Norwich bulletin., 1917-08-23
SPRAY FOR LEAF
 SPOT OF TOMATOES Resin Fish Oil Soap Added to 6er- deaux Mixture Promises a Method of ControI

The addition of resin fish -oil soap to Bordeaux mixture promises to control tomato leaf-spot, although Bordeaux alone has not prevented losses. Plant disease specialists in the fed eral department of agriculture de- scribe the leaf-spot disease as one which causes defoliation of the plants. greatly reduced yields. and inferior on the leaves and sometimes on the stems. They first appear as tiny dots, having dark or water soaked ap
 pearance. Gradually they enlarge and turn brown, and the leaves shrivel and drop. beginning at the base of the plant.
 Making the Solutions.
 Bordeaux mixture Is best prepared arate ingredients. The copper sul- phate should be mixed in the propor- tions of a gallon of water. preferably soft water, to pound of the sulphate crystals and there should be five gal Ions of this stock solution for each acre of tomatoes to be sprayed. The crystals should be dissolved in the usual way by suspending them in a burlap bag which touches the surface of the water; the solution should be well stirred
 The lime suspension or milk of lime, is also a pound to gallon, but only three -fourths as many gallons needed as of the copper solution. Thus, if there are twenty gallons of the cop per solution there would be only fif- teen of the lime milk. The lime should be slaked gradually by pouring the water on in small quantities and at intervals until all has crumbled. F'i- nally larger quantities are added with constant stirring until the volume is com pleted. If quickliTne can not be had and hydrated lime is available use as many pounds of the latter as of copper sulphate. but do not increase the quantity of water Air -slaked lime must not be used.
 The resin fish-oil soap suspension is made with a pound of soap to a gal lon of water. As with the lime only three -fourths of the quantity of water is necessary. Hot water will hasten the dissolvinS of the soap. To avoid the formation or troublesome Jumps the water must be added slowly at first with constant stirring.
 Preparing the Mixture.
 For general commercial operations two 50-gallon barrels with outlets at the bottom are placed a raised platform so their outlets will be high CT than the top of the spray tank. To make 100 gallons measure eight gal Ions of the copper-sulphate solution into one barrel and six gallons of the milk of lime into the other. Add to each enough water to make fortv- thoroughly, and then let the two so- iuuons run with equal rates into 9 trough leading to the spray tank At the same time add six gallons of the resin fish -oi1 soap solution very grad ually and in a small stream through the spray-tank strainer along with the copperlime mixture. The copper and lime should be mixed before the soap is added.
 Notifications of the method may be used for smaller quantities.
 Applying the Spray.
 A traction sprayer such as that en1- ployed in the spraying of potatoes may be used except where the vines ] are too large. There should be three | nozzles for each row, one to spray downward and two on the sides spray l ing toward each other. These lateral 1 lozzles should be set low and pointed ] slightly mp to get the spray on the | Under side of the leaves. Thorough ] spraying, repeated at from seven to | en day intervals. is necessary for the | pest results. and must be continued l through August. When the plants are oo large for a traction sprayer in the 1 -ows. roadways should be opened and he spraying continued with long lines | ,f hose.