.01.2021 8429 views
A sustainable approach to integrated pest management
There is more scrutiny today than ever before regarding conventional herbicides, fungicides and insecticides, and regulations are tightening. “Complete replacement of synthetic chemistries is impractical,” said Nicholas Body, Alltech Crop Science (ACS) European technical manager. “The future of integrated pest management (IPM) programmes will include the best tactics from a variety of approaches, including nutritional and natural technologies, allowing the producers to reduce inputs while maintaining crop quality and improving sustainability measures.“ With today’s global trend among retailers to be very strict on chemical residues, building the best programme, including all type of technologies, is mandatory. “The use of predictive tools, such as disease models, and preventative, such as elicitors of natural defences, allows us to increase the quality of harvest with only a minimal use of conventional pesticides,” said Body. A balanced nutritional programme is a vital component of an effective IPM programme. “An unhealthy plant, from a nutritional standpoint, is not able to defend itself against a potential pathogen attack,” said Body. Healthy plants have a better chance of resisting disease pressures, and bioavailable micronutrients can support plants’ inherent defences. “If you trick a plant into thinking it’s going to be attacked, then the plant can develop its own metabolic pathways to fight the disease,” Body explained. However, plants are not naturally proactive. “They are reactive organisms,” continued Nicolas Body. “Something must trigger a reaction in a plant to be defensive, unlike an immune system that can react on its own. By using biologicals, such as nutritionals and activators, we can elicit a response in the plant.” Efficient crop management is moving towards a more proactive management of inputs. “We’ve been taught to scout fields, find what’s wrong and then fix it,” said Nicolas Body. “We’re moving to a new perspective where we can act on plant and soil health instead of acting on disease.” Better nutrient management, especially nitrogen, is a key component of this movement and is crucial to sustainability. The focus is to reduce the amount of fertiliser applied to fields and hopefully improve the environment by minimising the application of excess nitrogen. Many European farmers are faced with soils that have been depleted after many years in production. These cannot always provide a perfect balance between exported nutrients and the input fertilisation. With a loss in organic matter and beneficial microbes, the soil is also losing its capacity to act as a buffer. Fortunately, conservative and regenerative approaches to soil management are on the rise, and most farmers are implementing these techniques. Body agrees that a total-system approach will serve crop farmers best in the future. “We continue to research how and when to use biologicals — whether it’s natural activators, foliar micronutrients, natural inoculants or biofungicides — with conventional methods in cropping systems to help producers with environmental stewardship,” he explained. “As any market progresses, we see increasing management of smaller and smaller pieces of the total system.” Source - https://www.freshplaza.com
Kenya - Insurtech startup raises $6M Series A to derisk smallholder farmers
Pula, a Kenyan insurtech startup that specialises in digital and agricultural insurance to derisk millions of smallholder farmers across Africa, has closed a Series A investment of $6 million. The round was led by Pan-African early-stage venture capital firm, TLcom Capital, with participation from nonprofit Women’s World Banking. The raise comes after Pula closed $1 million in seed investment from Rocher Participations with support from Accion Venture Lab, Omidyar Network and several angel investors in 2018. Founded by Rose Goslinga and Thomas Njeru in 2015, Pula delivers agricultural insurance and digital products to help smallholder farmers navigate climate risks, improve their farming practices and bolster their incomes over time. Agriculture insurance has traditionally relied on farm business. In the U.S. or Europe with typically large farms, an average insurance premium is $1,000. But in Africa, where smallholding or small-scale farms are the norms, the number stands at an average of $4. It is particularly telling that the value of agricultural insurance premiums in Africa represents less than 1 percent of the world’s total when the continent has 17 percent of the world’s arable land. This disparity stems from the fact that the traditional method of calculating insurance through farm visits is often unaffordable for these smallholder farmers. Thus, they are often neglected from financial protection against climate risks like flood, drought, pestilence and hail. Pula is solving this problem by using technology and data. Through its Area Yield Index