For Control of the Worst Crop Diseases, The Answer is Chemigation

Ask any farmer, and you’ll find that there is no crop without its dreaded pest. Additionally, new forms of harmful fungi and insects seem to appear every year targeting various crops—and the best and most cost-effective answer has been found to be the precise control gained through chemigation.

For the last several years, a costly infection called Zebra Chip disease has been frustrating western and Mexican potato growers. The devious disease doesn’t clearly manifest until late in the season, when it is evident in the tubers. When afflicted potatoes are sliced and put in the fryer, a pattern of black-and-white stripes—hence the name—appear on the chips. Of course, the manufacturer is not going to pay for potatoes it can’t use, and this disease, when it enters an area, can infect 5% to 6% of a crop, though losses have been much higher. That may seem like a small percentage, but considering that one year’s crop can number 1.3 to 1.4 million potatoes, it’s a substantial loss.

Fortunately, methods have been devised to catch infected tubers long before they reach the chip manufacturer. But with so much loss being affected, growers have been on alert for a cure, or at least a reliable method of control.

Unfortunately the cause of this disease has not been isolated and is still being researched. Managers at CSS Farms, a grower with three Texas facilities, have correlated that when a field was infested with the potato psyllid, a common potato insect pest, Zebra Chip disease was more prevalent. In its nymph stage, the potato psyllid injects a toxin into the plant. The toxin in itself causes yellowing and stunting of the potato plant and significant yield reduction. It is speculated by Mexican growers that the adult psyllids may vector the disease that causes Zebra Chip, and fortunately, when potato psyllids are controlled through chemigation, it appears to have curbed Zebra Chip.

“We observed in 2005 that when the potato psyllids liked the crop, it seemed that the Zebra Chip levels were higher,” says Grant Monie, manager with CSS Farms. “This year, with the psyllid populations much lower, we have not seen the levels of Zebra Chip that we saw last year.”

The key to controlling the psyllids has been precisely timed chemigation—the exact application of insecticide through an irrigation system. “We have to target them in the adult stage, when they’re laying eggs,” Monie says. “If we wait, and the eggs grow into the nymph stage, we have a harder time controlling them.”

The adults lay their eggs, and nymphs hatch, on the underside of the leaves. Formerly, pesticide had to be applied from a plane, which was more costly and placement on top of the potato crops was not effectively controlling psyllids. And placement is as important as timing.

CSS exclusively utilizes chemigation systems from Agri-Inject, Inc., a leading provider of chemigation and fertigation systems. “They can apply chemigation exactly when they need it, which has proved important to them,” says Arnold Paige, manufacturer’s rep for Agri-Inject. “They don’t have to worry about hiring planes or running ground rigs.”

“We’ve done very well with Agri-Inject,” Monie concludes. “Because of the quality and accuracy of their chemigation and fertigation units, we only use their products.”

For more information about this article or chemigation and fertigation systems, call Arnold Page at Agri-Inject at 1-800-446-5328, 5500 East Highway 34, Yuma, Colorado 80759 or Email: inject@plains.net or visit their website at www.agri-inject.com to locate a dealer near you.