07/19/1991

Auburn Field Day Features Fruit, Vegetable Tours

CLANTON, ALA.— Mowing blackberry brambles to 12 inches tall reduced yield about 12 percent, but dramatically reduced labor intensive pruning and harvesting problems in Alabama Agricultural Experiment Station research, according to researchers at a Fruit and Vegetable Field Day held recently at the Chilton Area Horticulture Substation here.

Auburn researcher Allison Busby told the crowd of over 100 commercial growers and home gardeners that blackberries normally require pruning three times per year. In tests at the Substation, researchers used a bush hog to mow blackberries to six-inch and 12-inch heights after final harvest in mid-July in 1990, which eliminated further pruning. This year they harvested 6,450 pounds from the six-inch mowing, 8,100 pounds from the 12-inch mowing and 9,400 pounds from the hand-pruned bushes.

"It is a tradeoff of some yield for some reduced production cost," Busby noted. She also pointed out that the blackberries that were mowed to 12 inches tall were perfect height to pick and tended to produce more berries on the tops and outsides of the plants, making them easier to harvest, especially in U-Pick operations.

Busby also told the crowd about Navaho, a relatively new thornless variety of blackberry that has performed well in tests at the Chilton Area Horticulture Substation. It is the only thornless variety with an upright growth pattern. In addition to ease of picking, Navaho also produces large berries with high sugar content, according to the Auburn researcher.

The fruit growers showed particular interest in a new planting of Asian pears. Auburn researcher Bill Dozier pointed out that the trees are in their third growth year, but some are already producing fruit this year. Some of the most popular varieties grown commercially in California, 20th Century, Meteitsu, Ya-Li and Doitsu, have all been decimated by fire blight and probably aren't suited to growth in Alabama. Other varieties that appear to be better suited to central Alabama and have not been affected by fire blight include Kikusui, Erishinte, Chojuro, Shinko, Hosui and Sevui. Dozier stressed that the researchers are just in the third year of looking at the odd-shaped, dark orange-colored pears, and no yield information or definitive growth data have been taken yet.

Commercial strawberry producers heard some impressive production figures for berries grown on a raised hill and annual plastic system at the Substation. Though the berries were gone, the 18-inch tall, plastic covered beds remained for the visitors to see. To use this system, Auburn researcher David Himmelrick said the soil must not contain rocks, which will tear the thin plastic used to cover the raised beds. Prior to applying the four-foot-wide black plastic, the hills are formed, or bedded, an irrigation tube is added, and the bed is injected with a combination of methyl bromide and chloropicrin for disease and weed control.

When kiwi plantings were installed five years ago at locations throughout south and central Alabama, Experiment Station researchers thought the kiwi at Clanton would be at the northern limits of production. Instead, Chilton County appears to be about as far south as kiwi can be grown, because of a lack of chilling hours, according to Auburn researcher Arnold Caylor. In tests at the Chilton Area Horticulture Substation, researchers were able to avoid freeze damage to kiwi by using either a mist system or trunk wraps. If freeze damage can be avoided, Caylor said that kiwi may produce better in more northern areas of Alabama.

In addition to hearing reports from Auburn researchers, the visitors were able to sample many of the fruit varieties grown at the 161-acre research facility, which is one of 21 outlying research units of the Main Agricultural Experiment Station at Auburn. Of particular interest were AU Rubrum, AU Producer, AU Amber and AU Cherry plums, all of which were released by the Experiment Station. Auburn researcher Joe Norton, who developed the varieties, provided samples of each plum and told the visitors the production advantages of each fruit.

The visitors also heard presentations by horticulture researchers on watermelon varieties by George Boyhan, sweet corn by Steve Kovach, peaches by Arlie Powell, apples by Dozier and grapes by Caylor.

Jim Pitts, superintendent of the Chilton Area Horticulture Substation, said the unusually large crowd on hand for the field day is indicative of the interest in fruits and vegetables in the State. "We appreciate this interest by commercial growers, U-Pick operators and home gardeners. We also appreciate the faculty members from Auburn taking their time to participate on the program," Pitts concluded.

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By:
Roy Roberson