FIREBLIGHT.

Wairarapa Age, 13 March 1929, Page 4

FIREBLIGHT.

THE DISEASE AND REMEDIAL MEASURES. OBSERVATIONS BY MB. J. W. WHELAN. When he addressed the Wairarapa High School agricultural class yesterday, Mr. J. W. Whelan made in reply to a question, ftcxne informative observations on the subject 1 of fireblight, which disease, as he remarked, has appeared on a serious scale in the local district. Fircblight, Mr. Whelan observed, [was a bacterial disease. It first made Pits appearance in this country about [nine years ago in the Auckland district. KThe primary infection was through the .blossom and the tree was thus inoculat >ed with the disease. From one season to another, fireblight was carried on in “hold-over cankers. 11 The disease formed definite cankers in trees, generally round buds. There was quite a distinct line between the healthy wood and the diseased wood. If, in Masterton, they could cut out every canker in the district, probably they would have no fireblight next season. One hold over canker, however, was capable of producing enough bacilli to infect a whole district. Fireblight w r as a very virulent disease. Hawthorn carried these hold-over cankers. Thus it was impossible to control fireblight in orchards unless the hawthorn was cut out. In the spring, an ooze exuded from the cankers. This ooze, carried by bees and other insects, inoculated the flowers they subsequently entered. In about six weeks, the flower commenced to droop and wilt and turn black. The foliage also took the infection and turned black, and a little later on the disease attacked the fruit. There was

not much danger, after the blossom season, of long-range infection, but there was the danger of eating insects carrying the disease from one part of a tree' to another. In infected areas, orchardists had to be on the alert all the time to cut out infected portions of trees.! In some instances a whole tree would turn black. The disease took its name from the fact that a badly infected tree resembled one blasted by fire. It was a peculiar feature infected foliage would hang on, sometimes right through the winter. Until hawthorn had been eradicated, Mr. Whelan added, they did not stand much chance of getting fireblight controlled in Masterton. In most districts the disease attacked pear trees first, but in this district it attacked sturmer apple trees even before the pears. Where the disease occurred, all diseased growth must be cut out well below the visible infection and all cuttings must be-burnt as soon as they were taken off. Cankers were as great a menace lying on the ground as on the tree itself. Mr. Whelan said that he believed the Department would rigorously enforce the process of cutting out diseased growth in infected orchards instituting prosecutions where this was not done voluntarily.