A new major concern for growers in apple-producing areas in China, the United States and Canada in the last couple years is the rapid decline of established apple trees. It’s known as sudden apple decline (SAD), or rapid apple decline (RAD). The same trends are applicable to other fruit trees.
A large surge in fruit prices in China was due to “extreme weather,” a spokesperson from the NBS told Beijing-based business magazine Caixin.
Typically, visibly affected areas of the tree trunks exhibit cankers, cracks or dead phloem and cambium. The damaged tissue usually becomes visible in the lower trunk within two feet of the soil line.
Could the causation relate to the emerging Grand Solar Minimum (GSM) combined with overly dense fruit orchards and an overuse of herbicides?
Winter injury of the lower trunk can also occur if trees grow late into the season and then encounter extreme temperature drops in late November or December, before the tree has become fully acclimated to cold temperatures. Young trees that are “pushed” with too much nitrogen fertilizer may continue growing late into the season, thereby making trees more susceptible to winter damage.
Glyphosate and GSM are a poor tandem, as exposure is known to reduce by several degrees the winter hardiness of trees exposed to glyphosate drift. Trees exposed to drift may experience more extensive winter damage than would occur in the absence of glyphosate [see “Effects of Glyphosate on Apple Tree Health,” N.Y. Fruit Quarterly 21(4):23-27].
Weather-related stress — specifically, unseasonable cold — could be an underlying cause of SAD, researchers reported this month in PLOS ONE. Early freezes are becoming more common across the eastern United States.
Study results show that the occurrence of severe cold followed by drought, or either one individually, might not directly cause RAD, but could have weakened the trees and led to the proliferation of insects and infection by opportunistic pathogens.
In hard-hit North Carolina, researchers have found ambrosia beetles infesting the graft union of dying trees. These stubby insects burrow into weakened trees and cultivate fungus for their larvae to eat. Those fungi or stowaway might harm the trees, an idea that Sara Villani, a plant pathologist at North Carolina State University in Mills River, and colleagues will start to test in June. Researchers there will also test ways of boosting the tree immune systems.
The common cherry bacterial pathogen Pseudomonas syringae has been reported as an apple pathogen in South Africa, and several phytoplasmas (phloem-limited, insect-transmitted bacterial pathogens that lack cell walls) have been identified in other parts of the world.
Tight space available to root in high-density orchards creates intense competition for nutrients and water, especially for inadequate root-systems, which are thus unable to maintain heavy crops, foliage and biomass in extreme weather.
Modern apple farming methods could also be a factor that is making trees poorly suited to withstand a GSM. RAD is most common in dense orchards, which are increasingly planted because they are efficient to manage. Instead of about 250 trees per hectare, high-density orchards can have 1,200 or more. Tightly packed trees must compete for nutrition and moisture. They also have shallow roots, which make them easier to trellis but more vulnerable to drought and cold.
“I’m not criticizing the system,” plant pathologist Awais Khan of Cornell told “Science” magazine, “but it’s not robust for these kinds of fluctuations.”
Did The New York Slimes accidentally let an intern or stringer file a report on the kakistocracy? Is this how the Crime Syndicate is going to deal with GSM and fruit tree challenges related to herbicide? If so, will the last person alive turn off the lights. Even if you aren’t an unaware pajama person, how will you know if the fruit you consume isn’t antibiotic tainted?
“Since 2016, the Environmental Protection Agency has allowed Florida citrus farmers to use the drugs streptomycin and oxytetracycline on an emergency basis only, but the agency is now significantly expanding their permitted use across 764,000 acres in California, Texas and other citrus-producing states. The agency approved the expanded use despite strenuous objections from the Food and Drug Administration and the Centers for Disease Control and Prevention, which warn that the heavy use of antimicrobial drugs in agriculture could spur germs to mutate so they become resistant to the drugs and ultimately threaten the lives of millions of people.”
Current Conditions in the Orchards of Michigan
“Our season is still running between seven to 12 days behind normal when looking at both flowering stages and growing degree day totals,” wrote Robert Tritten of Michigan State University on May 21. “This has been one of the latest years’ growers can remember getting fruit crops planting.”
Winter Watch Takeaway
There is a severe price to pay for ignoring and not adapting to the colder Grand Solar Minimum.