Voluntary Grower Response Plan for Huanglongbing
To provide California citrus growers with a strong toolbox of science-supported strategies and tactics to protect their orchards from Huanglongbing, the Citrus Pest & Disease Prevention Committee endorsed a response plan for growers to voluntarily employ in California.
The recommendations – which are grouped based on a grower’s proximity to an HLB detection – represent the most effective tools known to the citrus industry at this time and are meant to supplement the California Department of Food and Agriculture’s required regulatory response. They were developed by a task force consisting of growers from various regions across the state and scientists, including Dr. Beth Grafton-Cardwell and Dr. Neil McRoberts.
Growers are encouraged to use as many methods as feasible for their operation in order to limit the spread of the Asian citrus psyllid (ACP) and HLB, as the cost to manage the Asian citrus psyllid is far less than any potential costs or loss to the industry should HLB take hold throughout our state.
The Best Practices at a Glance
The complete best practices document, which includes the scientific rationale for the best practices, can be downloaded here. The following grid is intended to provide a brief, digestible format of the best practices.
| wdt_ID | CATEGORY | SCENARIO 1 | SCENARIO 2 | SCENARIO 3 | SCENARIO 4 |
|---|---|---|---|---|---|
| 1 | Orchards outside a 5-mile HLB quarantine |
Orchards between 1 and 5 miles from HLB detection |
Orchards within 1 mile of HLB, but not known to be infected |
Orchards with HLB |
|
| 2 | AWARENESS | • Stay informed: communicate with others, such as Grower Liaisons, Cooperative Extension, or Pest Control Advisors, and attend meetings. • Get to know your neighbors. • Sign up for alerts on CitrusInsider.org. |
All actions from Scenario 1, plus: • Help educate your neighbors about the seriousness of HLB. • Be prepared to help with communications and spray applications. |
All actions from Scenario 2, plus: • Offer to lead your psyllid management area’s communication network. |
All actions from Scenario 3, plus: • Help connect your neighbors to organizations that assist homeowners with citrus tree removal. |
| 3 | SCOUT FOR ACP | • Deploy trained scouts every 2 weeks. • If ACP are found, treat before they reach 0.5 nymphs/flush. |
All actions from Scenario 1. | All actions from Scenario 1, plus: • Pay special attention to vigorously flushing trees or areas under high ACP pressure, such as edges that border residences, or where ACP have previously been found. |
All actions from Scenario 3. |
| 4 | CONTROL ACP WITH INSECTICIDES | • Try to eliminate psyllids. • Apply extra treatments within label limits if ACP populations start to increase before a scheduled areawide treatment. • In mature orchards, a perimeter-only treatment can be applied if the center is free of psyllids. • Treat the orchard border before the center. • Make applications at night when psyllids are inactive. • When treating for other pests, utilize insecticides known to have efficacy against ACP. |
All actions from Scenario 1, plus: • Treat the entire orchard at least 3 times per year with an ACP-effective, long-residual insecticide. Coordinate with your liaison, PCD, and/or local task force for timing. If psyllids exceed 0.5 nymphs/flush between the 3 applications, treat again, if an additional treatment is within label limits. |
All actions from Scenario 1, plus: • Treat the entire orchard at least 3 times per year with an ACP-effective, long- residual insecticide. Coordinate with your liaison, PCD, and/or local task force for timing. • Treat the orchard border before the center. • If psyllids exceed 0.5 nymphs/flush between the 3 applications, treat the entire orchard again if an additional treatment is within label limits. • Make applications at night . • Use ACP-effective insecticides when treating for other pests. |
All actions from Scenario 3. |
| 5 | YOUNG TREES/REPLANT PROTECTION | • Consider additional protectants for young trees and replants, such as psyllid-proof mesh covers, kaolin, or insecticides. | All actions from Scenario 1, plus: • Treat orchards in their entirety (do not use border treatments). |
All actions from Scenario 2, plus: • Replant with tolerant/resistant trees as they become available. |
All actions from Scenario 3. • Infection of unprotected replants is highly likely if ACP are present. |
| 6 | BARRIERS/REPELLENTS | • Create barriers and/or apply repellents to limit ACP establishing on the perimeter of the orchard. | All actions from Scenario 1. | All actions from Scenario 1. | All actions from Scenario 1. |
