VIA EMAIL: dpr12001@cdpr.ca.gov

December 3, 2012

Linda Irokawa-Otani

Regulations Coordinator

Department of Pesticide Regulation

1001 I Street, P.O. Box 4015

Sacramento, California 95812-4015

RE: DPR 12- 001 Volatile Organic Compounds in the San Joaquin Valley Ozone Nonattainment Area; 

Modifications to Text of Proposed Changes

Dear Ms. Irokawa-Otani:

On behalf of California Grape & Tree Fruit League, a nonprofit agricultural trade association representing 

fresh grape, berry, and deciduous tree fruit grown in California, I write to submit additional comment on 

the proposed action on nonfumigant use prohibitions on certain crops in the San Joaquin Valley ozone 

nonattainment area when using products with agricultural uses containing abamectin, chlorpyrifos, 

gibberellins, or oxyfluorfen during May 1 through October 31 if the volatile organic compound (VOC) 

emission limit is triggered. For fresh table grapes, growers need the flexibility to utilize an array of plant 

health materials to produce a marketable crop in the face of weather related challenges and pest pressures. 

The proposed action to limit the use of the liquid form of gibberellins will disrupt cultural practices 

employed by fresh grape growers in the San Joaquin Valley. As you may know, gibberellins have 

multiple beneficial uses in a table grape vineyard. For example, gibberellins are applied in a vineyard 

before bloom to stretch the berry cluster. The pre-bloom application creates a looser berry cluster, 

allowing for better air circulation which can reduce incidences of fungal disease. Gibberellins are also 

applied at bloom as a thinning spray to reduce the number of berries in a bunch, which serves to aid the 

growth and maturation of remaining berries. Following berry set, sizing sprays are applied to promote 

growth and development. Stretch, thinning, and sizing sprays directly contribute to proper growth and 

development by enhancing the architecture of the grape bunch to create spacing and sizing benefits while 

reducing the need to use additional fungicide materials to combat disease. While the proposed increase

from 8 grams/AI/acre to 16 grams/AI/acre more closely reflects stretch and thinning needs, limiting liquid 

formulations to 16 grams AI/acre underestimates table grape needs for proper sizing development.

The previous limitation of 8 grams AI/acre for all table grape varieties overlooked variety specific 

cultural practices. According to the survey used to support the 8 grams AI/acre recommendation, 

Proposed Exemptions to San Joaquin Valley Ozone Nonattainment Area Use Restrictions, emphasis was 

placed on thinning and sizing “needs” for the varieties Ruby Seedless and Crimson Seedless, while all 

other varieties were combined under “Other.” Thinning application recommendations for use of
2

gibberellins suggested rates as low as 0.5 to 1 grams AI/acre, and up to 16 grams AI/acre for sizing 

applications for Ruby Seedless as sufficient to ensure proper development and maturation. 

Of concern, the survey influenced the decision to set an exemption rate at 8 grams AI/acre; a rate which 

did not account for the full range of gibberellins uses and use rates, within cultural practices for table 

grape production. As a result of comment received, the proposed exemption rate of 16 grams AI/acre is 

an improvement however continues to fall short of recognizing sizing needs. Label language on 

gibberellins ranges 20-128 grams AI/acre for sizing applications. Application rates of gibberellins vary 

depending on grape variety and growers are careful to calculate the amount requisite for optimal 

development and maturity knowing that both under and over application of gibberellins can delay 

development on color and sugar, negatively affect maturation, and/or reduce fruitfulness which can 

severely impact the marketability of the crop. The potential for altering gibberellins programs, under a 

proposal that underestimates use rates is concerning given the devastating effects from restricting use of 

liquid gibberellins on table grapes.

The League’s previous comment sought a change to permit DPR the ability to remove an active 

ingredient as a regulated material, if use patterns demonstrate it no longer fits the selection criteria for top 

nonfumigant VOC contributor. We support the proposed change to add subsections 6884(d) and (e) to 

allow the Director to propose removal of an active ingredient or crop and the addition in subsection (f) to 

allow for an exception for use of a high-VOC formulation, provided data reveals that a greater amount of 

an active ingredient of a low-VOC product must be applied to achieve the same efficacy, which could 

have the effect of offsetting VOC emission reductions.

Thank you for the comment opportunity. The scope of any such regulation should strive to be effective in 

reducing risk of reaching the trigger limit while only focusing on what is absolutely necessary to remain 

below the trigger. The California Grape & Tree Fruit League views this as an occasion to provide 

information to DPR to assist in the understanding of the benefits of important materials, such as 

gibberellins, and needs for optimal table grape development. Should you have additional questions please 

do not hesitate to contact me at the League by email (cvaladez@cgtfl.com) or by calling the League 

office.

Sincerely,

Christopher Valadez

Director, Environmental & Regulatory Affairs