IIC)2 DISEASES XOT DUE TO PARASITES OR OF UXKNOWX ORIGIN 



The debt of the Associations will be secured in the manner provided 

 in articles 28 and 29 of the regulations aforesaid. 



x\rt. 6. No alteration can be made in the present administrative 

 organisation of the Antiphylloxera Associations 



DISEASES NOT DUE TO PARASITES 

 OR OF UNKNOWN ORIGIN. 



922 — Measures to prevent Injury by Frost in Catalonia, Spain. — via ravkntos 



TosE, in Rcsiimcn de A'^riculiura, XXVIIIth Year, Part 2, pp. 68-80, Fig. 2. Barcelona, 1916 



Observations on frosts and the best methods of preventing injury thereby 

 in the vine-growing zone of the lyower Ebro. Under normal working con- 

 ditions it is not always jjossible to make use of the instruments which allow 

 of forecasting the arrival of cold waves a sufficient time beforehauvd as 

 in meteorological Observatories. There is, it is true, a relation between 

 the temperature at the moment of sunset and the minimum temperature 

 which can be reached during the night, but this relation changes with the 

 variations of the mistiness and hygroscopic conditions of the air, and the 

 value of these factors varies, even in a short time, within very wide limits. 

 On the other hand, observation and long practice enable vine-growers to 

 foresee the arrival of frost with some approximation to the truth, but 

 certainly not with all the desired accurac}^ where it is a question of com- 

 bating low temperatures by smoke, a costly and troublesome method which 

 of course should only be applied when really indispensable. Good results 

 have been obtained with automatic alarms. Their cost is not excessive and 

 the}" are easy to use. The}' consist of a Richard thermometer set up in the 

 middle of the vineyard at a height of 20 to 25 cm and communicating with 

 a bell, actuated by the current of three Lablanche cells, which rings 

 when the temperature sinks to the danger limit : one fourth of a degree 

 centigrade above zero. That is the time when the fires must be lit. An 

 excellent kind of fuel for the purpose is creosote briquettes. They are placed 

 in IvESTOUT furnaces, or even in simple wooden boxes, slightly sunk into the 

 ground and arranged round the vineyard at a distance of 26 feet apart. 

 On burning them under these conditions for a period of 5 hours, the cost 

 (including material, labour, etc.) is about i6s. per acre, which is far from 

 being an excessive amount, as the injury which the frost would have pro- 

 duced in default of treatment must be taken into account. From a large 

 number of observations and experiments the writer concludes that low tem- 

 perature control in Catalonia is fully justified and remunerative. It would 

 be much more so if the vine-growers were to form an association and create 

 a special organisation for this purpo.se, with a system of well placed watch 

 Stations. 



