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THOSB ABNORJ'IAI. LSjWrSS 



Apples, Nimerous snmples of tipple leaves have been mailed to the 

 University this' fall witli the question "Waj the brovmish areas?" The aiiswer 

 is not necessarily the sanio in each case, since the brooming doesn't always 

 follow tlie same pattern. Some loaves show mainlj'' burned out scab spots 

 Vv'ith tlio brovmish area extending a quarter of an inch or more beyond the edges 

 of the spot* Hero it is evident that \vhatever spray material v;as used, it 

 was caustic enough to eliminate the spot and a little of the normal loaf 

 tissue for good measure. Under the right weather conditions (probably hot, 

 muggy weather) a wettable sulfur plus lead arsenate might be rosponsiblo. 

 And if lime sulfur ivero used, marginal burning as "vgII might result. Scab 

 infections at frequent intervals in spring and early summer, have set the 

 stage for a considerable amo^ont of burning from subsequent sprays. 



But spraying doesn't account for all of the abnormal leaves. The 

 nutritional sot up of the tree soem.s to be another important factor. It is 

 a matter of common observation that a?i impoverished tree is much more subject 

 to spray burn than a vigorous tree. The latter is able to withstaxid almost 

 any spray program within reason, while a slight lack of balance or a deficiecy 

 of an essential element such as magnesium, nay m.anifest itself in off color 

 foliage if not actual scorched areas. Very characteristic magnesium do- 

 ficioncy symptoms ( a ;/ellcwing or broiming of the leaf tissue between the 

 veins) is apparent in some orchards this fall» 



The practice of setting young trees on an area v.here an old orchard 

 has been removed, ivithout first replenishing all essential mineral, elcm.onts 

 through the use of high magnesium lime, manure, complete fertilizers, cover 

 crops, etc., may bring to light real deficiencies in 5''0ung trees, if not 

 actual defoliation. Old apple trees do not necessarily exert a toxic effect 

 on the next planting altiiough they may remove certain available mineral 

 elements so ocizpletuly as to place tho young tree on sljort rations. 



Peaches . Within the past fev/ woeks the writer was as]s':ed to examine 

 two peach orchards in which some of the trees show abnormal leaves. In 

 both cases the diagnosis v;as arsenical burning of tho tvigs. One of those 

 orchards has boon dusted with load arsenate several tines and v;as practically 

 defoliated. The other was adjacent to an apple orchard and some of the 

 nearby peach trees had received too much drift from the o.pplc treos. 



Arsenical bu>-ning of peach twigs nay be easily recc-nizGd by tho 

 broijnish color of tho bark, cracking of the bark wlierc the injury is severe, 

 gur:My masses here and there and early defoliation, "'Hiere only a slight 

 ano-i.mt of injury occurs the leaves may hang on fairly v/oll although they 

 may appear yellcrvvish and some of then may suggest certain virus diseases, 

 such as X-Disease, These two ailuonts should not be confused however, since 

 the latter is characterized by a yollovash appoaraiaco in irregular areas 

 of the leaves, tliosc areas later turning brown and dropping ai/ay, leaving a 

 ragged or lacy appearance. As in arsenical injury the older leaves tend 

 to drop first. 