| 7 | VISUAL SURVEY FOR HLB | • Conduct a survey for HLB symptoms in the orchard perimeter and the uppermost part of the canopy once a year. | • Conduct a survey for HLB symptoms in the border rows/trees and in the uppermost part of the canopy twice a year. | • Conduct a survey for HLB symptoms in the entire orchard, including the uppermost part of the canopy twice a year. | All actions from Scenario 3. |
| 8 | DIRECT CLAS DETECTION PROTOCOL | N/A | • Test foliage and psyllids from 10 trees in each corner of the block (40 trees total) using direct methods of bacterium detection (such as PCR). | • Test foliage and psyllids from all perimeter trees using a direct method of bacterium detection (such as PCR). • Test additional trees through a laboratory or commercial kit. |
All actions from Scenario 3. |
| 9 | TREE HEALTH | • Ensure appropriate nutrient and water applications to tend to your grove’s root health. | All actions from Scenario 1. | All actions from Scenario 1. | All actions from Scenario 1. |
| wdt_ID | CATEGORY | SCENARIO 1 | SCENARIO 2 | SCENARIO 3 | SCENARIO 4 |
|---|---|---|---|---|---|
| 1 | Orchards outside a 5-mile HLB quarantine |
Orchards between 1 and 5 miles from HLB detection | Orchards within 1 mile of HLB, but not known to be infected | Orchards with HLB | |
| 2 | AWARENESS | • Stay informed: communicate with others, such as Grower Liaisons, Cooperative Extension, or Pest Control Advisors, and attend meetings. • Get to know your neighbors. • Sign up for alerts on CitrusInsider.org. |
All actions from Scenario 1, plus: • Help educate your neighbors about the seriousness of HLB. • Be prepared to help with communications and spray applications. |
All actions from Scenario 2, plus: • Offer to lead your psyllid management area’s communication network. |
All actions from Scenario 3, plus: • Help connect your neighbors to organizations that assist homeowners with citrus tree removal. |
| 3 | SCOUT FOR ACP | • Deploy trained scouts every 2 weeks. • If ACP are found, treat before they reach 0.5 nymphs/flush. |
All actions from Scenario 1. | All actions from Scenario 1, plus: • Pay special attention to vigorously flushing trees or areas under high ACP pressure, such as edges that border residences, or where ACP have previously been found. |
All actions from Scenario 3. |
| 4 | CONTROL ACP WITH INSECTICIDES | • Try to eliminate psyllids. • Apply extra treatments within label limits if ACP populations start to increase before a scheduled areawide treatment. • In mature orchards, a perimeter-only treatment can be applied if the center is free of psyllids. • Treat the orchard border before the center. • Make applications at night when psyllids are inactive. • When treating for other pests, utilize insecticides known to have efficacy against ACP. |
All actions from Scenario 1, plus: • Treat the entire orchard at least 3 times per year with an ACP-effective, long-residual insecticide. Coordinate with your liaison, PCD, and/or local task force for timing. If psyllids exceed 0.5 nymphs/flush between the 3 applications, treat again, if an additional treatment is within label limits. |
All actions from Scenario 1, plus: • Treat the entire orchard at least 3 times per year with an ACP-effective, long- residual insecticide. Coordinate with your liaison, PCD, and/or local task force for timing. • Treat the orchard border before the center. • If psyllids exceed 0.5 nymphs/flush between the 3 applications, treat the entire orchard again if an additional treatment is within label limits. • Make applications at night . • Use ACP-effective insecticides when treating for other pests. |
All actions from Scenario 3. |
| 5 | YOUNG TREES/REPLANT PROTECTION | • Consider additional protectants for young trees and replants, such as psyllid-proof mesh covers, kaolin, or insecticides. | All actions from Scenario 1, plus: • Treat orchards in their entirety (do not use border treatments). |
All actions from Scenario 2, plus: • Replant with tolerant/resistant trees as they become available. |
All actions from Scenario 3. • Infection of unprotected replants is highly likely if ACP are present. |
| 6 | BARRIERS/REPELLENTS | • Create barriers and/or apply repellents to limit ACP establishing on the perimeter of the orchard. | All actions from Scenario 1. | All actions from Scenario 1. | All actions from Scenario 1. |
| 7 | VISUAL SURVEY FOR HLB | • Conduct a survey for HLB symptoms in the orchard perimeter and the uppermost part of the canopy once a year. | • Conduct a survey for HLB symptoms in the border rows/trees and in the uppermost part of the canopy twice a year. | • Conduct a survey for HLB symptoms in the entire orchard, including the uppermost part of the canopy twice a year. | All actions from Scenario 3. |
