440 EXPERIMENT STATIOlSr RECORD. 



on those varieties not seriously liable to russeting or on those very susceptible 

 to fungus attack. The varieties which were found to be either imniuue or sus- 

 ceptible to scab, rust, sooty blotch, fruit specks, and rot are indicated. Taking 

 all things into consideration, Including the'difliculty of making self-boiled lime- 

 sulphur, this mixture appears to have no special advantage over the commercial 

 lime-sulphurs as a fungicide for apples. 



When commercial lime-sulphur is substituted for Bordeaux it should be used 

 at the rate of li gal. per 50 gal. of water for all 3 sprayings. For the insecti- 

 cide lead arsenate at the rate of 3 lbs. of paste or li lbs. of powder per 50 gal. 

 of mixture may be added in the last 2 sprayings. The treatment recommended 

 for the pear and quince is similar to that for the apple. For peaches, cherries, 

 and plums, where there is always danger of burning from Bordeaux and also 

 often from commercial lime-sulphurs, especially if used with lead arsenate, self- 

 boiled lime-sulphur appears to be the best fungicide since it produces on the 

 whole the least injury of any spraj tried. The 8 : 8 : 50 formula for all 8 spray- 

 ings has given the best results. 



In the 2 years' work with peaches lead arsenate has done little to prevent the 

 attacks of curculio, and since it seems to increase the danger of spray injury 

 when combined with lime-sulphur, the authors advise leaving it out unless there 

 is considerable danger from sawfly injury, when it can be added in the second 

 spraying as with apples. 



Orchard spraying experiments, W. W. Bonns (Maine Sta. Bui. 198, pp. S2, 

 pis. 5). — Spraying experiments were continued at the Highmoor Farm in 1911 

 (E. S. R., 25, p. 538), and cooperative experiments were conducted in 3 nearby 

 orchards. The formulas used in the Highmoor experiments included lead arse- 

 nate at the rates of 2 lbs. and 4 lbs. to 50 gal, of water, lime-sulphur at the 

 rates of li, 1§, and 2 lbs. to 50 gal. of water, plus 2 lbs. of lead arsenate in each 

 case, and Bordeaux mixture 3 : 3 : 50 plus 2 lbs. of lead arsenate. The results 

 are presented in detail and discussed. 



Seasonal conditions combined with other inhibitive factors were unfavorable 

 for the development of fungus and insect injury to any practical degree, hence 

 no valuable data for estimating the fungicidal or insecticidal value of the 

 sprays were secured. In the case of fruit russeting none of the percentages 

 from any plats were high and all so nearly alike that no deductions are war- 

 ranted. The relation of lime-sulphur injury to strength of solution was not 

 Indicated in any way. 



In view of observations made in 1911 the author is now inclined to the 

 opinion that calyx injury, which was found quite generally on fruit sprayed 

 with lime-sulphur in 1910, may be due as much to lack of vigor in the tree as 

 indicated by the tissues of the fruit, as to the caustic action of the spray. 



A form of injury known as sunscald was produced by sunlight on fruit di- 

 rectly exposed to the sun upon the southern sides of trees. The sunscald 

 appeared as discolored sunken spots or maculations with a sharply defined 

 margin. Spraying during hot weather appeared to increase the severity of 

 sunscald where injured areas were present before the last spray was applied. 

 Also the amount of scald, though relatively small, varied directly with the 

 strength of lime-sulphur used. Injury on the lead-arsenate plats was less in 

 amount but qualitatively equally serious. Scald injury on the Bordeaux plats 

 was very slight. 



Aside from fruit russeting a large percentage of the apples on the Bordeaux 

 plat showed more or less Bordeaux injury, the fruit appearing to be either well 

 mottled with dull-brown flecks a few millimeters in diameter or speckled with 

 minute dots. This gave to the fruit a general soiled dull-brown hue. The col- 

 oring of the fruit from this plat was far below that of the apples on any of 



