The cost of spraying three times should not exceed fifteen cents a tree. The results from spraying orchards which contain a great deal of brown rot and have never before been sprayed will probably not be so good the first year as in better kept orchards, but by spraying regularly each season the disease can be well controlled.
Mr. Cashman: Please state what you mean by 3-4-50 there.
Mr. Stakman: 3-4-50 Bordeaux mixture means three pounds of bluestone or copper sulphate, four pounds of lime, and fifty gallons of water. The copper sulphate should be dissolved in twenty-five gallons of water, the best way being to put it into a sack and hang the sack in the water. The lime should be slaked and then enough water added to make twenty-five gallons of milk of lime. Here is where the important part of making up the spray comes in. Two people should work together and pour the milk of lime and the bluestone solution together so that the streams mix in pouring. It is very important that the mixing be thorough and the mixture should be used fresh.
The President: Do you add any Paris green at any time or arsenate of lead?
Mr. Stakman: Always add arsenate of lead two times, when the buds are swelling and when the plums are the size of green peas.
The President: How much?
Mr. Stakman: I would rather leave that to Professor Ruggles. We used from 2-1/2 to 3 pounds and Mr. Ruggles, I think, found 2-1/2 pounds was enough.
The President: That is, 2-1/2 pounds to 50 gallons of water with the other ingredients?
Mr. Stakman: Yes.
Mr. Dyer: I would like to ask if you have ever used arsenate of lead for spraying plums?
Mr. Stakman: In the experiments which we conducted in co-operation with Mr. Ruggles, of the Division of Entomology, we always used arsenate of lead in the first two sprayings to kill the curculio.
Mr. Dyer: I had quite an experience, so I want to know what your experience was.
Mr. Stakman: We never had any trouble with it.
Mr. Dyer: I have had an experience of thirty years, and I have never seen or had on my place any brown rot, and I never was troubled with any curculio, and I practically always used arsenate of lead.
Mr. Cashman: Isn’t it a fact if you begin spraying your plum trees when they are young and spray them early, at the right time, you have very little trouble with the brown rot? And spray them every year?
Mr. Stakman: Yes, that is it. You might be disappointed the first year if the orchard had never been sprayed, but by spraying year after year you finally cut it down.
Mr. Cashman: You said a pressure of 200 pounds ought to be used?
Mr. Stakman: Yes, but it isn’t necessary to get an expensive power sprayer to keep up that pressure. There are sprayers on the market that cost from $30 to $40 which have a pressure tank by which the pressure can be maintained at from 175 to 250 pounds without any great amount of trouble, that is, for a small orchard. If you have a big enough orchard for a power sprayer, of course get it.