io8 



Commercial Gardening 



if the atmosphere and soil are allowed to become too dry. Consequently 

 the best natural remedies or preventives are the judicious application of 

 water to the soil, pathways, and foliage, taking care that it is of the 

 same temperature as that of the house itself. If these pests should get 

 the upper hand, it will be necessary to fumigate or vaporize the houses 

 to get rid of them. 



Slugs and woodlice are sometimes troublesome, and will spoil the fruits 

 if not suppressed. When cutting the fruits an eye may be kept on the 

 slugs, everyone seen being dispatched on the spot. Traps of pieces of 



potato, beetroot, carrot, or mangel-wurzel may also 

 be used for the slugs and woodlice, examining the 

 pieces at intervals and destroying the pests in 

 them. 



Eelworms. These minute eel-like pests often 

 play great havoc with Cucumbers and Tomatoes 

 in market nurseries. They are the outcome of 

 a pest known as Heterodera radicicola, and are 

 hatched in the soil from minute eggs. About 

 seventy-five of the young worms go to an inch 

 when placed end to end, so that it requires a 

 good lens to discover them. 



The cause of the appearance of Eelworm seems 

 to be due almost entirely to the superabundance 

 of rich organic manure in the soil, and to over- 

 doses of water and too high a temperature. 

 Wherever soil has been highly enriched with 

 large quantities of stable manure, and perhaps 

 chemicals in addition, the Eelworms appear, being 

 themselves no doubt the natural development from 

 eggs laid in decaying organic material. Their 

 presence undoubtedly indicates a sour or acid con- 

 dition of the soil, which is fatal to the plants. 

 The fibrous roots are invaded by the Eelworms, 

 and in a short time become irregular warty neck- 

 laces, partly exposed on the surface of the soil, as shown in the sketch 

 (fig. 473). 



Many remedies have been tried to extirpate the Eelworm disease, 

 and although some at first have apparently checked its advance, it is 

 only for a short time. Carbolic solutions and sulphate of copper applica- 

 tions have proved useless, and every other suggested remedy, including 

 naphthalene and solution of permanganate of potash, so long as erroneous 

 cultural methods prevail. These consist in having a soil too rich in 

 humus, and then rendering it sour and devoid of oxygen by the applica- 

 tion of too much water, in addition to which may be mentioned too high 

 a temperature (over 90 F.), and a stuffy atmosphere due to bad ventila- 

 tion. By altering these things, and using a little basic slag or slaked 



Fig. 473. Cucumber Roots infested 

 with Eelworms 



