50 EXPERIMENT STATION EECOKD. [Vol. 35 



Preventive treatments, Including copper sprays and polysulphids, have not 

 proved to be effective. Suggestions are given regarding the employment of 

 phosphorus and potassium fertilizers and measures for securing earlier ripen- 

 ing of the wood. 



A disease of apricot in the Rhone Valley, J. CHiFrLOT and Massonnat 

 {Rev. Hort. [Parish, S7 (1915), No. 21, pp. 5JtO, 5^-?).— In portions of the Rhone 

 Valley apricot trees are said to be affected with a disease characterized by the 

 drying of the flowers, leaves, and young branches, followcnl by gummosis, 

 separation of the bark from the wood, and discoloration of the latter. The 

 trouble appears to be caused by the same fungus as that reported above by 

 Faes as occurring in Switzerland. 



Spring conditions will not permit the use of strong sprays, but removal of 

 all affected portions is recommended. In winter, the use of copper sprays at 

 1.2 per cent strength is advised, with the addition of soap and gelatin to secure 

 better spreading and adhesion. 



Summer outbreaks of downy mildew, H. Faes {Terre Vand., 6 {lOlJf), No. 

 32, pp. 338-3 Jfl). — Recent tests have confirmed the view that mildew attack on 

 grape leaves occurs by way of the lower surface only, and that spraying fi-om 

 below is sufficient if the fungicide is applied thoroughly and in proper strength, 

 preferably with an admixture of materials suited to increase its spreading and 

 sticking qualities. The attack is said to occur mainly when the leaves are 

 young, but it may occur later. 



Spotting of citrus fruits, H. S. Fawcett (Mo. Bill. Com. Hort. Cal., Jf {1915), 

 No. 9, pp. -^34, 435). — It is stated that for a number of years past, especially 

 during moist, cool weather, lemons and sometimes oranges have been observed 

 to develop, after coming to the packing house, green spots which may later 

 become brownish or reddish and somewhat sunken, and which do not increase 

 in size after their formation. 



It has been shown that typical green spots can be developed by so pressing 

 and rolling lemon fruits against boards as to cause injuries, also that oil from 

 one lemon pressed out on the injured surface of another produced the tjiiical 

 sinking of the tissue between the oil colls. Green spots were produced by 

 presssure on the surface of the rind sufficient to liberate the oil but not suffi- 

 cient to cause a visible break in the rind. It has also been noticed that pick- 

 ing green fruit while wet favored the formation of the spots. The oil on fruit 

 kept in moist air produced a greater effect than on fruit kept dry, which is 

 thought to be due to its slower volatilization under these circumstances. 



The picking of the fruit only under dry conditions is recommended. 



Work connected with insect and fung-us pests and their control {Imp. 

 Depf. Agr. West Indies, Rpt. Agr. Dept. Dominica, 191^-15, pp. 11-17, fig. 1). — 

 This reproduces a preliminary report by W. Nowell on his investigation of the 

 black root disease of lime trees in Dominica caused by RoseUinia bitnodes, said 

 to be the only disease of lime trees of really serious importance in the island 

 at the time. The disease is known only on estates with fairly recent forest 

 clearings. It is thought to be distinct from a closely similar disease on cacao. 

 Soil and situation favox-able to the rapid development of the lime ti*ees seem 

 also to favor the disease. The greater seriousness of the disease during the 

 years reported upon is ascribed largely to a period of extremely wet weather, 

 but still more to the cumulative character of the disease and the increased 

 number of contacts among the growing and interlacing roots. On reaching the 

 light, the fungus produces spores, which can cause infection some distance 

 from the point of origin. 



It appears that thorough ventilation of the collar and of the main roots near 

 their points of attachment, in addition t<> rendering early detection easy, may 



