DOCUMENTATION AND EVALUATION

The progress, strengths, and weaknesses of the BIOS program are documented and evaluated, along with the changing needs of participants. BIOS uses a range of informal and formal evaluation techniques and collects data on acreage enrolled, crop yield, pest damage, the adoption of selected management practices, the use of targeted agricultural chemicals, and attendance at group meetings. During initial farm visits, application forms and interviews were used to collect baseline data on these variables. After the 1993o94 season, the CAFF Foundation mailed out a survey to assess outcomes; 18 of the 26 farmers returned completed surveys (a 69-percent response rate).

Survey results showed that BIOS growers farmed 11.5 percent of total almond acreage (67,028) in Merced County in 1994 and incorporated BIOS practices on about 879 acres, or 11 percent of this land. Thus, each farmer enrolled an average of 32 acres in the project.

According to first-year results, the project increased farmers’ use of management practices to enhance naturally occurring biological processes for pest and soil management. Cover-crop use increased from 12 percent to 92 percent of the farmers involved. The cover-crop practice consisted of seeding a mixture of legume and grass species to fix atmospheric nitrogen, provide habitat for beneficial arthropods, and improve soil quality. Releases of beneficial arthropods to help manage insect and mite pests increased from 60 percent to 80 percent. The utilization of Bacillus thuringiensis, a selective insecticide that does not kill beneficial arthropods and can be used instead of broad-spectrum insecticides, increased from 41 percent to 65 percent. (See Figure 1)

BIOS promoted the planting of perennial insectary plants to provide year-round habitat for beneficial arthropods-a new practice for participating farmers. Forty-seven percent of the survey respondents planted perennial insectary plants. The number of farmers applying compost or manure did not change during the 1993o94 season. (See Figure 1)

BIOS farmers markedly decreased use of targeted agricultural chemicals in the 1993o94 season. Employment of broad-spectrum organophosphate insecticides fell from 35 to 0 percent, use of the herbicide Simizine by 24 to 6 percent, and mean applications of synthetic nitrogen fertilizer by 46.6 percent (from 200 to 107 lbs/acre). (See Figure 2)

For the 1993-94 season, crop yield and the percentage of insect damage (worm-reject level) were similar for BIOS blocks and comparison blocks from the ten farms that reported harvest results. Mean yields for the 10 BIOS and comparison blocks were 1,935 and 1,871 pounds per acre, respectively. (See Figure 3) Mean worm-reject levels were similar (BIOS blocks 0.6 percent and comparison blocks 0.7 percent). (See Figure 4) These results suggest that BIOS management techniques do not lead to yield reductions or to increases in pest damage in the first year. These data are consistent with harvest data reported by Hendricks (1995) in his long-term study of almond production in Merced County.

Farmer satisfaction with harvest results during the first year of BIOS was high. Eighty-eight percent of survey respondents were satisfied (n=15), compared to 12 percent who were not (n=2). Farmer satisfaction with harvest results in comparison blocks was similar. After one year with the Merced BIOS project, 47 percent (n=7) of respondents planned to increase their acreage under BIOS management. Ten of the 26 farmers placed all their almond acreage under BIOS management at the beginning of the project.

BIOS participants are encouraged to convey their criticisms and suggestions to management team members and CAFF Foundation staff by talking to team members or using the suggestion box at events. At each management team meeting, and in group focus sessions, members discuss how well program activities are going and which areas need improvement. Such discussions have led to appropriate modifications. The 1994 BIOS Grower Evaluation was mailed out with the 1994 BIOS Grower Survey. (See Table 1)