SOME INFRA-RED EFFECTS ON GREEN PLANTS 851 



possible that an equal amount of energy in the visible region would have 

 produced a similar injury. More work needs to be done before it can 

 be definitely established that the infra-red is more injurious to plant 

 tissue than the visible region when compared on an equal energy basis. 



The fact remains that such fruits and other similarly constructed 

 plant organs absorb energy in both the visible and infra-red and are not 

 designed to eliminate this energy rapidly by the evaporation of water 

 from their surface. Such types of "sun scald" have been observed by 

 Ramsey (18) on onions harvested and exposed to sunlight in crates and 

 by Le Clerg (16) on honeydew melons exposed to sunlight when the leaves 

 were killed by fungi. Cases have also been reported of sun scald on the 

 trunks of young apple trees. There is the possibility that all such types 

 of sun-scald injury may be produced by high radiation values in both the 

 infra-red and visible regions, 



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3. Arthur, John M., and W. D. Stewart. Transpiration of tobacco plants in 

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4. Brown, H. T., and F. Escombe. Researches on some of the physiological 

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10. Curtis, O. F. What is the significance of transpiration? Science 63: 267-271. 

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11. Forsythe, W. E., and E. M. Watson. The tungsten lamp. Jour. Franklin 

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