Winter Greens Production Workshop

Tuesday, January 14, 2020


As part of Perennia’s ongoing Getting Into the Weeds series, please join Perennia Vegetable Specialist Rosalie Gillis-Madden and David Blanchard of Pleasant Hill Farm for an in-depth examination of winter greens production in Nova Scotia.

Winter greens production can offer a new marketing opportunity for Nova Scotia growers at a time of year when cash flow may be low and price points for fresh local produce are high. Some systems require only modest capital investment and have low operating costs because they avoid the use of supplemental heat and lighting. Because local winter greens can be harvested within a day or two of purchase by the consumer, locally-produced greens have a freshness and quality advantage over imported greens that are one to two weeks post-harvest by the time they reach the consumer. This workshop will examine infrastructure requirements, capital costs, operating costs, income potential, crop and variety selection, and horticultural considerations such as planting dates, fertility, and pest management.
This workshop will be offered in-person at three locations and as an online webinar on February 14th.  There is no cost to attend.  Seating is limited and registration is mandatory.  For further details and to save your seat, please click on the following links:

Changes Coming for the Use of Chlorothalonil (Bravo®) Products

Tuesday, January 7, 2020

By Jill MacDonald, Perennia Research Associate

Chlorothalonil is a contact and protectant fungicide that controls a broad range of fungal diseases. It is used on a number of crops. Due to the recent re-evaluation of chlorothalonil by the Pest Management Regulatory Agency (PMRA) there are changes that will affect how growers use the product, in relation to how it is mixed, loaded and applied. The re-evaluation has caused a discontinuation of Bravo 500 and Ridomil Gold SL/Bravo Twin-Pak formulations. The final day that these products will be available for purchase is May 10th, 2020, and the final day that growers will be able to make applications of these products is May 10, 2021.  After this time, it will be the responsibility of the grower to properly dispose of any leftover product.

How will these changes affect how I use chlorothalonil products?

Changes to Number of Applications Permitted

There have been several changes made to the number of applications that are permitted on fruit and vegetable crops, it is important to check how your crop is affected. The full list of changes, including application rates and REIs can be found here.

A few of the crops that are undergoing changes to the number of applications permitted per season:
Blueberry (HB)
Celery, field
Cherries (sweet and sour)
(2 spring + 1 post-harvest)
Cole Crops
Cucurbit Vegetables
Onion, dry bulb
Onion, green bunching
Peach, nectarine
(2 spring + 1 dormant)
Potato, table
Tomato (not for processing)

Additional PPE, Buffer Zone Changes and REI

New requirements have been put in place to protect the applicator and persons who are handling the product, by increasing the amount of personal protective equipment (PPE) required. It is recommended to read the revised product label to obtain information on PPE and changes to the buffer zone requirements and restricted entry intervals (REI) for certain activities. Growers are reminded to have the updated label available to staff members who may come in contact with the product, as well as making them aware of the changes.

Implementation of Vegetative Filter Strips

Use of chlorothalonil requires a 10 meter (32’) vegetative filter strip (VFS) to be planted, if there is an aquatic ecosystem downhill from the field or sprayed area. A VFS is different than spray buffer zones: the filter strip is typically perennial, hardy, deep-rooted native vegetation that can slow runoff and filter out any pesticides that the runoff may contain. 


Introduction of Closed-system Transfer

The PMRA will now require growers, under certain circumstances, to use a closed-transfer and application system. The closed-system transfer specifically focuses on mixing and loading of the product. All potato applications, or any applications when more than 340 kg a.i. are handled in one day will be subject to these requirements.  When product is directly transferred from the tote to the sprayer tank, this will now require dry poppet connections which comply with closed-transfer. Dry poppets are available from several manufactures and are also known by several names, such as dry poppet couplings or valves. Syngenta currently supplies a female dry poppet to male cam lever adapter with each tote of Bravo Zn. Many chemical handling systems and sprayers are fitted with cam lever connections from the factory, in this case you can purchase a dry poppet to cam lever adapter. The existing dry poppet valves on the 450L totes of Bravo®ZN are already compliant with the closed-system transfer requirement and will not need to be altered.

Additional Important Changes

Hand harvesting of processing tomatoes and application through irrigation systems on strawberries and cucurbits (cantaloupe, muskmelon, honeydew, squash, pumpkin, watermelon and cucumber) is now prohibited.

For further details, please visit

Getting Into the Weeds - November 19th, 2019

Thursday, November 14, 2019

This winter, Perennia Horticulture Specialists Rosalie Gillis-Madden and Jennifer Haverstock, are planning a workshop series called "Getting Into the Weeds."  This series will offer an in-depth look into certain aspects of horticulture production.

