364 Journal of the Department of Agkiculture. — Oct., 1922. 



PLANT DISEASES IN THE WESTERN PROVINCE. 



VI. 



Notes by V. A. Putterill, M.A., Division of Botany. 



Wood-destroying Fungi in the Orchard. 



The interest taken in any fungus by people not directly concerned 

 with a study of plants of this group dej^ends almost entirely on 

 whether it happens to be one of the large showy kinds such as mush- 

 rooms and toadstools or the amount of damage it does to living plants, 

 timber, and foodstuffs, if it happens to be one of the microscopic 

 fungi. Belonging to the same group as do toadstools and mushrooms, 

 namely, the group of fleshy fiingi, there are a large number which live 

 on the wood of trees, either on living trees or on dead stumps or 

 timber. Those which are able to attack living trees are called para- 

 sites (from the Greek word meaning one who lives at another's 

 expense) ; those which can live only on dead wood are called sapro- 

 phytes (plants which live on dead organic matter). 



Some parasites are not able to live apart froin the living host 

 plant, others are able to live saprophytically as well. Some can enter 

 the host without difficulty, others are wound parasites, that is, they 

 can only gain a footing into the host plant when the latter is injured. 

 Of the fleshy fungi which live on living trees some are of strikiiig 

 appearance. For instance, in the Western Province a hirge, hand- 

 some, bright sulphur yellow fungus, Polyp'>riiis suJphiirctis, is very 

 common on oak trees, and can be seen every winter for that niattei' in 

 the Government Avenue, Capetown. Others, however, are not nearly 

 as evident, and ordinarily are only noticed when actually they ..le 

 being looked for. Of these perhaps one of the most common in ihe 

 west, is one known botanically as ScJiizophyllu m commune, a vsmail 

 bracket or fan-shaped fungus (Plate I, see figs. 1 and 2), about half an 

 inch wide, greyish white and hairy on the upper surface and bearing 

 purplish or mauve gills on the under side. It is on these gills that 

 the spores are produced by which means the fungus is disseminated. 

 The individual spores are oval l)odies and very small, being only 

 about one five-thoustvndth of an incli in length; they are produced 

 in countless numbers as can easily be deinonstrated by placing one of 

 the brackets of SrJiizop/iy}lii i/i on lihick ]>aper and c(vvering with a. 

 dish of some sort, and making juovision tliat the air inside the dish 

 is kept moist. After twenty-foui" liouis a white spoic print of thei 

 gills will ])v seen to have been prodnct'd. 



Schizo]>]iyU u III com inline occnis on a great ?iurnl)ei' ol different 

 ])lants, and is common loo on (h'ad wood such as stumps, fencing 

 posts, logs of wood, and s(^ on. It is a very common occurrence too 

 in orchards, on living fruit trees, and also on dead braiiches. Stone 

 fruit trees sucli as apricots, peaches, and prunes seem to be most com- 

 monly affected. It was on this account that the author carried out 

 an investigation on this fungus (published elsewhere*) with the 



* The Biology of Schkojihylliim conimunr Fr,, with special reference to its parasitism, 

 by V. A. ruttcnll, M.A., Division of Botany, Union Department of Agriculture, 

 Science Bulletin No. 25. Obtainable from this office. Price Sd. prepaid. 



