Horticulture: September 2005

The third year of the Noble Foundation's hoop house strawberry variety trial concluded in May 2005.

There were a few changes made in the 2005 trial. "JP4" was dropped and replaced with "Camino Real." Also, "Treasure" was reintroduced after being absent from the 2004 trial. "Festival" was not included in this year's trial due to unavailability. Varieties included in the 2005 trial that were part of the 2004 trial include "Camarosa," "Chandler," "Sweet Charlie" and "Ventana."

Harvesting the 2005 hoop house strawberry variety trial.

In the previous two trials, transplants were produced from tip cuttings obtained from Canada. In August 2004, we decided to use dormant plants to establish the 2005 trial primarily because of difficulty encountered obtaining tips of the desired varieties. The plants obtained from Lasson Canyon Nursery in Redding, Calif., were field grown in fumigated soil and harvested during February 2004. Following harvest, the plants were placed in cold storage at 30 degrees F for about 6 months prior to being shipped via overnight air freight.

Upon arrival at the Noble Foundation on Sept. 8, 2004, the plants were transferred to 4-inch containers filled with a peat-lite growing mix and placed in one of our greenhouses, where they received frequent watering.

We considered transplanting the dormant plants directly into the hoop house. However, because there was a risk of injuring the plants due to high soil temperature (beds were covered with black plastic mulch), we chose to grow them in containers and transplant them into the beds at the end of the month under cooler conditions.

After three weeks in the greenhouse, the plants had generated additional roots sufficient to maintain an intact root ball when transplanted.

On Sept. 30, 2004, three rows of transplants were set into each of four beds equipped with black plastic mulch and drip irrigation. Rows were spaced 12 inches apart with individual plants in each row spaced 16 inches apart. Each variety (treatment) was replicated four times with each of the four beds serving as a replication. Each treatment contained 72 plants, 18 per replication. Plants were fertilized and irrigated according to previously established practices. Blossoms that formed during the fall were removed so as not to impede plant development.

Unless potentially damaging low temperatures or storms threatened, the house remained fully vented October through April. When temperatures were forecast to drop into the teens prior to flowering, the house was closed and heavy weight row covers were draped over the crop. Beginning March 1, vents were adjusted as needed to maintain a target temperature range of 70 F to 80 F for the purpose of forcing berry production. When freezing temperatures threatened, the house was closed and the row covers applied.

Harvest began on March 21 and ended on May 2. Results for marketable weight and berry size are reported in Table 1.

For the second consecutive year, Ventana was the top-yielding variety (1.60 lbs/plant). Treasure, the top yielding variety in 2003, continued to fare well in 2005 (1.22 lbs/plant). Camino Real, the only new variety in this year's trial, produced the largest-sized fruit (0.84 oz/berry).

Ventana continues to impress with its capacity to produce heavy yields of good-looking, large-sized fruit. Based on our trial results, Ventana appears to be the current variety of choice among varieties tested for hoop house strawberry production in southern Oklahoma and north Texas.

The use of dormant plants to establish a hoop house strawberry planting appears to be a viable alternative to using transplants grown from runner tips. Dormant plants purchased from Lasson Canyon Nursery currently are priced at $0.07/plant. Expect to pay an equivalent amount per plant for next-day air shipment to Oklahoma.