Insurance product, the insurtech startup leverages machine learning, crop cuts experiments and data points relating to weather patterns and farmer losses, to build products that cater to various risks. But getting farmers on board has never been easy, Goslinga told TechCrunch. According to her, Pula has understood not to sell insurance directly to small-scale farmers, because they can suffer from optimism bias. “Some think a climate disaster wouldn’t hit their farms for a particular season; hence, they don’t ask for insurance initially. But if they witness any of these climate risks during the season, they would want to get insurance, which is counterproductive to Pula,” said the founder in a phone call. So the startup instead partners with banks. Banks provide loans to farmers and make it compulsory for them to have insurance. With the loan, banks can pay the insurance on behalf of the farmers at the start of the season. But at the end of the season, the farmer has to repay the loan with interest. “The unit economics doesn’t work for us to work with farmers directly. But with banks, we know they provide loans to farmers with much better margins to pay for insurance. Also, we work together with government subsidy programs since they’re also interested in protecting their farmers.” Through its partnerships with banks, governments and agricultural input companies, Pula is at the center of an ecosystem that provides insurance to smallholder farmers and has amassed 50 insurance partners and six reinsurance partners. Its clientele includes the likes of the World Food Programme and Central Bank of Nigeria as well as the Zambian and Kenyan governments. Social enterprises like One Acre Fund, startups like Apollo Agriculture, and agribusiness giants like Flour Mills and Export Trading Group are also among Pula’s clients. Co-CEOs with agricultural backgrounds When Goslinga met Njeru in 2008, she worked for Syngenta Foundation for Sustainable Agriculture (SFSA). There, she started Kilimo Salama, as a micro-insurance program for more than 200,000 farmers in Kenya and Rwanda. She met Njeru who was the lead actuary at UAP Insurance, a partner to the Kilimo Salama program, at the time. After staying with Syngenta for six years and recognising the need to provide standard insurance products for smallholder farmers, Goslinga left to start Pula with Njeru in 2015. However, it wasn’t until two years later that Njeru joined fulltime as he had a six-year engagement with Deloitte South Africa from 2012 as a consultant actuary. The pair both act as co-CEOs. “When Thomas and I launched Pula in 2015, we had one goal in mind: to build and deliver scalable insurance solutions for Africa’s 700 million smallholder farmers,” Goslinga said. “With our latest funding, now is the time to break into new ground. In our five years since launching, we’ve built strong traction for our products. However, the fact remains that across Africa and other emerging markets, there are still millions of smallholder farmers with risks to their livelihoods that have not been covered.” According to Goslinga, the COVID-19 pandemic helped Pula double its footprint and size as rural farming activities and operations continued despite pandemic-induced lockdowns. Therefore, the new financing will scale up operations in its existing 13 markets across Africa, where it has insured over 4.3 million farmers. They include Senegal, Ghana, Mali, Nigeria, Ethiopia, Madagascar, Tanzania, Kenya, Rwanda, Uganda, Zambia, Malawi and Mozambique. Likewise, the Kenyan startup hopes to propel its expansion for smallholder farmers in Asia and Latin America. Pula is one of the few African startups disrupting the farming industry with technology. Its Series A investment attests that investors’ appetite for agritech startups is still on the rise. A week ago, Aerobotics, a South African startup that uses artificial intelligence to help farmers protect their trees and fruits from risks, raised a Series B round of $17 million. Last month, SunCulture, a Kenyan startup that provides solar power systems, water pumps and irrigation systems for small-scale farmers, raised $14 million. Another startup is Apollo Agriculture which raised $6 million Series A, akin to Pula. Not only did the pair raise the same round, Apollo Agriculture and Pula both deal with providing financial resources to smallholder farmers. But while both companies might look like competitors, even to the admission of Goslinga, she argues that the startups are partners and complement each other. As part of the new fundraise, TLcom’s senior partner Omobola Johnson will join Pula’s board. However, it was her colleague, Maurizio Caio, the firm’s managing partner, who had something to say about the round. “The potential for the insurance market for smallholder farmers in Africa is huge, and under the leadership of Rose and Thomas, Pula has rapidly established a strong presence throughout the continent and has several high-profile clients on their books. We are confident of Pula’s potential for growth in spite of the pandemic and look forward to partnering with them as they execute the next phase of their journey,” he said in a statement. For the lead investor, Pula’s investment marks the culmination of its busiest run of investments having led and co-led rounds in Okra, Shara, Autochek and Ilara Health within the past year. Christina Juhasz, CIO at Women’s World Banking, the other investor in the round, explained that the organisation cut a check for Pula “given the legions of women engaged in small-hold farming and securing the food supply for communities around the globe.” Source - https://techcrunch.com
