View Poster Application

DEHYDRATOR ONION YIELD RESPONSE DIFFERS BY BIOSTIMULANT PRODUCT AND GROWTH STAGE AT APPLICATION

Applied Research

Michael Rethwisch
Farm Advisor - Crop Production and Entomology
University of California Cooperative Extension
Blythe

Abstract

Dehydrator onions are a crop that continues to expand in acreage in the California low desert.  Biostimulants may be a viable way to increase production, but little research on dehydrator onion yield responses to these types of product existed, with the most recent research being conducted almost 20 years ago with a single product.  Since then, many new biostimulant products and chemistries have become commercially available, but with no comparative data existed for their efficacy.  This project was initiated to fill this informational void.  During the 2019-2021 production seasons, onion yields resulting from the application ten (10) biostimulant products were document.  Three (3) products were initially applied pre-germination or early emergence with the other seven (7) products being first applied when multiple leaves were present.  Field trials were conducted on differing varieties and soil types to determine the consistency of results.   During 2021, comparisons of two (2) vs. three (3) applications of foliar products were also conducted, with the two applications being made at third and fifth green leaf stage, while the three application regimen also included applications at the seventh green leaf stage.  Yield data indicated that for the products applied pre-germination/early emergence the best yield response was noted from two applications of Liquid Seaweed Concentrate (emergence with second application at the fifth green leaf).   For Guarantee Complex, a single application was best.   Several foliar based products averaged 4+% increases in yield (Vitazyme at 20 oz./acre, single application, CytoPower with two applications).  Several products resulted in yield decreases when a third application was made, however, this was not true for all products.  Results were fairly consistent over the two years, providing high confidence that certain biostimulants can provide a positive economic return.  The yield results also indicate that the onion development stage is an important factor for targeting effective usage of biostimulant products, and that biostimulant products also differ greatly for their ability to increase dehydrator onion yields.    

Poster has NOT been presented at any previous NACAA AM/PIC

This poster is being submitted for judging. It will be displayed at the AM/PIC if not selected as a State winner. The abstract will be published in the proceedings.

Click to view Poster

Authors: Michael Rethwisch, Kassandra Allan, Lauren-Elizabeth Pope, Nathan Tribby
  1. Rethwisch, M. Farm Advisor - Crop Production and Entomology, University of California Cooperative Extension - Riverside County, California, 92225
  2. Allan, K. Student Assistant 3, University of California Cooperative Extension - Riverside County, California, 92225
  3. Pope, L. Student Assistant 3, University of California Cooperative Extension - Riverside County, California, 92225
  4. Tribby, N. Student Assistant 3, University of California Cooperative Extension - Riverside County, California, 92225-1649