Jul 27, 2017

BASF’S Pristine relieves summer disease pressure

{Sponsored} Vigilance and proactive fungicide applications have positioned California grape growers for healthy yields.

Wet winter weather patterns continued into spring, particularly in northern and coastal California. Conditions were conducive for high disease pressure but growers were prepared.

“The continual moisture allowed powdery mildew and botrytis to really stay active on the leaf surfaces,” said Dawn Brunmeier, technical service representative for BASF. “There can be latent periods where the disease could be active and no symptoms are showing on the leaves so that’s why the protection is so important.”

The coastal region experienced similar conditions, said Kate Walker, BASF technical service rep. Bloom lasted longer than usual due to moderate temperatures.

“Some areas had some rain events during that time period,” said Walker. “So a lot of growers were making applications for botrytis during bloom, especially when those rains came through.”

A heat wave in June helped suppress powdery mildew pressure.

“As all diseases, powdery mildew has optimum temperature for production. Once the temperature exceeds 80-90 degrees, powdery mildew won’t produce as many spores,” Walker added.

Although vineyards in southern California weren’t as wet, disease risk stayed high through most of spring and early summer.

“If growers had not sprayed fungicide they would have had severe powdery mildew,” said Leigh Ann Harrison, a BASF technical service rep based in southern San Joaquin Valley. “When it comes to botrytis, we’re still not seeing the symptoms because growers have been vigilant about putting on the applications.”

Table grapes — most of which are found in the southern region — tend to be more susceptible to sour rot, so growers in the area were looking out for that disease as well, Harrison said.

Growers throughout the state used Pristine® fungicide to proactively manage disease pressure. With two modes of action, pyraclostrobin and boscalid, Pristine® provides optimal disease control in grapes. The fungicide helps manage powdery mildew, botrytis and bunch rot, in addition to providing plant health benefits.

“Pristine® may be applied at full bloom, where you would get the plant health benefits along with disease control for powdery mildew,” said Brunmeier. “Or it can go at botrytis timing which would be the bunch closure, pre-close timing.”

“We consistently see an increased brix at the time of harvest when growers use it at bloom,” Brunmeier said. “During the season we see increased photosynthesis and reduced canopy temperature after those bloom spray applications.”

Growers can learn more about Pristine® fungicide by visiting www.GrowSmartGrapes.com or by contacting their local BASF representative.

Always read and follow label directions. Pristine is a registered trademark of BASF.