Spicy, delicious peppers are much loved by consumers, but a problem called Stip disorder, which damages some pods, is causing heartburn for some producers and processors.

It was first reported and studied in Florida and California-grown peppers around 1995, but there are reports of Stip disorder as early as 1975 in Texas, and it was more recently officially declared in New Mexico and Arizona chile pepper fields.

Researchers and producers as far away as Australia and Israel have published studies describing the problem.

“Stip disorder, is likely caused by a physiological disorder, possibly combined with abiotic stress factors, including hot temperatures,” says Mark Uchanski, vegetable physiologist at New Mexico State University (NMSU) at Las Cruces, who made a formal announcement of the problem in the state at the New Mexico Chile Conference, attended by pepper growers, processors, and industry representatives.

When he asked for a show of hands of those who had seen Stip-like symptoms on farms or at processing facilities, only a few hands were raised. He then displayed a series of ugly Stip-infected chile photos, and asked for another show of hands. More hands were elevated.

Chile peppers are New Mexico’s signature crop, and in the state Stip is more often found in green chiles, infrequently in red chiles, and so far hasn’t been detected in paprika peppers.

“We don’t have exact numbers on financial losses due to Stip disorder,” Uchanski said. “I’ve heard of pepper loads rejected at the processor due to this problem.”

Initial visual signs of Stip include a hazy, orange-red area inside the pepper pod. Later symptoms include depressed, oval dark-brown or black spots (lesions) one-quarter to one-half inch in diameter. The lesions move toward the pod exterior. A cut-open pod with Stip reveals a layer of dead cells.

“The interior of the infected pod interior appears smashed, similar to an accordion,” Uchanski said. “It’s similar to when an apple is cut open and the fruit browns quickly — so does the chile pepper.”

Symptoms worsen during the ripening and post-harvest periods. The brown tissue rarely moves to the pod cuticle (waxy outer layer). Secondary decay organisms are absent in fresh pods. There are no foliar symptoms with the disorder.

Uchanski says microscopic analyses of infected pods have clusters of collapsed (dead) cells. The browning is caused by the release of tissue cell contents combined with oxidation. 

There is no sign of a puncture wound from insects or infection. The finger is sometimes pointed at stink bugs, which Uchanski calls a highly unlikely culprit.

Florida and California have gained a great deal of knowledge about Stip disorder since it was first found about 17 years ago, he said.

Stip has been considered a minor problem in New Mexico and Arizona, but Uchanski’s announcement at the conference suggests otherwise — that it is likely a larger and more widespread problem than originally thought.