Tunnel Talk(s) in 2024

 Introducing the latest addition to Perennia’s extension portfolio, TunnelTalk! 

This series aims to provide a recurring virtual space for producers of all shapes and sizes to come together and discuss all things protected agriculture. The main topic for discussion will vary month to month, with outside expertise on relevant topics, grower roundtables, shared experiences with techniques and technology, and group troubleshooting. This series of meetings is intended to be driven by grower feedback, so if there are any topics you'd like to see featured in these meetings, don't hesitate to communicate them! 

Upcoming sessions:

January 10 from 8:30-9:30 with Guest Speaker Anna Teston

The main topic of discussion will be anaerobic soil disinfestation (ASD). Join our in-house protected crop specialist and Anna Teston to hear about her research in this space and experience conducting ASD on farm. Anna is a Research Plant Pathologist with the United States Department of Agriculture Agricultural Research Service. Her research program focuses on developing disease management strategies for horticultural crops in controlled environment agriculture, including high tunnels. She has been studying ways to reduce the impacts of soilborne diseases in high tunnels, including the use of anaerobic soil disinfestation, grafting and soil steaming.

This session will start off with a presentation, followed by participant questions. As always, there will be space for a general round table to voice concerns/pain points/success stories amongst the group after the main presentation.

February 7 from 8:30 - 9:30 with Guest Speaker Caitlin McCavour

The main topic of discussion will be nutrient management planning in soil-based systems. Join our in-house protected crop specialist and soil specialist for a discussion on some of the unique challenges tunnel and greenhouse spaces present when it comes to nutrient management planning. This session will start off with a presentation from Caitlin McCavour, followed by grower questions. As always, there will be space for a general round table to voice concerns/pain points/success stories amongst the group. 

March 13 from 8:30 - 9:30 with Guest Speaker Dr. Anissa Poleatewich

Dr. Anissa Poleatewich will summarize her work examining biological-based product efficacy against botrytis! 

Stay tuned for quarterly updates on upcoming dates and topics. For registration and question submission, visit our website!

Hope to see you there

-Talia 

Your choice of mulch dramatically affects plant growth and yield!

 This year we carried out demonstrations on 3 biodegradable mulches and 3 non-biodegradable mulches to see how they compare in a sweet potato production system here in Nova Scotia.

As horrible as this year turned out to be, it was the perfect year to trial plastic mulches as for many they made the difference between growing a marketable crop.. or not. Sweet potatoes are a challenging crop to grow in N.S, they need a long season with warm soils to produce tubers that make grade.

We demonstrated six different mulches, 3 biodegradable, and 3 nondegradable to test a variety of colours and thicknesses/material. There was a 30% difference in yields between the highest and lowest performers as well as differences in tuber grades (sizing) for each mulch. Before I talk about the treatments, it’s important to remember that this is not a replicated trial; the results highlight striking differences between mulches, but this is by no means conclusive.

Treatments:

-          Dubois, black, 1 mil embossed plastic (non-degradable)

-          Heartnut Grove, green, 1 mil (non-degradable)

-          Solar Shrink, black, 0.5 mil (non-degradable)

-          Film Organic “88”, black, 0.8 mil (biodegradable)

-          Dubois Bio360, black, 0.5 mil (biodegradable)

-          Dubois Bio360, clear, 0.5 mil (biodegradable)

Method:

-          3 rows, 400ft long, of each of each mulch was laid on June 13, 2023. Raised beds were 10" high, 28" wide.

-          Slips planted in late June. Management practices identical to rest of field (fertility, pesticides, etc)

-          12ft sections from each row were harvested Sept 19. Weighed for above and below ground biomass; tubers graded with a standard sizing board (<1.5”; 1.5” – 2.0”; 2.0” – 3.5”; >3.5”).

Results:

The table 1 below details specific results, with green highlighting showing the best performer in each category/column. Here are some brief takeaways:

-          The three non-degradable mulches produced the highest grade A (2” – 3.5”) tubers.

-          The green mulch produced the highest average weight per tuber (160 g) and stimulated root growth over shoot growth (root to shoot ratio).

-          The two Dubois biodegradable mulches were slightly too thin. The black 0.5 mil adequately controlled weeds but was severely degraded by September. The clear 0.5 mil had ruptured by July 20^th and was overrun by weeds.

-          From these results I would recommend choosing a black biodegradable mulch no thinner than 0.6 mil and a clear biodegradable mulch no thinner than 0.8 mil.

-          We did not assess the cost difference between each mulch or consider the added cost of removing nondegradable mulches at the end of the season. These costs needed to be factored in to determine the profitability of using each mulch.

Table 1. results of mulch demonstration

    Please reach out to me at tmorcom@perennia.ca to discuss mulches, our results, or your plans for next year.

    Tim

Cover Cropping Question Bonanza!

Interested in an opportunity to discuss your farm-specific cover crop questions with a Perennia specialist? Check out two upcoming virtual events, where the entire session is driven by YOU! Questions can be submitted beforehand, or live during the event, as your ideas are sparked by discussion happening in real time. 

