592 ANNUAL REPORT OF THE Off. Doc. 



ever, where there are old tankers, it is desirable to prune out as 

 much as possible of this trouble where it is on smaller limbs and to 

 gouge out the dead spots, soak them thoroughly with some fungi- 

 cide like corrosive sublimate or sulphate of iron and dilute sulphuric 

 acid and then paint the wound with white lead paint. 



PEAR LEAF BLIGHT AND FRUIT SPOT. 



This is one of the commonest diseases of pears and it occurs on 

 quinces as well. It not only spots up the fruit, making it unsightly 

 and partially or wholly unmarketable, but it defoliates the trees, 

 •utting down their vegetative vigor and productiveness. Trees 

 iffected for three or four years with pear leaf blight soon get in 

 a stagnant condition. They bloom profusely, in fact they are snowy 

 white with blossoms, but they set little fruit. The remedy for trees 

 in this stagnant conditions is to prune them back pretty severely, re- 

 moving two-thirds of the bearing wood and fruit spurs and then 

 spray them after the foliage has formed, with Bordeaux mixture. 



This disease is so easy to prevent that in my own orchard I use 

 4-4-50 formula of Bordeaux for this purpose. About two or three 

 treatments are ample for this disease. The first treatment should 

 be made between May 15 and June 1, when the trees have come into 

 full leaf and when the young pears are three-fourths of an inch in 

 diameter. Of late years the Kieffer and the Le Conte pears have 

 been attacked seriously by this disease, although ten years ago it 

 occurred very slightly on these varieties. 



PEACH AND PLUM ROT. 



It may be well to call your attention to some of the diseases 

 which are not so easily controllable. The brown rot of peaches and 

 plums is a very disastrous disease. It occurs from the Great Lakes 

 region, the northern limit of peach culture, to the Gulf, and with in- 

 creasing severity as one goes southward or toward the ocean, [t 

 is less serious in the mountains than it lower altitudes. So far we 

 have been unable to control this disease satisfactorily by spraying. 

 Bordeaux mixture will reduce its ravages to some extent, frequently 

 there being 50 per cent, less rot on sprayed trees, but this is not re- 

 garded as satisfactory. 



The dormant spraying with either Lime-sulphur-salt or with Bor- 

 deaux also produces some good effects, but I have seen the rot occur 

 very badly on trees thoroughly sprayed for two consecutive seasons 

 with Lime-sulphur-salt wash, so that it does not prevent the trouble. 



We have carried on elaborate experiments with this disease and 

 are working hard upon it, but so far we have not mastered it. 



APPLE ROOT ROT. 



Here is another fungus disease that has baffled all attemps at a 

 remedy. In fact it is a very unpromising, almost hopeless type of 

 trouble. We have no treatment that we can apply to the roots in 

 the way of fungicides or germicides and so far the apple root rot has 

 remained strictly unconquered. When all the other troubles are 

 straightened out perhaps we may be able to get some hold on this 

 difficult problem. 



