225 



Plant Sanitation, 



doubtful. In practically all instances, only the white mycelium has been seen, 

 so that it is quite possible that these white threads do not represent the same 

 fungus in all cases. Only in a very few species can fungi be identified from 

 mycelium alone. 



It has been kept under, on nutmeg, by cutting off and burning affected 

 branches. Where it occurs on old stems, the white threads should be rubbed 

 with the lime-sulphur mixture, recommended for Horsehair Blight (Tropical 

 Agriculturist, December, 1905). Primings which show Thread Blight must not 

 be buried. 



During a recent visit to the luw-couutry, I found the combination of Thread 

 Blight and Horse-hair Blight on bushes in the jungle ; the tea in the same district 

 is attacked by the latter but not by the former. At the same time I learnt that 

 the name Thread Blight has been commonly applied to any white threads in the 

 soil. These may be part of any one of thousands of fungi ; they are the vegetative 

 part of the fungus, corresponding in function to the root, stem, and leaves of a 

 flowering plant. It is not possible, and never will be possible, to identify a fungus 

 from the threads alone, but it is quite certain that the majority of them are 

 harmless. True Thread Blight grows on the leaves and stems of living irtants. 



SPRAYING MIXTURES. 

 At the opening of the new spraying season it may be of some advantage to 

 call attention to a point connected with the operation which hitherto has been 

 strangely neglected. That point is the suitability or unsuitability for mixing of 

 various materials used in spraying. Fruit-growers and managers of spraying experi- 

 ments not infrequently mix materials without any consideration of the chemical 

 reaction which may take place between two or more of them. In combining insecti- 

 cides and fungicides there is, of course, a desire to battle with the two classes 

 of fruit pests in one operation ; but if the materials chosen for this double 

 purpose will decompose each other and enter into fresh combinations, it is 

 important to consider what those combinations will be, whether they will be 

 harmful or inert, and whether they will be mechanically objectionable on account 

 of the difficulty of passing the mixture throughout the nozzles of a spraying 

 machine. 



Extremely few fruit-spraying trials have been made in this country, but 

 they have been numerous in the United States, and it was the practice of mixing 

 materials in that country which led me to make some inquiries as to the effects 

 of such mixing, and as to mixtures which seemed worth trying if they could 

 be used without decomposing the effective elements. 



Some mixings cause partial decomposing of constituents, and yet leave 

 them apparently effective. A notable example is the combination of Paris green 

 and Bordeaux mixture. Messrs. Blundell, Spence & Co., manufacturers of Paris 

 green, state that the addition of Bordeaux mixture to it decomposes the Paris 

 green, producing a much less poisonous and efficient combination of the coppe 1 ' 

 and the arsenic. But it is partly for the purpose of reducing the poisonous action 

 of Paris green that the addition of Bordeaux mixture to it is commonly recom- 

 mended and practised in the United States- The mixture has stood the trial 

 of prolonged experience, and its effectiveness as an insecticide and fungicide 

 combined has been demonstrated in the numerous experiments. The objection to 

 it, as to Paris green alone, is that it often seriously injures the foliage of fruit 

 trees, even when used in such moderate proportions as 8 oz. of Paris green with 

 Bordeaux mixture containing 8 lb. of sulphate of copper to 100 gallons of water. 



