Page 4 



BETTER FRUIT 



September, 1919 



Rots starting from mechanical injuries, such 

 damage can be eliminated aim 



truly judged until it is eaten — and 

 whether it be fit to eat early or late in 

 its season is dependent upon its "keep- 

 ing quality." Consider, then, some of 

 the factors that influence the keeping 

 quality of apples — factors that produce 

 storage diseases. There are two general 

 divisions of storage diseases: 



1. Parasitic, or those caused by such 

 organisms as bacteria and fungi, or 

 molds. 



2. Non-parasitic, or the so-called 

 "physiological diseases." 



Those in the latter class are frequently 

 not regarded as diseases, but as "condi- 

 tions," but call them what you will, 

 they cause pathological abnormalities. 



Parasitic Diseases. 

 The parasitic diseases may be classi- 

 fied into two general groups: (1) Those 

 which may be prevented by spraying 

 and good orchard sanitation, and (2) 

 Those which may be prevented by 

 proper handling of the fruit. As an 

 example of the first class we have the 

 Northwestern anthracnosc. This dis- 

 ease is confined to the Pacific North- 

 west and is most serious west nf the 

 Cascades. It is present to some extent 

 in the White Salmon Valley, and it has 



Penicilium, known better as "blue mold" rot, 



a fungous disease that develops in storage. 



Careful handling is recommended to reduce 



this trouble to the minimum. 



as bruises and slight punctures. This type of 

 ost entirely by careful handling. 



been serious in the Hood River Valley, 

 but it docs not exist, so far as known, 

 in any of the major apple districts of 

 the State of Washington. This disease is 

 caused by the fungus Neofabrxa Mali- 

 corticis, which lives over from year to 

 year in cankers on the branches. Its 

 spores are matured in midsummer, but 

 they require moisture for germination, 

 and hence the disease does not spread 

 before the fall rains. These rains 

 usually begin before the apples are 

 picked, and the fruit therefore may be 

 infected before it leaves the tree. The 

 spores may germinate and cause an 

 early rotting of the fruit, but hard, late- 

 season apples are usually not attacked 

 until after they are in storage and have 

 begun to soften. However, if the skin 

 happens to be broken the fungus may 

 secure immediate entrance and rotting 

 proceeds at once. Fruit infection is 

 prevented by spraying with bordeaux 

 mixture before the apples are picked, 

 but to control the limb cankers later 

 applications are necessary. 

 Apple scab is another fun- 

 gous disease of importance 

 in some localities of the 

 Northwest, but fortunately 

 is not prevalent in the great 

 apple-producing districts of 

 the State of Washington. 

 The fungus usually pro- 

 duces its scab spots before 

 harvest, but infected apples 

 of course arc not sold in 

 the general trade. But late 

 matured spores may lodge 

 on sound fruit antl infect 

 the aijples after they arc 

 picked and stored. Scab 

 injury is superficial and af- 

 fects the appearance rather 

 than the eating quality of 

 the fruit. But scab is fre- 

 quently a vital factor in the 

 keeping quality of apples, 

 for various other fungi, in 

 themselves incapable of 

 penetrating the sound skin 

 of the fruit, gain easy ac- 

 cess through the scab spots 

 and cause the fruit to rot. 

 From this standpoint alone 

 the exclusion of scabby 

 fruit from the higher 



grades is justified. The prevention of 

 scab is accomplished by good orchard 

 sanitation, accompanied by fungicidal 

 spraying at such intervals as to protect 

 the fruit from bud to harvest. 



The ijarasitic diseases of ajjplcs in 

 storage that can be prevented by proper 

 liandling of the fruit are those due to 

 attacks of organisms which gain en- 

 trance through skin punctures. When- 

 ever the skin of a mature apple is 

 broken a fungous rot is almost sure to 

 develop. The fungi which most fre- 

 quently cause these rots are incapable 

 of penetrating the sound skin, but rots 

 speedily result when they gain access 

 to the llesh and juice of the apple. Skin 

 broken on green apples has a chance to 

 heal, but this power is lost as the fruit 

 matures, hence the great importance of 

 careful handling to prevent mechanical 

 injuries of ripe apples. 



Among the fungi of this class which 

 cause storage rots the most common 

 is Penicilium, the familiar "blue mold." 

 Another common fungous rot is caused 

 by Alternaria, which is a "black mold." 

 These two are the most common in the 

 Northwest, but rots due to other "molds," 

 — pink, white, gray, and various other 

 colors, also occur. Careful handling 

 will reduce these rots to a minimum, 

 and in picking, hauling, putting the 

 apples over the grading machines, and 

 in packing attention should be given 

 this detail. The mechanical graders 

 now in general use are of great utility, 

 but like all conveniences, their benefits 

 may obscure some abuses. The ma- 

 chines are frequently crowded, so that 

 the apples pile up either at the sorting 

 end or in the bins, resulting in numer- 

 ous stem punctures. Another prolific 

 cause of broken skin is found in finger- 

 nail punctures. Fvery handler of ap- 

 ples should be required to wear gloves. 

 Greater care in box nailing should be 

 insisted upon also, for protruding nails 



Continued on page 23. 



.Jonathan apple affected with what is known as .Jonathan 

 spot. This disease is not a fungous disease. It usually 

 develops after the apples are placed in storage and is be- 

 lieved to be caused by over-irrigation and allow ing the fruit 

 to remain on the tree until it is too ripe. Idaho lost 40,000 

 boxes of .Jonathans in 1917 from Ibis cause after the fruit 

 had all been placed in storage. 



