206 NEBRASKA STATE HORTICT 'LTLRAL SOCIETY. 



braska on apple orchards to show the growers the beneficial effects of 

 spraying to produce fruits free from these pests and to determine just 

 what its cost would be under Nebraska conditions. This work was car- 

 ried on in twenty-two orchards, representing eighteen localities in thir- 

 teen counties. The conclusions drawn from this work are based on the 

 results under all sorts of conditions extending over this period. 



Apple scab and the codling moth worm are the two most troublesome 

 pests the growers have to contend with in this state. The apple scab is 

 a fungous disease that develops rapidly under certain favorable weather 

 conditions and infests both the leaves and fruits of most of our cultivated 

 varieties of apples. It makes its appearance about the time the trees are 

 in bloom causing numerous brown patches upon the leaves and a scabby 

 lilie growth upon the fruits. Tlie worm so often found inside the apples 

 Is the larva of a small moth. This pest has reached such a stage of de- 

 velopment in eastern Nebraska that we cannot expect to get more than 

 10 to 15 per cent of the apples free from the worms without spraying. 



Four sprayings are necessary to hold these two troublesome pests 

 in check. Spraying to prevent apple scab should be regarded as a pre- 

 ventative and not as a cure, for when the disease ohce gets into the tissues 

 ef the plant any spray material that we could use with safety to the tree 

 would not stop its development. The object then is to thoroughly coat all 

 parts of the tree with something that will prevent the spores from germi- 

 nating. The materials most commonly used for this purpose are lime 

 sulphur solution or Bordeaux mixture. Lime sulphur is a commercial 

 preparation that may be bought on the market in a concentrated form. 

 It should be diluted about thirty times before being put on apple trees. 

 As a similar spray, Bordeaux mixture may be made by slacking four 

 pounds of store lime in a small quantity of water and diluting it to twenty- 

 five gallons and then adding to it twenty-five gallons of water in which 

 four pounds of copper sulphate (blue stone) has been dissolved. Lead 

 arsenate in the proportion of two pounds to fifty gallons of spray material 

 Is used for controlling the worm. 



The first application is for scab only and should consist of either lime 

 sulphur or Bordeaux mixture. The proper time for making the first appli- 

 cation is just before the flowers open. The second application should con- 

 sist of the same material as the first application plus two pounds of lead 

 arsenate dissolved in each fifty gallons and should be put on immediately 

 after the flowers begin to drop. This is the most important spraying and 

 it should be directed downward and with as much force as possible in 

 order to get some of the poison into the blossom end of the apple before 

 the little lobes cross. About three weeks later, the second spraying 

 should be repeated. The fourth and last application should be given about 

 the middle of July and should consist of lead arsenate and water two 

 pounds to fifty gallons. 



The department of horticulture found that the cost of these four ap- 

 plications, including the cost of all material and labor was about twenty- 

 four cents per tree. A grown apple tree in an ordinary year should bear 

 over five bushels, making the cost of producing clean fruit free from 

 worms less than five cents per bushel. 