Understanding disease-induced microbial shifts may reveal new crop management strategies
While humanity is facing the COVID-19 pandemic, the citrus industry is trying to manage its own devastating disease, Huanglongbing (HLB), also known as citrus greening disease. HLB is the most destructive citrus disease in the world. In the past decade, the disease has annihilated the Florida citrus industry, reducing orange production for juice and other products by 72%. Candidatus Liberibacter asiaticus (CLas) is the microbe associated with the disease. It resides in the phloem of the tree and, like many plant pathogens, is transmitted by insects during feeding events. Disease progression can be slow but catastrophic. Symptoms begin with blotchy leaves, yellow shoots, and stunting, and progress into yield decline, poor quality fruit, and eventually death. Currently, the only thing citrus growers can do to protect their crops from HLB is control the insect vector. Dozens of researchers are trying to find ways to manage the disease, using strategies ranging from pesticides to antibiotics to CLas-sniffing dogs. Understanding the plant microbiome, an exciting new frontier in plant disease management, is another strategy. Dr. Caroline Roper and first author Dr. Nichole Ginnan at the University of California, Riverside led a large research collaboration that sought to explore the microbiome's role in HLB disease progression. Their recent article in Phytobiomes Journal, "Disease-Induced Microbial Shifts in Citrus Indicate Microbiome-Derived Responses to Huanglongbing," moves beyond the single-snapshot view of the microbial landscape typical of microbiome research. Their holistic approach to studying plant-microbe interactions captured several snapshots across three years and three distinct tissue types (roots, stems, and leaves). What is so interesting about this research is the use of amplicon (16S and ITS) sequencing to capture the highly intricate and dynamic role of the microbiome (both bacterial and fungal) as it changes over the course of HLB disease progression. Ginnan et al. surmised that HLB created a diseased-induced shift of the tree's microbiome. Specifically, the researchers showed that as the disease progresses, the microbial diversity increases. They further investigated this trend to find that the increase in diversity was associated with an increase in putative pathogenic (disease-causing) and saprophytic (dead tissue-feeding) microbes. They observed a significant drop in beneficial microbes in the early phases of the disease. Arbuscular mycorrhizal fungi (AMF) were one such beneficial group that the authors highlighted as showing a drastic decline in relative abundance. The depletion of key microbial species during disease might be opening the door for other microbes to invade. Certain resources may become more or less available, allowing different microbes to prosper. Dr. Roper and Dr. Ginnan hypothesize that when HLB begins, this depletion event triggers a surge of beneficial microbes to come to the aid of the citrus tree. They suspect that the microbes are initiating an immune response to protect the host. As the disease proliferates, the citrus tree and its microbiome continue to change. Dr. Ginnan, the lead author on this study, found that there was an enrichment of parasitic and saprophytic microorganisms in severely diseased roots. The enrichment of these microbes may contribute to disease progression and root decline, one side effect of HLB. Survivor trees, or trees that did not progress into severe disease, had a unique microbial profile as well. These trees were enriched with putative symbiotic microbes like Lactobacillussp. and Aureobasidium sp. This discovery led the researchers to identify certain microbes that were associated with slower disease progression. Dr. Ginnan says their "aha" moment during the research was in the data analysis. "Originally we were looking for taxa that increased and decreased in relative abundance as disease rating increased," she said. "Our differential abundance analysis ended up revealing clear enrichment patterns replicated in multiple taxa." This is the moment they began to develop the individual patterns they were seeing into a broader disease model. This research is the foundation for future projects and collaborations that the authors are excited to continue to develop. They are motivated by the potential function of the microbiome to manage crop diseases. In the near future, they hope that these discoveries and an understanding of beneficial microbes can help establish a microbiome-mediated treatment plan to protect crops from diseases like HLB. In addition, the model they've developed can be applied to understanding diseases of other tree crop systems. Source - https://www.eurekalert.org