'Cover Crops - Ask Us Anything!' taking place December 13 @ Noon 

Did you try cover cropping for the first time in 2023? Been doing it for a while but struggled with the wet conditions? Whatever your questions about cover crops, we’ve got answers!  

As a follow-up to last year’s Cover Crops: Ask Us Anything webinar, join Perennia cover crop experts Berry Specialist Sonny Murray and Fields Crops Specialist Caitlin Congdon for a live question-and-answer webinar about cover crops! Attendees are encouraged to submit questions in advance and join us on December 13 at noon to hear the answers and tune into the discussion.

Registration details can be found here!

'Cover Crops and Split Nutrient Application - Ask Us Anything! (Protected Ag Edition)' taking place February 6 @ Noon

This session takes a look at cover cropping and split nutrient applications in protected spaces! A spin-off inspired by the session listed above, this is a great opportunity to ask any questions you may have about implementing these practices in your tunnels. 

Join Perennia’s subject experts, Protected Crop Specialist Talia Plaskett, Berry Specialist Sonny Murry and Fields Crops Specialist Caitlin Congdon, for a live question-and-answer webinar! We will also be featuring two season farmers as well, to give their two cents on their own experience, and comment on practice feasibility. Where cover crops are a relatively new practice to protected spaces, we still have a lot to learn. The more perspectives we can bring to the table to come up with a solution, the better! 

Attendees are encouraged to submit questions in advance and join us live on February 6 at noon to hear the answers and tune into the discussion. Registration information can be found here!

Looking forward to seeing you there!

-Talia

Interpreting a Compost Analysis

The incorporation of compost into your production spaces is a great way to recycle nutrients and carbon back into the soil, turning waste into something that will feed future crops and soil microbes. The variety of materials incorporated into compost, however, is highly variable. Plant residue, municipal solid waste, food processing waste, pulp or paper mill solids, manure and seafood wastes are all contenders for being included in a compost. The range of materials, each with their own broad ranges of nutrient concentrations, makes it a highly inconsistent product between batches, even where the supplier remains consistent. This variation in composition is going to have implications for nutrient management planning year to year - we can't necessarily apply the same volume from year to year and expect the same impact on our soils. 

In order to approach our nutrient management and compost applications with increased accuracy, it is recommended to submit compost samples for analysis. Nova Scotia's provincial lab services offer this as an option, and the report will break down the nutritional composition of the compost for next season's planning. Once we can better quantify the amount of nitrogen (and other key nutrients) in the compost, application volumes and a plan for additional supplementation throughout the growing season can be put together to meet the crop needs, and reduce accidental over-fertilization. 

For greenhouse soils, where all overhead precipitation has been excluded, compost analysis is especially important. Some composts tend to run high in salts (ex. calcium, magnesium etc), and while these are crucial nutrients for crop production, it is important that they are not being over-supplied to the soils. With a lack of a seasonal reset via rain and snow in protected spaces, these salts can accumulate quickly over time, impacting crop health and productivity. 

Now that we have the data...what does it mean?!

The Department of Agriculture has an interpretation document outlining the line items included in a compost analysis report and the impact that each nutrient has on crop production. Once you have a good understanding of what is included in the report, Perennia has created a fact sheet that provides further information on some of the metrics included, and the implications that these metrics have on our nutrient management plan. Below is a brief summary of some of the information presented in the factsheet, but I highly recommend you check it out for yourselves! 

__________________________________________________________

Finished composts typically contain low levels of a wide variety of nutrients (though this is highly dependent on the materials included in the mix). This lower level of nutrients can translate to a tendency to apply large volumes of compost, however this can lead to excessive levels of certain nutrients in the soil in some cases. It is typically recommended that compost is not the sole fertility source for crops, but one of a handful of additives that come together to provide the target nutrient ranges for the crop in question. 

C:N Ratios

The amount of carbon present in a compost, in relation to nitrogen, impacts nutrient cycling, and how quickly nutrients will become plant available. Composts typically range from 8:1 - 30:1. If your compost has a ratio:

•  >40:1, there is a good chance that any nitrogen that is present in the soil/compost will be 'tied up' through the process of breaking down carbon. This can lead to nitrogen deficiencies in your crop.
• 12-22:1, there is more nitrogen available than the microbes need, meaning it will become plant available more readily
• 25-32:1, it will slowly become plant available over the course of a few years.

Nitrogen

The provincial lab analysis of compost reports on total nitrogen in the sample, however nitrogen has many forms in compost. 'Organic nitrogen', which is the nitrogen included in microbial, animal and plant tissues, is not immediately plant available. It must be mineralized in the N cycle before a plant is able to take it up and use it for growth. The rate of mineralization is difficult to forecast, as it is dependent on a handful of variables (temperature, moisture, C:N ratio of the compost). When compost is the only source of nitrogen in a production system, it is challenging to match the times of peak demand for the crop, with the availability of high amounts of useable (i.e. mineral) N. 

