No. 6. DEPARTMENT OF AGRICULTURE. 593 



easily rubbed off, but the disfigurement detracts from the market 

 value of the apples. They may develop at any time from June to 

 the end of the season when moisture conditions favor. The best 

 control is from spraying begun as directed for Scab, and repeated 

 later in the season, during the first half of July. Thick tops and 

 moist situations, b}' hindering the rapid drying of the surface of 

 apples favor infection. Selection of a proper situation for the 

 trees, and proper pruning are important control measures. 



Apple Leaf Spots are of several difl:"erent kinds, caused by as 

 many distinct fungi. All of them interefere, in proportion to their 

 abundance, with leaf activities, which means with pioper nutrition, 

 and affected trees suffer more or less from retarded twig and limb 

 growth, poor development of fruit, and of fruit buds. The Scab 

 Leaf Spot has been referred to. Another that attacks very young 

 leaves early in the season, is the Orange Rust or Cedar Rust Leaf 

 Spot. The fungus also infects the fruit, usually at the apex, pro- 

 ducing rough areas with a yellowish cast. On the leaves the spots 

 are also orange yellow to brownish yellow, and later develop a rough 

 raised cushion on the under side. This fungus passes another stage 

 of its existence on the red cedar, producing the swellings we know 

 as ''cedar-apples." Apple leaves and fruit are always infected by 

 spores fronr such a source. T^nless there is wet weaflier coirtinuously 

 for about three days at the tinre when the apple leaves and fruit are 

 young and tender, there will be little or no infection even though 

 neighboring cedars are 'affected with the fungus. But the safe pre- 

 caution to take is to remove, in as far as may be possible, red cedar 

 trees from the vicinity of the orchard. Here, again, varieties differ 

 much in their susceptibility. Sjjraying may be effective if properly 

 timed ; but is difficult to predict, in this case, the times when condi- 

 tions Avill favor infection, and spraying has often failed. 



Probably the r.iost Avidespread type of Leaf Spot is the type 

 commonly known as Frog Eye Leaf Spor, caused by the fungus that 

 produces Black Rot of fruit, as well as a common type of limb 

 canker. Abundant leaf infection, usually accompanied by too early 

 defoliation, causes poor nutritiorr with weakened growth and poor 

 development of f-^uit buds. It should be guarded against in off 

 years as well as in bearing years. It may develop after the protec- 

 tion afforded by the early scab sprayings has Avorn off, and to insure 

 its control, a later apx)lication or two should be made early in July. 

 It is important to keep the Black Rot Cankers, that serve as a source 

 of contagion, cut out of the trees. 



The July spraying will control the Fruit Spot of apple, which is 

 caused by a fungus, and is characterized by rather definite, small, 

 brown, dead areas in the skin, with the fiesh discolored only a little 

 V ny underrreath. At first such spots are merely a nrore intense 

 grpcn or red than the normal skin. This particular trouble, which 

 attacks Baldwin, Belleflower and a large variety of apples as well 

 as the (,:iince, must not be confused with another trouble of Baldwin 

 and otluMs known distinctively as Fruit Pit, or perhaps more usually 

 as Baldwin Spot, although this last name is sometimes used loosely 

 for the Frr>it Spot. This Fruit Pit is not caused by a fungus, but 

 i«5 probably due to deficiency in proper water suppy, or to sudden 

 change from periods of rapid growth to periods of retarded growth 



38— G— 1911 



