84 AGRICULTURAL RESEARCH AND THE FARMER : 



disease was carefully studied and the following action is recom- 

 mended when the disease appears : — (a) Shade houses with Ught 

 shading of water white-wash; (6) Raise temperature of the 

 houses by closing ventilators and suitably increasing the boiler 

 heat, until the average day and night temperature is above 

 77 °F. ; (c) Earth-up base of plants to encourage new root produc- 

 tion; (d) Reduce watering to an absolute minimum, but give 

 an over-head damping when wilting is severe. By adopting 

 these measures growers have been enabled to carry their crops 

 right through the year instead of losing them in May as they 

 otherwise would have done. In one case 68 per cent, of the 

 plants on a nursery were showing symptoms of " Sleepy Disease " 

 before these methods were adopted, but a fortnight after only 

 10 per cent, remained wilted. 



Arum Soft Rot. — This is a disease of the arum lily, caused 

 by the parasite Bacillus aroidecB. It is extremely dangerous 

 when it gains foothold in a district, and in the past no cure 

 was known. The method of treatment was to destroy all 

 diseased corms and start afresh, with a consequent considerable 

 financial loss. After investigation, the following method of control 

 has been devised at thejStation and has so far proved satisfactory; — 

 After drying off the plants, all rootlets are removed from the 

 diseased corms, which are then thoroughly scrubbed and all 

 soft places cut out. After a final washing they are placed in 

 a 2 per cent, solution of Formaldehyde for four hours, care being 

 taken to keep as much of the foliage out of the solution as possible. 

 They are next removed from the solution and potted up in 

 clean virgin soil or sterilised soil. Fresh clean rootlets are 

 quickly formed and healthy plants result. 



This treatment has been the means of saving for one grower 

 the whole of his arum stock, which he valued at £3,000. 



II. Diseases caused by Insects. 

 Rothamsted Experimental Station. 



Insects and Allied Organisms in the Soil. — As has previously 

 been stated, the soil contains numerous organisms, about many 

 of which we know little or nothing. Information is particularly 

 lacking in regard to the higher forms of soil life, such as insects, 

 mites, millepedes, centipedes and earthworms. Research has 

 therefore been commenced on the soil of the Broadbalk wheat 

 field at Rothamsted, and the results so far obtained clearly 

 show that in this arable land the greater proportion of these 



