Nov. 2, 1908.] Agricultural Gazette of N.S. W. 877 



Apart from the application of electricity, the study of radio-culture, or 

 plant-growing under coloured glass, has occupied considerable attention for 

 many years past. Very interesting experiments have been conducted at the 

 Station de Climatologie Agricole de Jaivisy, mainly with red, blue, and green 

 glass. It has been found that not only was development and growth affected, 

 but that a change in the form of both flowers and leaves is possible. The 

 Sensitive Plant, (3Iimosa fudica) sank into a state of suspended animation 

 under the blue light ; in the control house, where plants were kept for 

 compaiison under ordinary conditions, it had increased fourfold in height ; 

 in the green-house sixfold ; while under the red light it had attained, 

 gigantic proportions, having increased in stature tifteen-fold. Under this 

 colour the natural sensitiveness of the plant was so abnormally intensified 

 that the slightest touch or breath sutflced to make it instantly droop its stem 

 and fold its leaves ; in the green light the sensitiveness was practically 

 unchanged ; while under the blue light the plant had become as stolid and as- 

 tough as a cabbage. 



It is thei-efore apparent that although radio-culture has scarcely emerged 

 from the experimental or suggestive stage, an expansive outcome lies before 

 it ; and as coloured glass-houses are 50 per cent, more costly than ordinary 

 glass-houses, an adaptation of the colour screens to the Thwaite electro-system^ 

 in ordinary glass-houses is bound to receive more attention. 



6. Professor Lemstroms Experiments. 



While the Thwaite experiments consist of the application of both 

 rays and current, and are confined to vegetables and flowers in glass-houses, 

 those of Lemstrom are of a different character. They are open-tield experi- 

 ments, in which only the current is applied, and rays form no part. In 1902' 

 and 1903 Lemstrom carried out experiments at Newcastle in England, at 

 Breslau in Germany, and at Atvidaberg in Sweden, and remarkable results 

 were obtained. Strawberries under this treatment showed an increase of 

 from 50 to 128 per cent., corn from 35 to 40, potatoes 20, and beet 26 per 

 cent. Lemstrom came to the conclusion that an all-round increase of 45 per- 

 cent, over normal crops on land of ordinary fertility might be reckoned upon.. 



His method was a wire net stretched across the field a little above the 

 surface. From a machine stationed in a building outside the field an electric 

 current was made to traverse the net. Occasionally it was necessary to raise 

 the net, as it must not be allowed to touch the plants. The current does not 

 act during rain, and its application to the plants during brilliant sunshine 

 was found to be injurious. 



The cause of the improvement effected is somewhat conjectural, but 

 probably on the one hand ozone and nitric compounds beneficial to the plants 

 are produced by the positive current passing from the points of the wire net 

 to the earth ; while, on the other hand, the negative electricity passing from 

 the earth to the points of the net stimulates growth by drawing up the sap- 

 from the roots. 