'Mineral nitrogen', specifically ammonium-nitrogen (NH4-N) and nitrate-nitrogen (NO3-N), are the plant-available forms of nitrogen. While these are key forms for plant production, they are easily lost to the environment if they aren't immediately taken up.

How do we know the amount of available nitrogen that is present in our compost analysis? Low N composts typically have low mineral (readily available) nitrogen. High N composts usually carry a fair amount of NO3-N, which is immediately plant available. Take a look at the table below, which estimates the breakdown of organic and mineral N based on your C:N ratio, and the total N (% dry weight). This chart was taken from Perennia's fact sheet linked above, and sheds some light on the percentage of organic, or plant -unavailable, nitrogen in a compost. 

From here, we can calculate how much compost we need to add in addition to our other amendments, in order to meet the target N needs of the crop in question. 

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Utilizing and understanding the tools available to us is a key step in maximizing on-farm productivity, and the inputs invested on the farm. Compost analysis, along with soil tests and water tests, are great ways to quantify and characterize our key production components, and figure out how they can work together to hit our crop-specific nutrient targets without overshooting them. 

For those who are interested in better understanding their compost analysis results, check out Perennia's fact sheet here, or contact your commodity specialist for further discussion! 

-Talia 

Finishing up 2023

 As we finish up our 2023 growing seasons, it is time to re-visit our standard cleaning procedures. Throwing out the old and preparing for the new is one of the most important components to protected production.

While this is going to look different for those in soil-based systems compared to those who are set up hydroponically, there are some key practices that can be adapted to any protected space:

1. Removing ALL organic matter from the greenhouse, and greenhouse vicinity
• dried up leaves, old soil, dirty pots and growing supplies are perfect hiding spots for pests and disease to overwinter. Its important that you eliminate as much potential habitat and food source as possible
• Don't hesitate to do this in stages. Clean out the big stuff, and come back a second and third time to get rid of the bits and pieces that were not picked up the first few times. 
• Do not leave piles of plant material or old soil next to your greenhouse. As much as these serve as habits inside the production space, they will do the exact same thing outside. No matter how well the inside is cleaned, if you have a major source of insects just steps away from the greenhouse...there will be problems
2. Collect all old growing supplies from the year, and remove from the space for cleaning. Pots, carrier trays, pruners, clips, support stakes/string etc. should be dealt with to reduce pathogen and pest load into the new production cycle. Pots, carrier trays and pruners can all be sterilized and re-used, but be aware of the cleaning agent used here - some are going to cause more harm than good! Wooden stakes, while tempting to re-use these, cannot properly be sterilized because they are highly porous. Disease transfer from year to year from re-using stakes is possible.
3. Consider swapping out ground cover if you are using something more substantial than plastic mulch! While this isn't something typically tackled on a yearly basis, following a heavy disease year it can be worth considering getting a new cover put over the ground. If you are considering this, remove the old cover before going forward with suds and sanitizer! That way your ground layer will be scrubbed back to a base layer of clean, and you can be confident that nothing is hiding out in tiny cracks and crevices throughout the old ground cover.
4. Lets get soapy!
• Giving all growing surfaces a soapy scrub is going to grab hold of any bacterial, viral and fungal agents that are still in the space and wash them away. 
• The best strategy for washing a greenhouse is to start at the top and work down - and this includes your ceiling! Failure to wash the top of the grow space creates a disease bank that can literally rain down on your future crop.
• Once you have applied your soap, give the production space a thorough rinse and allow it to air dry
5. Once you have allowed the space to airdry after cleaning, it is time to bring in the big guns- Sanitizer! There are a lot of sanitizers on the market to chose from, but they do have a few things in common:
• Contact time is important. Different products have different required contact times in order to be effective. Be sure to check what the required contact time is for your product of choice, and do your best to adhere by that. Otherwise there is no guarantee that the product will sterilize to the degree that you are hoping for
• Organic matter will de-activate sterilizing agents. Any of those leaves or soil bits that got left behind in pots and seeding trays will actually render your product useless. 
• Consider how corrosive your cleaning agent is. Bleach is effective, but does impact the longevity of growing equipment, both for plastics and other materials.
• TEMPERATURE. Sanitizer efficacies significantly decrease at lower temperatures. While it is difficult to justify heating a protected space for cleanout, it is a key factor in maximizing your product efficacy.

Here are a few other considerations for your end-of season wrap-up:

-Once the production space and tools have been cleaned, be conscious of what is coming into the space. Just because you aren't actively growing plants, doesn't mean you are immune to accidental spread! Clean clothes/shoes/growing supplies should be the only thing that enter the space for as long as possible to maintain the clean slate.

