Vol. XVIIl. No. 448. 



THE AGRIOULTDJCAL NEWS. 



203 



According to an article in The Times for February 21, 

 1919, Prof. H. Maxwell- Lefroy gave an interesting talk at 

 the Royil Institute on the protection of stored wheat in 

 Australia against the attacks of weevil. 



At the request of the Wheat Commission, Professor 

 Maxwell-Lefroy went to Australia to endeavour to save 

 the large quantities of grain which had accumulated there 

 awaiting shipment, and which was being severely attacked 

 by insects, and to devise means of protecting the new crop 

 from attack. The problem had to be considered in two 

 parts : one, the prevention of attack in the case of grain 

 free from insects; and the other, the cleaning of the infested 

 wheat, an I the killing of the insects in it. 



The weevil attacks started in the scattered grain on the 

 ground, whtre the moisture conditions were favourable, and 

 Iben extended to the stacks The trouble was largely due to 

 the faulty construction of the stacks, and the action of mice, 

 which cut the bags and allowed the grain to scatter on the 

 ground. 



Great success followed simple changes. The railway 

 sleepers on which the stacks were made were properly 

 spaced so as 10 give the necessary ventilation, naphthali-ne 

 was used to prevent insects breeding on the ground in 

 spilled wheat, and the I oof was properly constructed before 

 the stack wag made. When he sacks were all in, and the 

 stacks complete, the sides were closed with cloth. This 

 was very successful, and new wheat stored in this manner 

 came through the season in excellent condition. 



The case of infested grain was different. The insects 

 had to be killed to prevent I urther damage, an.l the grain 

 had to be cleaned to make it fit for human consumption. 

 It was found that the application of heat was the most 

 satisfactory method of killii'g the insects. A temperature 

 of 145 degrees Fahrenheit, maintained for three minutes, 

 killed all the insects in the wheat. The grain was not 

 injured by a temperature of 158 degrees. 



Machines for heating the grain and cleaning it of 

 weevils were in operation, one of these being capable of 

 treating 20,000 bushels of wheat a day. 



' H. A. B. 



SUGAR INDUSTRY. 



IMMUNE VARIETY OF SUGAR-CANE FOR 

 PORTO RICO- 



An account of a serious new cane disease in Porto Rico, 

 known as mottling or Mosaic disease, was published in the 

 Agriadhiral News for September S, 1917, at page 289. 

 In this article it was stated that practically all varieties, 

 and particularly the Bourbon were affected. The disease 

 did not appear to be caused by any specific organism ; never- 

 theless the trouble was of a highly infectious character. 

 The losses caused were very great, sometimes resulting in 

 the destruction of the entire crop. 



In connexion with the above remarks, a letter in a recent 

 issue of Science (May 16, 1919) which deals with a .Japanese 

 variety of cane found to be immune to this disease in Porto 

 Rico is of great interest. It appears that at the Federal 

 Experiment Station in Porto Rico, out of twenty varieties 

 growing there one only, the Japanese variety, Kavangire, 

 showed no sign of the mottling disease. Further trials 

 conducted there by Mr. H. Bourne of Barbados, under the 



direction of Professor Earle, showed thit this particular cane 

 w^s the only one that could be relied upon to resist infec- 

 tion after inoculation. 



The Kavangire cane is tall growing and very slender, 

 but the yield, under some conditions at least compare* 

 favourably with other varieties. A yield of 70 tins per 

 acre for this cane is reported for one plot. No analysis of 

 the Kavangire variety, as grown in Porto Rico, are available, 

 but according to some reports from other countries where it 

 is grown it varies from 14 ".38 per cent, sucrose to 16"85 per 

 cent sucrose, while its purity coefficient varies from 84 9 t* 

 89-67. 



This variety appears to have given satisfaction in those 

 parts of the Argentine where the warm weather extends ovet 

 a sufficiently loug period to enable it to mature. But on 

 account of the fact that it requires a long season for maturity, 

 it is not recommended for cultivation in sub-tropica' countries. 

 In conclusion it may be added that this cane appears to be a 

 strong ratooner and to have considerable resistance to root 

 disease, borer, and stem rot. 



CANE PLANTING ON THE FLAT IN 

 ST. CROIX. 



In the Ae;ricultiiral Neivs, May 18, 1518, there 

 was published a note on experiments on sugarcane 

 cultivation at the Slob Experiment Station, St Croix. The 

 manager of the station, Mr. Edward Gedde, has recently 

 forwarded to the Imperial Commissioner of Agriculture for 

 the AVest Indies, a copy of his report on experiments carried 

 out on similar lines during the season 1918-19. 



From this report it would appear that Mr. Gedde i> 

 convinced that the results of two previous years with regard 

 to the advantage of planting cane on the flat as compared 

 with planting between banks have been fully confirmed. 

 Under varying conditions of manuring, etc. the result from 

 planting on the fiat has in every case been a larger yield of 

 plant canes i hough not always of ratoons. Besides this, the 

 cost of cultivation on the flat is considerably less than that 

 between banks, thus producing increased profit on the crop. 

 The figures given for eighteen plots on each .system are : flit 

 planting, 27 8 tons of cane per acre ; between banks, 23'7 

 tons per acre. The expenses of cultivation were per acr« 

 $38"88 for flat planting, and $49 76 for planting between 

 hanks. 



Experiments as to the effect of pen manures stored i* 

 various ways are of much interest. The questions of the 

 advisability of allowing cane fields to lie fallow, of the effectt 

 of various green dressings, and of the benefits accruing from 

 rotation of crops are aiso receiving attention. 



The result of one experiment, namely the disposal of 

 the cane trash, might have been predicated. The trash od 

 one Sell was removed, while that on another was burnt, 

 and the ash turned in. In the following crop the lattM 

 produced, as might have expected, a higher yield, for althougk 

 soiiie valuable constituents were doubtless lost by burning, 

 yet the ash contained much fertilizing matter. It would 

 seem that the system of using the cane trash as a mulch for 

 the growing canes, which is generally practised in many of 

 these islands is probably the best way of utilizing this 

 material. 



These experiments, which have now been conducted for 

 three years, will be of increasing value if continued, and will 

 prove as a basis of reliable information not only for th* 

 sugar-cane planters of St. Croix, but for those in other 

 places as well. 



