Roberts 2/ described Alternaria mali in 1914 before the careful work of 
Wiltshire By) Mason —/ , Neegaard ay and others, who since have laid a workable 
foundation for the classification of species of Alternaria. Roberts establishex. 
Alternaria mali primarily because the spores had minute pointed spines on their 
surfaces. In the modern concept Alternaria tenuis auct. (as used by authors) 
is a broad species embracing many hiotypes whose characteristics fall within 
the concept for the species, yet may vary in chain length, spore size, or other 
details. 
Neegaard 5/ considers Alternaria mali Synonymous with Alternaria tenuis. 
In following the present concept of Alternaria tenuis the problem of identifying 
the cause of alternaria rot of apples would be simplified by accepting 
Neegaard's synonymy. 
Apple Scab (Venturia inequalis (Cke.) Wint. 
Apple scab is worldwide in occurrence. Although scab lesions are super- 
ficial they affect the grade and price of apples both at harvest and following 
storage. Affected fruit may or may not be distorted. Fruits with scab spots 
are unattractive in appearance and lose moisture faster than normal fruits, and 
scab spots open the way for decay by other fungi. 
Scab infection takes place in the orchard, but established spots may 
enlarge and new ones form during cold storage. Scab that develops during stor- 
age is called "storage scab''; it develops from late-season infections in the 
orchard, but is not visible at harvest. Storage scab usually develops slowly 
during cold storage, but can appear at any time during the storage period. The 
new lesions appear as brown to shiny black depending on the variety of apple 
and perhaps other factors. 
Phillips and others (131) found that scab development on apples was as 
rapid in controlled-atmosphere storage with 5 percent C0, and 3 percent 0, at 
B8e te asin normal) storage) at) 32. . 
An adequate spray program is effective in the control of all phases of 
scab (143). 
Botryosphaeria Rot (Botryosphaeria ribis Gross. & Dugg. 
Fenner (54) described botryosphaeria rot in 1925, but apparently it 
caused little loss until after 1950. 
In 1951 Clayton and Fink (43) reported botryosphaeria rot (also known as 
bot rot, white rot, and clear rot) to be the cause of minor losses in North 
Carolina, In 1952, Weaver (175) found that losses from botryosphaeria rot and 
black rot (Physalospora obtusa (Schw.) Cooke) caused much concern among apple 
growers in Maryland and neighboring States. Some fruits were completely rotted 
2/ Roberts, John W. Experiments With Apple Leaf-Spot Fungi. Jour. 
Agr. Res. 2:57-66. 1914. 
3/ Wiltshire, S. P. The Foundation Species of Alternaria and Macro- 
sporium Trans. Brit. Mycol. Soc. 18:135-160. 1933. 
4/ Mason, E. W. Annotated Account of Fungi Received at the Imperial 
Bureau of Mycology. List II, Fascicle 1:1-43. 1928. 
5/ Neegaard, Paul. Danish Species of Alternaria and Stemphylium. 
Oxford University Press. London. 560 pp. 1945. 
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