-For those who are growing in soil, producers should consider removing plastic on spaces that are not being used for production. The lack of rainwater coming onto your tunnel soils will result in the accumulation of salts in the soil. One of the best ways to tackle this is to allow the snow and rain that come with the winter to run through the soil. Come growing season, this will allow for better uptake and use of supplemented nutrients, and less stress caused by buildup over time. Plastic removal can be a pain, so even doing so every few years is going to be hugely beneficial. For more information on soil salinity in high tunnels, check out this fact sheet!

-Looking to maximize the performance of over-wintered cover crops? Unheated, double poly inflated greenhouses are not going to give enough protection from those cold winter nights. The addition of one or two layers of ground cover can work wonders for your cover crop, reducing large fluctuations in temperature and buffering against cold snaps. It also helps to protect soil moisture for your cover crop. As our day lengths turn around, these plants will see a huge boost in productivity in February and March, increasing the amount of in-house biomass generated to be worked back into the soil before bringing in the cash crop. 

Row cover is best installed after a cold snap or two in the greenhouse space. This should function to kill some of the pests that may still residing in the space, before adding the additional layer of protection

Here's to a fresh start!

Posted by: Talia Plaskett

Join us tomorrow to be a part of the minor use pesticide priority selection process

 The session for field and greenhouse vegetable crops will take place virtually via Zoom on Wednesday, November 22 from 10 AM to 12 PM. 

Perennia’s minor use representative, Michelle Cortens, and the provincial minor use coordinator Deney Augustine Joseph will briefly outline the process. Then as a group you will be guided through the different crops to assess the priority pest control needs for insects, weeds/growth regulators, and diseases. If you have potential solutions on your radar (products registered in other crops or for other uses) or have heard of products you might be interested in, please bring those along as well.

 Any grower is welcome to attend, so if you know of someone who would like to attend please let me know so I can include them on the contact list. If you can’t make the meeting, please send us your critical pest issues and any potential solutions for consideration at the meeting.

The selected priorities will then be submitted on behalf of the province and used in ranking the national priorities.

If you are interested in attending, please contact tplaskett@perennia.ca or tmorcom@perennia.ca for the meeting link and password.

 - Tim

Q&A with CropLife - Happening November 22 at 1pm AST

The Protected Agriculture Stewardship Standards are new on the block and apply to any crops grown in structures such as greenhouses, shade houses, hoop houses, high tunnels, containers and warehouses. These standards were established to assist protected producers in the identification and mitigation of risks associated with the application of conventional and biological pest control products. With the implementation of these standards starting January 1, 2024, there is not much time to get things sorted.  

Join Perennia’s Protected Crop Specialist and Dr. Justine Taylor for a session dedicated to answering your questions about these new standards! Dr. Taylor is the executive director of stewardship and sustainability for CropLife Canada.  In this role Justine supports both industry stewardship efforts as the executive director of the Agrichemical Warehousing Standards Association and contributes to the larger sustainability efforts of Canada’s plant science sector. Justine comes to this role after nearly 10 years in the greenhouse sector covering science and government relations issues for the Ontario Greenhouse Vegetable Growers. A keen supporter of collaboration, Justine contributes to several cross-sectoral initiatives and sits on several local volunteer boards in her home town of Windsor, Ontario. Justine holds a Ph.D. from the University of Alberta with a focus on analytical chemistry.

Check out our website for more information and registration options. Questions can be submitted beforehand or during the live event to provide clarity on the new standards and how they affect your farm.

Hope to see you there!

-Talia

Annual Selection of Minor Use Pesticide Priorities

Please save the date for our annual selection of minor use pesticide priorities for Nova Scotia crops. The session for field and greenhouse vegetable crops will take place virtually via Zoom on Wednesday, November 22 from 10 AM to 12 PM. 

Perennia’s minor use representative, Michelle Cortens, and the provincial minor use coordinator Deney Augustine Joseph will briefly outline the process. Then as a group you will be guided through the different crops to assess the priority pest control needs for insects, weeds/growth regulators, and diseases. If you have potential solutions on your radar (products registered in other crops or for other uses) or have heard of products you might be interested in, please bring those along as well.

 Any grower is welcome to attend, so if you know of someone who would like to attend please let me know so I can include them on the contact list. If you can’t make the meeting, please send us your critical pest issues and any potential solutions for consideration at the meeting.

The selected priorities will then be submitted on behalf of the province and used in ranking the national priorities.

If you are interested in attending, please contact tplaskett@perennia.ca or tmorcom@perennia.ca for the meeting link and password.

-Talia

NEW Guidelines Surrounding the Purchase of Pest Control Products in Protected Spaces

Attention Protected Producers! There is a new national standard on the block.

The Protected Agriculture Stewardship Standards were established to assist protected agriculture operators in the identification and mitigation of risk associated with pesticide application. This set of standards was drafted by a multi-stakeholder committee including CropLife Canada in collaboration provincial and federal grower groups. Health Canada's Pest Management Regulatory Agency (PMRA) and Agriculture and Agri-Food Canada (AAFC) acted in an advisory capacity to guide development of the standards.

