306 THE FRUIT GROWERS GUIDE. 



be rusted, or their tender skins affected so as to invite mildew. Ventilate early and 

 carefully to avoid these evils. 



Scalding. This is generally caused by a low night temperature, with the consequent 

 deposition of moisture on the berries, and its rapid evaporation from their tissues by 

 the sun. There are, however, two kinds of " scald," one on the upper side of the berries 

 of Muscats exposed to the sun, which causes the part to shrink and become brown ; the 

 other may occur on the lower side of the berries of Lady Downe's, and sometimes over 

 the whole berry. Gentle warmth in the hot-water pipes, a little air at night, with free 

 ventilation by day, form the best routine for preventing the evil, but it is not always 

 effectual with Muscats, for when the weather has been dull and suddenly becomes 

 bright, the skins of the berries are too tender to bear the full force of the sun in struc- 

 tures with large panes of clear glass. A double thickness of herring or single pilchard 

 netting drawn over the roof lights is necessary, in some cases, to avoid the scorching of 

 the berries on the upper side of the bunches. With a temperature of 65 to 70 night 

 and day by artificial means, and not exceeding 80 with sun without full ventilation in 

 the last three weeks of the stoning process, scalding is avoided, for when the berries 

 change colour they are safe. Grapes must not be hurried in stoning. 



Rust on Grapes. This is the result of injury to the skin of the berries whilst 

 tender, hardening it so that they swell irregularly, giving them a rusty appearance, and 

 greatly detracting from their value when ripe. It may be caused by brushing the 

 bunches with the hand to secure a better set of berries when that is roughly done, or 

 rubbing them with a hat or the hair of the head. These are causes of disfigurement in 

 grapes and should be avoided, but rust is the most common in houses where the heating 

 and ventilation are badly conducted. Over-heating the pipes so as to produce a dry 

 atmosphere, with or without fumes from sulphured pipes, is the most frequent cause of 

 rust in early houses. Inefficiently heated houses should have more piping and it should 

 be spread more so as to radiate the heat at a lower temperature and more equally. 

 Grapes are often rusted in the immediate neighbourhood of the hot-water pipes and 

 nowhere else in the house. That means over-heating or sulphuric fumes. Avoid the 

 use of sulphur on the pipes whilst the grapes are young. A sudden check is another 

 great cause of rust. Allow the temperature to rise from sun heat to a high degree in 

 the morning without air, then admit it in quantity so as to cause a cold draught, 

 and the consequence is rusted berries, generally on the side from which the draught is 

 fiercest. Rust prevails on outdoor grapes because the atmosphere has been warm and 



