No. 6. DEPARTMENT OF AGRICULTURE. 595 



establishing itself. Attention should be given to conservation of 

 soil moistni-e in dry weather by shallow cultivation or by mulching; 

 and the soil should be of the best possible texture and fertility. 



I have left for the last the emphasizing of general sanitation in 

 the apple orchard, because it enters more or less into the control of all 

 these apple diseases. It means keeping at a minimum the sources 

 of contagion, and at a maximum the general well-being of the trees. 

 And this means such things as cleaning up waste fruit, cutting out 

 useless limbs, making way with worthless Avayside trees, avoiding 

 injuries and bruises on roots or trunks or limbs, skill in pruning, 

 and the constant practice of such general good care as will make for 

 the vigor and healthfulness and fruitfulness of the orchard. 



Spraying, we may think, is a necessary evil. The profitableness 

 of any spray api>lication will depend (1) on the presence in the par- 

 ticular locality of the disease or diseases which it is especially de- 

 signed to combat; (2) on the susceptibility of the variety to the 

 disease; (3) on the general seasonal and other conditions that 

 influences infection; (4) on care in selection and application of 

 the spray material. For example, it would be manifestly unwise 

 to spray for Bitter Rot where it does not exist, or on a particular 

 variety of apple that is immune to it, or with a material that will 

 iQot give the protection desired; if we could only foresee the kind 

 of season, and be able to predict the occurrence or non-occurrence 

 of our enemies, fortunate indeed would we be. 



Most of the disease 1 have discussed do occur throughout Penn- 

 sylvania. It is for the grower to study his varieties and local condi- 

 tions with reference to adopting the most economical and profitable 

 means of prevention; and it is in these days for specialists to co- 

 operate with growers in devising and putting into practice the most 

 efl'ective measures. 



The most important peach diseases are Yellows, Leaf Curl, Black 

 Spot or Scab, and Brown Rot. 



The symptoms of Yellows are ripening of fruit a few days to 

 several weeks ahead of the normal time for the variety which prema- 

 ture fruit is insipid, with perhaps red splotches on the surface or 

 streaks through the flesh ; premature development of leaf buds, giv- 

 ing slender pale shoots, or branched broomlike growths and ab- 

 normal development of leaves so that they are narrow and yellow- 

 ish green, inclined to curl. The disease develops slowly and is hard 

 to diagnose from any one symptom. It must not be confused with 

 yellowed foliage resulting from such things as poor drainage, thin 

 soil, winter injury or borer attack. As soon as Yellows can be 

 identified, the affected tree should be marked for early .removal and 

 destruction. It is worthless and may prove a menace to others. 

 Peach trees may be reset in jflaces from which affected trees have 

 been removed. Care should be exercised to get nursery stock free 

 from danger of Yellows infection. 



In Peach Leaf Curl the growing leaves show very decided dis- 

 tortions in the form of puckerings, and the color of affected parts 

 becomes reddish or yellowish. Affected leaves may fall in June. 

 Trees suffer in wood growth and in fruit bearing from interference 

 with leaf activities. The fungus seems to be carried over winter by 

 spores that lodge between bud scales, or in other protected places, 



