Weather limitations on the application of dinoseb-in-oil for cane vigour control in raspberry

Data on crop growth suggested that only 8 days are available for timely spraying of dinoseb-in-oil for control of cane vigour in raspberry in east-central Scotland. Crop records were linked with meteorological data to indicate the dates between which this 8-day period might fall. The meteorological data were then examined to assess the probability and likely duration of conditions suitable for spraying within the period when the crop is amenable to the spray treatment. The results indicated that unfavourable weather conditions may severely restrict the opportunities available for spray application by conventional equipment, the main limitation being high wind speed. The likelihood of rain after application putting the spray treatment at risk was found to be low. The infinitely compound Poisson distribution was found to be suitable for graduating the observed frequency distributions of suitable spraying conditions. Diagrams of frequency distributions were produced which can be used to assess the spraying capacity required to ensure timely application over the total area of a grower's plantations. It is suggested that the approach used in this investigation could be satisfactorily applied to a wider range of crops and spraying operations.