Workshops and field days provide a format where growers and PCAs can explore BIFS/IPM topics using a ‘hands-on’ approach. A field day takes place "on-site" and in a seasonally relevant timeframe for demonstrating BIFS/IPM techniques. Ten field days were conducted during the three years of the project. Some field days were particularly well attended, such as pest identification for Spanish-speaking farm workers. Other topics included use of pre-veraison water stress to improve wine quality, and spider mite and leafhopper identification. And, finally 7 half-day research seminars were organized for Lodi growers and PCAs during the three years of the BIFS project.

Newsletters

Eighteen issues of the Lodi-Woodbridge Winegrape Commission Research/IPM newsletter were sent to all Lodi-Woodbridge growers, PCAs and winery personnel during the 3 years of the BIFS project. Each newsletter usually featured an article on recent research results pertaining to IPM/BIFS topics in viticulture as well as a "grower profile" on a Lodi grower implementing BIFS strategies. Copies of the newsletter can be found in the Lodi-Woodbridge 1997 Annual Report.

IMPLEMENTATION OF PRACTICES

The grower-cooperators that have agreed to place one or more of their vineyards in the BIFS project are central to implementation of the Lodi-Woodbridge BIFS project. Also important are the PCAs who monitor these vineyards. The Lodi-Woodbridge BIFS project staff work with these two groups on implementing as many BIFS strategies as possible in the demonstration vineyards. At the end of the third year of the project, there are 43 grower-cooperators with 60 vineyards in the project. These 43 growers manage over 50 percent of the acreage of vineyards in the Lodi-Woodbridge Crush District #11 and have enrolled a total of 2370 acres in the BIFS project. Most of these growers have PCAs who monitor the fields for them. Ten BIFS grower-cooperators act as their own PCAs doing the monitoring themselves. Thirty-three of the BIFS growers have licensed PCAs helping them with their pest monitoring and providing pest management advice. There are 16 PCAs directly involved in the BIFS project. Four of them are ‘in house’ employees of growers, four are "independent" PCAs who charge a fee for the monitoring and advising service and do not sell any products, and eight are employees of companies which sell agrochemical products.

All of the major winegrape varieties grown in Lodi are represented in the BIFS project, with demonstration vineyards in Zinfandel (32 percent of BIFS vineyards), Cabernet Sauvignon (20 percent), Chardonnay (18.3 percent), Merlot (15 percent), Sauvignon Blanc (5 percent), French Columbard (3.3 percent), Carignane (1.7 percent), Chenin Blanc (1.7 percent), Muscat (1.7 percent), and Syrah (1.7 percent). Table 9 lists some of the basic management practices employed and the proportion of growers using them in the 60 BIFS vineyards. The proportion of vineyards in which a particular strategy was implemented changed from 1996 to 1998 in some categories. For example, the portion of vineyards with cover crops declined from 1996 to 1998. This was due in part to the fact that quite a few of the 22 additional vineyards that joined the BIFS project after its inception did not have cover crops. This will probably change in the next few years. All of the vineyards were monitored weekly, which has a big influence on the number of vineyards sprayed for mites and leafhoppers. Seventy-two percent of the vineyards in 1998 did not spray for either pest, up from only 46 percent of vineyards that remained unsprayed in 1996. This is in spite of the fact that mite populations were higher in 1997 than they had been in previous year. Mite pressure in 1998, however, was comparable to pressure in 1996 (see ‘Spider Mites’ section below). The project has encouraged growers to reduce the use of pre-emergence herbicides for under-the-vine weed control. As a result, the proportion of vineyards with contact herbicide only under-the-vine weed management strategies has increased from 19 percent in 1996 to 39 percent in 1998, while the proportion of vineyards using pre-emergence herbicides declined from 70 percent in 1996 to 59 percent in 1998. Over the life of the BIFS project many growers installed drip irrigation, bringing the use of this technique in BIFS vineyards to 73 percent in 1998, up from 57 percent in 1996. This has the effect of increasing the efficiency of water use and decreasing the amount of fertilizer required by up to 50 percent.

Table 9. Biologically integrated farming practices and the percent of growers using them in Lodi-Woodbridge BIFS vineyards in 1996-1998, from Table 6 of the Lodi-Woodbridge BIFS Final Report, page 26.

