At a recent crop walk event that I attended, there was a bit of discussion surrounding the weather. That isn’t entirely surprising given the record-setting high temperatures (and major lack of moisture) that the prairies have been experiencing this summer. Producers were doing all that they could to supply the water that the developing crops required, but it is a close thing.
There was also a bit of discussion about whether the smoke was having some impact on the crops and their development. I would say that up until the last few weeks, the smoke that was present wasn’t nearly as bad as I remember from back in 2018, when everything was a sickly sepia-toned mess, and being outside for any amount of time felt a bit like I imagine smoking a couple of packs of cigarettes might feel like. Whatever it felt like, it wasn’t pleasant, and it definitely had an effect.
What impact might smoke have on plant growth?
It is hard to predict what affect that smoke might have on the plants. I’m not sure if the smoke has any direct impact on the plants themselves, but I suppose that would depend on what the chemical composition of the smoke was. Extended periods of smoke can reduce the amount of sunlight that penetrates the atmosphere, which would have a range of effects. To pull together some evidence-based speculation, let’s look at two other seasons, where we saw smoke or other weather changes that might be useful to look at.
Back in 2018, the smoke cover was heavier and lasted longer than in 2021 (since it started earlier). That summer, we saw plants with reduced vigour and plant growth. There were some delays in maturity and some stretching of plants.
Looking at 2019, the weather was a lot cooler than in some comparative years, which was supported by weather data collected from several weather stations. It was cool, cloudy, and there was a lot more moisture. Pulling solar radiation data for the same period also showed depressed levels compared to other years, as you’ll see from the chart I dug up from an old presentation. So, there was some shading and reduced sunlight to deal with.
Theoretically, having a bit of shading can reduce sunscald and could potentially reduce the impact of high temperatures and reduced moisture levels, but I’m not sure that this held true in 2021. It seems like we might have had some heat trapping and a dampening of the day and night temperatures, but that would be hard to prove without a deep dive into the weather station data.
If the above observations and guesses come into play, I would think that plant growth would be affected. Plants may not develop entirely normal, either experiencing delays in maturation, or perhaps growing a little bit differently. I’m not sure how much flavour and sweetness will be affected. Regardless, it will be hard to separate the effects of smoke from that of extreme high temperatures and a lack of moisture.
Hopefully we all get some rain soon to help suppress the fires and to balance things out. Or at least to clear the smoke a bit.