Good May Come Out OF Chou Moellier Failure

Press, Volume XCVIII, Issue 28802, 24 January 1959, Page 9

Good May Come Out OF Chou Moellier Failure

The partial failure of a crop of medium stem chou moellier which the Crop Besearch Division was saving for seed may well prove to be a mixed blessing. Less than half, the expected yield is likely to be harvested because of blackrot infection which was followed by secondary stem infections of dry rot and ring spot. The division has taken seed from both affected and unaffected plants and is subjecting them to glasshouse trials to evaluate resistance to the disease. This may result in an improved strain of chou moellier being developed. Dr. Harvey Smith, a plant pathologist with the division, said that the stand had been sprayed in September for aphid control with success and although there had been a slight build-up of aphids later on there had been no harmful effects. A blackrot infection of some of the plants had been noticed during the winter, but because a similar infection had not affected the yield of thousand-headed kale the previous year it was not ex-

pected that the chou moellier would suffer. It appears that the’ secondary infection of dry rot and ring spot fungi developed on the blackrot affected areas and the combination of the diseases must have moved rapidly after flowering. Many plants died and others, less affected, bore shrivelled pods. Chou moellier is the most susceptible of the brassica crops to blackrot and the worst affected districts in New Zealand are at Balclutha and Palmerston North in the heavier rainfall districts. Chou moellier has a fairly high resistance to ring spot and dry rot. Overseas authorities recommend the treatment of seed before sowing to prevent blackrot but in New Zealand the prevalence of soil infection produces the need for the breeding of resistant strains. “As one problem is eliminated it enables another to be pinpointed,” Dr. Smith said. This crop may stimulate the production of a resistant chou moellier."