62 THE FRUIT GROWER'S GUIDE. 



from 65, for this gives a sudden and, it may be, a disastrous check to growth. Even 

 in dull weather a little air is advantageous, as it keeps the foliage from becoming so 

 soft and thin as to be unable to withstand the sun on its reappearance. After very 

 dull weather the foliage is liable to be scorched : this is a serious evil, and is best 

 averted by a little extra fire heat in the daytime, so as to allow of moderate yet safe 

 ventilation. In the ventilation of a house in bright weather suddenly following a dull 

 period, it is better to allow the heat to rise somewhat high than to admit air to keep it 

 down, as with a comparatively close house the evaporation from the foliage will not be 

 nearly so great as where abundance of air is admitted, for it is excessive evaporation 

 that leads to shrivelled leaves and shrunken fruit. With a steady increase of air from 

 day to day the foliage will become gradually hardened through being inured to a changed 

 condition of circumstances, and the crops that were in jeopardy may thus be saved. 



During spring the greatest care is necessary in admitting air to fruit houses. Sudden 

 changes of heat and moisture through improper ventilation have a most disastrous 

 effect. It is not sound practice to supply the full volume of air at once that will be 

 required for the day. The right method is to afford a little early, and add more as the 

 heat increases, at frequent, rather than distant, intervals, until the requisite amount is 

 secured. The reduction should proceed in a similar manner, but it need not be so 

 gradual, as a high temperature in the afternoon, accompanied as it is, in most cases, by 

 an increase of moisture, causes more growth in the swelling fruit than does anything 

 else. Sharp currents or draughts must be avoided. In windy weather ventilation 

 may often be given by the side lights when it is not possible to admit any or very 

 little air by the top sashes without occasioning a too great inrush of cold, also on the 

 opposite side of the structure to that against which a rough wind beats ; in fact 

 ventilation requires judgment and careful management, due regard being had to the 

 weather, particularly the difference between outside and inside temperatures, in 

 changing the air and regulating the heat in fruit houses. 



Syringing. Evaporation is continually taking place in glazed structures, as may be 

 seen by the condensing of moisture on the glass when the house is wholly or partially 

 closed, and when air is admitted the vapour passes away by the ventilators. To restore 

 this air moisture recourse is had to syringing or damping available surfaces as an 

 essential for free healthy growth. In this way a fruit tree is provided with support, 

 roots and branches, as well as the foliage and fruit, being replete with necessary 

 nutriment, but when the atmosphere is arid, especially at night, the tissues are dried, 



