This Monday morning was not a good one. Upon arriving at the Plant Clinic, I heard an annoying beeping sound from our minus 80 freezer. Coupled with the warm room, it dawned on me that the air conditioning was not functioning. Checking the logs, I surmised that the ambient temperature in the lab was out of range as of 11:00pm (2300) yesterday night. To make things even more annoying, it was only our wing of the building (on the first floor) that had our a/c out-of-order, even the 2nd floor had a/c. So the morning was spent making sure that all incubators, refrigerators and freezers were working okay. Could hear that some of these machines were stressed. Now, we have a couple of fan circulating air in hopes of cooling the room a little. I even got desperate that I looked for a portable a/c unit for a temporary fix…. but none to be had in town. So many of the samples are now in the refrigerator on hold until we can process it. Sheila, the diagnostician, is off to Petersen Building (home of the Department of Plant Pathology & Microbiology at Texas A&M) to do some nematode extraction and count [it is cooler there]. This is the Texas heat in the summer.
The heat will do a number on pathogen, yet we do see quite a bit of root rots this time of the year. Why does disease even occur when the heat is not conducive to it? My best explanation is that when a plant is stressed (from the heat) and have wilting or even scorching symptoms, we tend to water it more thinking that it needs more water. Sometimes, this can translate to a saturated growing area. Furthermore, if the plant is stressed and cannot optimally imbibe the water – every time water is give, it just keeps the growing environment wet. Perhaps there are times were a pathogen may be present. It takes the opportunity to enter and establish itself on a weaken plant. Together our actions and infection of the pathogen hasten the decline and demise of a plant. So what can we do? I would advice to take great care when watering. It may not be a bad idea to use a probe or a wooden dowel to pierce into the soil to the root depth to see if there is moisture present. It is is wet, you may be able to wait just one more day or more. Choose more heat tolerant plants in the future. Mulch to insulate the root region. Provide some shade via shade cloth or some big potted plant placed strategically. Do not plant too close to a wall that can radiate heat.
Too much heat. It does not do humans good. It does not do plants any good either. Hang on and happy gardening. Cooler times are coming soon.