Jeff Franklin from AAFC Kentville is bringing the update from last week temperatures, which is quite positive as the last couple of weeks. At this time most grapevines have bud burst, depending on the locations and varieties the development can be slightly lower, for example in Pinot noir and Riesling. On the other hand, L'Acadie blanc and Frontenac have been growing steadily during the last couple of weeks with a good shoot development.
The first table shows the temperature base 5⁰ C and 10⁰ C from 2019 until 2022 accumulated from March 1 until May 30. At the end
of each section, it’s possible to see the average of the last 5 and 10 years
respectively.
|
Category |
2019 |
2020 |
2021 |
2022 |
5 year average |
10 year average |
|
Plant development
(Base 5ºC) |
224.4 |
244.0 |
323.1 |
332.9 |
280.2 |
295.1 |
|
Insect development
(Base 10º) |
64.1 |
98.8 |
125.8 |
138.9 |
108.2 |
120.6 |
Figure 1. Degree day accumulations as of May 30, 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.
Since a couple of weeks ago the temperatures have increased
and kept constant, therefore the averages values based for 5ºC and 10 ºC have increased. Like last week the season 2022 has the highest
accumulation of degree days in the last years until May 30, both for 5ºC and 10 ºC, and it’s even higher than 2021. The weekly values are similar
to last week when compared with the average of the last 5 and 10 years, 2022
shows higher values than these averages.
In the following
column graph, you can see the values from 2004 until 2021 and at the end the
average of the last 5 and 10 years respectively.
Figure 2. Degree day accumulations as of May 30, 2022
base 10⁰ 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.
In this graph you can observe the increase of temperature in
2022, with higher temperatures than the average of the last 5 and 10 years. Like
last week, it’s even higher than 2021. Looking at the previous recent years on
the graph, it’s interesting to see 2017, which was a very good year and
currently slightly lower than 2022. Let’s keep an eye to the forecast, to see
how the weather continues to evolve and influences the plant physiology.
Last week was mentioned that plant growth will develop faster with the increase of temperatures, which has been the case during the last couple of weeks. It’s recommended to keep an eye on early varieties and sections where the secondary, in some cases even tertiary, shoots are developing faster, it’ll be possible to start shoot thinning or ‘suckering’ depending on the shoot. Before proceeding with this task, look at the areas to be worked, to decide where is necessary to proceed and choose accordingly to your production desires.
Considerations to keep in mind:
- Avoid thinning before the flowers (know as inflorescences) of grapes are visible (0.8 to 4 inches).
- In the case of late shoot thinning, more than 12 inches, the shoots can lignify on the base, making shear usage necessary. This will take longer and be more expensive.
- Remove the weak and unfruitful shoots from crowded areas.
- If the primary shoot has good health conditions, secondary and tertiary shoots can be removed.
Moreover, it’s time to keep an eye on the spraying
applications and one good strategy is to look at your records. Areas and
varieties prone to have infections are the priority for the spray applications.
Before spraying, check the vineyard development in the areas expected to be
applied to have a good coverage and to safely protect the vines. In this way
the environment will be respected, and your resources will be used efficiently.
In the following photos, you can see some varieties at
different growth stages through this week.
Figure 3. On the left L’Acadie blanc and on the right
Frontenac this week.
Figure 4. On the left Riesling and on the right Pinot
noir this week.
Finally, last week Thomas Harrington, Agriculture Technology Specialist at Perennia, hosted the Weather Station Apps and Website Training Session, which is currently available on YouTube. You can watch it in the following link or directly here: