WESLACO — Scientists at the Texas A&M Agricultural Research and Extension Center at Weslaco say the fungus that ruined most of this year’s melon crop probably won’t return. Not with the vengeance it had this year, anyway.
The culprit, responsible for an economic loss of up to $66 million and some 2,000 jobs, is gummy stem blight. This fungus routinely shows up early in the melon season and is routinely controlled by fungicides.
But this year, unusually heavy spring rains and cool temperatures helped this fungus get a foothold. Fungal spores poured into the cantaloupes as they formed their rind netting, a situation akin to an open wound. And once the fungus got in, it wouldn’t turn loose; nothing could control it. Melon fields continue to shrivel and die.
Plant pathologist Dr. Tom Isakeit says it’s rare to see this fungus develop to the point of ruining fruit. In fact, Dr. Benny Bruton, a veteran U. S. Department of Agriculture fruit rot expert who was called in to help evaluate the situation, told Isakeit he’d seen this type of fruit rot only once before, in Oklahoma.
“In a typical year, we won’t see this type of disaster again,” said Isakeit. “It’s not like vine decline (monosporascus) that we have to deal with year after year. Gummy stem blight will be easier to deal with than other diseases out there.”
Even if all the elements were to fall into place again next year, Isakeit said, the melon industry will be better prepared.
“The proliferation of this disease caught everybody by surprise this year,” he said, “so awareness in the future will be key. Plus, (Texas A&M plant pathologist) Dr. Marvin Miller and I will soon start fungicide tests that will ultimately give us a better arsenal to combat gummy stem blight in the future.”
Amid the melon ruin and the flooding of low-lying areas, it may be difficult to appreciate the benefits of the rains the Valley has received. Rising levels in reservoirs have restored a guarded optimism in growers who feared running out of irrigation water sometime this year.
Rains have also helped leech soils of salts that have built up from months of heavy irrigation. These salts choke off plant life. The leeching of salts has especially benefited the Valley’s citrus orchards and sugarcane fields, said Dr. Darek Swietlik, assistant director at the Texas A&M-Kingsville Citrus Center at Weslaco.
Fruit set in citrus orchards, he said, varies from very good to very light. Grapefruit orchards that sustained heavy defoliation after a December freeze now seem to have a light crop this year. Despite the light freeze, though, oranges seem to be carrying a good crop.
As fruit growth continues, Swietlik said, it will become easier to assess the size of the citrus crop for this fall and winter.
The Valley’s other major fall and winter crop, sugarcane, is experiencing a bad news/good news rain situation. The bad news is that rains prevented growers from going into their fields on schedule to apply herbicides, resulting in serious weed problems in some areas.
Sugarcane breeder Dr. Jim Irvine at the Weslaco Center says fields that were abandoned because owners knew they wouldn’t have irrigation water this year are very weedy and have no chance of recovery.
Thanks to the rains, though, many growers have yet to irrigate, saving what water they do have for the hottest times of the year.
Another plus in the Valley’s sugarcane fields is the shift from an old disease-prone sugarcane variety, NCo-310, to CP72-1210. Drought and a disease called sugarcane smut in the older variety helped make for a short harvest last season. This newer variety, developed by Texas A&M and others, is more resist to disease and produces more sugar.
“I’m optimistic this variety will be productive,” Irvine said.