THE EFFECT OF SEED DISINFECTION UPON THE OAT CROP IN NORTHERN IRELAND

Abstract

SUMMARY This paper deals with a series of experiments carried out in Northern Ireland over a period of three years in order to determine the value of various seed treatments for controlling smuts and for use as general seed disinfectants in connection with the cultivation of the oat crop. In so far as the control of oat smuts is concerned and at the concentrations used in these experiments, copper sulphate and copper carbonate proved to be of some value but caused definite injury to the crop, while sulphur and gypsum proved to have no fungicidal value. Formaldehyde gave complete control in nearly every case, the sprinkle method being considered more satisfactory than steeping, as it is more easily carried out and as the results obtained indicate that in some cases steeping may cause crop injury. The organic mercurial–“Ceresan”– gave almost as good results as formaldehyde. As general seed disinfectants the organic mercurials–“Ceresan” and “Abavit B”–proved to be more satisfactory than formaldehyde, the average increase in grain yield from these plots being approximately 30 per cent, above the yield from the formaldehyde plots which in turn showed a yield increase of 16 per cent above the controls. It is suggested that the greater efficiency of organic mercurials is due to the fact that the fungicide is retained by the grain at the time of sowing and remains operative during the early stages of crop development without causing injury to the plants. The fact that oat grain has been treated with “Ceresan” and “Abavit B” at varying intervals before sowing with complete success indicates that this method of treatment possesses a distinct advantage over the formaldehyde method where, in order to preclude possibly injury during germination, it is necessary to carry out the treatment immediately prior to sowing. No causes of poisoning as a result of the use of organic mercurials have occurred so far and it is possible that by taking reasonable precaution the. use of these compounds for seed dressing may be safely advocated.