Jeff Franklin, from AAFC at KRDC, is bringing the weather update in terms of temperature after the heat wave. The last couple of days have been with an unusual heat wave, which can increase the vineyard growth rate and make some vineyard activities difficult. Even though the conditions have been warm, fungal disease management is something to keep in mind at all times.
The first table shows the temperature base 5⁰ C and 10⁰ C from 2019 until 2022 accumulated from March 1 until July 26. 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) |
927.1 |
1014.3 |
1107.8 |
1079.6 |
1025.2 |
1033.3 |
|
Insect development
(Base 10º) |
493.6 |
597.1 |
635.5 |
612.0 |
583.3 |
587.9 |
Figure 1. Degree day accumulations as of July 26, 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.
At this time, we can see how the difference between 2021 and
2022 has diminished the last week due to the increase of temperatures.
Moreover, compared to the 5- and 10-year average, it increased the accumulation
on 2022 the last 7 days. Currently, the forecast is showing warm temperatures
for the next week, it’ll be interesting to keep an eye in the degree days and
plant phenology the next couple of days.
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.
.v2.jpeg)
Figure 2. Degree day accumulations as of July 25, 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.
As previously mentioned, the trend changed last week due the
heat wave of the last couple of days. 2022 is slightly higher than the 5- and
10-year average. Compared to previous seasons, the differences are smaller, and
the most notorious year is 2006.
Berry growth is
moving smoothly with nice development, even though the conditions have been
quite warm the last week. Hybrids are moving along with good development,
depending on the variety and location the growth will vary. On the other hand, Vitis
vinifera are growing steadily, but slightly behind compared to the hybrids
due the phenological stages and the location in the province.
Figure 3. On the left Castel and on the right Frontenac.
Figure 4. On the left
L’Acadie and on the right Chardonnay.
Figure 5. On the left Riesling
and on the right Geisenheim.
Mentioned last week, Downy Mildew pressure has been quite
high with the current conditions, high moisture, and warm temperatures. Even
though the conditions have been changed to less humidity and warmer, which can
be suitable for other diseases such as Powdery Mildew, it’s necessary to keep
an eye in the vineyard for symptoms on the canopy or the clusters.
Figure 6. Leaf with Downy Mildew this week.
Figure 7. Chardonnay
berries this season with Downy Mildew.
In last week publication was recommended to
- Scout minimum 3 times per week the vineyard
- Check the most susceptible varieties, and
- Spray according to the situation.
Moreover, it’s necessary to check other diseases as well, differentiate with other fungal diseases to spray the proper fungicide to keep control in the vineyard. For this information and to have an access to the Grape Production guide, please check the previous publication in the following link about Downy Mildew management tips.