Canada - Sask. anticipates spending less on business risk programs
The Saskatchewan budget scheduled for March 18 turned out to be a non-event as the Legislature shut down amid COVID-19 concerns. Earlier that day the government announced a spending plan of $14.15 billion, but couldn’t say how much the virus will cost the health system or how much revenue the province could expect to take in. Finance minister Donna Harpauer said the province has access to $1.3 billion in cash if needed. Premier Scott Moe said the government would provide the funding needed to fight the pandemic. Cabinet will require special warrants to get money out of the door. Of the total, the agriculture ministry will see spending drop by $22 million or almost six percent to nearly $369 million. The major decrease comes in business risk management spending, which is always based on federal forecasts. The estimates project $15.8 million less spending for AgriStability and $15.9 million less on crop insurance premiums. Agriculture Minister David Marit said the federal forecasts were done in December. “It is important to note that business risk management spending is government by federal-provincial agreements and the amount that we spend in any one year is impacted by commodity prices and program participation,” he said through an emailed statement. “We recognize that the markets are very volatile and those spending forecasts will be adjusted through the year.” One area that will see some additional spending is irrigation development. Marit said $5 million will be used to conduct additional analysis of the potential, including a study of the Westside Irrigation and Qu’Appelle South Irrigation projects. Part of that work will include land identification and soil suitability assessments. “It is too early to indicate the costs required to build irrigation infrastructure,” he said. Marit added that investment from the federal government and the private sector would be required to develop the infrastructure. Source - https://www.producer.com
Managing frost damage on late-season corn for silage
Late corn plantings and cool autumn temperatures create a recipe for frost damage on corn grown for silage. The extent of the frost damage on the corn depends on the temperature, duration of the temperature, and corn growth stage at the time of the frost. Conditions for a frost Air temperatures below 32°F for four to five hours will result in frost damage to the stalk, leaf, and husk. Air temperatures that drop to 28°F for a few minutes and return to 32°F can result in similar injury. Air temperatures between 32°F and 40°F typically result in less frost damage. Frost at temperatures above 32°F usually occurs under conditions of clear skies, low humidity, and no wind. These conditions are ideal for rapid heat loss from the corn leaves. Under these conditions, temperature of the corn leaves can be less than the air temperature. Thin stands of corn and corn stands at the edges of fields are more likely to receive frost damage at temperatures above 32°F than thicker stands and the centers of fields. The uppermost leaves of the corn plant are most susceptible to frost damage at temperatures between 32°F and 40°F. Growth stage at time of frost Management of corn damaged by frost will depend on the stage of growth at the time of frost. Corn will ensile well at moisture levels less than 70% for upright silos and less than 75% moisture for horizontal silos. Corn harvested at 62% to 68% moisture (late-dent stage) is ideal for ensiling. Frost damage prior to the late-dent stage will result in corn that is too moist for silage harvest. Frost at these higher moistures will reduce yields and may reduce quality. Management of corn damaged by frost will depend on the stage of growth at the time of frost. (Photo: Courtesy of University Kentucky) Corn moisture content can be determined with a microwave or forage moisture tester. A simple field technique for determining corn moisture content is to squeeze a ball of chopped corn forage in your hand for 30 seconds. Release the ball of chopped forage and examine its shape. You can gain a rough estimate of moisture content based on the descriptions in Table 2. If you would prefer to not use the silage chopper to help determine whole plant moisture, then you can use a tobacco or corn knife to chop several corn plants. Be careful to chop up the corn plants into pieces that are similar in size