PIGGYBACK RESEARCH

• Piggyback research is designed to improve understanding and success of BIFS management and is important to the continued success of the demonstration projects. Four piggyback projects were undertaken during the 3 years of the Lodi-Woodbridge BIFS project:
  
• On-Farm Demonstrations of Alternatives to Methyl Bromide. This project was a collaboration with the Bio-Integral Resource Center (BIRC) and the California Department of Pesticide Regulation (DPR) to examine and test soil treatments that offer alternatives to methyl bromide use.
  
• PestCast Weather Station Network for Disease Management in the Lodi-Woodbridge Winegrape Commission. This project enabled the purchase of three automated weather stations that were incorporated into WEATHERNET, an automated pest phenology and weather information network in San Joaquin County, which is operated by University of California Cooperative Extension. Pestcast is a program of UC IPM, DPR, and US-EPA designed to expand the use of computer-based crop disease forecasting in California.
  
• Cooperation with USDA Natural Resources Conservation Service. This project was developed to demonstrate to Lodi-Woodbridge growers that the various soil building BIFS strategies are beneficial to important soil characteristics. The U.S. Department of Agriculture Natural Resources Conservation Service (NRCS) soil quality laboratory developed a soil testing kit that can be used in the field to "monitor" soils for effects on soil quality of various management practices.
  
• Eco Labeling for Winegrapes. The Lodi-Woodbridge BIFS project coordinator together with a steering committee and funding from US-EPA held an all-day conference on this topic. Leaders in this field from around the country were brought to describe their programs and afternoon interactive breakout sessions were held to encourage the development of working groups who might develop programs in their regions.

DOCUMENTATION AND EVALUATION

This section is based on summarizing the projects’ own impact assessment activities and summarizing the second annual review by the program advisory review board and UC SAREP Director, as well as initial analysis by the UC SAREP Director and staff on the third annual report/final report. This section (as required in Section 597 of AB 3383) provides "an analysis of the monitoring activities, a summary and assessment of pesticide and fertilizer use data, and an analysis of the success of each project in meeting the standards for integrated farming systems." The UC SAREP BIFS request for proposals defines integrated farming systems as systems where farmers integrate the following elements into their production systems: (1) Biological and cultural control of pests; (2) On-farm habitats for beneficial insects, mites, and spiders; (3) A strong emphasis on soil-building practices, often including biological nitrogen fixation to supply all or part of the nitrogen needed by crop plants; (4) Reduced reliance on agricultural chemicals.

Analysis of Monitoring Activities

Each of the BIFS vineyards were monitored by BIFS staff on a weekly basis. A data sheet was left with the grower as soon as the vineyard was checked and a copy of the data sheet was faxed to the PCA at the end of the day. The variables monitored were ones that the grower and PCA would use in making pest management decisions, such as pest numbers, life stages present, and numbers of natural enemies, if present. The most important pest problems monitored in Lodi vineyards are grape leafhopper (Erythroneura elegantula), variegated leafhopper (Erythroneura variabilis), Willamette mite (Eotetranychus willamettei), Pacific mite (Tetranychus pacificus), omnivorous leafroller (Platynota sultana), powdery mildew (Uncinula necator) and bunch rot (Botrytis cineria and other fungi). The primary purpose of the monitoring program was to provide the Lodi-Woodbridge growers and PCAs an example of how a monitoring program might be carried out, its data interpreted and the results used in management decision-making. For details of the monitoring form and protocols see page 15, figure 3 in the Lodi-Woodbridge BIFS Final Report. Important highlights of the Lodi-Woodbridge BIFS monitoring program are discussed below.

Leafhoppers

Weekly monitoring of leafhopper populations allows for growers and PCAs to be presented with up-to-date numerical or graphical summaries for each vineyard. Many scientists feel that Lodi is at the limit of distribution for variegated leafhopper and 1996 numbers reflected this; few vineyards had significant numbers of this pest. In 1996, nineteen BIFS vineyards were treated with Provado insecticide whereas in 1997, only 15 vineyards were sprayed, and in 1998 only 11 were treated (Figure 2). The Lodi-Woodbridge BIFS economic threshold for leafhoppers is 15 nymphs per leaf, more conservative than the UC-developed threshold of 20 nymphs per leaf. Only 8 vineyards below this threshold received an application in 1998, and 10 in 1997, whereas 14 vineyards were sprayed below threshold in 1996. This result shows that intensive monitoring and discussion of threshold levels can reduce the use of chemicals for leafhopper control.

