Roger A Duncan

Pomology Farm Advisor, Emeritus
Stanislaus County
UC Cooperative Extension Stanislaus County
Modesto, CA 95358
(209) 525-6800
raduncan@ucanr.edu Create VCard

Biography

Prior to retiring in 2024, I conducted applied research and education programs directed towards orchard growers, pest control advisors, consultants, and other industries related to the approximately 200,000 acres of almonds, canning peaches, and other orchard crops in Stanislaus County.  I also served as a source of information for growers of other miscellaneous tree fruit species. Although Stanislaus County is one of the largest tree crop acreage areas in California, the large clientele base (2125 farms) is comprised mostly of small acreage growers, where approximately 75% of the farms are 40 acres or fewer. My research efforts include evaluation of rootstocks, varieties, orchard design and pruning systems, alternatives to pre-plant fumigation, labor reduction in peaches, tree fertility and integrated pest management.

Education

M.S. Plant Science / Plant Pathology, C.S.U. Fresno. 1990
B.S. Plant Science / Plant Pathology, University of California, Davis. 1987

Specialty

Almonds, canning peaches, misc. tree fruit

Areas of Expertise (click to see all ANR academics with this expertise)

Bibliography

Peer Reviewed

  • Duncan, R.; Adaskaveg, J., et al. (2011). Diseases. UC IPM Pest Management Guidelines: Peach. UC ANR. Pub #3454. April 2011.
  • Duncan, R.; Day, K., et al. (2011). Nematodes. UC IPM Pest Management Guidelines: Peach. UC ANR. Pub #3454. April 2011.
  • Holtz, B.; Duncan, R., et al. (2011). Sample Costs to Develop an Orchard and Produce Flood Irrigated Almonds: San Joaquin Valley North. 2011.
  • Holtz, B.; Duncan, R., et al. (2011). Sample Costs to Develop an Orchard and Produce Microsprinkler Irrigated Almonds: San Joaquin Valley North. 2011.
  • Hasey, J.; Norton, M., et al. (2011). Sample Costs to Establish and Produce Processing Peaches in the Sacramento and San Joaquin Valleys: Extra Early Harvested Varieties. 2011.
  • Hasey, J.; Norton, M., et al. (2011). Sample Costs to Establish and Produce Processing Peaches in the Sacramento and San Joaquin Valleys: Late Harvested Varieties. 2011.

Non-Peer Reviewed

  • Curtis, R.; Gradziel, T., et al. (2011). Almond checklist: disease and insect susceptibility, kernel quality and â??fitâ?? for your farming operation and style. Western Farm Press. September 2011.
  • Gradziel, T.; Curtis, R., et al. (2011). Almond checklist: disease and insect susceptibility, kernel quality and “fit” for your farming operation and style. Western Farm Press. September 2011.
  • Duncan, R.; Northcutt, G. (2011). Despite challenge by blossom blast, Stanislaus County almond trees set an average or better crop. Tree Nut Farm Press electronic newsletter. May 2011. 2011.
  • Norton, M.; Duncan, R. (2011). Field Performance of Sixteen Rootstocks in an Unfumigated, Sandy Loam, Replant Location. County Publication. 2011.
  • Duncan, R. (2011). Hull samples for boron analysis. Almond Doctor weekly blog. Merced County. August 2, 2011.
  • Duncan, R. (2011). Hull sampling at harvest to determine boron deficiency. Tree and Vine Newsletter. Merced County University of California Cooperative Extension. September 2011. 2011.
  • Haseyy, J.; Adaskaveg, J.E., et al. (2011). Management of Peach Leaf Curl - New Approaches for an Ever Present Disease. The Scoop on Fruits and Nuts in Stanislaus County. 15, 3. 2011.
  • Duncan, R. (2011). New Options for Almond Rootstocks. County publication. May 12, 2011.
  • Duncan, R. (2011). New Peach Blossom Thinning Machine Improves Fruit Quality and Yield While Reducing Hand Labor Needs. Stanislaus Farm Bureau Newsletter. February 2011. 2011.
  • Norton, M.; Duncan, R. (2011). Review of String Blossom Thinner Trials in Stanislaus County. County Publication. 2011.
  • Gradziel, T.; Curtis, R., et al. (2011). Selecting almond varieties – Bloom, pollination and harvest considerations. Western Farm Press. August 2011.
  • Curtis, R.; Gradziel, T., et al. (2011). Selecting almond varieties â?? Bloom, pollination and harvest considerations. Western Farm Press. August 2011.
  • Duncan, R.; Anderson, K. (2011). Stanislaus Area Orchard and Vineyard Service Directory. 2011.

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