Almond growers throughout Central California say they’re battling a surging rat infestation throughout greater than 100,000 acres of orchards, leading to financial hardship and harm.
Throughout Fresno, Merced, Kings and Kern counties, almond farmers have reported a rise in rodent populations because the rodents use irrigation canals and different waterways to unfold throughout agricultural fields and orchards, in accordance with a e-newsletter from the Almond Board of California.
The affect could possibly be important as California is house to 80% of the world’s almond manufacturing. The Golden State’s almonds have been as soon as the highest export to China however retaliatory tariffs have resulted in China in search of almonds from different nations as a substitute.
The e-newsletter doesn’t say what sort of affect the infestation may have on almond costs for shoppers in California or the U.S.
Roof rats normally spend their lives above floor however have been burrowing underneath almond and different nut timber as a result of absence of canopy throughout the chilly winter months, in accordance with the e-newsletter.
A California Division of Meals and Agriculture survey performed throughout fall 2024 revealed that as much as 32 rats have been captured per evening at some almond orchards, resulting in tree harm from burrowing within the root zone, consuming nuts and disrupting the tree’s vascular system. Rodents additionally harm irrigation tools and different infrastructure within the orchards.
Losses from rodents have ranged between $109 million to $311 million in California, in accordance with the CDFA survey. Bills embrace drip line replacements, which value between $56 million and $168 million, and crop losses, which vary between $43 million to $129 million. There have been additionally prices related to direct tree harm, farm tools repairs, equipment cleansing and changing broken timber, in accordance with the survey.
The CDFA report mentioned the numbers could possibly be underestimating the precise monetary burden and that there could possibly be extra impacts, together with to newly planted orchards and the cleanup after harvests.
Almonds ripen on a tree on April 9, 2025, in Ceres, Calif.
(Tomas Ovalle/For The Occasions)
The Almond Board of California reported that one almond grower needed to substitute their complete drip irrigation system for $20,000 and that the rats had brought on fires by chewing via the irrigation wiring. One other grower additionally had 50% crop loss as a result of excessive harm from the rodents. The grower reported having to exterminate between 50 and 100 rats per day.
Almond growers are utilizing bait stations and aluminum phosphide remedies of burrows within the winter and, throughout non-winter months are turning to snap traps, owl packing containers and fumigating the rats by making use of carbon monoxide or carbon dioxide into burrows, in accordance with the e-newsletter. These methods could be labor-intensive, costly and ineffective for big infestations.
Scientists have suggested growers to make use of monitoring tunnels, cameras and ink playing cards to observe rat conduct of their orchards. They will then implement focused baiting applications utilizing oats handled with diphacinone — a slow-acting poison — and maintain the bait stations full for about 4 weeks.
After the bait stations, snap traps could be positioned in trapping tunnels for a long-term answer to the rat infestations, in accordance with the e-newsletter.
The California Division of Fish and Wildlife can also be warning trappers and hunters to maintain a watch out for presumably contaminated wildlife within the space, and to not eat the contaminated meat, over issues the blue meat is an indication that the animal could have consumed poison meant for rats.