Spider Mites

In 1996, there were few BIFS vineyards with mite populations that exceeded the economic threshold and six BIFS vineyards were sprayed. However, in 1997 the mite pressure was much higher and 21 vineyards were sprayed with propargite (Omite®). In the following year, mite populations returned to levels similar to those seen in 1996, and six BIFS vineyards were sprayed (see Figure 10 and 11 in Lodi-Woodbridge BIFS Final Report, page 35). An important element of BIFS projects is that in addition to monitoring for pest species, beneficial species were recorded and in some vineyards growers were able to hold off applications of miticides until the resident predaceous mites controlled the pest mite (Figure 3).

Diseases

Bunch rot is a complex of pathogens that becomes important in winegrapes after the sugar in the grapes begins to rise rapidly (about mid-summer). Levels of infection depend on a complex of factors such as weather conditions, presence of damage to the grape bunches, and canopy microclimate. The practice of leaf pulling is very important in reducing bunch rot problems. During the three years of the BIFS project, approximately 50 percent of the growers used leaf pulling in their vineyards, no significant increase or decrease in the use of the practice seems to have occurred.

Summary and Assessment of Pesticide and Fertilizer Use

A consultant working with the Lodi-Woodbridge BIFS project coordinator and the UC SAREP BIFS coordinator obtained and analyzed 1992-1995 pesticide use data from the Department of Pesticide Regulation (DPR) for winegrapes in San Joaquin County. These data were used to determine county pesticide use averages for winegrapes and were then compared to the averages in vineyards enrolled in the Lodi-Woodbridge BIFS project. The Lodi-Woodbridge BIFS project coordinator also obtained 1996, 1997, and 1998 pesticide use data for the BIFS vineyards directly from the participating growers. Comparisons were made among BIFS enrolled vineyards (BIFS enrolled), BIFS growers’ vineyards not enrolled in the BIFS project (BIFS non-enrolled), and the rest of the Non BIFS growers in San Joaquin County (non BIFS). Data from 1992 through 1995 is prior to the initiation of the BIFS project and can be looked at as pre-project use patterns. Data for 1996, 1997, or 1998 are still not available from DPR. Nevertheless, pesticide use data from the BIFS project enrolled vineyards for these years was summarized using the Lodi-Woodbridge BIFS database and has been included in the analyses.

Pesticide use data can be presented in different ways; the Lodi-Woodbridge BIFS project presented data as 1) Total amount of active ingredient (a.i.) applied per acre during the year, (calculated by taking the total amount of the chemical used that year and dividing it by the total vineyard acreage i.e. both treated and untreated); 2) Proportion of growers applying a particular chemical; and 3) Proportion of the total vineyard acreage receiving the particular chemical.

Insecticides

The use of most organochlorine (OC), carbamate and organophosphate (OP) pesticides in the Lodi-Woodbridge BIFS, pesticides under reevaluation under the Food Quality Protection Act of 1996 (FQPA), is very low and has been since before 1992. The use of Dimethoate®, Lannate® (methomyl), and Sevin® (carbaryl) has declined to almost zero in all grower groups from 1992 to 1996 (Figs. 18a-c in the Lodi-Woodbridge BIFS Final Report, page 47). Dimethoate® and Sevin® were not used at all in the BIFS vineyards, once the project started in 1996, and the use of Lannate® declined to zero in 1997 (Fig. 18a-c in the Lodi-Woodbridge BIFS Final Report, page 47). In 1995 a new insecticide, Provado® (imidacloprid) was registered for use against grape and variegated leafhoppers in California. This material has proven to be very effective against both leafhopper nymphs and adults. It is required in very small amounts (0.75 oz or less) and appears to be much less environmentally disruptive than the OP’s and carbamates. The re-entry time into the vineyard after treatment and the pre-harvest interval is only 24 hours so many growers are willing to watch leafhopper populations develop before treating them, knowing that they can treat right up until harvest if numbers become unacceptable. This has resulted in many growers using sound economic thresholds in leafhopper management.

