Plant Sanitation. 



140 



[August, 190S 



Bordeaux mixture thus avoided. Except 

 the injury following its use in a wet 

 season, Bordeaux mixture furnishes an 

 entirely satisfactory fungicide for both 

 apple scab and bitter-rot , perhaps better 

 than can be expected of the lime-sulphur 

 wash; but the latter has the advantage 

 of being a combined insecticide and fun- 

 gicide, and does not injure the fruit or 

 foliage, or at lea«t it would so appear 

 from these preliminary experiments. 



This self-boiled mixture could reason- 

 ably be expected to readily control the 

 powdery mildews of fruit, some of which 

 have long been known to be preventable 

 by the application of sulphur in some 

 form. Owing to its greater adhesive- 

 ness, it should perhaps largely supplant 

 dry sulphur and liver of sulphur in the 

 treatment of various mildews. 



If the results of last year's experiments 

 are borne out by further tests, the most 

 important fuuction of this fungicide 

 will doubtless be the control of peach 

 diseases. Heretofore, practically no 

 known fungicide could be used on peach 

 foliage without injurious results, and 

 for this reason orchardists have been 

 unable to combat some of the more im- 

 portant peach diseases and to prevent 

 the annual loss of several millions of 

 dollars' worth of fruit caused by them. 



Bordeaux mixture, the standard fungi- 

 cide, cannot be used on peach trees 

 during the growing season without 

 danger of serious injury to the foliage. 

 While a weak Bordeaux mixture may be 

 used in a dry season without injurious 

 results, the same mixture applied in a 

 wet season, when most needed, will 

 iisually defoliate the trees. The other 

 forms of copper, such as ammoniacal cop- 

 per carbonate and acetate of copper, are 

 even more toxic than Bordeaux mixure. 



It is apparent, then, that an efficient 

 cheap fungicide that can be used on the 

 fruit and foliage of the peach without 

 injurious results will be of inestimable 

 value. The self -boiled lime-sulphur mix- 

 ture gives promise of meeting these 

 requirements, and it is hoped that the 

 results already secured will be substan- 

 tiated by further investigations. Under 

 some unfavourable weather conditions 

 injury to the foliage or fruit might pos- 

 sibly develop, and heavy beating rains 

 might wash the sulphur away, so that 

 its fungicidal effect would be partly lost. 

 It seems likely, however, that a lime- 

 sulphur mixture, either self-boiled or 

 unboiled, will prove to be a safe and 

 valuable fungicide for use on fruit trees 

 and other plants duriug the growing 

 season. — U. .s. Department of Agricul- 

 ture, April 18. 1«08. 



