656 EXPEEIMENT STATION EECOED. 



very small specks on the leaves. From 1 to IJ pts. was sufficient to spray a 

 good-sized 10-year old peach or nectarine tree. 



The number of applications of the bait necessary to protect any given crop 

 of fruit will vary according to local conditions and the season. By beginning 

 when the early apricots and peaches are from one-fourth to one-half grown 

 and distributing the bait carefully and evenly once every 10 days to 2 weeks 

 in fine weather and immediately after each rain during the rainy periods the 

 early broods of the fruit fly will be destroyed and thus prevent the maggots in 

 the fruit, especially if reasonable care has been taken in collecting and de- 

 stroying refuse fruit. If the early baiting is carefully done it should not be 

 necessary to bait so persistently in the latter part of the season unless there 

 is an outside source of infection. 



" It is, therefore, evident that the treatment of stone fruits for the destruc- 

 tion of the fly is an important factor in protecting the apple crop from infec- 

 tion later in the season. The poison-bait method just described for stone fruits 

 is equally applicable for citrus fruits. By a judicious distribution of the 

 poisoned bait over the tree, hedges, vines, bushes, etc., in the yard for the de- 

 struction of the fruit fly, the house fly will also in all probability be destroyed 

 to a large extent." 



Experiments with arsenicals in combating- the grapevine pyralid, H. 

 MoRSTATT (Wehtbau u. Wcinhandcl 27 {1909), yos. 12, p. 109; 13, pp. 119, 

 120). — A brief account of the injury due to Conch i/Iis amhigueUa, and of ex- 

 periments with arsenicals. 



Spraying- v. dusting, F. W. Faurot {Missouri Fruit Sta. Bui. 19, pp. 3-24, 

 pis. 16). — The results of comparative tests of commercial dust, homemade 

 dust, and liquid sprays conducted by the author in cooperation with this 

 Department in the vicinity of Anderson, Mo., are here reported. 



Experiments upon Lansingburg apples reported in tabular form show that 

 93.8 per cent of the fruit on untreated trees the first of June dropped after 

 that date and 80 per cent of the fruits that fell were wormy. From the 

 selected trees in various dusted plats from 75 to 9.3 per cent of the fruit 

 dropped, and from one-third to one-half of the dropped fruit was wormy, while 

 from the sprayed plat only 31.2 per cent of the fruit dropped, of which but 

 7.2 per cent was wormy. Dust was found to be about intermediate in value 

 between no treatment and spraying for controlling the codling moth. A plat 

 that received 10 applications of commercial dust gave only 66 per cent of the 

 fruit free from worms. 



Dust was found to be entirely ineffective against bitter rot. A plat that 

 received 13 applications of commercial dust gave only 2.3 per cent of the 

 fruit free from bitter i*ot. Records of the merchantable fruits and culls at 

 picking time from 5 trees treated with homemade dust, 30 trees treated with 

 commercial dust, 70 sprayed trees, and 9 untreated trees, show a gain of from 

 83 to 85 per cent of merchantable fruit in favor of the sprayed plat over either 

 the dusted or the untreated plats, while if only the fruits actually picked from 

 the trees are considered the gain was about 95 per cent in favor of the sprayed 

 plat. 



Experiments with Black Twig apples show a difference as to apple scab of 

 over 87 per cent in favor of the sprayed plat and emphasized the inefficiency 

 and impracticability of dusting for the control of fungus diseases. Counts of 

 merchantable fruit and culls showed a difference of over 56 per cent of mer- 

 chantable fruit in favor of a sprayed plat when compared with dusted plats 

 and of over 73 per cent when compared with an untreated plat. 



Gauo trees were sprayed under 200 lbs. pressure with Bordeaux nozzles and 

 with vermoral nozzles with 1/10 in. openings. in the caps, but after the mixture 