Figure 4 presents the percentage of BIFS growers using Provado® which declined from year 1 through year 3 of the BIFS project (Fig. 19a in the Lodi-Woodbridge BIFS Final Report, page 49). In 1996, 51 percent of BIFS vineyards were sprayed for leafhoppers, while in 1997, 28 percent were sprayed, and by 1998, the proportion sprayed had decreased to 18 percent (see Figure 2). This occurred despite the leafhopper numbers being similar in both growing seasons (Fig. 4 in the Lodi-Woodbridge BIFS Final Report, page 28). This is strong evidence that some BIFS growers that treated for leafhopper in 1996 tolerated higher leafhopper numbers in 1997 and 1998. This result emphasizes the importance of stressing monitoring in any BIFS project because it can result in pesticide use reduction. In each of the three years of the project, at least half of the BIFS growers did not treat for leafhoppers (Figure 2).

Herbicides

Simazine (Princep®) is a pre-emergence herbicide that has been found contaminating ground water in some parts of the Central Valley of California. It is a very cheap and effective material and many growers are reluctant to stop using it for these reasons. From 1993 to 1995, before the BIFS project began, the proportion of the vineyards treated with simazine was fairly constant within the different categories of growers. It is interesting to note that between 70-80 percent of the BIFS growers were using simazine on their non-BIFS acreage, more than the rest of the county’s growers where approximately 50 percent were using simazine. However, the product’s use has declined on BIFS enrolled vineyards through each of the three years of the BIFS project (Figure 5). The use of the other 4 pre-emergence herbicides (oryzalin, oxyfluorfen, norflurozon, and diuron) has declined significantly during the life of the project.

Evaluation of the Project in Meeting Integrated Farming Systems Standards

The Lodi-Woodbridge BIFS project developed a survey to evaluate the progress of the Lodi-Woodbridge Winegrape Commission’s BIFS/IPM project from its inception in 1992. The BIFS project has been the Commission’s primary focus from 1996 through the end of 1998, so that much of the data from the survey is indicative of the success of the BIFS project and the BIFS approach to integrated farming implementation. The term IPM was used in the survey, rather than BIFS, due to the district wide recognition of the term IPM and because the project was initiated as an IPM program. This survey addressed grower attitudes, perceptions, and degree of adoption of integrated farming systems. Returned (completed) questionnaires totaled 288 out of 608 originally mailed out. The survey response rate was 47 percent with a ±5 percent sampling error rate.

Forty-seven percent of the growers have had some contact with one of the 43 BIFS growers and just over half have talked with the Lodi-Woodbridge BIFS staff (Figure 37, Lodi-Woodbridge BIFS Final Report, page 65). Five out of the top six sources of information rated by respondents as their most important source of information were "people sources." The most important source was their PCA, followed in order of importance by other growers, Farm Advisors, field crew, and winery personnel (Figure 46, Lodi-Woodbridge BIFS Final Report, page 73). This confirms the value of the BIFS method of emphasizing what has been called a "farmer-to-farmer" approach to technology/information transfer. Sixty-five percent of the growers have attended a NGM, showing the extent of this kind of outreach activity during the BIFS project (Figure 38, Lodi-Woodbridge BIFS Final Report, page 66).

Respondents were asked if they had changed the amount or type of monitoring since the establishment of the Lodi-Woodbridge BIFS/IPM project in 1992 (Figure 41, Lodi-Woodbridge BIFS Final Report, page 68). Two-thirds of the respondents (66 percent) reported monitoring their vineyards more frequently since 1992. Sixty three percent said that they increased their monitoring for beneficial organisms. Over half the respondents spend more time monitoring their vineyard per visit since the start of Lodi-Woodbridge BIFS/IPM project and 49 percent said that they are monitoring more systematically. Sixty five to sixty-eight percent of the growers are using monitoring and economic thresholds for leafhoppers and mites, respectively, while 82 percent used monitoring and need-based spraying for weeds (Figures 47, 48, and 50, Lodi-Woodbridge BIFS Final Report). Fifty-eight percent of the respondents monitor for predacious mites. This indicates that the BIFS/IPM project has had a significant impact on growers’ monitoring habits.