In collaboration with NSDA Regional Offices, the inaugural session is taking place on Tuesday, November 19th, from 10:00 - 11:30 at locations across the province.  Topics for discussion include: High Tunnels – site selection and preparation, and long term nutrient management, as well as soil-less substrate and different potting technologies. Using remote technology, we are excited to welcome guest speakers from across North America.

  • Elizabeth Buck, Extension Vegetable Specialist, Cornell Cooperative Extension Vegetable Program Avoiding a “Tunn”-el of Trouble: Site Selection and Prep
  • Judson Reid, Extension Vegetable Specialist, Cornell Cooperative Extension Vegetable Program High tunnel soils: Long term nutrient management for crop health
  • Shawn Mallen, Sales and Hydroponics Manager at A.M.A., Horticulture Inc. Substrate and Potting Choices in Tunnel Production
Admission is free, but space is limited, so we ask that you register in advance.  The deadline to register is Nov 18th at noon.  For details on how to register and to find the location nearest you, please click here!

Garlic spacing

Friday, September 27, 2019

John Zandstra from Ridgetown College in Ontario did some research on garlic spacing back in 2000, using the cultivar 'Music.'  A spacing of 10 cm between cloves and 65 cm between rows was standard practice in Ontario at the time.  They tried several spacings in a couple of different trials:
  1. 65 cm (25.5") between rows, 
    1. Cloves spaced at 5 cm (2")
    2. Cloves spaced at 10 cm (3.9")
    3. Cloves spaced at 15 cm (5.9")
  2. Cloves spaced 10 cm (3.9") apart
    1. Rows spaced at 65 cm (25.5")
    2. Rows spaced at 45 cm (17.7")
    3. Rows spaced at 25 cm (9.8")
    4. Rows spaced at 15 cm (5.9")
In the first trial, they found that decreasing the clove spacing from 10 cm to 5 cm resulted in a decrease in bulb weights by 15%, however yields increased by 74%.  For growers looking to increase their seed garlic quickly, but have limited acreage, a closer clove spacing may make sense.  Increasing row spacing from 10 cm to 15 cm did not affect bulb size, but decreased yields by 32%.  

In the second trial, significant increases in yield were found as garlic row widths narrowed, and bulb weights only dropped a little bit. Depending on the flexibility of your market and their willingness to accept slightly smaller bulbs, narrowing row spacing can have dramatic affects on yield.  To read the full report on the spacing trial, please click here.

Zandstra 2000: 10 cm between cloves with variable row widths, cultivar 'Music"

WANTED: Your post-harvest garlic losses.  I am working on a garlic storage disease factsheet, but I need your punky garlic for a photo op.  Growers who are registered farms in Nova Scotia: please bring samples to either Perennia (32 Main Street, Kentville, NS or 199 Dr Bernie MacDonald Drive, Bible Hill, NS) or to your Nova Scotia Department of Agriculture Regional office.  It is recommended that samples are brought in on Monday, Tuesday or Wednesday so they are not sitting on a truck or in an office over the weekend.

Lingering effects of Hurricane Dorian

Thursday, September 12, 2019

The Nova Scotia Federation of Agriculture recently sent an alert directing growers who continue to be in emergency situations impacting animal welfare, crop storage, etc.  (no power, generator failures, challenges accessing fuel for generators, access to reefer trucks, etc.) to contact Nova Scotia’s Emergency Management Office.  For more details, please see the full NSFA statement here.  

Late-season foliage loss in winter squash

Wednesday, September 11, 2019

Hurricane Dorian caused widespread damage in Nova Scotia.  Many cucurbit plants lost significant amounts of foliage.  Late-season foliage loss in winter squash and pumpkin leave the fruit exposed to sunscald.  If your crop has lost enough foliage so that there is no longer sufficient canopy protection to prevent sunscald, it is recommended that you harvest your squash and pumpkins.

Fig. 1. Sunscald on butternut squash, three
weeks post-storm.
Sunscald injury (Figure 1) occurs when cucurbit fruit are exposed to direct sunlight during the later stages of fruit ripening - while this year this is predominantly due to Hurricane Dorian, this can also occur as a result of powdery mildew, bacterial wilt, Phytophthora blight, or other pests.  Sunscald injury will result in rind tissue collapsing in the exposed area.  Initially the rind may appear water-soaked - on pumpkins this can be hard to observe at first and the area might just appear slightly sunken.  Darker skinned squash (particularly green acorn) will show sunburn fairly quickly.  Affected tissues can look bleached (Figure 2) and the rind may slough off when rubbed.  Over time, the fruit tissue may become tan, brown, or black (Figure 3), a result of secondary pathogens invading, and will eventually collapse.

