52 



BOOKS AND BULLETINS. 



prunes, lo ; cherries, 6; figs, i; nectarines, i; various 

 others, 2 per cent. The products are largely shipped 

 east. Good tables are given showing the actual yields of 

 orchards and vineyards, the dates of fruit shipments by 

 many growers in many years, the favorite varieties of 

 fruits for canning and drying, and a chapter is added 

 upon the flora of the Vacaville district. The plates in 

 this volume are the same as in the "California Views." 

 which we noticed last month. 



Bulletin No. 53, Michigan E.xperiment Station. 

 Spraying with tlic Ais^nites. By A. y. Cook. Pp. S. 

 Professor Cook has varying results with spraying for 

 the curculio. lie finds that the insect is destroyed when 

 rstins are infrequent, but frequent showers wash the 

 poison from the smooth fruits. He finds 

 Arsenities carbolized plaster a good remedy also, 

 and Carbol- under like conditions. This is prepared 

 Ized Plaster by stirring one pint of crude carbolic 

 for Curculio. acid in fifty pounds of plaster. This pow- 

 der is thrown freely over the trees. Pro- 

 fessor Cook makes the following conclusions ; " The ar- 

 senites and carbolized plaster will protect against the 

 plum curculio if they can be kept on the tree or fruit. 

 But in case of very frequent rains the jarring method will 

 not only be cheaper, but much more effective. Again, 

 as our wild fruits are more cleared away we must have 

 plums in our orchards to protect the apples from the cur- 

 culio. When apples are seriously stung they become so 

 gnarled and deformed as to be worthless. It will pay, 

 then, to set plum trees near by or among the apple trees. 

 Then we will escape mischief among our apples from the 

 curculio, and will only need to spray our apples once, 

 to destroy the codling moth, and can treat the plum trees 

 three or four times with paris green or carbolated lime 

 in case we have only occasional showers, or can jar the 

 trees when the rains are very frequent. For the apples 

 we can use london purple, one pound to 200 gallons of 

 water. For the plums we must use paris green, one 

 pound to two or three hundred gallons of water." We 

 suggest to Professor Cook that he add kerosene emul- 

 sion to the arsenite mixture to increase its adhesiveness. 

 Great injury to foliage has been reported from many 

 parts of the country from the use of lon- 

 Arsenites don purple, particularly upon the peach, 

 and foliage. Professor Cook made many experiments 

 to determine the cost of this injury, and 

 his conclusions are these: " London purple is more in- 

 jurious to the foliage than is paris green ; and white ar- 

 senic — arsenious acid — is more harmful than is either 

 london purple or paris green. This is doubtless owing 

 to the soluble arsenic which is quite abundant in london 

 purple, and almost absent in paris green. " 2. "Peach 

 foliage is especiallv susceptible to injury, and cherry 

 foliage the least so of any of the kinds treated." 3. "It 

 would seem that london purple and white arsenic, used 

 just before a rain, are more harmful than when used 

 during a drought. We not only saw greater injury when 

 a rain followed spraying within two or three days, but 

 secured the same results by spraying soon after treat- 



ment with pure water. This also accords with the view 

 that the injury comes from the presence of soluble ar- 

 senic." 4. "It would seem that spraying soon after the 

 foliage puts out is less harmful than when it is delayed 

 a few days, or better a few weeks. " 5. " London purple 

 may be used on apple, plum, cherry, pear and most or- 

 namental trees, but on these should never be stronger 

 than one pound to two hundred gallons of water. If the 

 application is to be repeated, as it must be for the cur- 

 culio to prove effective, or if it is to be used in June or 

 July, paris green should be used in the same proportion 

 as above, or else we should use only one pound of lon- 

 don purple to three hundred gallons of water. I now 

 think that this necessity is more due to time of applica- 

 tion than to the fact of increased quantity of the poison. " 

 6. "If the arsenites are to be used on the peach to de- 

 fend against the curculio, paris green only should be used, 

 and that not stronger than one pound to three hundred 

 gallons of water." 7. "The injury done to the foliage 

 is never immediately apparent. It usually shows some- 

 what the second day, but the full injury is frequently 

 not manifest till the fifth day, and often not till the 

 tenth." 



The bulletin details experiments to determine if suffi- 

 cient poison falls upon the grass un- 

 der heavily sprayed trees to cause Arsenites 

 injury to stock. Samples of grass and Pasturing, 



were analyzed and others were fed 



to a horse ; both the chemist and the horse declared that 

 the poison was not sufficient to cause damage — an inter- 

 esting conclusion. 



Professor Cook recites instances of heavy loss to bee- 

 keepers in neighborhoods where orchard- 

 ists sprayed their trees while in bloom. Arsenites 

 The adult and immature bees were alike and Bees, 

 killed. This destruction of bees is entirely 

 unnecessary, as there is no occasion whatever for spray- 

 ing trees when in bloom. 



Bulletin No. 6, Ohio Experiment Station, contain- 

 ing notes of experiments upon various insects. By Clar- 

 ence M. Weed. Pp.38. Illustrated. Mr. 

 Weed has repeated his experiments of Arsenites for 

 a year ago upon the destruction of the the Curculio. 

 curculio on cherries and plums by means 

 of london purple. It has now been proved by several 

 observers that the adult curculio feeds upon leaves and 

 fruits, and spraying with the arsenites has become a set- 

 tled practice in many parts of the country. Mr. Weed's 

 general conclusions must be convincing in the efficiency 

 of this method of dealing with one of our worst pests : 

 I. "That about three-fourths of the cherries liable to 

 injury by the plum curculio can be saved by two or three 

 applications of london purple in a water spray, in the 

 proportion of one ounce to ten gallons of water. 2. That 

 a sufficiently large proportion of the plum crop can be 

 saved by the same treatment to insure a good yield when 

 a fair amount of fruit is set. 3. That if an interval of a 

 month or more occurs between the last application and 

 the ripening of the fruit, no danger to health need be 