The standards apply to any crops grown under structures, such as greenhouses, shade houses, hoop houses, high tunnels, warehouses, containers etc. This new motion requires a certificate in order to purchase any pest control products registered for use in protected spaces effective January 1, 2024. This includes biological-based products, as well as conventional chemistries. 

There are two general streams associated with this new set of standards:

Category 1PA -> Protected Ag Operators using any closed loop irrigation/chemigation systems. A closed loop system is one where any excess irrigation/chemigation liquid delivered to the crop is captured via trough. drainage tile, or other similar conveyance system. Operators using these systems are referred to as Category 1Pa Operators. 

NOTE: warehouse production structures and freight container growing operations with no subterranean plumbing and continuous flooring are excluded from this group

Category 2PA -> Protected Ag Operators not using closed loop irrigation/chemigation systems are referred to as Category 2PA Operators. 

The path forward looks different depending on which of the two streams your particular farm falls into.

A few additional tidbits:

-For those who have both types of irrigation/chemigation on their farm, a category 2 waiver is not needed. Follow through the path for Category 1PA. 

-For farms that have multiple locations/addresses - 

• A site spanning multiple address that are adjacent to one another will be considered a single site
• Multiple addresses that are NOT adjacent to one another will each be treated as a separate assessment, and a separate registration must be completed. 

-What happens if I am currently a Category 2PA operator, and we install a closed loop system in all/some of our operation?

•     When a category 2 waiver is completed, the operator agrees to terms, including notifying the AWSA of any changes in use, scope, or category. In these cases, the operation should be audited for compliance with the Standards. Once successfully audited, a certificate will be issued which renders the original category 2 waiver redundant. 

Stay tuned for details on an upcoming virtual Q&A session with a representative from CropLife in the next month! This will be a great opportunity to get clarity on the new standards effective January 1, 2024. Deadline to Register is December 31, 2023. 

In the meantime, feel free to explore AWSA's page on the Protected Agriculture Stewardship Standards and the resources provided there. 

-Talia 

Just a Reminder...it's Soil Sampling Season!

 Soil testing is a great way to understand the current nutritional status of your production space. When taken properly, the sample will give information on which nutrients are already present in the soil, the degree of nutrient availability (through CEC and pH values) and make suggestions on lime applications where needed. This information can then be used to determine the best inputs for efficient and economical crop production in the upcoming year. 

Soil sampling can be done any time of year, however most producers opt to take them in the fall immediately following harvest. The results generated through soil analysis can vary depending on the time of year, but they typically don't change a lot from the fall to the following spring. This timing also allows for a larger window to develop the fertility plan for the following season, and allows slow-acting amendments such as lime, and elemental sulfur to work their magic before the next batch of plants move in. Whichever time of year you chose to soil sample though, it should remain consistent over the years. Outdoor crops see a recommended interval of testing every 2-3 years, but protected soils (tunnels, greenhouses, etc.) should be tested on a yearly basis as it is more susceptible to big changes from year to year compared to a field soil. 

Unsure of what test you should be submitting? The field soil test is suitable for all soils, including those contained in tunnel/protected spaces. If you are a hydroponic producer, with crops grown in containers or grow bags containing soilless substrate (Ex. Sunshine mix, Promix etc), or are looking to get your potting mix tested for nutritional breakdown, then you are looking for the greenhouse soil paste analysis, listed as G1P on the general submission form for Nova Scotia's lab. 

For information on how to take a soil test, check out Perennia's latest guideline here. 

Once we have our soil test, what do all these values mean?

There are a handful of resources available to you to help interpret your soil results:

• Perennia's Soil Test Report Interpretation for Nova Scotia
• Nova Scotia's Analytical Lab's Soil Test Interpretation Ratings for Nova Scotia Crops

As always, if you have any questions regarding your soil test, feel free to reach out to your commodity specialist for further discussion.

Happy sampling folks!

-Talia 

Equipment Demos, Cover Crops, Mulches…and More!

On Thursday, September 28, join Horticulture Nova Scotia and Perennia Food and Agriculture for a morning filled with equipment demos, “all about mulches”, cover crops, climate-related info and more!

 

Important: As our last stop has very limited parking, we will have a bus available to transport you along the route!

Date:

Thursday, September 28 from 8:30 a.m.-12:30 p.m.

Starting location:

6727 Brooklyn Street, Kings County

 

Agenda

 

8:30 – 8:45         Meet at 6727 Brooklyn St.
Welcome and, yes, there will be coffee! Note: CEU and OFCAF points are available.

 

8:45 – 9:20         Discussion and demonstration of equipment for cover cropping and reducing tractor passes.

 

9:20 – 9:30         Travel to 99 Bligh Rd.

 

9:30 – 10:00       Degradable mulch trial results - discussion and display.

 

10:00 – 10:45     Key equipment demonstrations for mulch. 

 

10:45 – 11:00     Travel to Living Labs site on Hwy #221.