to those cut by the silage chopper. Frost at Milk Stage When a frost occurs on corn at the milk stage, the moisture content of the plant is too high for proper ensiling. The leaves of the plant will dry very quickly, which causes the entire plant to appear to be drying more quickly. However, the entire plant will dry down similarly to corn that was not injured by frost. If the corn at milk stage is ensiled immediately after frost, then nutrients will leach away, the silage will be sour and wet, and livestock consumption will be low. Waiting to harvest frost-damaged corn at the milk stage will improve silage quality but will decrease dry matter yield. Up to 10% dry matter losses will occur the first 10 days after the frost, and up to 20% dry matter will be lost 40 days after the frost. In addition, mold may develop in the ears and cause further yield reductions. Because of these factors, a compromise between dry matter yield and ideal ensiling moisture must be made. In some cases, the corn will need to be harvested when it is too wet for silage. In these situations, chopped grain, hay, or straw can be added to the silage to decrease overall moisture. In general, 30 pounds of dry matter per ton of silage are required to reduce the moisture percentage by one point. For example, if the corn was at 78% moisture and the target moisture was 68%, then 300 pounds of dry matter would be required for each fresh ton of silage. One concern of frost occurring at the milk stage is high nitrate levels. High nitrate levels are toxic to cattle and will occur most frequently when the corn has been under drought stress prior to the frost. Ensiling will reduce nitrate levels 40% to 60%. To reduce the risk of nitrate toxicity, allow the ensiling process to occur for at least 21 days before feeding. See ID-86, Using Drought-Stressed Corn: Harvesting, Storage, Feeding, Pricing, and Marketing, for more information on nitrate levels in corn. Another option for corn with high moisture content is to feed the corn as green-chop. Cattle will consume less green-chop corn than ensiled corn. However, the quality of the frost-damaged, green-chopped corn is better than the quality of the ensiled corn at milk stage. If the corn is to be fed as green-chop, then check the corn for nitrate levels before feeding. A diagnostic test is available for determining nitrate levels, which is usually available through your county Extension office. Frost at Dough Stage If a frost occurs when the corn is at the dough stage, then whole corn is often too wet for silage harvest. Typically, several drying days are necessary before whole corn will be at the proper moisture for silage harvest. The corn should be harvested as soon as it reaches the desired moisture of 70% to 75%. The balance between waiting to harvest corn for silage at the ideal moisture and harvesting to prevent yield loss still must be considered. However, corn damaged by frost during the dough stage will require less time to dry down than corn damaged during the milk stage. If a frost occurs when corn is at the early dent stage, then whole corn may need to dry a couple days before it is ready to harvest. (Photo: Colleen Kottke/Wisconsin State Farmer) Frost at the Dent Stage If a frost occurs when corn is at the early dent stage, then whole corn may need to dry a couple days before it is ready to harvest. If a frost occurs when the corn is at the mid- to latedent stage, whole corn is at or very close to ideal moistures for ensiling. Corn damaged by frost at the mid- to late-dent stage should be harvested for silage immediately because whole plant moisture should be close to ideal for harvest and waiting to harvest could cause yield reductions. Summary Management of frost damage to corn grown for silage depends in part on the stage of growth when the frost occurred. Corn in the milk and dough stages is too wet for chopping and ensiling. The corn plants need to dry down before chopping occurs. Waiting to harvest frost-damaged corn will improve silage quality but will decrease dry matter yield. Producers must balance between expected yield losses and quality gains by waiting to harvest. Source - https://www.wisfarmer.com
New Zealand - Fans get to work as spring frosts threaten precious grapes
