60 



or not an excess of soap would have any beneficial effects in the kero- 

 sene and petroleum emulsions. The soap was used according to the 

 regular formula and from that up to as high as 2 pounds of soap to 

 the gallon of water, so that there was a large excess of soap. The 

 results were not any better than those where the usual amount had 

 been used. In fact, any amount of soap in excess of that necessary to 

 make a proper emulsion he had found valueless. On the other hand, 

 in the summer tests the soap in the emulsions was more injurious than 

 the oils. He stated that ho had found quite -io per cent of scale dying 

 during winter without any treatment, and he took this fact into con- 

 sideration in making up the results. Frequent communications had 

 been received f I'om orchardists saying that the cold weather had killed 

 the scale. Mr. Scott considered that careful estimates should be made 

 of the scales that die without treatment in determining the percentage 

 killed by the application of washes. 



Mr. Quaintance asked if anyone had had an}" experience with the 

 lime, salt, and sulphur wash in the fall, and how early it had been 

 used. In Maryland the fall weather is usually more favorable for 

 spraying work than the spring. 



Mr. Sanderson remarked that while he had done no work with the 

 wash himself, several orchardists of Delaware had used it, made up 

 according to the standard formula. He had examined a badly infested 

 orchard about ten da3\s ago that had been thoroughly treated with the 

 wash, and the trees at that time were still quite thoroughly coated. 

 A careful examination of infested twigs showed that from 50 to 75 per 

 cent of the adult females were alive. He had had slight experience in 

 the use of crude oil on trees in foliage. Fifteen or 20 plmn trees had 

 been sprayed thoroughly, covering the leaves, but no damage had 

 resulted, and the scales had been very largely killed. 



Mr. Quaintance desired to know of Mr, Sanderson what the weather 

 conditions were in connection with the use of the lime, salt, and sul- 

 phur wash in Delaware, to which Mr. Sanderson replied that he had 

 no record of this. It was his experience that the scale was more 

 readily killed in the Southern sections than in Northern sections. He 

 had tried kerosene emulsion of the ordinary strength, diluted 10 times, 

 and had noted very little change in results from its use. 



Mr. Marlatt remarked, in reference to Mr. Scott's experience with 

 emulsion, that the emulsion is often more dangerous to trees than 

 pure oil — that is, if it is put on in a very strong mixture — for the 

 reason that a thick emulsion wash adheres to the bark, and much more 

 oil is held on a given area with the emulsion than would be in a thin 

 pure-oil spray. 



Mr. Smith stated that in the soap emulsion the oil is held longer in 

 contact with the trees. The soap holds the oil, prevents its evapora- 

 tion, and it is thus held longer in position than when put on pure. 



