Garlic Harvest

Monday, July 20, 2020

As we move toward garlic harvest season, there are some important factors to keep in mind that will help determine the best time to harvest. 

Harvest timing is very important in preventing post-harvest diseases. Garlic should be harvested with five to six green leaves and before the cloves start to pull away from the stem. Green leaves correspond to the wrapper leaves around the cloves which protect them from light, moisture, and heat during storage. As the wrapper leaves start to deteriorate, the cloves will continue to grow and pull away from the stem causing the bulb to split open. Besides being unmarketable in this condition, exposed cloves make for poor storability. 

Check out Perennia’s new “Garlic Storage, Post-Harvest Diseases, and Planting Stock Considerations” factsheet for more information.

Water Use Efficiency

Wednesday, July 8, 2020

As members of the agriculture industry, we feel the effects of the weather in everything we do and even more so in a year full of challenges, like the one that we’ve had so far. With so little rain in June for most parts of the province (Table 1) and irrigation ponds running lower than usual for this time of year, it is important to take some steps to ensure efficient water usage.

Table 1. Precipitation in Nova Scotia in June 2020 compared to the historical average from June 1981-2010.

Weather Station Location

Total Precipitation June 2020 (mm)

Average Precipitation for June 1981-2010 (mm)

Percentage of Historical Average Rainfall for June (%)


























Make sure irrigation equipment is in good working order.

A cracked irrigation pipe or a leak at a loose fitting may seem like a small issue when there are so many other things that need to be done in the run of a day – especially when labour is already in tight supply. Over the course of a week, you may be losing significant amounts of water which could make the difference for one of your crops later in the season. Check all components and connections in the irrigation system regularly and carry out preventative maintenance when possible.


Although trickle irrigation is more efficient than overhead types, it is still possible to have breaks or poor connections. These lines should be checked and maintained as well.

Irrigate in the morning or evening to avoid excess evaporation.

Where there is limited irrigation equipment or there are many crops that need to be irrigated, it may not be possible to avoid irrigating when the water is most likely to evaporate, when the sun is blazing and the wind is high. Irrigating when there is less chance of water loss to evaporation may be a more efficient method but may also exacerbate disease infections. If there is disease present already, or the crop is particularly susceptible to fungal infections, irrigating at night may provide the cool and damp temperatures needed for disease to flourish. Weigh the benefits of each option and choose what makes the most sense for your crop.


Greenhouses can experience water stress as well.

In the field, drought stress usually develops over time, allowing the plants to get used to the environmental changes little by little, but in the greenhouse where the environment is more controlled, an abrupt reduction in water supply may cause severe physiological stress in the plants. Be sure to monitor water supply and start rationing if necessary, to ease the shock that would be caused by sudden drought stress.


Be prepared to make tough choices.

In long periods of drought there may come a point where water supply is so limited that there isn’t enough capacity to water every crop sufficiently. Some factors to consider in deciding which crops take priority for water include critical growth stage, effect on marketability, value of the crop, etc.

For more information, check out OMAFRA’s factsheet “How to Prepare for Irrigation During Water Shortages”.

Things are Heating Up for Insects

Tuesday, June 23, 2020

Insect development relies on the accumulation of heat throughout the season to progress through their life stages, allowing their development to be tracked with the use of degree day models specific to the insect. By tracking the degree days, the timing of key activities such as adult flight and egg hatch can be predicted, facilitating scouting and pest management activities. To calculate degree days for a particular insect, there are two pieces of information that need to be known: the base temperature (the minimum temperature required for the development of that insect), and the biofix date (the date on which degree day calculations for that insect will begin). The equation used to calculate degree days for insect development is:

GDD = ((Tmax + Tmin)/2) – Tbase

In the equation, Tmax and Tmin refer to the maximum and minimum temperatures on a single day. Using this equation, the growing degree days can be calculated anywhere that has daily temperature information available, making it possible to tailor the model to a particular geographic area. Being able to customize data is important in Nova Scotia where we have a number of microclimates with sometimes significantly different weather often caused by the geography and proximity to the Atlantic Ocean or the Bay of Fundy. Environment Canada lists all of the weather stations available in Nova Scotia both past and present, and can provide the temperature data needed to calculate degree days. Choose the closest weather station logging hourly data for the current year. It is important to note that while degree day modeling can be a useful tool, development models from other geographic areas are not necessarily validated for use in Nova Scotia. Degree day modelling should be used in conjunction with, not as a replacement for, regular scouting.

