Nevada County Picayune and Gurdon Times Newspaper Archive

Farm and Home with Rex Dollar

Recently there have been several calls regarding fireblight on pear trees.

Fireblight is a major disease of pears and apples in Arkansas. The disease is caused by a bacterium, Erwinic amylovora, and is characterized by killing of blossoms, fruiting spurs and branches.

If the disease is severe enough, limbs or entire trees may be killed.

The disease will begin at the blossoms and can move down the terminals rapidly, sometimes having potential to kill an entire tree in a single season.

Leaves of infected branches wilt rapidly, wither and turn brown to black. Bark of infected limbs and branches is dark and dehydrated. When the bark is peeled back, the inner tissue is dark. Later in the season, cankers with sunken margins may form on branches or limbs. These cankers function as an overwintering point for the bacteria.

For infected trees it is recommended to cut out infected limbs at least 10 to 12 inches below visible stem discoloration. Cutting tools should be sanitized with 70% alcohol with each cut by spraying the alcohol on the cutters with a spray bottle. Twigs and branches that are cut out should be discarded or burned.

Control of sucking insects, such as aphids, after bloom may help reduce disease by eliminating feeding wounds and lowering dispersal of the pathogen by insects. Bactericides, such as streptomycin, have been effective when used during the blossom phase of this disease in some cases.

Applications should begin at the start of bloom period and continue throughout bloom at five- to seven-day intervals.

Fireblight is more severe if tree growth continues late into the season. Do not apply nitrogen after August 15.

Two varieties of pear which are highly susceptible to fireblight are Aristocrat and Autumn Blaze. Some varieties of pears that are only moderately susceptible include Capital, Bradford, Fauriei, Red Spine and Whitehouse.

FARMER'S MARKET

The Nevada County Farmer's Market is scheduled to open on Friday, May 19, at 8:00 a.m. on Highway 67 North under the large oak tree.