| 8 | DIRECT CLAS DETECTION PROTOCOL | N/A | • Test foliage and psyllids from 10 trees in each corner of the block (40 trees total) using direct methods of bacterium detection (such as PCR). | • Test foliage and psyllids from all perimeter trees using a direct method of bacterium detection (such as PCR). • Test additional trees through a laboratory or commercial kit. |
All actions from Scenario 3. |
| 9 | TREE HEALTH | • Ensure appropriate nutrient and water applications to tend to your grove’s root health. | All actions from Scenario 1. | All actions from Scenario 1. | All actions from Scenario 1. |
| wdt_ID | CATEGORY | SCENARIO 1 | SCENARIO 2 | SCENARIO 3 | SCENARIO 4 |
|---|---|---|---|---|---|
| 1 | Orchards outside a 5-mile HLB quarantine | Orchards between 1 and 5 miles from HLB detection |
Orchards within 1 mile of HLB, but not known to be infected | Orchards with HLB | |
| 2 | AWARENESS | • Stay informed: communicate with others, such as Grower Liaisons, Cooperative Extension, or Pest Control Advisors, and attend meetings. • Get to know your neighbors. • Sign up for alerts on CitrusInsider.org. |
All actions from Scenario 1, plus: • Help educate your neighbors about the seriousness of HLB. • Be prepared to help with communications and spray applications. |
All actions from Scenario 2, plus: • Offer to lead your psyllid management area’s communication network. |
All actions from Scenario 3, plus: • Help connect your neighbors to organizations that assist homeowners with citrus tree removal. |
| 3 | SCOUT FOR ACP | • Deploy trained scouts every 2 weeks. • If ACP are found, treat before they reach 0.5 nymphs/flush. |
All actions from Scenario 1. | All actions from Scenario 1, plus: • Pay special attention to vigorously flushing trees or areas under high ACP pressure, such as edges that border residences, or where ACP have previously been found. |
All actions from Scenario 3. |
| 4 | CONTROL ACP WITH INSECTICIDES | • Try to eliminate psyllids. • Apply extra treatments within label limits if ACP populations start to increase before a scheduled areawide treatment. • In mature orchards, a perimeter-only treatment can be applied if the center is free of psyllids. • Treat the orchard border before the center. • Make applications at night when psyllids are inactive. • When treating for other pests, utilize insecticides known to have efficacy against ACP. |
All actions from Scenario 1, plus: • Treat the entire orchard at least 3 times per year with an ACP-effective, long-residual insecticide. Coordinate with your liaison, PCD, and/or local task force for timing. If psyllids exceed 0.5 nymphs/flush between the 3 applications, treat again, if an additional treatment is within label limits. |
All actions from Scenario 1, plus: • Treat the entire orchard at least 3 times per year with an ACP-effective, long- residual insecticide. Coordinate with your liaison, PCD, and/or local task force for timing. • Treat the orchard border before the center. • If psyllids exceed 0.5 nymphs/flush between the 3 applications, treat the entire orchard again if an additional treatment is within label limits. • Make applications at night . • Use ACP-effective insecticides when treating for other pests. |
All actions from Scenario 3. |
| 5 | YOUNG TREES/REPLANT PROTECTION | • Consider additional protectants for young trees and replants, such as psyllid-proof mesh covers, kaolin, or insecticides. | All actions from Scenario 1, plus: • Treat orchards in their entirety (do not use border treatments). |
All actions from Scenario 2, plus: • Replant with tolerant/resistant trees as they become available. |
All actions from Scenario 3. • Infection of unprotected replants is highly likely if ACP are present. |
| 6 | BARRIERS/REPELLENTS | • Create barriers and/or apply repellents to limit ACP establishing on the perimeter of the orchard. | All actions from Scenario 1. | All actions from Scenario 1. | All actions from Scenario 1. |
| 7 | VISUAL SURVEY FOR HLB | • Conduct a survey for HLB symptoms in the orchard perimeter and the uppermost part of the canopy once a year. | • Conduct a survey for HLB symptoms in the border rows/trees and in the uppermost part of the canopy twice a year. | • Conduct a survey for HLB symptoms in the entire orchard, including the uppermost part of the canopy twice a year. | All actions from Scenario 3. |
