man, it's hot
Now that we're about to set a heat record for the summer (approaching 70 consecutive over-100F days in central TX), some thought is in order.
I am trying to keep some indeterminate tomatoes alive. They're trying to flower but, of course, won't set fruit. My peppers are going bananas, (we'll, they're mostly sweet banana peppers, but anyway ...), and my basil is holding on. However, although I've mulched religiously, they all still wilt seriously in the afternoon. I have to water every other day.
It occurs to me that these conditions may be somewhat extraordinary. The average air temperature for the last few months has been 92F (highs around 104, lows around 80, with DP~70). That pretty much means the deep ground temperature is about 92F. I suspect this deep ground temperature is higher than ever. When you have fewer days over 100F, the temperature deep underground won't be as high.
Now, sure, the average temperature in, say, Phoenix, is a lot higher than that. But there's a difference. There the dew point is a lot lower, so moist ground will be cooler, especially at night.
I know people who swear that their plants are dying, though they're careful about keeping them watered. Are they dying because of hot roots, instead of from hot air?
So, does anyone know what the effect on plants is of high root temperatures?