Vineyard frost fans have been doing their bit to protect one of Marlborough's biggest money spinners after a few cold starts in October. The fans, which pull warm air down onto the vines, are used when grapes start to bud - as a spring frost can lead to crop loss. Blenheim experienced four frosts in the first week of October, while all of October 2018 had only two frosts. But Marlborough Plant and Food research scientist Rob Agnew suspected frost fans would have been used more out in the Wairau Valley because of its colder climate. Villa Maria viticulturist Stuart Dudley said because Marlborough was a cool climate viticulture region there were definitely areas that were exposed to spring and autumn frosts. "The fans work by effectively bringing down warmer air," Dudley said. "It's called an inversion layer, effectively it's the same principle that is used by helicopters to protect the crops, but wind machines are a lot more reliable. "For us, as viticulturists, the wind machines are great, because if you get a forecast saying it might get to zero [degrees Celsius] and then you would have to toss up whether to spend the money on helicopters or not, whereas if you've got a frost fan the decision is already made, you just have to flick it on." Most were automatic, with a start temperature just above zero, but some grapegrowers had started switching from two-bladed fans to four or five, which were quieter, Dudley said. A Neighbourly poll showed 50 per cent of respondents who lived next to a vineyard were used to the sound. However, 17.3 per cent of respondents said they struggled to sleep at night because of the sound. Hawkesbury resident Nigel Taylor said noise from frost fans was something "you get used to". "You hear the two-bladed ones more than those with four or five," Taylor said. "You can definitely hear them but they don't interrupt us, you learn to live with it. "They're temperature-controlled so you notice when they turn off too, it's not a major disruption." Jenny King said rural residents knew living next to a vineyard could come with some noisy nights. "It's a small price to pay," King said. "It doesn't make for a great mood the next day but it's one of those things." King said she tended to hear the helicopter from the cherry orchards in Springlands more. Marlborough resident Ben Wallace said the fans were "minimally disruptive". "The benefits of frost fans for the local economy far outweigh the noise you have to put up with," he said. Source - https://www.stuff.co.nz
USA - Northern NY apple research tests hail netting as pest management[:ru]US
Real-time, regional, in-orchard research funded by the Northern New York Agricultural Development Program is helping apple growers quickly respond to pests with the latest management practices, the organization said. "Pest management is one of the largest investments fruit growers must make in terms of time, labor, and materials to produce marketable fruit and maintain healthy trees," says Michael Basedow, a tree fruit specialist with the Cornell Cooperative Extension Eastern NY Commercial Horticulture Program, Plattsburgh, N.Y. With a grant from the Northern New York Agricultural Development Program, Basedow provided weekly pest scouting data to help growers quickly respond to orchard pests with appropriate pest management tactics. He also initiated a project to evaluate whether exclusion netting used for protecting apple from hailstorm damage might also protect the fruit from orchard pests. A series of hailstorms in 2017 damaged the regional apple crop. One grower reported more than 60 percent of his acres suffered damage. Basedow says, "Growers selling hail-damaged fruit for juice that would otherwise have sold at retail prices can see as much as a 98 percent decrease in the economic value of their crop." Basedow worked with commercial growers in Clinton and Essex counties who had installed hail netting. Trials in France and Quebec, Canada, had shown success in limiting damage by codling moth and other orchard pests, but the use of drape-style netting had not been well-evaluated under northern NY orchard conditions. Employees at a Clinton County orchard install hail netting to a row of apple trees. Photo: A. Galimberti, CCE Clinton County, NY "We are constantly looking at ways to increase the use of integrated pest management practices that allow us to produce a commercially viable crop while also making the best use of growers' time, labor, and money. We wanted to see if the hail netting might be an effective practice to add to our apple growers' IPM toolbox," Basedow said. The research provided weekly trap data on four key apple pests in northern NY: codling moth, Oriental fruit moth, obliquebanded leafrooler, and apple maggot. "Results from the trial showed that traps in the trees under the netting caught significantly fewer of the four key pests compared to the unnetted trees, however," Basedow says, "the pest pressure levels in 2018 for three of the four key pests was such that the feasibility of using hail netting for pest exclusion is still uncertain. The netting may help reduce pest numbers enough to reduce the total number of orchard sprays needed for some pests, such as apple maggot, where spray decisions are based on well-established economic thresholds." Basedow adds that the sites with the most effective pest exclusion were those where the hail netting was tightly tied to the lower limbs and trunks of the apple trees. The orchard with the best control applied the netting to trees grown to a tall spindle training system with the netting secured tightly to the trunks. Source - https://www.freshplaza.com
