12 STATE HORTICULTURAL SOCIETY. 



4-6-50 formula, but after the first two sprayings a 3-5-50 formula can be 

 used, and for use as late as August it will often be better to use a 2-3-50 formula, 

 or to make use of soda Bordeaux mixture, which discolors the fruit less than 

 the lime Bordeaux. 



It is quite desirable to make use of stone lime rather than air-slaked 

 or hydrated lime, as it remains in suspension better and has greater adhesive 

 qualities. For these reasons, too, it is well to dilute both the lime and copper 

 sulphate when mixing and to stir them well while they are being poured 

 together. The addition of soap or glucose also tends to increase the ad- 

 hesiveness of the mixture but has not made any marked difference in our 

 experiments. 



TIME OF APPLICATION. 



No general rules can be given as to the time or the number of applications 

 as both will vary in different seasons. The best way is to observe carefully 

 the spray upon the vines and also the extent of the disease both in sprayed 

 and imsprayed vineyards. To lessen the danger of infection care should 

 be taken that none of the diseased grapes from the previous crop are left 

 upon the vines after pruning, and it is a good plan to plow the vineyard 

 before growth begins, taking pains to bury as much as possible of the leaves 

 and rotten grapes upon the ground. From the fact that it can be done at 

 a very slight expense, the spraying of the vines with a solution of copper 

 sulphate (two pounds to fifty gallons), while the wood is still dormant is 

 recommended. For this purpose the copper sulphate solution is better 

 than the Bordeaux mixture as the latter has to undergo a chemical change 

 to become soluble, before it forms an effectual fungicide. 



The first regular spraying with Bordeaux mixture should be made just 

 before the blossom buds open. If done at this time, it will be more effectual 

 than if applied just after the growth has started. A second application 

 of Bordeaux mixture should be given the vines after the fruit has set, when 

 it is about the size of a small pea. As an insurance against the rot and as 

 a remedy for the other fungous diseases, some of which are almost sure to 

 attack the vines, it will always pay to make the above applications, but just 

 how many additional applications can be given and the intervals that should 

 elapse will depend almost entirely upon the climatic conditions and the 

 prevalence of the disease. When the weather is wet and muggy, and partic- 

 ularly when the disease is Cjuite troublesome in unsprayed vineyards, it 

 will not be too much to make four more applications at intervals of about 

 ten days. It will be well to spray once a week when there have been frequent 

 heavy showers, although it might be possible to wait two weeks if the spray 

 has not been washed off. This will make six applications of Bordeaux 

 mixture and one of copper sulphate solution the maximum that is likely to 

 be required, while three or four might answer in seasons when there is little 

 rot. One should not make the mistake of waiting until the rot has appeared, 

 as in many instances it has been found that failure to spray the vines just 

 before the fruit sets may result in the loss of from twenty-five to fifty per 

 cent of the crop. 



THE IMPORTANCE OP THOROUGHNESS. 



Even though the material is properly prepared, and applied as recommended 

 above, the treatment will not be effectual unless the applications are suffici- 

 ently thorough to coat every grape and to keep the leaves covered. Thus, 



