Fresno County Strawberry Research 1996-98

Richard Molinar, farm advisor
Michael Yang, farm advisor assistant
UC Cooperative Extension 
Fresno County

During 1996-98, Richard Molinar, farm advisor, and Michael Yang, farm advisor assistant, carried out six research projects briefly summarized below. For a complete summary of each research project, contact Richard Molinar, UCCE Fresno County, 1720 S Maple Ave., Fresno, CA 93702; 559-456-7555; e-mail rhmolinar@ucdavis.edu
Or check back on this page at a later date.

I. Black Plastic for Weed Control in Camarosa Strawberries

Summary

Black plastic mulch applied in February reduced the amount of weed growth considerably as compared to the clear mulch. Yield was not adversely affected, and in fact, was increased significantly (p< .10) in the black plastic. Fruit did not appear to be injured where it contacted the black plastic.

II. Black Plastic for Weed Control in Chandler Strawberries

Summary

There was no significant difference in yield between black and clear plastic mulches applied in February on the Chandler variety. There was also no difference in berry size between the treatments. Black plastic mulch did provide effective weed control without sacrificing yield. Fruit quality was not affected by the black plastic, and there was no evidence of fruit burn as mentioned in several sources.

III. The Effect of Red and Black Plastic Mulch on Chandler Strawberry Production

Summary

Red plastic mulch significantly reduced the yield of Chandler strawberries (p=.10) compared to a black plastic mulch. Strawberry runner plants were able to survive and grow under the red mulch, competing with the mother plants and reducing yields. There was no growth under the black mulch. There was also no difference in berry size.

IV. The Effect of Planting Dates on Yields of Two Varieties of Strawberries

Summary

Chandler and Camarosa varieties planted September 11 and August 26 resulted in higher yields than plantings made on September 24 and October 3. Chandler plants stored and planted on the four different dates resulted in poorer crown survival than Camarosa plants on the later planting dates.

V. Traditional Close Shearing vs. Moderate Thinning in Two Fields of Chandler Strawberries

Summary

Two trials were conducted in 1996-97 to determine the effect of light winter pruning vs. the traditional shearing of plants prior to laying clear plastic. The results in two separate Chandler fields showed no significant difference between close shearing and only moderate thinning of plants.

VI. Comparison of Camarosa, Gaviota, Carlsbad, and Chandler Varieties of Strawberries in Fresno County 1998

Summary

Camarosa, Chandler, and Carlsbad all yielded significantly more total berries (p<.05) than Gaviota in a replicated trial in Fresno County. Yields from the three varieties were 34-54 percent higher than the new University of California variety (Gaviota). Both Camarosa and Chandler also yielded significantly more marketable berries than Gaviota. Carlsbad was the largest berry at 29 grams, followed by Camarosa (26.6 gm.), Gaviota (23.5 gm.), and Chandler (23 gm.).