European corn borer (ECB) is a pest of a number of crops in Nova Scotia. There are two types of ECB, with significantly different development schedules. The univoltine type completes one life cycle in a growing season while the bivoltine type can have two lifecycles in a growing season, though in cool summers the second generation of the bivoltine corn borer may not be able to complete its development.

Mature larva in silk tunnel
European corn borer larva in a corn stalk. Photo:  

Both univoltine and bivoltine types of European corn borer use a base of 10°C and a start date of April 1st for degree day development models. As of June 21st, 239* degree days had been accumulated in Kentville and 190 in Debert. According to the model, at 231 degree days, about 5% of pupae are emerged for univoltine types, with egg laying starting to occur around 425 degree days. For bivoltine types, about 50% of 1st generation adults are emerged by  281 degree days, with a second generation starting their flight around 792 degree days.

For more information on European corn borer in Nova Scotia, check out Perennia’s new fact sheet!

*These numbers were generated with CIPRA software, AAFC, Saint-Jean-sur-Richelieu, Quebec.

How Perennia Agricultural Services is Adapting to Working in COVID-19

Friday, May 29, 2020

During this time of COVID-19 restrictions, members of the Perennia Ag Services staff are adapting how we work to ensure the health and safety of our staff and clients. Check out the following bulletin for details on how we're working to best serve you in these challenging times.

Upcoming Webinar on U-Pick and On-Farm Produce Sales

Wednesday, May 27, 2020

The recent announcement that u-picks will be allowed to operate this summer brings with it the task of figuring out how to make that happen while adhering to COVID-19 guidelines. On June 2nd from 4-5pm, join us for a webinar on “Strategies and Adaptations for U-Pick and On-Farm Produce Sales”. This will be an opportunity to discuss practical management strategies to reduce risks associated with COVID-19. Speakers include Perennia Horticulture and Food Safety specialists as well as Farm Safety Nova Scotia.

Representatives from Perennia’s Horticulture Team, Horticulture Nova Scotia and the Nova Scotia Department of Agriculture will also be on hand as we address your questions and concerns. There will be a question and answer session live during the webinar, so come prepared!

Please visit the following link to register for this informative session.
We look forward to having you there and working together to have a successful season!

Time to keep an eye out for cabbage maggot

Monday, May 25, 2020

With a cool start to the spring this year, insect pests have been a little later getting out and about than we would typically see. Now that there are warmer days upon us, it's important to pay attention to when those insect pests will be active so that control measures can be taken in a timely fashion.

Cabbage maggot (Delia radicum) is a particular challenge in brassica crop production. It overwinters in the pupal stage, emerging in the spring, usually coinciding with the bloom of yellow rocket and serviceberry. From a degree day perspective, emergence begins around 161 Degree Days (DD) at a base of 4°C, with peak flight occurring around 250 DD for the first generation of cabbage maggot. As of Friday May 22, 2020, 175 DD (base 4°C) had been accumulated in Kentville. Other Delia species, Delia platura (seedcorn maggot) and Delia florilega (bean seed maggot) are also on the move in the Valley.

Cabbage maggot larvae in soil. Photo UMass Extension.

Once the first generation of adults has emerged in the spring, they take flight and lay their eggs. It is important to know when peak flight is taking place so that you have the opportunity to alter planting times or deploy control measures, such as insect netting, accordingly.  For scouting purposes, eggs can usually be found small clumps on the soil around the base of your seedlings. For more information on cabbage maggot, including concerns about pesticide resistance, check out Perennia’s fact sheets “Cabbage Maggot” and “Chloropyrifos Resistance in Cabbage Maggot”.

April Shower Bring May... Insect Pests

Tuesday, May 19, 2020

As we head into late May, things are finally feeling like spring and the soil is warming up. With warmer soils come more productive growing days, but also a cozier habitat for pests, including wireworm!

This time of year, wireworms move up to the warmer top layers of soil, feeding on newly seeded or transplanted crops. In fields you know to be problematic areas for wireworm, consider growing a less susceptible crop and practicing crop rotation. Consider cover crops such as brown mustard and buckwheat to combat existing populations. Avoid planting highly susceptible crops such as cereals or potatoes in problematic areas.

Wireworm attacking a lettuce transplant. Photo courtesy Rosalie Gillis-Madden, Perennia.

For more information about wireworms, including how to set up a bait trap, check out Perennia’s new wireworm fact sheet.