38 TEMPEKATURE FOR VINERIES : VENTILATION. 



ripe Grapes are required to be cut in the month of June, the manage- 

 ment or treatment necessary to secure this end may be stated in 

 general terms, as follows : 



1. Temperature. At the commencement, a night temperature of 

 about 60 will be sufficient until the Vines have started to grow. The 

 heat should be raised gradually to 70 by the time they come into 

 flower. When the Grapes are fairly set, a lower temperature may 

 be maintained until after the stoning period, when, if necessary, a 

 rise of a few degrees may be allowed. When the Grapes commence 

 colouring a lower temperature may be maintained, but fire-heat is very 

 frequently required in order to maintain a bracing atmosphere. 



For day temperatures a rise of 5 by fire heat may be allowed in 

 dull cold weather, and of 10 or more, if by sun-heat, up to 80 or 90, 

 as the season advances. In very cold weather, however, it is better 

 to have a lower temperature than to maintain a high one by over- 

 heated pipes. 



2. Ventilation, or Air-giving. The object sought to be obtained 

 by ventilation is not merely the maintenance or regulation of the tem- 

 perature, but also the admission of fresh air, which is a most important 

 factor in the well-being of the Vines. The night temperatures are 

 mostly regulated by the amount of firing or heat applied, but the day 

 temperature, or amount of sun-heat, is regulated by ventilation. In 

 Vineries a little air should be admitted by the top ventilators early in 

 the morning, or as soon as it may be observed that the temperature 

 has risen or is rising above the required point, and this air should be 

 gradually increased as the day and the temperature advances, and 

 should also be reduced in a like manner in the afternoon, endeavour- 

 ing, if possible, to close early enough to secure a slight rise in the 

 temperature after doing so. We prefer closing early at all times, and 

 " bottling up," as it were, the sun's warm rays, to the rigid rule of 

 keeping to a given temperature, and the consequent early application 

 of fire-heat for its maintenance. As the Grapes commence colouring, 

 air must be given freely both by day and by night, on both sides of 

 the house, etc., for the admission of brisk fresh air. 



Moisture. This, in its relation to the atmosphere, is of the greatest 

 importance to the healthy progress of the Vine, and demands special 

 attention. A close moist atmosphere is necessary to induce the buds 

 to break freely, and afterwards it is necessary to assist in supplying 

 nutriment to the Vines through the leaves. A very great proportion 

 of the nutriment to plants is absorbed through the leaves. Again, 

 moisture is necessary to prevent the destruction of the leaves by red 

 spider and other insects. 



From the commencement, then, a moist atmosphere must be main- 

 tained, and the higher the temperature the greater the evaporation, 

 and the greater the amount of moisture required. It is difficult to 

 supply too much. When the Vines are started they should be 



