How to make Bordeaux and Burgundy mixtures in small quantities.

Date:
[1950]
Catalogue details

Licence: Public Domain Mark

Credit: How to make Bordeaux and Burgundy mixtures in small quantities. Source: Wellcome Collection.

    2/2
    Bordeaux mixture should always be used the day it is made. It is best to pour it into the spraying machine through a fine wire gauze strainer or a piece of muslin to prevent any dirt from clogging the nozzle. BURGUNDY MIXTURE This is similar to Bordeaux mixture, except that washing soda is used instead of lime. It is probably still the most widely used potato spray and is very effective. As a general spray, it is said to he rather more liable to cause scorching than Bordeaux mixture, but it is quite safe for use on potatees for the control of blight, and on peaches and almonds for the control of leaf curl. The details for making the spray are similar to those given above for Bordeaux mixture, washing soda being used in place of the lime. The proportions are: Copper sulphate 4, 0z. Washing soda... .. 9 02. Clean water 24 gal. The washing soda should be in fresh crystalline form and should be crushed to make it dissolve more readily 3; if it is old and broken down to a white powder, the soda solution made from it will be too strong. POINTS TO REMEMBER Do not guess weights. Have the correct amounts of copper sulphate, hydrated lime, or washing soda weighed out. The sprays should be applied before the disease makes its appearance, or ah least in the early stages before much spread has occurred; they are pre= ventive, not curative. It is generally necessary to spray: potato crops two or three times during; the growing season at intervals of 2 to: 3 weeks, to renew any deposit washed: off by rain and to ensure that all new growth is preperly covered and protected Spray on a fine day, but preferably; not in direct, hot sunlight ;_ early) mornings or evenings are often the best times. The spray will then dry before: rain comes and will stick satisfactorily) to the surface of the plants. Do nob spray if a frost is likely to be experienced: the same evening. The spray should reach and cover thee under sides of the leaves, if possible, as: well as the tops and stems. If nee sprayer or syringe is available, Bordeaux or Burgundy mixtures may be applieci to potatoes’ by sprinkling from és watering-can with a fine rose, but ¢: fine misty spray from a suitable nozzld is preferable. Spraying may prove injurious rathey than beneficial in the neighbourhood op! certain industrial towus, owing to inter:- action between substances in the spray) and acid fumes in the air. Local advice: should therefore be sought before spray; ing within about ten miles of large industrial centres.