8 3 2 



The Cultivation of Watercress. [fee-., 



undoubtedly a prosperous industry. Some of the early beds 

 are now rented at £30 per acre, while others can be had for 

 £15 and less. 



The original cost of formation of many of these beds was 

 considerable, as much as ;£ioo per acre being expended upon 

 them, according to the amount of earth to be excavated. If 

 plants are to be purchased, these may cost as much as £10 

 per ton, and usually two tons are required to plant one acre. 



Where springs are numerous, the surrounding ground can 

 soon be made adaptable to them at a small cost, and at the 

 present time it is questionable if it would ever pay to lay out 

 money in the preparation of new beds on the lines mentioned 

 above. 



Pests. — In common with all other cultivated plants, 

 watercress is subject to numerous enemies in the form of 

 animal and plant life, of which the following are most fre- 

 quently met with. The fresh-water shrimp (Gammarus 

 fluviatilis) attacks the young shoots, thereby doing a con- 

 siderable amount of harm ; it can, however, be kept in check 

 by the use of quicklime, which is applied to the incoming 

 water, and therefore in no way harms the plants. The water 

 beetle (Dytiscus marginalis) is a common and voracious occu- 

 pant of most cress beds, but it is very doubtful if it does any 

 real harm. The Caddis worms (Limnepltilus flavicornis) 

 find a home in many beds, and are never in water that is con- 

 taminated. When a bed becomes badly infested, it is found 

 best to clear it of plants in the autumn, and drain out the 

 water for several weeks; when the bed is again flooded the 

 worms will float to the surface, and can then be drained into 

 the storm or surplus water. Fresh-water snails in their various 

 stages of development are also a source of trouble and annoy- 

 ance to the grower. 



The turnip fly (Phyllotreta nemorum) does not confine its 

 ravages to seedling turnips, but, in addition, does consider- 

 able damage to cress beds, more especially when the crops 

 are badly nourished, and when the banks are infested with 

 weeds of the cabbage tribe, whereon the flies find shelter and 

 food, until such time as the cress affords an opportunity for 

 attack. 



Weeds. — The abundance and variety of weeds to be found 



