278 STATE BOARD OF AGRICULTURE. 



REPORT OF THE HORTICULTURAL SECTION. 



Director R. S. Shaw : 



Dear Sir — The experimental work of tlie horticultural .section the 

 past year has consisted of a continuation and development of many o^' 

 the projects previously reported and the initiation of some new projects 

 that seemed desirable. 



During the past year further investigations were made of spraying and 

 dusting fruits and vegetables for the control of the common insects and 

 diseases of fruits and vegetables. There were some very important re- 

 sults obtained from this work which may be briefly mentioned at this 

 time. 



The lime-sulfur solution is now considered a standard material to use 

 as a dormant spray for scale and as a summer spray on apples and some 

 other fruits to control fungus diseases. The inconvenience and expense 

 of the distribution, over a large marketing area, of this liquid form of the 

 compound make it desirable, on the part of the manufacturer, to market 

 it in the form of a powder. Experiments of the past season indicate that 

 this dry lime sulphur, used at the strengths recommended by the manu- 

 facturers, is not as efficient for summer spraying as the liquid form. In 

 view of the fact that in many rural towns the local agents of spray ]na- 

 terials have discontinued handling the liquid form for the dry liii:e-sul- 

 phur, the inefficiency of the powdered forms should be more generally 

 known. 



Extensive tests were also made of the numerous arsenical compounds 

 being offered for spraying purposes. Tests of calcium arsenate on a]»- 

 ples and peaches showed severe foliage injury. When lime was used with 

 the calcium arsenate, foliage injury was still considerable, but less tliaii 

 when used alone. Therefore, we cannot recommend the use of this ma- 

 terial for spraying such fruits. On potatoes, however, calcium arsenate 

 proved a very satisfactory material, giving good results on insect control 

 and doing no injury to the foliage. 



The use of magnesium arsenate on peaches and apples also resulted in 

 severe foliage injury, and, therefore, at the present time it cannot be re- 

 commended for fruit-tree spraying. Arsenate of lead still remains the 

 standard arsenical compound for fruit spraying, but unless it is used with 

 Bordeaux mixture or lime-sulfur solution, two pounds of lime should be 

 added to each fifty gallons of the spray to prevent burning. 



The comparative tests of lime-sulfur dust with lime sulfur spray were 

 continued and showed just as efficient control of scab and codling-moth 

 worm with the dust as with the spray. On sour cherries, however, the 

 dust did not control the shot-hole fungus quite so efficiently as the lime- 

 sulfur spray. A comparative test of the dust and various sprays on cur- 

 rents and gooseberries proved that Bordeaux mixture was the most ef- 

 ficient spray in controlling the anthracnose. Further details of the re- 

 sults of our spraying and dusting ex])eriments will be found in Special 

 Bulletin No. 102, published recently. 



The fruit tree record work previously reported has been continued and 



