NEWSLETTER ARTICLES

Strawberries, Soils and Water

STRAWBERRY YIELDS OF NORMAL VERSUS "J" ROOT PLANT

In previous years strawberries in the Santa Maria area were planted in a 5-6" deep slot on 40" wide beds. The crown was placed at the bed surface, the root straight down, and the soil pushed in around the roots. This allowed the roots to grow in a normal pattern.

The 64" wide beds covered with plastic, created some planting concerns. The hole punch wheel jabs a slot with a uniform spaced location to plant. The difficulty is for the workers to plant the roots straight down. It is easier and quicker for them to plant "J" roots. Workers place the crown at the soil surface, the hand then pushing the center of the root into the slotted area, leaving the end of the lower roots near or above the ground surface. This severely limits crown and root growth. Some workers twist the roots to make it easier to place them in the slots. The twisted mass of roots further reduces growth. Planting the two center rows of the bed is more difficult, and a higher percentage of these plants have "J" roots than the outside two rows.

A trial in 1998 was established to evaluate the yields of "J" root plants in comparison with normal roots. The variety Camarosa was planted on November 7, 1997. The plants from McArther were dug on October 29, 1997. The plant rows were 10" apart with plants spaced 14" apart within the rows. The randomized block-designed trial consisted of 4 plots planted as "J" roots and 4 plots planted using a trowel to place the roots straight down. The plots were 30' long on 64" wide beds. A controlled release fertilizer at the rate of 120 pounds of nitrogen per acre was applied 4-1/2" deep and 2" to the side of the plants.

The trial received the same fertigation, irrigation, pest control, and picking schedule as the commercial field. The strawberries were harvested on a 3-4 day schedule by the growers’ commercial strawberry pickers. The fresh and freezer yields are based on the growers’ high standards for fruit quality.

Strawberry yields of normal versus "J" root plants are shown on Table 1. Differences between "J" root plants and normal roots showed plant growth and strawberry yields were affected earlier in the season. Fresh fruit yields were reduced by 18.5% with "J" roots compared to a 10.6% reduction for freezer fruit.

The season total yield showed that "J" root plants reduced yields 8,722 pounds per acre or 14.2%.

Following the last harvest, 40 plants were dug from each replication of the normal root plots. As the workers proceeded planting the trial, they were not as careful in placing the roots straight down. The workers in the first plot planted 0% "J" roots, the next plot had 2.5%, the third plot had 12.5%, and the last plot had 10%. All of the plants in the "J" root plots were planted as "J" roots.

In August 1998, at the end of the growing season, ten strawberry fields in Santa Maria were surveyed to evaluate the number of "J" root plants. Ten plants were dug in each of four locations within each field. The results of this survey showed that the percentage of "J" root plants ranged from 25-77.5%. The average of the ten fields was 54% "J" root plants.