Fig. 2. Sunscald on Sweet Mama, three weeks post-storm.
Typically, it is recommended that pumpkins and winter squash are harvested when they are fully mature for optimum quality and storability.  Fully mature pumpkins and winter squash will typically have a more hardened skin that is resistant to puncture with a thumbnail.  Fully mature
fruits will often have lost rind surface gloss and may have ground-spot yellowing.  Mature fruit that are left attached to vines are prone to infection in the stems and fruit.  As long as pumpkins have started to turn colour, they will continue to ripen off the vine if held under proper conditions.  When harvesting, avoid bruising the fruit or damaging the skin as this will result in storage rots setting in.

Proper curing and storing will greatly enhance the storability of your crop.  Note that chilling injury will occur if stored below 10°C (50°F).

Fig. 3. Sunscald on Sweet Mama with secondary infection,
three weeks post-storm.
The best conditions for ripening pumpkins are in a well-ventilated area at 27- 30°C (80-85°F) with relative humidity of 80-85%.  The curing period should be about 10 days.  This will help the fruit to ripen, the skin to harden, and any wounds to heal.  After curing, pumpkins should be stored in a cool, dry place (10 - 15°C or 50 - 60°F) with a relative humidity of 50-70%.

The best conditions for ripening squash are in a well-ventilated area at 21- 27°C (70-80°F).  How long squash will typically keep under optimal storage conditions depends on squash type.  Cornell has a chart outlining optimal storage temperatures and relative humidity based on squash type, which can be found here.  Note that if Acorn squash is stored below 13°C, it will become stringy.

The goal is to maintain enough humidity so that the fruit doesn't desiccate but not so much that condensation occurs which can promote bacterial and fungal growth.  Storing at higher temperatures results in weight loss, and at lower temperatures chilling injury can occur.  All fruit that is placed in storage should be free from disease and in good condition to promote the longevity of the crop's storage life.  Pressure bruises from packing fruit too tightly or too high can also result in reduce marketability of your squash and pumpkins.

Onion smut

Tuesday, August 20, 2019

Fig. 1. Infected leaves can become
bloated and split open, releasing spores
and contaminating the surrounding
soil.  Photo taken early August, 2019.
Onion smut only infects Alliums, and is a disease that can lie dormant in the soil for 15+ years, even in the absence of a host crop.  A cold spring such as we had this year results in the onion flag leaf emerging slowly, increasing the likelihood of smut infecting the onion.  The smut fungi can only penetrate and infect young seedlings - if the cotyledon escapes infection until it is mature, no further infection can occur despite high disease pressure. For this reason, healthy transplanted onions or onion sets typically avoid being infected by smut since they do not emerge in infected soils.  The infection period is from two or three days after the seed germinates until the first leaf is about three inches tall (about 10-21 days, depending on the year.)

Fig. 2. Black streaking on the onion bulb, August.
Early infections can result in seedling death, and plants that do survive will have characteristic black spots, blisters, and/or streaking (Fig. 1, 2).  Some infected plants will shed their outer leaves in the second month of growth, and continue growing, free of infection.  However, this year I'm seeing many infected plants that have survived the first few weeks of infection, and the smut fungus has continued to grow, systematically colonizing the plant.  These plants are are usually stunted.  Black pustules can infect as deep as the third or fourth scale (Figure 3).  Many infected plants will dry up, wither, and die by harvest.  Infected bulbs that do make it into storage shrink more rapidly, and are more prone to bacterial rots which can contaminate other bulbs in storage.

The causal fungi, Urocystis magica (synonym: U. cepulae) and U. colchici, can be transmitted from one field to another by surface drainage water, wind-blown soil, tools and farm equipment, soil in your shoe or truck treads, or any other method that transports soil.  Have you read Perennia's fact sheet about biosecurity in horticulture crops?

Fig. 3.  Smut infections penetrating several scales deep.

Long crop rotations are an important tool to limit the build up of disease in the soil.  Conventional growers that are planting into a known infected field should use seed treatments or an in-furrow fungicide application.  If organic or small-scale growers have a field history of onion smut, it is recommended to transplant onions into the field, rather than plant from seed in the infected soil.  Growers with smaller plantings should also remove and destroy diseased seedlings and plants to avoid building disease levels in the soil.