New Zealand Institute Science Congress. 509 



On Thursday Mr. J. H. Edmundson, of Napier, gave a lecture 011 

 " Liquid Air." It was illustrated by lantern-slides of famous investigators 

 in the science of liquefaction, and by diagrams. Following upon the 

 explanations, the lecturer carried out some very remarkable and spectacular 

 experiments showing the results of extremely low temperatures. These 

 included the liquefaction on the stage of atmospheric air and pure oxygen. 



Discussion on the Flax Industry. 



The problems of the New Zealand flax industry were discussed at a 

 general session of the Congress on the morning of Thursday, 27th January. 



The subject was introduced by Mr. A. Seifert, who gave an account 

 of the dimensions of the industry, and mentioned the ravages of the 

 yellow-leaf disease, which had caused during the last year the abandon- 

 ment of 5,000 acres of flax swamp. He compared the return per acre of 

 land under flax with that of land grazed for dairy-produce, and concluded 

 that the growing of flax was a much more profitable method of utilizing 

 the land. Compared with the difficulties confronting other types of fibre, 

 New Zealand flax was in a favourable position, but it was necessary to 

 obtain immunity from the yellow-leaf disease. His firm had made some 

 experiments with fertilizers, and, though it was too early to give definite 

 results, they were so far in favour of the use of fertilizers, especially super- 

 phosphate. 



Dr. J. W. Mcllraith spoke on the economics of the flax industry. The 

 price of flax had steadily risen, and at a greater rate (136 per cent, in the 

 last twenty years) than other agricultural products (104 per cent, during 

 the same time). In the " nineties " flax formed only ^ per cent, of our 

 exports ; now it formed 3 per cent. He concluded that it would have been 

 profitable to grow more flax in the past, and mentioned the existence of 

 large swamp areas which he thought should be utilized. 



Mr. A. H. Cockayne mentioned the improvement of the Manawatu swamps 

 by draining, after which pure stands of flax automatically sprang up. The 

 district now possessed 23,000 out of the 50,000 acres of flax in New 

 Zealand. The gross returns per acre were greater than for any other form 

 of agriculture except orcharding. Diseases were now the limiting factors 

 of production ; of these the yellow-leaf disease was the most serious, 

 rendering 6,000 acres unproductive. He exhibited specimens of diseased 

 plants, showing how the outer leaves of the fans assume a yellow colour and 

 ultimately shrivel up, while the next inner leaves are attacked, and so on. 

 The problem his department had to solve was whether the disease was 

 caused by bacteria, fungi, insects, or other pests. They had isolated six 

 species of bacteria infecting the roots, none of which had developed under 

 experimental conditions any pathogenic symptoms. A nemotode worm 

 had also been investigated — one of these worms is the cause of a disease 

 called " yellow stripe " in the similar monocotyledonus daffodils — but the 

 numbers found were not sufficient to account for yellow-leaf disease. 

 Insects also failed to account for the disease, though they caused trouble 

 of another sort. Finally a fungus had been isolated, Ramularia phormii, 

 and was held to be the cause of the disease. The delay in its isolation 

 was the difficulty of sterilizing the surface of the roots, owing to their great 

 porosity. Field experiments showed that only that portion of the root 

 which absorbs water could be infected ; this was not the primary root, 

 but the secondary or tertiary branches. Once these are infected, the 

 fungus spreads and reaches the primary roots. As it destroys the water- 

 absorbing roots, the fungus prevents the absorption of water. When 