Canada - Moisture kick-starts canola spray discussions
The decision whether to spray for sclerotinia stem rot in canola begins with a moisture assessment about three weeks before flowering. The situation before that point is almost irrelevant, given the canola plant’s ability to crank up yield potential in response to improved growing conditions. Sclerotinia stem rot can go from no risk to high risk with a timely period of regular rains and humidity. Moisture before flowering will result in the emergence of spore-producing apothecia. Under ideal warm and moist conditions, it takes around three weeks for sclerotia to germinate and release ascospores. Moisture during flowering will enable ascospores to infect canola petals and grow into leaf and stem tissues when the infected petals fall into the crop canopy. Spraying after flowering or after symptoms have appeared on the plant is too late, so the decision has to be based on the risk situation before and during the spray window — which is 20 to 50 per cent flower — and the forecast of weather and yield to come. Risk of economic levels of sclerotinia stem rot increases with the following: • A wet soil surface underneath the canola canopy for most or all of the day. This promotes germination of sclerotia and production of apothecia, the tiny mushrooms that release sclerotinia spores. • The presence of apothecia, which are a sign that spores will be present. Other options for spore detection are the Spornado (from 20/20 Seed Labs) or DNA-based petal tests (from Quantum Genetix and Discovery Seed Labs). • Higher yield situations. Yields are difficult to predict, so a better indicator may be a canopy dense enough to create the humid microclimate that favours disease. If you walk through the canopy in early afternoon and your pants get wet, the field has favourable conditions for infection. • Moderate average temperatures of 15-25°C and moderate rainfall that favour host infection while extending the bloom period and reducing sloughing off of leaves, thus maintaining potential infection sites. • Extensive sticking/clumping of petals in the crop canopy, especially in the leaf axils and bases. • A history of significant levels of sclerotinia in the specific field or in adjacent fields. Host crops include canola, soybeans, sunflowers, potatoes and pulses. Risk of economic levels of sclerotinia stem rot decreases with the following: • Dry conditions through the flowering period. • A poor canola canopy that allows for a lot of air flow. When doing the wet pants test, if the canopy and your pants and boots are dry at 8-10 a.m., then the field has less favourable conditions for the disease. • Well below- or above-average temperatures (less than 10°C or more than 25-30°C) and limited rainfall. • A large rainfall event over one or two days that is followed by several days of dry, warm conditions. • Continuous rain events that may lead to washing off of petals from plants and remove spores from the air, while trapping spores in water droplets that form on the tops of the apothecia. Note that a moisture situation like this that actually reduces sclerotinia stem rot risk would be unusual. Management approaches if the potential for disease is uncertain include: • Apply the lowest rate of fungicide. Use programs or lowest-cost products to keep costs as low as possible. • Always use highest label water rates to get the most coverage and best efficacy. • If perked-up fields are to rebound and achieve target yields, they will likely have to branch out and flower for longer. In this situation, “full flower” (50 per cent flower) could last a week or more. This can be an effective time to spray, especially in a situation where moisture changed dramatically for the good and the crop canopy is slowly filling in. Farmers in this situation may choose to wait a little longer to assess crop recovery before making the spray decision. • Generally, early infections cause more yield loss than later infections, which is why the economic benefit of a fungicide application is usually higher with early applications. • Consider an “on-off” or zone-spraying approach, basing it on previous yield maps or current NDVI maps. Fungicide application could be turned “on” for areas with high yield potential and “off” for typically low-yielding areas • If you need to spray so you can sleep at night, then spray. But leave a few test strips to compare disease amounts and yield. This can help with future decisions. Conditions where a grower may want to spray more than once include: • Variable crop staging that extends the flowering period. • Thin stands mean branchier plants and an extended flowering period. • Note that continued rain throughout flowering will add to the yield-loss risk for the first two scenarios. • Regrowth after a hail. • In any of these situations, assess yield potential and crop stage relative to the calendar when pencilling out the potential return on investment. Source - https://www.mountainviewgazette.ca