DISEASES 



494 



use of remedial measures until after the f^^l^'i nre in 

 evidence. With many quiek-actinir il [■-.-ii^.-s ir is tlien 

 too late, andiu fact with some the spr:iv |.uii]| , » lnii the 

 trees are in full leaf and fruit, is .if -.r.m.laiy luipor- 

 tance. The fruit-rot or gray mold {Jfn,nli,i fni.-li,j,iia) 

 of the cherry, plum and peach is of this type. To eradi- 

 cate this pest, it is not enough to wait until the disease 

 is in the trees, for then, if the weather is warm and 

 moist, the crop is destroyed. Here, again, the work of 

 preveiiti.iii -Ii.inl-l l.iL-iii" tlie winter before; by destroy- 

 ing all iiiu' >! !i I'i::. 722) and blighted branches 

 the dis. :i-c i : : . i :.i its weakest point. 



Anotijtr 1 1 i (1 1 - ' I'liiiection that must be kept in 



mind is the Kthci..! licalth of the plant. Every tree or 

 shrub should be well nourished and come to its ap- 

 pointed task in good health. This means the best 

 form of the plant for the purposes intended, obtained 

 by the use of the pruning knife or other means. Fungi 

 do not love the sunshine half as well as the shade, and 

 an open-topped tree needs less spraying than one with 

 the branches crowded. This will also obviate in some 

 measure another point of weakness, namely, overload- 

 e attempting to carry a double comple- 

 1 breed more decayed fruit aud foliage 

 .re not overloaded. Thinning, in other 

 I essential to healthfulness as spraying, 

 soil and situation are more important 

 I either. Naturally, the question of remedies for fun- 

 gous diseases comes in only after all the conditions for 

 the best growth of the plants have been met. 



The number of fungi injurious to the horticulturist is 

 large, and spacepermits of the iiieutidii of l.ut a fi-w 

 under the several crops. Apples: A~.)'\r fi"i:i iIm- rust 

 and scab used above for general illu-traihiii. tin n- are 

 the ripe-rot {Glceoxporium fnictig, hh „, \ pi.u.l.rv mil- 

 dew {Podosphwra Oxittirmilh., i, au.l iIm- liv.-l.litrh't {Ba- 

 cillus amylovonts) . Tlie lii-r nt' tli-- tln'-'- grows also 

 upon the grape, and the lin- lili-lit :(ti nk- the pear and 

 the quince, upon the fi.Dm r h. m- a -i i i-us , n.-mv. In 

 this fire-blight we ha\-.. a liartni ,1 ' ^. ,^,. in |.)a7its, 

 that resides durinL' th.- V, int. ■!■ Ill i!m ■ . ,• I . .-..n- 



veyed to flowers l.y ill-.. t- w III. 'li ^ I- /.-of 



cracked, blighted st. m^ in -inin:. - , . :i~ed 



branches should havi' 1.. ■ n p. i ,.,\..il. 



Quinces: The black-rot . ^ , . , ,„„| 



rust (Rcestella auraiilii ,.ii\,-. 



Plums, in addition to tli.- i . i I : Mi^'ht 



(GylindrosporiumPadi), whil.- tli. .Ii. rr> 1. .- ili.' 'sh.it- 

 hole" fungus { Septoria eerusiiu:]. Peaches arc some- 

 times much afflicted with the \e&t-c\iT\[ExoaitCitii deform- 

 ans, Pig. 723), and the scab or "gray back" (Cladospo- 



ing. A peach tre 

 ment of fruit wil 

 than many that a 

 words, is often as 

 and a congenial 



724. Currant 



cdby 



DISEASES 



The afliected trees produce tufts of small branches upon 

 the older branches, with slender leaves, known as "Pen- 

 nyroyal sprouts" or "willow shoots." Trees with these 

 "bushes" are fit subjects for the burn heap. 



Of the small fruits, the grape leads in the number of 

 fungi, the black-rot and ripe-rot previously mentioned 

 being among the chief, while the anthracnoae (i 



rium carpophiliim). The most obscure disease of the 

 peach is the "yellows," a name given to a contagious 

 disorder that manifests itself in a premature ripening of 

 thefruit, which takes on au unnatural spotting of red or 

 purple, with the flesh streaked and the taste insipid. 



lotna atnpelinum) and downy mildew {Phtsmopara viti- 

 cola) are quite destructive. Blackberries and raspber- 

 rise suffer from similar diseases, the leading ones be- 

 ing the rust {Puccinia Peckian a), requiring the destruc- 

 tion, root aud branch, of the infested plants, and the an- 

 thracnose (Glceosporhim wnc^im I, amenable to spray- 

 ing. Currants and gooseberries are similarly akin, and 

 have nearly the same fungi ,asleaf-.spot( Septoria Hibis, 

 Fig. 724) and anthracnose {Glceosporium liihis), in ad- 

 dition to which the gooseberry is badly troubled with a 

 mildew {Sphwrothi-ca 3fors-L'i-(t], that may be kept off 

 by sulfide of potassium, one ounce to two gallons of 

 water, as a spray. Strawberries have the leaf-blight 

 {SplKerelhi Fragariw, Fig. 725) as the leading fungous 

 trouble, and this sometimes requires heroic treatment, 

 even to the burning over of the bed in autumn to de- 

 stroy the infested leaves and the germs they contain. 



Annual Plants. In the previous discussion, peren- 

 nial crop plants only have been considered. With the 

 annuals the treatment is in large part the same, except 

 that there are no live plants in winter to be considered, 

 no stems and branches to be cleansed, and there is the 

 very important difference that it is possible to grow the 

 annuals upon new ground each season. While it is im- 

 possible to move the vineyard or fruit garden, it should 

 be the rule not to grow an annual upon the same piece 

 of soil continuously. In one sense the grower can move 

 away from his troubles by practicing a judicious rota- 

 tion of crops. However, the truck grower and the gar- 

 dener in a small way should not trust entirely to this 

 itinerancy, but instead should place the spraying ma- 

 chine upon the same footing as the plow or planter as a 

 necessary implement; and as insects compete with fungi 

 for the possession of his crops he should spray for both, 

 and usually this can be done at the same time. The 



