402 The Profitable Culture of Vegetables. 



host. Therefore, apart from other considerations, the sup- 

 pression of weeds is of importance in regard to the health of 

 crops, and not only should those on cultivated land receive 

 attention, but also those on headlands, in hedgerows, and on 

 waste places. 



SPRAYING MACHINES AND THEIR USE, WITH 

 MATERIALS AND FORMULA. 



SPRAYING MACHINES. For the smaller holdings knapsack sprayers, 

 of which there are several good makes on the market, are probably the 

 handiest machines. They are cheap and effective, need only one man to 

 work them, and will, with care, last many years. Those fitted with brass 

 ball-valves should have the preference ; some machines have rubber valves 

 but these are liable to be injured by paraffin. Ordinary garden syringes 

 are not suitable for spraying purposes ; the spray is too coarse and much 

 of the wash is wasted, whilst notwithstanding this, all parts of the plants 

 do not get properly covered with the wash. 



More powerful machines, mounted on wheels or runners, may be used. 

 They will cover much more ground in a day than the knapsacks, but require 

 more space between the plants, so that unless the crops are so arranged 

 that all the plants can be reached by the spray when the machine is on a 

 path, or unless the rows are a considerable distance apart, there is great 

 difficulty in working them in a growing crop. They have the further dis- 

 advantages of greater cost and of generally needing three men to work 

 them. It is therefore only on the larger holdings, or where a group of 

 small holders combine in the purchase and working of one, that these larger 

 machines are advisable. 



Every machine should always be emptied and washed out with clean 

 water immediately after using, and should never be allowed to stand with 

 with any unused wash in it. 



APPLYING THE WASH. With most washes, a fine misty spray with 

 plenty of force behind it is advisable. The spraying must always be done 

 thoroughly and completely, but it is not necessary to make the plants 

 dripping wet to ensure this ; an even damping of the whole plant is quite 

 effective and much more economical of material. Particular attention 

 must be given to the lower surface of the leaves and to any leaves which 

 are near the surface of the ground. Repeated sprayings may be necessary, 

 but it should be borne in mind that one spraying thoroughly done is much 

 more effective than two only partially done. 



With many washes, and especially so with Bordeaux mixture, it is im- 

 possible to get an even distribution of the solid portion of the wash unless 



