Jeff Franklin from AAFC Kentville is bringing the weather update, which is quite positive to keep grapevine growth in a proper way. Currently, the plants are growing in a good rate, especially the ones with earlier bud burst and on locations with warmer conditions. Mentioned last week, grapevines like Lucie Kuhlmann and Frontenac have been growing steadily and are already in shoot thinning process and in some cases even starting to tuck. In the case of vinifera varieties, the early ones are in shoot thinning process as well.
The first table shows the temperature base 5⁰ C and 10⁰ C from 2019 until 2022 accumulated from March 1 until June 6. 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) |
277.5 |
313.6 |
416.4 |
383.1 |
342.9 |
360.2 |
|
Insect development
(Base 10º) |
86.7 |
137.8 |
184.4 |
160.8 |
141.3 |
155.4 |
Figure 1. Degree day accumulations as of June 6, 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.
Like previous weeks, the positive trend continues showing
higher values than the average of the last 5 and 10 years. Currently 2022
presents 160.8 base 10⁰ C, which is
slightly lower than 2021 with 184.4 base 10⁰ C, as consequence of the decrease of temperatures last week. Despite
that, the temperatures have helped positively to the vineyard development,
independently if they’re hybrid or vinifera.
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.
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Figure 2. Degree day accumulations as of June 6, 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.
This graph shows the increase of temperature in 2022, with
higher temperatures than the average of the last 5 and 10 years. The difference
this time is in 2021, the temperatures were slightly higher than this year
until June 6. Compared to the recent previous years, it’s important to highlight
that currently 2022 is slightly higher than 2017 and 2012 is still the warmest
year in this graph.
Last week it was mentioned that shoot thinning will be
recommended to start soon depending on your varieties and the location. The main
considerations shared last week to keep in mind are:
- 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.
Related to spray applications, remember that scouting a
couple of times per week is highly recommended. The priority areas are the
places where usually appears first the symptoms by diseases or insect damage.
Therefore, keep track of locations and disease symptoms throughout the vineyard
to spray accordingly to what is affecting to the vines.
The following photos show vineyards before and after shoot
thinning and Erineum mite in Geisenheim.
Figure 3. Single cane before and after shoot thinning
Figure 4. Double cane before and after shoot thinning
Figure 5. Erineum
mite in Geisenheim
Finally, today Thursday June 9 from 6:30 pm until 7:30 pm, the Best Practices session 2 will take place. At this time the main speaker will be Jeff Wentzell from NSDA. Registration is required and it’s possible in the following link or try the hyperlink: https://perennia.zoom.us/webinar/register/WN_mRSKqvAoSwm3wZ-pNN4TzQ
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