Lack of access to orchards poses sanitation problems in nut crops


It is often said that a person’s most valuable ability is availability, so it stands to reason that an orchard’s most valuable attribute is accessibility. You can’t troubleshoot in an orchard if you can’t get into it.

While it might seem pretty obvious in hindsight, it came as a surprise to researchers at the University of California Cooperative Extension (UCCE) who conducted a survey last winter to survey nut growers on the navel worm management (NOW). The insect is the main pest for almond and pistachio growers and also presents problems for nut growers.

The survey was developed by Phoebe Gordon, Orchard Systems Advisor, Madera and Merced Counties, and Houston Wilson, Integrated Pest Management (IPM) Specialist, with input from UCCE’s IPM advisers. It was funded by industry councils for each of the state’s three major nut crops.


The survey was conducted at seven UCCE grower meetings in the San Joaquin and Sacramento valleys, with orchard owners, ranch managers, and pest management advisors (PCAs) answering questions about NOW monitoring methods and management practices to get a clearer picture.

“It’s important for everyone to know what’s going on with the navel orange tree – especially the extension,” Gordon says. “We need to know what works and what doesn’t to guide research efforts. “

The survey had some limitations, Gordon says, in that the only respondents were those who attended the meetings, which is rather a small sample. In addition, it was not exhaustive because she did not want to weigh down the producers during the meetings.

Phoebe gordon

Additionally, due to COVID-19, the ballot had to be cut short so they could not conduct the ballot at two of the meetings held in the southern San Joaquin Valley. This likely had an effect on the results, particularly with regard to sanitation, as the North San Joaquin Valley and the Sacramento Valley both receive more rain than the South San Joaquin Valley.

Nonetheless, Gordon says she was somewhat surprised by the responses from producers regarding sanitation. The reason for the interest in sanitation is that it is the most effective way growers have to avoid problems with NOW, the most damaging insect pest they face.

“You have to remove the mummies from the trees because (NOW) larval mortality is higher when the nuts are on the ground, and you should still shred them, even if the pistachio mummies are difficult to shred,” says -she.


NOW is a big problem not only because of the physical damage to nuts, but it correlates with aflatoxin, a toxic compound produced by mold that can grow in damaged NOW nuts.

Gordon had expected cost to be the biggest obstacle for producers in achieving good sanitation. In the past, many producers have complained about the costs of labor and / or equipment. But in the survey, only 30% of producers cited labor / equipment costs as the most important, and just under 20% cited labor / equipment availability. equipment.

By far the most common response – growers were asked to choose all that applied – was difficulty in accessing the orchard. It wasn’t even close, as lack of access was cited by over 50% of producers. “From a research perspective, it’s fascinating,” says Gordon. “I thought it would be a cost, not an access. “

This raises a number of questions for researchers, she says. For example, can growers make more use of cover crops to help penetrate wetlands in orchards? Do growers need lighter equipment to get into orchards in bad weather? Does the industry need to find new ways to clean up orchards and reduce the threat of NOW?

There is no doubt that producers are concerned about NOW. According to the survey, less than 10% of producers said the effectiveness of the sanitation is unclear. “At least they believe me,” Gordon says.

Gordon says she and Wilson hope to conduct a broader investigation in the future, possibly by mail. They hope to deepen their questions with more nuanced questions while also getting more feedback from producers in the southern San Joaquin Valley.



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