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one spraying with lead arsenate killed half the caterpillars present. At 

 the date of spraying, the sprayed rows showed a higher percentage 

 of infestation than the unsprayed ones, on account of their proximity 

 to some maize. In using the lead arsenate spray, two pounds of lime 

 should be added to the liquid to prevent burning. Zinc arsenite has 

 several advantages over lead arsenate ; it is cheaper, only one pound 

 being necessary in 50 U.S. gallons of water ; it washes off more readily, 

 and there is therefore less danger of any being left on the fruit at 

 picking time, and it is decidedly less poisonous to man than is lead 

 arsenate. Either lead arsenate, zinc arsenite, or Paris green, may be 

 added to Bordeaux mixture. During the summer of 1914 some 

 successful results were obtained in the use of sweet maize as a trap 

 crop, and it is recommended that ten to twenty rows of tomatoes 

 alternate with two of maize. If a single row of maize is planted 

 across the field, it usually does not get thoroughly pollinated, 

 and the ears will not be sufficiently attractive to prevent the 

 caterpillars from wandering to the tomatoes ; also, the maize 

 must be planted at such a season as to be in an attractive 

 condition when the first tomatoes are forming, i.e., it must 

 have yoimg silks, otherwise the insect prefers the tomatoes. This 

 maize must be destroyed before it has matured sufficiently to become 

 unattractive to the larvae. Where the acreage of tomatoes is large, 

 the most practical method of disposal of wormy fruits is to dump them 

 into a pond, or to bury them. They should be covered with at least 

 a foot of well-packed soil, more if it is sandy. In one experiment, 

 conducted by Dr. P. H. Rolfs, the infested tomatoes were carefully 

 picked up from one field, while in a neighbouring one they were 

 neglected. In the former at the close of the season there was scarcely 

 any increase in the larvae, and only 5 per cent, of the fruit was attacked, 

 but in the neglected field, 80 per cent, of later pickings was ruined. 

 At the close of the picking season, plants with infested fruit should 

 be burned or ploughed under as soon as possible. 



The first preventive measure against root-knot in tomatoes, a disease 

 caused by a nematode, Heterodera radicicola, should be to see that 

 the seed-bed is not infested. Three methods of purifying the soil 

 (taken from U.S. Dept. Agric, Bur. PI. Ind., Bull., No. 217) are given : 

 (i) punch eight or nine holes per square yard into the seed-bed to a 

 depth of a foot, and pour into each | oz. (a tablespoonful) of carbon 

 bisulphide, quickly filling the holes with soil, and tramping it down ; 

 (ii) saturate the soil with a mixture of 1 part of commercial formafin 

 with 100 of water, using 1| U.S. (1^ Impl.) gallons of the mixture per 

 square yard for a shallow seed-bed, and more for a deep one ; (iii) 

 for greenhouses, steam should be passed under considerable pressure 

 through the soil by means of iron pipes with I inch holes every few 

 inches, or tile drains, laid at the bottom of the beds a foot or two apart. 

 The beds should be covered with straw, sacking or boards, to keep in 

 the heat, which should be maintained from a half to two hours. Place 

 some raw potatoes on the surface farthest from the pipes, and when 

 these are thoroughly cooked all the nematodes will have been killed 

 and the steam may be turned off. In badly infested fields, the plants 

 should be ploughed up and burned, and the field planted during the 

 remainder of the year, and also at least during the year following, with 

 some plant not affected by this worm. Among such immune, or 



