R. Scott Johnson,
Interim Director,
 Kearney Agricultural Center

Extension Pomologist
Ph.D., Cornell University, Ithaca, NY, 1982

Phone (559) 646-6547     FAX (559) 646-6593
E-mail: sjohnson@uckac.edu

Department of Plant Sciences,
 University of California, Davis

Areas of Specialty:
Freestone peaches, nectarines,
 plums, kiwifruit, apples

Web Site:  UC Fruit Report

Research Statement
I am the Extension Specialist for apples, kiwifruit, fresh shipping peaches, nectarines and plums. My responsibilities include the coordination of research and extension activities for these commodities by acting as a liaison between Farm Advisors and the Pomology Department and between the fresh fruit industry and the University of California.

My research has focused on improving the efficiency of cultural practices in stone fruit production. Under this general objective are four areas that I have concentrated on:

bulletReduction of tree size with dwarfing rootstocks.
bulletNitrogen fertilization practices for good fruit size and quality and minimal ground water contamination.
bulletWithholding of water during certain periods of the season when fruit growth and subsequent yield are not adversely affected.
bulletStudies with early and late season peaches on the response of fruit size and yield to thinning level and time.

The objective of all these studies is to improve the efficiency of a grower's operations by reducing his inputs of labor, fertilizer and water without adversely affecting yield and fruit quality.

Selected Publications

2000.  Handley, Dale F. and R. Scott Johnson.   Late Summer Irrigation of Water-stressed Peach Trees Reduces Fruit Doubles and Deep Sutures.  HortScience 35(4):771.

2000.  Johnson, R. S., J. Ayars, T. Trout, R. Mead and C. Phene.  Crop coefficients for mature peach trees are well correlated with midday canopy light interception.  Proc. 3rd International Symposium on Irrigation Horticultural Crops.  Acta. Hort. 537:455-460. 

1998.  Rosecrance, R. C., R. S. Johnson, and S. A. Weinbaum.  The effect of timing of post-harvest foliar urea sprays on nitrogen absorption and partitioning in peach and nectarine trees.  J. Hort. Sci. & Biotech. 73(6):856-861.

1995.  Daane, Kent M., R. Scott Johnson, Themis J. Michailides, Carlos H. Crisosto, Jeff W. Dlott, Hugh T. Ramirez, Glenn Y. Yokota, and Dave P. Morgan.  Excess nitrogen raises nectarine susceptibility to disease and insects.  California Agriculture 7/8:13-18.