THE LOCAL PLANT DOCTOR. 35 



test, together with confirming experiments on the trees, Mr. 

 ^Yallace has shown that exactly the reverse is true as regards the 

 fungicidal value and in his experiments it has been uniformly 

 proven that the codling moth is almost perfectly controlled when 

 this combination is used. In other words, lime-sulfur plus arsenate 

 of lead has much more fungicidal value than lime-sulfur alone and 

 is at least as effective an insecticide as when lead arsenate alone is 

 used. 



4. The burning qualities of lime-sulfur are actually reduced 

 by the addition of arsenate of lead and not increased as we were 

 told would be the case. 



5. Arsenate of lead is the only fungicide which, so far as we 

 know at the present time, may be used with safety in the lime-sulfur 

 solution. Arsenite of lime, so highly recommended and urged 

 by some investigators last year has proven, not only in our 

 experiments this season, but in the experiments of others in 

 widely separated parts of the country, to be entirely unsafe and 

 especially dangerous to the foliage. 



6. The addition of lime or the presence of sediment in the lime 

 sulfur does not appear to materially affect the burning qualities 

 one way or the other. 



7. Precipitation by carbonic acid gas (gas sprayer) does not 

 reduce the fungicidal value of lime-sulfur when used alone or of 

 lime-sulfur with arsenate of lead added. It tends to increase the 

 arsenical injury by setting free some arsenic, when arsenate of lead 

 and lime-sulfur are used together. This is especially injurious 

 to peach foliage. 



8. The soluble sulfids in the lime-sulfur solution are not prob- 

 ably a factor in causing russeting of the fruit. The russeting which 

 appeared on the lime-sulfur sprayed trees this season was very 

 probably due to the wetting of the fruit merely, since unsprayed 

 trees in the same orchard have been, in all cases observed by us, 

 practically as badly russeted as the sprayed trees. In fact, in 

 our own experiments both last year and this, lime-sulfur sprayed 

 trees have had less russeting of the fruit than the unsprayed trees 

 beside them. Cordley as a result of his observations this season 

 holds that under certain conditions lime-sulfur is responsible for 

 russeting of fruit. 



