Coordinating psyllid management with citrus flush

Because the Asian citrus psyllid stakes its reproduction on new citrus flush, there is a lot of interest in tailoring management to citrus phenology.  “Phenology” is an uncommon word, but it boils down to how plant development changes over time.  For instance the development of the spring flowering flush is a phenological process and names like “feather flush,” “popcorn,” and “full bloom” describe phenological stages.

Gene Albrigo has been involved in phenological modeling to predict flowering intensity and bloom time since well before the HLB era.  He has recently turned to using this model to help improve psyllid management in two ways: reducing psyllid reproduction on new flush through pre-emptive  psyllid management, and reducing negative impacts of insecticides on bee pollinations.  In other words his goal is to kill adult psyllids before they can lay eggs on tender new flush but not hurt pollinator bees with applications late in the flush, when flowers have emerged. This can be done by using the models he and collaborators developed and have maintained for more than 10 years.

Gene has worked with several regional growers, selecting some blocks to manage psyllids based on phenological predictions, leaving others as controls with calendar or sampling-based sprays.

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A May feather flush with psyllid damage.

Gene recently reported results from the first two years of developing this approach.  Results are positive, with reductions in adult psyllid numbers and egg-laying using the phenology-based approach, spraying once just prior to budbreak and again about 4 weeks later.  This also allowed a bloom period that was free of insecticide applications, leaving the pollinators to range at the appropriate time.  These results are promising for psyllid management during the floral flush, and I expect this approach to expand to become a standard practice.

Photosynthesis and kaolin particle films – Welcome Juanpablo

Kaolin particle films are having promising effects in managing Asian citrus psyllid, but they also have effects on photosynthesis.  To help dig into this, a new member has joined our lab: Juanpablo Salvatierra Miranda, or “JP.”  He’s 4 months into his first round of experiments, and he’s already made some important observations.  He’s focusing on the how photosynthesis changes over the course of a day – “diurnal photosynthetic dynamics” – in response to kaolin particle films of different colors.

color buckets

JP comes most recently from his native Chile, where he was working for a private agricultural research company. He has experience in horticulture of vegetables, wine grape, and citrus. His Master’s thesis will consider how different colored films affect growth and photosynthesis, as well as how these affect the development of huanglongbing symptoms in the field.

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JP Salvatierra applies white kaolin film in one of his experiments.