 

11:00 – 12:00     Living Labs site intro, cover crops demonstration, and lots info on related climate change adaptation.

12:00 – 12:30     Travel back to starting point; event concludes.

Hope to see you there!

Cucumber Green Mottle Mosaic Virus Confirmed in Nova Scotia

 Cucumber Green Mottle Mosaic Virus (CGMMV) is a highly infective, highly stable tobamovirus which infects members of the Cucurbit family, including pumpkins, squash, melons, gherkins and bitter gourds. The damage inflicted on the host plant and fruit can be extensive, resulting in significant yield losses. Weeds such as nightshade, pigweed and purslane can serve as alternative hosts between curcurbit crops, however the virus itself can remain infectious for many months on crop residue, soils, and growing surfaces/tools.

Symptoms of infection will vary between species and strains of the virus, however mosaic mottling of leaves is a common denominator across these variables. At the early stages of infection, the cucumber plants will continue to grow and bare fruit. As the infection becomes more severe, fruit mottling and distortion can be observed. The plant itself will eventually stop growing, or show severe distortion. Unlike some other viruses in this group, CGMMV's ideal growing conditions mimic those for cucumber production, creating a scenario that supports rapid propagation of virus particles within infected plants. 

CGMMV is most commonly reported to originate from infected seed, but is also easily spread through contact with inoculated tools/workers and existing wounds on the plant. Chewing/sucking/piercing insects, while not listed as a major source of transmission of this virus, may contribute to spread in an already infected production space. 

What can be done?

There are a handful of things that can be done to reduce the chances of infection, and reduce the risk of spreading amongst the crop once the first symptomatic plants have been identified:

1 - Purchase verified, disease-free seed from a reputable supplier. Seed saved from infected cucumber plants are likely also infected, and with its stable shelf life, the virus could survive for many years. Seed can always be submitted for additional disease testing to accredited labs if you are unsure.

2 - Establishing, and maintaining, strict biosecurity protocols on farm. For greenhouse spaces, this means:

•    Adhering to an agreed upon order of entry - the most 'valuable' plants, such as seedlings, or newly transplanted crops are visited earlier in the day, before visiting the least 'valuable plants, such as those that are nearing the end of their harvest window. Once you have been 'contaminated' by the lesser value spaces, you will not re-enter the spaces containing the more susceptible crops
• Wearing clean clothes when working with your crop. These clothes cannot come from the field, or spaces where they may have come into contact with disease-causing agents. The use of greenhouse-designated coveralls or lab coats is a good way to limit transmission of pests and disease from the outside. The same goes for footwear - having designated footwear that is worn in the greenhouse is a good way to limit accidental introductions. Alternatively, the use of footbaths containing virkon, or other sanitizing agents, can limit spread as well. 
• Designate production supplies to each greenhouse - instead of having one pair of pruners that float around between all the spaces, try and have a set for each production space. Harvesting buckets, carts, and other lower-cost items should not be shared wherever possible, to limit potential movement of diseases and pests across the farm. For larger tools (sprayers, lifts, ladders), adopt a regular schedule of cleaning before/after use to prevent accidental spread.
• House sanitizing agents (ex. virkon, alcohol, bleach) within each greenhouse for tool sterilization. 
• Regular cleaning and sterilization of greenhouse tools to prevent build-up over time. This should be done more frequently than just between cropping cycles. The timing will depend on the item - pruners should be cleaned and sterilized very regularly, whereas larger tools like carts may see this less frequently. 

3 - Ensure that your compost/waste plant material pile is located FAR away from your production spaces. Pests and diseases can proliferate in these piles, and easily be carried by wind or wings into your new healthy crops. 

•     If you have had previous issues with viruses in your space, that plant material should be destroyed, as opposed to composted, to reduce the risk of re-occuring infection

4 - Enforce a strict, regular scouting program on farm, including documentation of location, timing, severity and which pests/disease was spotted. 

5-  Stay on top of your insect pests. Allowing piercing/sucking pest populations to grow only increases the risk of disease transmission throughout the production space once a virus has been identified. 

6 - If symptomatic plants have been identified, contact your commodity specialist. Isolating this area of the greenhouse as best as possible is a good course of action in the meantime, and making sure that infected clothing/tools are not used in asymptomatic parts of the greenhouse. Disease confirmation can be done through the use of immuno strips, or most reliably through an accredited lab, before coming up with a plan of action.

 

For more information on CGMMV, check out Alberta's 2016 factsheet here

If you have any questions, or suspect infection amongst your crop, reach out to your commodity specialist for further discussion.

-Talia 

Preparing for September Storms

September is typically characterized by threats to the province by tropical storms and full-fledged hurricanes. It is important to stay informed on the timing, and track, of all monitored storms in order to give yourself as much time as possible to come up with a plan of action and prepare the farm.

Check out Environment Canada's Hurricane Track for updated information on all monitored storms.

