"Our biggest concern right now is the lack of general rainfall we've had," said Anthony Ohmes, regional agronomy specialist for the MU extension office in Mississippi County. "Once it gets about 95 degrees, it doesn't really matter if it gets hotter."
The highest risk from the weather is to soybean plants, which are now in their pod production, or reproductive cycle, Ohmes said.
"A lot of times with heat like this, the pods will be thrown off," agreed David Guethle, regional agronomist for the Stoddard County extension office.
Heat slows reproduction because of the energy used. "The plant has to use energy at night to cool down," Guethle said. "That's taking away from carbohydrates that are going into seeds."
The number of pods that turn into flowers will depend on "how much irrigation they've got and how hot it is," Guethle continued.
At this stage in the soybean process, the plants require about a quarter-inch of water each day, Ohmes said. Without proper precipitation, there will be added stress, pod loss and smaller beans.
"Over the last three to four weeks, there has been a lot of irrigation going on," Guethle said.
High heat can affect the irrigation, Ohmes said. "With higher heat, there are higher evaporative losses, especially with the older, high pressure systems," he said.
Another potential problem given the weather conditions are spider mites. "They thrive in the hot, dry weather we have," Guethle said.
Ohmes said farmers and gardeners need to keep their eyes open for these insects, especially in cotton, soybeans, tomatoes and garden vegetables.
Homeowners should also continue watering their gardens. Ohmes said morning is the ideal time to water, as midday watering brings the potential for scalding, and evening watering could bring about disease.
There could be one benefit to the heat -- corn will dry out more quickly.
"Most of the drying is done by Mother Nature, and farmers don't have to spend money for fuel to dry it down," Guethle said.
Corn is typically harvested at 20 to 25 percent moisture, but has to be dried down to 15 percent before taken to the storage facility.
Late corn could be at risk, though, as 40 to 50 percent of a crop can be lost with hot dry weather conditions two weeks before or after tasseling.
"For the most part, we're five weeks past tasseling, so that reduces the loss we'd have," Guethle said.
And it doesn't look like there will be a break in the heat any time soon. High temperatures are forecast in the 100s through Thursday, with Friday's high forecast at 99 degrees.