Page 28 



BETTER FRUIT 



March 



mixture containing an excess of lime. 

 As a precaution against burning in the 

 second and third appHcations 16 to 24 

 pounds of lime were added to each 200 

 gallons of spray with paris green at the 

 above strength. In spite of these precau- 

 tions, as early as June 11 apples were 

 noted in the paris green plat with black- 

 ened areas about their blossom ends. 

 These blackened areas increased in size 

 and became more conspicuous as the 

 apples grew. By picking time some of 

 the areas now shriveled had extended 

 about the blossom end until it covered 

 over a third of the surface of the fruit. 

 In some cases the burned tissue at the 

 end of the apple had dried and separated 

 from the normal portion and fallen away, 

 leaving the seeds exposed at the bot- 

 tom of circular cup - like depressions. 

 Some of the apples less seriously burned 

 showed deeply depressed calyx basins. 

 Nearly one-fourth of the picked fruit 

 from that portion of the orchard sprayed 

 with paris green was so seriously dam- 

 aged from this cause that it was rejected 

 from the first grade, and some reduced 

 to culls. The rainy weather prevailing 

 at the time nearly all the sprays were 

 applied intensified the damage from the 

 paris green, but the same unfavorable 

 weather conditions in the adjoining block 

 treated similarly with arsenate of lead, 

 failed to develop more than about 1% of 

 apples blackened at the blossom end. 



The burning of apples from arsenicals 

 of any kind produces the typical black- 

 ened areas. Some of the apples burned 

 in this manner by paris green are shown 

 in Fig. 13. Arsenical burning is very 

 different from bordeaux injury. The lat- 

 ter does not produce the blackened areas 

 at the blossom end, but instead leaves 

 the fruit roughened and russeted. The 

 two kinds of injury are so different in 

 appearance that they need never be con- 

 fused. Some varieties of apples are more 

 susceptible to burning from arsenicals 

 than others, and, like bordeaux injury, 



is sometimes increased by rainy weather 

 at spraying time. Though a bordeaux 

 of only three pounds blue vitriol and 

 four pounds quick lime to 50 gallons of 

 water was used at the time the petals 

 fell, considerable of the bordeaux russet- 

 ing appeared upon the trees sprayed first, 

 due to a heavy rain. If bordeaux mix- 

 ture has to be used at all at the time of 

 the drenching spray immediately follow- 

 ing the dropping of the petals, it should 

 be in a very dilute strength. It would 

 be better, in avoiding the russeting, to 

 use the full strength bordeaux mixture 

 earlier, while the trees are dormant, 

 entirely omitting it at the time of spray- 

 ing to fill the calyces. 



Properly made brands of commercial 

 arsenate of lead may be used at strengths 

 greatly exceeding that necessary for the 

 spraying of the apple without danger 

 from burning, though used without the 

 addition of lime, though a few instances 

 of burning with arsenate of lead have 

 been observed. Paris green should only 

 be used with the addition of lime, and 

 even then burning is likely to occur. 

 A property of arsenical sprays which 

 induces burning is supposed to be the 

 water-soluble arsenious oxide. The case 

 of burning cited resulted from the use 

 of paris green which contained, as shown 

 by analysis by J. K. Haywood, of the 

 Bureau of Chemistry, 2.40% water-soluble 

 arsenious oxide, which amount is not 

 excessively high for paris greens. This 

 amount, however, is much in excess of 

 that to be expected in lead arsenates, as 

 will be noted from the previous dis- 

 cussion. The average amount of water- 

 soluble arsenious oxide from eight differ- 

 ent brands of commercial arsenates of 

 lead tested was but forty-eight hun- 

 dredths of one per cent. 



Arsenical poisoning of fruit trees from 

 absorption of the arsenic through the 

 roots or by irritation at the crown of 

 the tree where an excessive amount of 

 spray is allowed to collect, has been sus- 



IRRIGATING THE STRAWBERRY FIELD 



pected in other fruit sections, but under 

 soil conditions in Missouri, and with the 

 methods of spraying recommended here, 

 no such trouble has been observed or 

 need be feared. 



Although an arsenate of lead spray is 

 primarily an insecticide there seems to 

 be good evidence that it also possesses 

 some fungicidal value. Aside from pro- 

 tecting the trees from leaf-eating insects 

 the foliage has been held upon the trees 

 in a vigorous condition late into the fall 

 by spraying with arsenate of lead only. 

 Unsprayed trees adjoining were stripped 

 of their foliage early in the fall by fungus 

 diseases. In the experiment at Olden 

 the beneficial effect of the single early 

 spraying with a dilute bordeaux mixture 

 and two later sprays of arsenate of lead 

 was most noticeable. Foliage in a very 

 healthy condition was retained upon the 

 sprayed trees well into November, while 

 many unsprayed trees were practically 

 stripped of their leaves by October. 



Thoroughness in applying the spray 

 has more to do with the results obtained 

 than the kind of spray used. It is safe 

 to say that there are more failures from 

 insufficient or poorly applied sprays than 

 from all other causes combined. 



For the first treatment following the 

 dropping of the petals, a tree is not thor- 

 oughly sprayed until the liquid has been 

 placed into the open calyx cup of every 

 small apple on the tree. Calyx tubes 

 point in all directions upon the tree, up, 

 down and at all angles, and it is mani- 

 fest that the spraying should not only 

 be done from all sides of the tree, but 

 from above and below. For this a nozzle 

 throwing a coarse spray, such as would 

 be given by a bordeaux, a coarse Ver- 

 morel or angle Friend, is desirable. The 

 spray should be driven with a high pres- 

 sure and the poison forced deep down 

 into the calyx chambers. If the tree is 

 small it may be sprayed from the ground 

 by the use of long spray rods and 

 nozzles turned at an angle with the pole, 

 or if the nozzle used does not permit of 

 such adjustment a crook should be made 

 at the tip of the pole so as to throw 

 the spray downward. Only small trees 

 can be sprayed from the ground. All 

 others must be reached from a high 

 tower built upon the spray outfit. Trees 

 properly pruned, with low heads and 

 open centers, are sprayed with much less 

 material and cost. The nozzles should 



Photograph by C. S. Reeves 

 STRAWBERRIES IN YOUNG ORCHARD OF DR. SMITH, WHITE SALMON VALLEY 



WASHINGTON 



