PREVENTIVE AND COMBATIVE MKAM'KK-. 71 



sites, much may be done to shorten the existence of a disease, 

 and to prevent its reappearance in the following .sprin".. 



Fungi which reach maturity on fallen leaves are easily com- 

 bated in this way. Hartig gives a striking example of tin- 

 success of this measure. In the English (larden, a lar-e park 

 in Munich, the leaves are carefully removed at frequent interval.- 

 as they fall, and utilized as stable-bedding ; here TiV/. ///*///" 

 in-' /-in n in, the black spot of tin- sycamore leaf, is hardly known, 

 whereas in the park at Xymphenburg, and in other place- 

 round Munich, where the leaves are allowed to remain lying, 

 the leaf-spot is very common. Ehytisma W /,-/', ////// can lie 

 nvated in the same way in osier-nurseries. In plum orchards 

 Polystigma rnl>i-uin may lie held completely in check by removal 

 of fallen leaves. So also the numerous mildews ( Krysipheae> 

 of our cultivated plants. Cherry leaves killed by '///<;//*///// 

 1'ijtli riixtonui remain hanging on the trees, but the disease ha- 

 almost disappeared since the practice of removing and destroying 

 these was introduced in gardens, like those of the Altenland, 

 once completely devastated by this parasite. 



The progress of the disease caused by X-fi-i<' '//////////////<" is 

 reduced if the branches which die during the summer be at 

 once removed and burnt before the red fructifying patches 

 appear. It would also be advisable to burn in the autumn 

 other dry brushwood, since it frequently contains Xn-fi-'m and 

 other wound-fungi, and if left over winter only serve- as a 

 nursery and source of infection tor all neighbouring tree- In 

 a similar way should be treated branches infected with sporo- 

 carps of Cucurbitaria /"///'//// and such-like rim-i. 



Immediate removal, burning, or burying of yoniii; tree- 

 attacked by Phytophthora omnivora is of advantage in prevent - 

 in- the distribution of the fungus by conidia and swarm-Spores 

 durini: summer, its hibernation in dead tissues, and its continued 

 distribution in the following spring. The hibernating oospore- 

 of many other lower fun-i may be similarly got rid of by 

 of the pi a ii t - i'e ma i ii s inhabited by them. 



II Removal and destruction of diseased plants or portions of these. 

 ill Tin- removal of -ymbii.iie organs comes here jiarticularly 



illlo lloll. A moll- -I |he-e aW the " W it C lie-' bloM|n-' \\llich 



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