478 Journal of Agriculture . [ii July. 1910. 



Peach Aphis. 



The life history of peach apliis ha.s never been thoroughly understood in 

 this State. It was always considered that either the insects or their eggs 

 were to be found during winter under or around the roots near the main 

 stem of the tree. To eradicate these, it was at one time thought a satis- 

 factory mode of treatment to mulch well the ground all round the tree with 

 tobacco, or to place in the soil either kainit or muriate of pota.sh. The 

 rationale of this treatment was that the .soil would become saturated with 

 nicotine or potash salts, whichever material was used, and that this would 

 act in a corrosive manner on the bodies of the insects, and so destroy them 

 as soon as they came into contact with the caustic substance in the soil. 



This method of eradication was not found to be definitely a success. 

 Then a suggestion came that possibly the insects laid some eggs on the 

 trees, and that these hatched in early spring. 



To determine this, as well as to endeavour to find a successful method 

 of coping with the pest, trials were made last winter in a 35-acre peach 

 orchard at Diamond Creek, belonging to Mr. A. S. Lowe. In the spring 

 of 1908 the whole orchard was severely vi.sited by the peach aphis, and 

 two double hose spray pumps were constantly at work for many weeks, 

 spraying with tobacco and soap sprays. At the end of November, and 

 early in December, the aphis was as pre^■alent as ever, even with all this 

 .spraying. 



The whole orchard was sprayed during the following winter, early 

 in July, with a red oil emulsion at a strength of i in 25. Some trees 

 were also treated with muriate of potash at the roots, and others with a 

 tobacco mulch. The experiment was varied as much as possible, such as 

 spraying different plots before and after pruning. 



The result was that, during the following spring, 1909, comparatively 

 little spraying was necessary. One pump was never used, and the other 

 only on occasional days for a few weeks. The season was a fairly normal 

 one for peach aphis, and in other orchards it was far more prevalent. One 

 year's experiment does not indicate permanent results, and it is intendeu 

 to further investigate on these lines, under the supervision ot the Vegeta- 

 tion Diseases Inspectors. 



During the season, many interesting features became prominent, and 

 there is still a great deal to bi- learned al)Out the habits of peach aphis 

 and also regarding the action of red oil. 



On some trees the aphis would appear in small clusters, and after a few- 

 days every insect would entirely disappear. The results were quite the 

 reverse of negative, and it is hoped that we are on the verge of a successful 

 method of dealing with the peach aphis trouble. One feature was entirely 

 overlooked in establishing the experiments, and that was the spraying of a 

 plot with red oil as the sole treatment. In each plot, some root treat- 

 ment as well was adopted. It is intended this season to spray with red 

 oil. without any tobacco or potash treatm.ent of the soil. 



Pruning. 



Orchardists will now be busy with the most interesting work of the year. 

 The old haphazard methods of pruning are passing away gradually, and 

 growers are beginning to prune, with a knowledge and a reason for every 

 ■cut made. A model tree will always be light on its topmost leaders, bearing 

 the major portion of the crop in the lower regions of the tree. The main 

 point to be noted is that a heavy wood growth in the upper portion of the 

 tree tends to reduce the bearing capabilities of the tree in its most useful parts. 



