ROOT CROPS IN SOUTHLAND

Southland Times, Issue 23408, 15 January 1938, Page 14

ROOT CROPS IN SOUTHLAND

SERIOUS EFFECTS OF DISEASE RESEARCH TO OVERCOME CLUB-ROOT A considerable amount of research into the growing of root crops is being carried out in Southland this season with the object of overcoming losses caused by club-root in swedes and the disease known as mottled heart in the same crop. It has been estimated that club-root alone represents a loss to Southland farmers of not less than £50,000 a year and the complete elimination of the disease would be extremely beneficial. Research undertaken in the past for the control of this disease has not been very successful and farmers have turned from one possible cure to another without any marked diminution of the trouble. About 10 years ago tests were first made for varieties of swedes which had a high resistance to the disease and a great deal was heard of the valuable characteristics of the Herning swede. Other varieties which were reputed not to take the disease came on to the market, but the faith of growers in the usefulness of some has been undermined except in the case of about one turnip variety which has given excellent results in Southland. No very successful swede variety to resist the disease has yet come on to the market. For a time the fertilizing system was blamed for the disease and the use of superphosphate and other acid manures discouraged. This also has not proved reliable although it is known that acid conditions favour the disease and many Southland farmers have now had experiences which indicate completely different causes without giving any hint of means to overcome the dishas been found that an early sowing of swedes on land may take pie disease very badly, while an adjoining piece of ground which has received precisely similar treatment but is sown down several weeks later may not be affected. On the other hand, the first sowing may not be affected, while a second sowing may be badly diseased. One Southland farmer ploughed for turnips last year an area which included pasture land which had not been cultivated for 30 years and also land cropped several times within recent years. In view of the general warning against rotation of swede and turnip crops in the same land for one or more seasons, he expected club-root to affect the crop on the portion of the paddock previously cropped, but to his astonishment the disease was apparent right through the crop and there was no variation on the freshly ploughed portion.

TESTS FOR NEW PREPARATION This season an English preparation with which the seed is treated prior to sowing together with a treated manurial mixture has been given prominence and many Southland farmers have used these preparations for much of their sowings this season, many leaving a small untreated control section. A great deal of interest is focussed, on the results of this treatment and it is yet too early to determine the effectiveness, although reports already to hand indicate that it does not completely eliminate the disease. In view of the previous results obtained from various experiments, widely different effects may be expected. In home gardens, a solution of permanganate of potash soaked into the holes before planting cabbages has proved effective, but such a treatment on the farm is obviously impracticable where root crops are to be sown. Experiments undertaken by the Cawthron Institute have proved that a deficiency of boron is chiefly responsible for the mottled heart condition in root crops and effective results have been obtained through the application of a light dressing of borax about 14 days before the sowing of crops. It has been found necessary to apply the borax a fortnight earlier than the seed as if sown at the same time it has a tendency seriously to affect germination. This practice has also been widely adopted in Southland this season and farmers are anxiously awaiting the results of the trials and hoping that the losses in the past through mottled heart will be eliminated.

Although many root crops in Southland were adversely affected by the very dry weather before Christmas, they have made a good recovery since the heavy downpour on Christmas Eve and the subsequent rains have stimulated growth very considerably. Although the salvage of hay has been light this summer, it is expected that root crops will be adequate provided clubroot does not make a heavy toll on the crops.