| 8 | DIRECT CLAS DETECTION PROTOCOL | N/A | • Test foliage and psyllids from 10 trees in each corner of the block (40 trees total) using direct methods of bacterium detection (such as PCR). | • Test foliage and psyllids from all perimeter trees using a direct method of bacterium detection (such as PCR). • Test additional trees through a laboratory or commercial kit. |
All actions from Scenario 3. |
| 9 | TREE HEALTH | • Ensure appropriate nutrient and water applications to tend to your grove’s root health. | All actions from Scenario 1. | All actions from Scenario 1. | All actions from Scenario 1. |
| wdt_ID | CATEGORY | SCENARIO 1 | SCENARIO 2 | SCENARIO 3 | SCENARIO 4 |
|---|---|---|---|---|---|
| 1 | Orchards outside a 5-mile HLB quarantine | Orchards between 1 and 5 miles from HLB detection | Orchards within 1 mile of HLB, but not known to be infected |
Orchards with HLB | |
| 2 | AWARENESS | • Stay informed: communicate with others, such as Grower Liaisons, Cooperative Extension, or Pest Control Advisors, and attend meetings. • Get to know your neighbors. • Sign up for alerts on CitrusInsider.org. |
All actions from Scenario 1, plus: • Help educate your neighbors about the seriousness of HLB. • Be prepared to help with communications and spray applications. |
All actions from Scenario 2, plus: • Offer to lead your psyllid management area’s communication network. |
All actions from Scenario 3, plus: • Help connect your neighbors to organizations that assist homeowners with citrus tree removal. |
| 3 | SCOUT FOR ACP | • Deploy trained scouts every 2 weeks. • If ACP are found, treat before they reach 0.5 nymphs/flush. |
All actions from Scenario 1. | All actions from Scenario 1, plus: • Pay special attention to vigorously flushing trees or areas under high ACP pressure, such as edges that border residences, or where ACP have previously been found. |
All actions from Scenario 3. |
| 4 | CONTROL ACP WITH INSECTICIDES | • Try to eliminate psyllids. • Apply extra treatments within label limits if ACP populations start to increase before a scheduled areawide treatment. • In mature orchards, a perimeter-only treatment can be applied if the center is free of psyllids. • Treat the orchard border before the center. • Make applications at night when psyllids are inactive. • When treating for other pests, utilize insecticides known to have efficacy against ACP. |
All actions from Scenario 1, plus: • Treat the entire orchard at least 3 times per year with an ACP-effective, long-residual insecticide. Coordinate with your liaison, PCD, and/or local task force for timing. If psyllids exceed 0.5 nymphs/flush between the 3 applications, treat again, if an additional treatment is within label limits. |
All actions from Scenario 1, plus: • Treat the entire orchard at least 3 times per year with an ACP-effective, long- residual insecticide. Coordinate with your liaison, PCD, and/or local task force for timing. • Treat the orchard border before the center. • If psyllids exceed 0.5 nymphs/flush between the 3 applications, treat the entire orchard again if an additional treatment is within label limits. • Make applications at night . • Use ACP-effective insecticides when treating for other pests. |
All actions from Scenario 3. |
| 5 | YOUNG TREES/REPLANT PROTECTION | • Consider additional protectants for young trees and replants, such as psyllid-proof mesh covers, kaolin, or insecticides. | All actions from Scenario 1, plus: • Treat orchards in their entirety (do not use border treatments). |
All actions from Scenario 2, plus: • Replant with tolerant/resistant trees as they become available. |
All actions from Scenario 3. • Infection of unprotected replants is highly likely if ACP are present. |
| 6 | BARRIERS/REPELLENTS | • Create barriers and/or apply repellents to limit ACP establishing on the perimeter of the orchard. | All actions from Scenario 1. | All actions from Scenario 1. | All actions from Scenario 1. |
| 7 | VISUAL SURVEY FOR HLB | • Conduct a survey for HLB symptoms in the orchard perimeter and the uppermost part of the canopy once a year. | • Conduct a survey for HLB symptoms in the border rows/trees and in the uppermost part of the canopy twice a year. | • Conduct a survey for HLB symptoms in the entire orchard, including the uppermost part of the canopy twice a year. | All actions from Scenario 3. |
| 8 | DIRECT CLAS DETECTION PROTOCOL | N/A | • Test foliage and psyllids from 10 trees in each corner of the block (40 trees total) using direct methods of bacterium detection (such as PCR). | • Test foliage and psyllids from all perimeter trees using a direct method of bacterium detection (such as PCR). • Test additional trees through a laboratory or commercial kit. |
