California Pepper Commission


Proposal Weir Foliar Applicatons of Potassium Materials

Proposal to the California Pepper Commission
For Support of Project in Year 2013

PROJECT TITLE: Foliar Applications of Potassium Materials to Bell Peppers

PROJECT STATUS: Continuing Project - 2nd year with modifications to Include Field Scale Plots

PRINCIPAL INVESTIGATOR: Bill Weir, Ph.D. - Extension Advisor,
University of California Cooperative
Extension, Merced, California
Phone - 209 777 7950

COOPERATORS: Bob Giampaoli,
Live Oak Farms
Le Grand, California


A foliar feeding study was conducted in 2012 in which KNO3 was applied to bell pepper at various timings throughout the growing season. Although yields were increased numerically, there were no statistical differences among treatment means. Results were encouraging in that they were similar to published findings in cotton and tomato.


Acting upon a suggestion by Bob Heisey, a continuing study was planned utilizing large commercial areas for each treatment rather than small areas treated by back pack sprayers. A discussion with Bob Giampaoli of Live Oak Farms led to a plan to treat approximately 10 acre blocks with each treatment and replicate them up to four times. Materials will be applied by Live Oak Farms equipment at intervals dictated in the protocol.

Fruits will be harvested by Live Oak Farms workers, transported to the packing shed, sized and packed according to normal ranch practices. Weights will be kept for each category of peppers, from each harvest, for each treatment. Live Oak Farms usually harvests peppers three times, and often make a fourth harvest for the reds market. All data will be subjected to an ANOVA and results presented in an annual report.


  1. Untreated check
  2. Potassium Nitrate (13-0-45)
  3. Score Foliars (7-28-4 with Zn, Fe and Humic acid)


Site location, setting up treatments and replications $1000.00
Application costs $1000.00
Harvest costs $500.00
Data collection and analyses $1500.00
Travel and miscellaneous $100.00

TOTAL $5000.00

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