ANALYSIS OF MONITORING ACTIVITIES

Section 594 of AB3383 requires that: "...policies and procedures shall include, but shall not be limited to, a mechanism for monitoring and summarizing pesticide and fertilizer use for each project with an assessment of overall reductions in pesticide and fertilizer use on each project." The following section of the RFP specifically addresses Section 594 (a):

Table 8. Section of UC SAREP request for proposals that sets the policies and procedures for monitoring programs in pilot demonstration projects

Except where noted, the descriptions of the monitoring programs described below have been excerpted from the Winegrape BIFS and West Side BIFS annual reports.

WINEGRAPE BIFS PROJECT

Vineyard Monitoring

Each of the 47 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 pests problems monitored for in Lodi vineyards are grape leafhopper (Erythroneura elegantula), variegated leafhopper (Erythroneura variabilis), Willamette mite (Eotetranychus willamettei), Pacific mite (Tetranychus pacificus), omnivorous leafroller (Platynota stultana), 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. Important highlights of the Winegrape 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 of numbers for each vineyard. PCAs and growers in Lodi generally agreed that, on a regional basis, grape leafhopper numbers were not as high as in many years. Many scientists feel that Lodi is at the limits of distribution for variegated leafhopper and this past summer’s monitoring reflected this fact; few vineyards had significant numbers of this pest. Eighteen BIFS vineyards had grape leafhopper populations that exceeded the economic threshold and they were treated with Provado insecticide.

Spider Mites

There were few BIFS vineyards with mite populations that exceeded the economic threshold. Six BIFS vineyards were sprayed for mites this season. Two BIFS growers whose vineyards were developing mite problems chose to purchase and release Metaseiulus occidentalis, a predacious mite, in their vineyards. In both cases the pest mites continued to build up and miticide treatments were still necessary.

Powdery Mildew and Bunch Rot

Powdery mildew can be a devastating disease in winegrapes and once an infection occurs it is very difficult to manage. Therefore prophylactic spraying is used to manage this disease. Because of the importance of this pathogen most growers have a very rigorous treatment program and as a result no mildew problems occurred in any of the BIFS vineyards this year.

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. There were no bunch rot problems in any of the BIFS vineyards this year, probably due in large part to the seasonal weather conditions, since bunch rot was not important throughout most of the region. Nevertheless, leaf pulling is very important in reducing bunch rot problems and 51% of the BIFS vineyards used this technique during the season.

Vineyard Management Practices

At the end of the growing season each grower-cooperator was asked to submit a summary of the management practices carried out in their BIFS vineyard(s) during the season. Table 9 contains a summary of the types of practices that were recorded for each BIFS vineyard.

Table 9. General Vineyard Practices Recorded for Each BIFS Vineyard*

* From C. P. Ohmart, 1996. Table 3 in Winegrape BIFS Annual Report

WEST SIDE BIFS PROJECT

Side-by-side comparisons of conventionally managed and biologically-based production systems were established at 16 sites in the fall of 1995 on 12 participating farms. The sites consist of two adjacent 20 to 40 acre blocks at each farm. One block is conventionally managed with the other block receiving a biologically based treatment. Discussions of how best to "standardize" inputs and the meanings of "conventional" and "biologically based" were conducted by the entire group of farmers and scientists during the fall of 1995.

The biologically based treatment in alternative plots varied from farm to farm depending on material source, planned use of the area, and period of availability. Compost or manure was applied in late 1995 in "alternative" plots at 12 sites. Cover crops were planted at three additional sites over the 1995 - 96 winter. Relative benefits of compost vs. manure additions are being evaluated at an additional site. Except for two farm sites, all sites were planted to processing tomatoes. The two other sites were planted to corn and cotton, respectively.

Compost/Manure Sampling

Representative compost samples were supplied by the BIFS participants and submitted to the DANR Analytical Service Laboratory for total content of C, K, N, Na, P, Ca, Mg and organic carbon. Based on the total compost N, and the soil P and K values, the attached guideline was prepared by the technical team and given to each grower for possible adjustments in their fertility programs.

Soil Quality Monitoring

To make useful evaluations, a number of key physical, chemical and biological soil attributes are being monitored at each demonstration site. A number of soil properties and sampling times have been selected for monitoring changes in soil quality.

Soil physical properties

About 50 percent of the fields differed with respect to soil textural class between the alternative and conventional plots. However, the plots were actually neighboring classes in the textural triangle, due to only slight differences in their clay content. The overall field textural class varied among sites with clay loam being the modal soil textural class. No significant difference (p>0.05) was determined between the initial water stable aggregates (WSA) values between the plots. This result suggests that the alternative and conventional treatments were allocated to homogeneous fields. The overall percentage of WSA under the slow wetting process was 80 percent, implying that the overall increase in WSA by the soil building practices would be at most 20 percent.

Soil chemical properties

No significant difference (p>0.05) between the initial values was consistently determined for initial soil pH, electrical conductivity (EC), cation exchange capacity (CEC), soil organic matter (SOM) and total N values in each agricultural system. This result suggests that the alternative and conventional systems were allocated to homogeneous fields.

Productivity and Product Quality Measures

Yield data and fruit quality determinations from these sites were taken at harvest. Yield data were obtained by measuring the area harvested for one load (double trailer) and obtaining the weight of tomato for the particular load from records compiled by each farm office. Three loads (double trailer each) for each treatment were taken. In addition, random sampling of fruit was done on-board the harvesting machine for maturity and grade-quality evaluations.

Due to the different tomato varieties used by the participating farms, statistical yield analysis for yield was made only for within-farm comparisons. Results of analysis showed no significant differences in yield between the conventional and alternative treatments in all participating farms (p>0.05).

Plant Stand Counts Following Cover Crops

Three participants grew cover crops following the 1995 cotton season. In addition to monitoring biomass production and major nutrient contents of the cover crop, succeeding plant stands were evaluated for each field for possible seedling pests or effects on plant establishment following cover crops.

IPM Activities

Cotton insect management continues to require insecticide inputs to achieve desirable levels of yield. During the past five years, the portion of the farm budget required for insecticides and acaricides has increased over the San Joaquin Valley. This trend raises problems for cotton profitability and long-term utility of these tools.

During the 1996 cotton season, four sites within the BIFS area were utilized as part of a Valleywide arthropod survey. Three of the sites were on BIFS cotton sites and the other was just west of the project community area. Weekly counts and plant development data were collected and summarized. Information from these fields were faxed weekly to BIFS participants for their information and guidance. In return, cooperators provided activity records for each field. In addition to pests, natural enemy populations were monitored. Analysis of data is incomplete but the populations of pests and natural enemies fell within a range of observations from other fields in the Valley. Fruit retention in these fields ranged from average to excellent.