94 STATE BOARD OF AGRICULTURE. 



We have another chiss of insects which do not chew, but which have 

 a snout and suck out the juices, and if you attempt to put on Paris green 

 for these you will meet with failure. For this class of insects, we must 

 take remedies that kill by contact, perhaps, like kerosene emulsion, 

 which, if it touches the insect, will kill it. 



Then we have other remedies that tend to drive away the insect, and 

 these can be used with success; still it is best to pin our faith to the 

 arsenites, so far as the chewing insects go, and generally, if we have to 

 use anything for the others, it is well to use the kerosene emulsion. 



Again, regarding the plant diseases. We should understand how they 

 work and how best we can fight them. These diseases, for the most part, 

 are of a fungous nature; they have nearly the same organs as the higher 

 plants; they have roots by which they get their food from the ''host,'' 

 i. e., the plant they feed on; they have stems and branches and develop 

 spores or seeds. These spores grow something the same as the seeds, 

 sending their roots into the host plant and destroying it. Eegarding 

 this class of diseases, if we can keep our plants covered with copper sul- 

 phate the spores cannot germinate. It has been found that a solution of 

 one ten-millionth part of copper sulphate will prevent the germination 

 of many of these spores. 



But this brings me to the second thought I have. 



WE MUST SPRAY EARLY. 



If the disease once enters the plant, nothing we can do in the way of 

 prevention will be of any avail. It it too late to get the full effect. 



We must get there first, and then we can hope for good results from 

 our spraying, and we must be thorough. 



It may now be of interest to consider how it is that this cojjper sul- 

 phate is of value. If we spray the tree, using the solution in water, the 

 water evaporates, and we have the copper deposited on the leaves. In 

 that form it does no injury to the foliage, but if a spore falls on the plant 

 it must have water to germinate and this same water dissolves the sul- 

 phate, and we have the solution present, wherever there is water enough 

 for the spore to germinate. The question was asked if a solution of cop- 

 per sulphate was as effectual as the mixture known as the Bordeaux mix- 

 ture, made six times as strong, and I replied that I thought it was. The 

 Bordeaux mixture, which is perhaps the best of all materials to put on, 

 from the fact that it will not burn the foliage if properly used, and that 

 the lime acts as a sort of whitewash, is not soluble. It is in suspension, 

 and we have to have the action of the carbonate of ammonia of the air, 

 to dissolve this. This dissolves the copper slowly, so that it needs to be 

 stronger to cover the season, and thus be effectual. I would certainly 

 make the Bordeaux mixture several times stronger than the copper sul- 

 phate solution. 



THE PRACTICE AT THE COLLEGE. 



Our own practice upon nearly fifty acres of fruit is like this. In the 

 spring we spray the trees thoroughly, before the buds start, with a solu- 

 tion of copper sulphate, using one pound in twenty-five gallons of water. 



