Regulations to Limit Neonicotinoid Product Use on Food and Feed Crops: Interpreting “Bloom”
The Department adopted regulations (Title 3, California Code of Regulations [3 CCR] sections 6990 through 6990.16) to limit neonicotinoid pesticide product use in the production of most food and feed crops. The new regulations, effective January 1, 2024, apply to soil and foliar applications of products containing the neonicotinoid active ingredients clothianidin, dinotefuran, imidacloprid, and thiamethoxam. These regulations are necessary to protect pollinator health by reducing residue levels of neonicotinoids found in the pollen and nectar of treated plants at levels toxic to bees. These regulations are in addition to any requirements found on neonicotinoid pesticide product labeling. In the event of a conflict between labeling requirements and these regulations, the strictest requirement must be followed.
This letter responds to questions on the definition of “bloom” in 3 CCR section 6990(a)(1) and its practical application. Subsequent letters may be issued to address other topics or questions.
Q1. For crops that are harvested after bloom (e.g., berries, tree fruit and nuts, fruiting vegetables) the regulations prohibit use during bloom. What does “during bloom” mean?
A: DPR determined the prohibition on neonicotinoid applications “during bloom” is necessary to protect pollinators from high neonicotinoid residues when pollinators are expected to visit crops.
Section 6990(a)(1) defines bloom as “the period from the onset of flowering until petal fall is complete.” The two key parts of this definition are:
- “Onset of flowering” means the beginning of the bloom period, once the first flower buds open and the pollen and nectar are accessible to pollinators.
- “Petal fall is complete” means the end of the bloom period, once there are no open flowers available for pollinators.
When the regulations prohibit use of neonicotinoids “during bloom”, use is prohibited from when the first flowers open until there are no open flowers available for pollinators. In most cases, this is a stricter standard than permitted by pesticide labeling or the apiary operator notification regulations in 3 CCR sections 6980-6984.
For crops that bloom throughout the growing season (e.g., strawberries or some varieties of tomatoes), crops that may be indeterminate blooming in certain regions of the State (e.g., lemons), or crops which may have secondary or “rat-tail” blossoms after petal fall (e.g., apples or pears), the bloom period may be extended to the point where an application of a neonicotinoid pesticide to a field or orchard may not be possible without risking a violation of the applicable regulation.
There are many examples of crops (e.g., peas, sunflower, zucchini) where the flowers may wilt or dry up but the petals don’t necessarily “fall” off the plant for some time. In such instances the end of bloom would be when the flowers have completely wilted or dried up and can no longer provide pollinator resources.
Q2. Is it ok to apply when only a few flowers are in bloom?
A. No. As mentioned above, DPR determined the prohibition on neonicotinoid applications “during bloom” is necessary to protect pollinators from high neonicotinoid residues when pollinators are expected to visit crops. DPR intended the definition of “bloom” to be a definition that users and enforcement personnel could consistently apply across the many food and feed crops grown in California.
Except for citrus in Fresno, Kern, and Tulare counties (see response to Question 5 below), this restriction applies once the first flower buds on the crop open and until there are no open flowers on the crop available for pollinators.
Q3. Does the bloom determination apply to weeds in the field?
A: No. 3 CCR sections 6990 through 6990.16 apply to the agricultural commodity being grown not to any weeds in or around the field which may incidentally be exposed to the pesticide.
However, some neonicotinoid pesticide labels may contain statements which prohibit application or drift to blooming weeds if bees are foraging in or adjacent to the treatment area. Other products may prohibit application to blooming, pollen-shedding or nectar-producing parts of plants if bees may forage for hours or days after application. Pesticide labeling requirements which are stricter than sections 6990 through 6990.16 must still be enforced.
Q4. Can applications be made to crops during bloom during times of the day that bees are not active?
A. No. For crops or applications subject to sections 6990 through 6990.16, the prohibition on application to crops “during bloom” includes prohibiting use during the times of day that bees are not active (e.g., one hour after sunset to two hours before sunrise). As mentioned in the response to Question 1, DPR determined the regulations in sections 6990 through 6990.16 are necessary to protect pollinators from high neonicotinoid residues when pollinators are expected to visit crops. These regulations are not only about acute exposure during or shortly after an application.
Neonicotinoid product labeling statements may permit applications to crops when bees are not active. For crops and applications subject to the regulations, the prohibition on application to crops “during bloom” is stricter than current neonicotinoid product labeling requirements and must be followed.
Q5. For citrus in Fresno, Kern, and Tulare counties, how do sections 6984 and 6990.4 affect each other?
A: Under 3 CCR section 6984(b) the Fresno, Kern, or Tulare Commissioner provides public notice of the official beginning and ending of the citrus bloom period in their county. As this declaration permits some blossoms to be accessible to pollinators at the beginning and end of the bloom period, it is important to note this is a shorter time frame than what “bloom” on citrus will be in the rest of California. During the declared citrus bloom period, all applications of neonicotinoids on citrus are prohibited by 3 CCR section 6990.4(a), including any use that would have been permitted by the product labeling and section 6984 while bees are inactive (e.g., applications after sunset or when the temperature is below 50˚F).
For all citrus, including citrus in Fresno, Kern and Tulare counties, the rate and timing restrictions in section 6990.4(c) are effective January 1, 2024. For example, section 6990.4(c) only allows soil applications of products containing imidacloprid between when petal fall is complete and December 6. After this date further imidacloprid soil applications are prohibited until conclusion of the next petal fall. This means that starting January 1, 2024, imidacloprid soil applications on citrus statewide will only be allowed after 2024’s citrus bloom is over. For citrus in Fresno, Kern, and Tulare Counties, it is only after the respective Commissioner declares that the 2024 citrus bloom period has ended that an imidacloprid product can be applied.
Notes: For all citrus, the date for the last soil applications of clothianidin is September 17 and in early 2024 would follow the imidacloprid procedures described above. For dinotefuran and thiamethoxam products the latest soil application date is February 10; this means pre-bloom soil applications containing these two active ingredients are possible in early 2024. For foliar applications to citrus, all four active ingredients share the same date of last application (November 20). Starting January 1, 2024 foliar applications of neonicotinoids on citrus are prohibited until after 2024’s bloom is over.
Q6. How do the regulations apply to tomatoes and similar crops grown from transplants?
A: Many fruits and vegetables grown commercially in California are grown from transplants. For example, peppers and tomatoes are grown for two to three months in a greenhouse or nursery, at which time the transplants may begin to flower. 3 CCR sections 6990 through 6990.16 do not apply to pepper, strawberry, tomato, or other transplants while they are in a nursery or greenhouse setting.
However, once the transplant is planted in the field the neonicotinoid regulations apply. For example, if the pepper, strawberry, or tomato transplants are in bloom when transplanted, application of a neonicotinoid is prohibited.
If you have any additional questions on this regulation, please direct them to the Enforcement Headquarters Branch.
Sincerely,