534 INSECTS 'AFFECTING VEGETATION 



in the contest with the anthracnose and it is important, since even 

 the most expert will overlook some of the diseased seeds in sorting. 



As soon as the plants are well up, and the first pair of true 

 leaves begins to unfold, spray thoroughly with Bordeaux mixture. 

 Probably the best formula to use is five pounds copper sulfate, four 

 pounds of stone lime to 50 gallons of water. A stronger solution has 

 been found to dwarf the plants, while the weaker solution is equally 

 as effective in preventing the anthracnose. This should be so thor- 

 oughly applied that every part, of the plant above ground will be 

 completely covered. 



In about ten days or two weeks the plants should have a second 

 spraying, using the same strength of mixture. This application 

 should be as thorough as the first. This is to cover and protect the 

 new growth of leaves and branches. Unless excessive rains wash the 

 mixture off, it will not be necessary to spray again until the pods are 

 forming, shortly after blossoming time. A third application of the 

 same strength and thoroughness should now be made. The nozzles 

 should be so arranged that the pods as well as stems and leaves will 

 be thoroughly coated. This is important. (N. Y. (Cornell) E. S. 

 B. 239.) " 



In most cases three sprayings will be sufficient. If the seed was 

 badly diseased and if the plants show an abundance of the anthrac- 

 nose, more sprayings will probably be necessary to insure a clean 

 crop. Excessive rains will also necessitate more frequent applica- 

 tions. The effect of heavy rains in washing off the mixture may be 

 overcome by adding to the Bordeaux mixture the following: two 

 pounds resin, one pound sal soda, one gallon of water. Boil to- 

 gether until of a clear brown color. Add one-half this amount to 

 each barrel of the Bordeaux. An extra spraying between the second 

 and third, and another after the third when the pods are nearly full 

 grown, will no doubt be sufficient in the worst cases. Repeated ex- 

 periments by the writer have shown that one or two thorough spray- 

 ings even after a large percentage of the plants are badly diseased 

 will insure a comparatively clean and profitable crop. 



The removal and destruction of diseased pods and stalks is also 

 a matter not to be overlooked. While the disease is most commonly 

 carried over in the seed, it has also been demonstrated that dis- 

 eased pods and stems thrown on the fields in which beans are to 

 be planted will result in a marked increase of the disease the next 

 season. For this reason all diseased pods and stalks should be 

 burned, or, if they go into the manure pile, the manure should not 

 be put on fields in which beans are to be planted. 



Cultivating or working in the beans when wet should be 

 avoided as much as possible. As already pointed out, the spores of 

 the disease are disseminated only when in drops of rain or dew. 

 When dry the mucilage in which they are enclosed fastens them 

 to the spot and they cannot be scattered. For the same reason string 

 or snap beans should not be picked when wet. The handling of a 

 single spotted pod may be sufficient to spread the disease through- 

 out an entire row, or spot all the pods gathered. Repeated crop- 