Once the forecast becomes a bit more clear on the storm track, daily tasks can be managed to try and reduce the amount of damage caused, or overall loss. Crops that are most vulnerable to weather extremes can be prioritized in order to save as much of the crop as possible. Things like cucurbits and field tomatoes are prone to splitting after heavy rain, so would fall high on the list of things to harvest before things get going. Consider postponing seeding new plantings or cover crops in the days leading up to a significant storm. Wind and pounding rain can cause erosion and flooding, which could easily dislodge tender seedlings or wash away the seed altogether.

Preparing Your Greenhouses

Greenhouse or high tunnel structures can be dealt with in a couple of different ways in the face of an impending storm, both with their advantages and disadvantages. If there is an option to remove the plastic from a structure, the chance of structural damage can be significantly reduced. While this would expose the crops beneath, and could result in crop damage and loss, the main infrastructure can be saved. It is a difficult decision to make, but ultimately compare the value of the crop to the value of the structure itself when weighing the options. For crops that are typically terminated mid September, a slightly earlier end to the season could be less detrimental compared to the loss of a structure. 

If removing the plastic isn’t an option, make sure everything is sealed up as much as possible to prevent the wind from tearing things loose. Latch and brace doors and vents, re-enforce end walls, and tie the sides of tunnels down tight. Most structures will have a rating for maximum wind speeds they can withstand. Take into consideration any shelter/exposure provided by the topography of your farm as well as the up to date weather forecast to help make an informed decision. 

It is also advised to unplug electrical equipment where possible to prevent a surge once power returns, and ensure that drainage systems are cleared and ready for large volumes of water. Make sure that the area surrounding the greenhouse is clear of items that could be picked up by the wind, and that any weak/old overhanging tree branches have been removed. 

If you have a generator, make sure you have plenty of fuel and that it’s in an accessible place. If you don’t have a generator and require power for your watering system, make sure to give the crop a good water before things get going. Its always a good idea to try and have some water set aside in barrels in case of emergency.

The Aftermath

Besides damage by wind and heavy rains, disease issues can be a big consideration after a storm event. Heavy rain can splash fungal spore or bacteria-containing soils around, facilitating the spread of infection. Crop protectant products may be washed away, leaving the plants vulnerable until they can be sprayed again, if at all. Wind and rain may cause physical damage to the plants themselves, causing them stress and areas of damage where infection can move in. High winds sweeping up the coast may even carry insects from elsewhere, resulting in a flush of insect pressure that would otherwise be unexpected. It is important to scout your remaining crops as soon as possible after a storm has passed so that there is opportunity to mitigate any pest pressure brought on by or worsened by the weather.

In the meantime, keep track of the forecast and plan ahead as much as possible. Stay safe everyone

-Talia

Winter (Greens and Cover Crops) is Coming

For those of you who anticipate winter greens production in your greenhouse rotation, now is a great time to make sure that you have your plan in place! Seeding date is crucial for plant establishment into the fall before light levels drop below critical values. Below is an example of the time to harvest for three different winter greens, and their corresponding planting dates. While these are not set in stone, and success is going to vary year to year based on climatic conditions, it demonstrates the impact that lower light conditions have on ready-to-eat winter greens:

    Spinach

• Planted September 19 --------> Harvested November 5
• Planted October 25 -----------> Harvested February 19

    Mustard

• Planted September 22 --------> Harvested October 29
• Planted October 26 ------------> Harvested February 12

Claytonia

• Planted September 22 --------> Harvested November 19
• Planted October 21 ------------> Harvested February 19

Consider the value and health of your summer cash crops when deciding which is going to make more sense for you going forward. Split seeding dates can be an effective strategy to try and get the best of both worlds, as suggested by David Blanchard in his two-part series presentation for the original 'Getting Into the Weeds' series. Anyone who is considering, or currently producing, winter greens production should check out this session! He goes into his experience growing certain types of greens, the pros and cons of different tunnel structures, and how to buffer against cold temperatures with relatively little input from supplemental heating.

                    Winter Greens Production Part 1 - Watch Here!

                    Winter Greens Production Part 2 - Watch Here!

Along that same vein, those of you who are considering implementing cover crops in protected spaces should start thinking about the plan for the upcoming season transition. Cover crop establishment is highly dependent on seeding date, alongside making sure the crop has sufficient water to germinate, and is seeded appropriately. Below is an image of a seeding date trial for a tillage radish+ oats mix implemented in 2022-2023. The greenhouse was subdivided into 4 sections, with the first planting date happening mid September shown on the far left of the image. Each of the remaining sessions were planted on a weekly basis, with the final planting date taking place mid October (far right of the first image). The amount of above-ground biomass is significantly different depending on planting date, with higher amounts of plant tissue in the early seeded treatment compared to the later one. More biomass translates to more organic matter generation in the space, which can in turn contribute to healthier soils and improved nutrient banks for next years crop. You can see a close-up of the density in the early planted cover crop on the right hand image below.

