Seasonal update 2022: post storm, GDD, ripening and harvest

Wednesday, September 28, 2022

Last weekend hurricane Fiona hit our province, affecting throughout the vineyards and particular areas with more negative effects than others. Damage registered across the province is berry skin damage, some berry splitting and trellis system with broken poles. Extra attention must be considered with varieties expected to be hanged longer, scouting to take a look at any potential botrytis and products to manage them in case to be necessary. Moreover, as previous publications Jeff Franklin from AAFC Kentville is sharing with us the weather information of growing degree days and presenting less changes compared the middle of summer. Hybrids are in harvest mode, while some vinifera varieties are starting to be picked. Just remember, it’s always important to reach out the wineries to know which are the grape ripening requirements and when would be the best time to harvest the grapes.

The last couple of days have been quite busy, with the first chance after the Fiona many growers checked their vineyards, assessed, and worked immediately to fix as much as they could. Moreover, as we’re in harvest mode, many returned the next day or the following one to harvest the necessary varieties to be processed by their winery. A couple of things to keep in mind:

  • Scout assessing the areas with more damage in the vineyard, paying attention to berry damage, cluster damage, net issues, and trellis system failure. If the grapes are expected to be hanged longer in the vineyard, asses the disease pressure.
  • Double check with the winery if they’re operating in normal conditions, ask which are the plans with the crop and report your fruit conditions to facilitate the decisions. Wineries will appreciate to have open communication to coordinate when the most appropriate time is to receive the fruit.
  • Keep track of any damage in your vineyard, such as fruit lost, damage in the trellis system, damage in protection system (nets, fencing or wailers) and cost to repair equipment. Also, keep original documentation related to any reparation or cost due to hurricane.

Figure 1. Frontenac blanc with berry damage after Fiona

The first table shows the temperature base 5⁰ C and 10⁰ C from 2019 until 2022 accumulated from March 1 until September 27. At the end of each section, it’s possible to see the average of the last 5 and 10 years respectively.






5 year average

10 year average

Plant development (Base 5ºC)







Insect development (Base 10º)







Figure 2. Degree day accumulations as of September 27, 2022.  All data are taken from the Kentville weather station, based on a start date of March 1, and calculated using the single sine method.

The last week the degree days increased, but like last week, the pace has diminished with the shift in the weather. Compared to the 5- and 10-year average, 2022 maintains a considerable higher accumulation of degrees. Now it’s possible to see a slightly difference with 2021 and the biggest difference is compared to 2019.

In the following column graph, you can see the values from 2005 until 2022 and at the end the average of the last 5 and 10 years respectively.

Figure 3. Degree day accumulations as of September 27, 2022 base 10 C. All data are taken from the Kentville weather station, based on a start date of March 1, and calculated using the single sine method.

Already mentioned in the previous table and last week, in 2022 the accumulation is higher than previous seasons and it is higher than the 5- and 10-year average. Compared to previous seasons of 2021, 2020 and 2018, it’s very similar to the current season and only overpassed by the season 2012. Depending on varieties and locations, ripening will move differently, for that reason it’s important to keep notes and compare with your previous records.

Ripening is moving through all the varieties in the province and with the shift of temperatures, it can diminish the speed of sugar loading and drop of acidity. Depending on the winery goals, it might be necessary to harvest earlier or later in the season. To know when the most convenient harvest date is, it’s important to reach the winery and establish an active communication plan to coordinate the harvest. The winery might request information to be able to take the best decision depending on the wine expected to be produced.

Figure 4. On the left Lucie Kuhlmann and on the right Frontenac blanc.

Figure 5. On the left Chardonnay and on the right Riesling.

Meanwhile ripening is moving along, some growers have already started harvest with the earliest grapevines depending on the winemaking purposes. Mentioned a couple of times in this post, active communication with wineries is fundamental to have the grapes harvested depending on the wine goals. It’s important to track grape ripening to help taking harvest decisions and inform to the winery on how the maturity is moving along in your vineyard. Remember, the results will be as good as the sampling performance. The sampled grapes need to be representative of the plot that they are coming from. It’s a good idea to collect a minimum of 100 berries from a specific variety and repeat in the same area(s) to be able to track the ripening process. Alab from Acadia University provides analytical services for grape ripening, please take a look at the lab webpage for more information