Respondents were given a list of IPM practices promoted by Lodi-Woodbridge BIFS for insect, mite, disease and weed management and asked which of these practices they have used. Reducing the per acre rate of pesticides with conventional spraying equipment was the strategy used by over three-quarters (76 percent) of the growers for insect control, 65 percent for weed control, and 58 percent for mite control. If the average grower reduces the rates of insecticides when spraying this will have a large impact on

overall pesticide use reduction. For example, if every grower were to use 25 percent less pesticide when they treat then we will have reduced pesticide use by 25 percent. A third of the growers use alternate row spraying when treating insect problems. Just by spraying every other row rather than spraying every row, insecticide use is reduced by 50 percent. Sixty five percent of LWWC growers use leaf pulling as an IPM strategy (Fig. 47 and 49 Lodi-Woodbridge BIFS Final Report, pages 74 and 76). Leaf removal is a cultural control practice that reduces the amount of disease (Botrytis bunch rot) but also reduces leafhopper nymphs and spider mite problems. Almost half of the growers in LWWC (46 percent) have cover crops.

Comparing the results of the LWWC grower survey presented above with Table 9 data from the 60 BIFS growers’ demonstration vineyards we can see that the BIFS demonstration vineyards still serve as model vineyards in two key areas, monitoring and use of cover crops. One-hundred percent of the demonstration BIFS vineyards are monitored weekly for insects and mites compared to 65 to 68 percent of the LWWC growers. Seventy-two percent (combining annual and perennial cover crops) of the BIFS growers use cover crops whereas only 46 percent of the LWWC growers use them.

Respondents were asked if they used IPM/BIFS practices in their vineyards before the LWWC project began in 1992 and if they are currently using IPM/BIFS practices for their vineyard pest management. Thirty nine percent of the growers said they were using IPM before 1992 and 61 percent said they are currently using IPM (Figure 6). Almost half the growers felt they were not using IPM before 1992 while only 23 percent said they are not now. The Lodi-Woodbridge BIFS project has had a significant impact on the numbers of growers practicing integrated pest management in the district.

The following paragraphs summarize conclusions from the 1997 annual review meeting and subsequent analysis by UC SAREP of the Lodi-Woodbridge BIFS project based on the final report:

• The in-season pest monitoring program is a strong point in this project. All fields enrolled in the project were monitored weekly during the season for key biological indicators important for pest management. Pest management decisions were based on this data and reductions in use of pesticides can be related to this intensive monitoring. Monitoring for soil biological indicators can be improved.
  

• The development of a data management system (the relational database) and the scope of information monitoring entered into this database is an outstanding accomplishment. This system should be adapted to other BIFS and BIFS-style projects.
  

• In 1996, baseline data on the previous years’ crop yields, fertilizer and pesticide use were not reported. The project supervisor was directed to collect and analyze these data and to submit them to UC SAREP by June 30, 1997. The pesticide use data for BIFS growers was presented from 1992 through 1998 however data of county growers for comparison was only presented for 1992 through 1995 as this was the most recently available data from the Department of Pesticide Regulation (DPR). This pesticide use data was summarized and presented in the 1997 annual report and the final report. However, the most important comparison, between BIFS growers and non-BIFS growers in the county for the years that the BIFS project was active, has not been presented. BIFS growers’ fertilizer use data was provided in the final report, however no comparison with county average use data was presented. For winegrapes, the amount of synthetic nitrogen fertilizer used is relatively low compared to other crops in the area, and fertilizer use associated with winegrapes has not been found to impact ground water quality. Yield data has not been presented for the BIFS growers or for county comparisons; the BIFS project manager was asked for this data but did not provide it.

• It should be noted that this project did not maintain side-by-side comparison plots over the three years. Instead, the project was designed more to support intensive on-farm monitoring and in-season decision making rather than obtaining data from conventionally managed comparison plots. The comparison of BIFS grower’s agricultural chemical use patterns with county averages can be an acceptable approach for analyzing impacts of a project, however, all relevant comparisons need to be done.