For more information on cover cropping in protected spaces, check out our session with Judson Reid from March 2023, where he discusses basic timelines and practices that will optimize cover crop performance indoors.

                    Cover Cropping in Tunnel Spaces - Watch Here!

As always, don't hesitate to reach out to our Protected Crop Specialist for all winter-greens production questions.

Posted by: Talia Plaskett

Storms: Planning for more than just your chips

 

It may seem early to start thinking about downy mildew or some of those other nasty fungal pathogens that are sure to be coming our way soon. However, as storm systems make their way up the Eastern Seaboard they usually bring spores with them from diseased fields all along the coast. In addition to transporting spores to our province they usually provide ideal conditions for fungi to colonize plants as these systems often bring with them sustained wet, cool, and humid conditions.

Downy mildew was positively identified in New Jersey last week and while it doesn’t look like storm Bret and the newly developing storm Cindy will be tracking over Nova Scotia anymore, it’s important to monitor systems coming up the Eastern Seaboard to correctly time preventative fungicide sprays and other IPM techniques such as trapping and scouting for new pests and ensuring physical barriers such as insect netting are in place as needed.

Over the last 2 years downy mildew has become a serious problem for cucurbit growers here as it is devastating when it gets a foothold in your field. Over the last 2 years both of the first confirmed occurrences in Nova Scotia happened in August, however, we need to be prepared for earlier occurrences as it is only one storm system away once it is detected along the eastern U.S coast. Along with fungal spores, these systems can bring with them novel insect pests to be mindful of as well.

Please reach out to your commodity support specialists if you have any disease or pest concerns!

Click here for excellent information on effective disease management, fundamentals of fungicides, herbicides and using weather stations for decision making on your farm

here for more information on downy mildew in Nova Scotia

Tim

Upcoming Tour for Greenhouse Soil Health

 Extra! Extra! Learn All About It!

Judson Reid and Talia Plaskett will be making the rounds in Nova Scotia July 3-July 5 for farmer-guided discussions on soil health in tunnel spaces! These sessions will be primarily focused around nitrogen management, and the crucial considerations to make when selecting nutrient inputs to make sure that we are supporting a healthy and resilient soil system, as well as maximizing the productivity on our target crops. This conversation is easily catered to production that is organic, conventional and everything in-between.  Feel free to bring your most recent soil test and tissue test results for some feedback and general discussion surrounding what those results are telling you.

Where soil health is a complex, multi-dimensional topic, the tour team will also be talking about the use of cover cropping in protected spaces. Where cover crops are hardly a new practice, the inclusion of this concept into tunnel spaces is not as commonly practiced. Cover crops offer a handful of benefits to protected producers, where erosion may not be the primary concern, but they can help facilitate drainage, fix nitrogen directly into the soil, maintain healthy microbial communities, and help to build organic matter in these highly productive, highly utilized spaces. 

The intention of these sessions is to provide a space for current and prospective tunnel producers to talk about soil health, and how protected production can lend to some unique challenges not typically seen in outdoor settings. So grab a friend, and register today for your closest tailgate meeting, for what should make for a very interesting session! 

More information can be found here

Posted by: Talia Plaskett

Cucurbit Downy Mildew was detected in New Jersey on June 13th, 2023

The first incidence of Cucurbit Downy Mildew was detected in New Jersey, United States on June 13th, 2023. Previously (in 2021 and 2022) Clade II has been detected in Nova Scotia, in the Annapolis Valley region, which predominantly infects cucumbers and cantaloupes. Clade I, which affects watermelon, pumpkin, squash, and zucchini has not yet been detected, but monitoring should still be undertaken in these crops on the chance that it does make an appearance.

It is important that growers remain vigilant and scout their fields regularly for this disease, as spores may be blown into the province by storm systems in the United States. We are not recommending protectant fungicides at this point in time, but strongly recommend weekly scouting for disease.  Downy mildew may be identified initially as water-soaked lesions that appear on the top side of the leaf, which may first appear on any region of the canopy. The most ideal time to identify these lesions are during or right after a heavy dew. The centre of the lesion initially appears chlorotic or yellow before eventually the tissue dies, becoming brown or necrotic (Fig 1 and 2). This disease is very fast spreading, the lesions will continue to spread across the canopy, and quickly kill the entire plant if left unchecked.  When conditions are humid, a “downy growth” may be observed on the underside of the initial water-soaked lesions. These symptoms may first appear before lesions on the upper leaf. This growth is particularly apparent in the morning, after a period of wet weather or dew formation.

Growers must stay vigilant, scout often, and report any positive findings they may see.

 

Figure 1: Chlorotic lesions associated with downy mildew infection on cucurbits.

Figure 2: Necrotic lesions associated with downy mildew infection on cucurbits.

If you suspect downy mildew in your field, please contact Dustin MacLean, the Field Plant Pathologist at dustinmaclean@perennia.ca or 902 324-9623.

 

 

Posted by Dustin Maclean, Horticulturalist and Field Plant Pathologist with Perennia