All actions from Scenario 3. |
| 9 | TREE HEALTH | • Ensure appropriate nutrient and water applications to tend to your grove’s root health. | All actions from Scenario 1. | All actions from Scenario 1. | All actions from Scenario 1. |
| wdt_ID | CATEGORY | SCENARIO 1 | SCENARIO 2 | SCENARIO 3 | SCENARIO 4 |
|---|---|---|---|---|---|
| 1 | Orchards outside a 5-mile HLB quarantine | Orchards between 1 and 5 miles from HLB detection | Orchards within 1 mile of HLB, but not known to be infected | Orchards with HLB |
|
| 2 | AWARENESS | • Stay informed: communicate with others, such as Grower Liaisons, Cooperative Extension, or Pest Control Advisors, and attend meetings. • Get to know your neighbors. • Sign up for alerts on CitrusInsider.org. |
All actions from Scenario 1, plus: • Help educate your neighbors about the seriousness of HLB. • Be prepared to help with communications and spray applications. |
All actions from Scenario 2, plus: • Offer to lead your psyllid management area’s communication network. |
All actions from Scenario 3, plus: • Help connect your neighbors to organizations that assist homeowners with citrus tree removal. |
| 3 | SCOUT FOR ACP | • Deploy trained scouts every 2 weeks. • If ACP are found, treat before they reach 0.5 nymphs/flush. |
All actions from Scenario 1. | All actions from Scenario 1, plus: • Pay special attention to vigorously flushing trees or areas under high ACP pressure, such as edges that border residences, or where ACP have previously been found. |
All actions from Scenario 3. |
| 4 | CONTROL ACP WITH INSECTICIDES | • Try to eliminate psyllids. • Apply extra treatments within label limits if ACP populations start to increase before a scheduled areawide treatment. • In mature orchards, a perimeter-only treatment can be applied if the center is free of psyllids. • Treat the orchard border before the center. • Make applications at night when psyllids are inactive. • When treating for other pests, utilize insecticides known to have efficacy against ACP. |
All actions from Scenario 1, plus: • Treat the entire orchard at least 3 times per year with an ACP-effective, long-residual insecticide. Coordinate with your liaison, PCD, and/or local task force for timing. If psyllids exceed 0.5 nymphs/flush between the 3 applications, treat again, if an additional treatment is within label limits. |
All actions from Scenario 1, plus: • Treat the entire orchard at least 3 times per year with an ACP-effective, long- residual insecticide. Coordinate with your liaison, PCD, and/or local task force for timing. • Treat the orchard border before the center. • If psyllids exceed 0.5 nymphs/flush between the 3 applications, treat the entire orchard again if an additional treatment is within label limits. • Make applications at night . • Use ACP-effective insecticides when treating for other pests. |
All actions from Scenario 3. |
| 5 | YOUNG TREES/REPLANT PROTECTION | • Consider additional protectants for young trees and replants, such as psyllid-proof mesh covers, kaolin, or insecticides. | All actions from Scenario 1, plus: • Treat orchards in their entirety (do not use border treatments). |
All actions from Scenario 2, plus: • Replant with tolerant/resistant trees as they become available. |
All actions from Scenario 3. • Infection of unprotected replants is highly likely if ACP are present. |
| 6 | BARRIERS/REPELLENTS | • Create barriers and/or apply repellents to limit ACP establishing on the perimeter of the orchard. | All actions from Scenario 1. | All actions from Scenario 1. | All actions from Scenario 1. |
| 7 | VISUAL SURVEY FOR HLB | • Conduct a survey for HLB symptoms in the orchard perimeter and the uppermost part of the canopy once a year. | • Conduct a survey for HLB symptoms in the border rows/trees and in the uppermost part of the canopy twice a year. | • Conduct a survey for HLB symptoms in the entire orchard, including the uppermost part of the canopy twice a year. | All actions from Scenario 3. |
| 8 | DIRECT CLAS DETECTION PROTOCOL | N/A | • Test foliage and psyllids from 10 trees in each corner of the block (40 trees total) using direct methods of bacterium detection (such as PCR). | • Test foliage and psyllids from all perimeter trees using a direct method of bacterium detection (such as PCR). • Test additional trees through a laboratory or commercial kit. |
All actions from Scenario 3. |
| 9 | TREE HEALTH | • Ensure appropriate nutrient and water applications to tend to your grove’s root health. | All actions from Scenario 1. | All actions from Scenario 1. | All actions from Scenario 1. |