BITTER PIT AND ITS CONTRIBUTING FACTORS. 



71 



Agriculture. A State Committee was appointed to collect pitted apples from unsprayed orchards, 

 and, on analysis, not the slightest trace could be found of either lead or arsenic or any other mineral 

 poison. 



As a result of the investigations and observations carried out in the laboratory and in the 

 orchard, I will now discuss the factors which explain some of the different phases of Bitter Pit. 



WHERE BITTER PIT ORIGINATES. 



In the apple represented in Figs. 90 and 91, showing the network of vessels, there are a 

 number of dark patches scattered here and there over it. These are the tough brown cells of the 

 Bitter Pit which occupy the position where meshes of the net ought to be. They still adhere, 

 whilst the ordinary pulp-cells were easily removed. 



Again, the Lord Wolseley apple reproduced direct from the object itself (Frontispiece) was 

 simply selected as a typical example of the pit, and, when the self-same specimen was cut lengthwise, 

 it was found that the brown spots occurred directly beneath the skin. Then, again, a simple 

 experiment may be performed of taking an apple— the Yates by preference, as there is no Bitter Pit 

 naturally there— and with a slender glass rod rounded at the end making an indentation without 

 breaking the skin. If the pulp is examined beneath the skin it will be found that in about ten 

 minutes it begins to discolour, and in about twenty minutes it will have turned quite brown. In 

 every case the discoloration occurs in the region of the network of vessels. ■ 



It is worthy of note that the brown spots are first formed in the zone occupied by the vascular 

 net. Not only is there ocular demonstration of the fact in the position of the tough brown spots 

 still adhering to the apple in which the network is shown (Fig. 90), but it is remarkable corroborative 

 evidence, more particularly as the existence of the network was unknown when the statements were 

 made, that several careful observers have independently located the earliest appearance of the 

 brown spots in the same position. 



Lounsbury (51), in his article on "Bitter Pit" in the Agricultural Journal of the Cape of 

 Good Hope, states — " The seat of the trouble is beneath the skin, and on cutting down through a 

 spot the flesh is found to be brown, dry, and tough for a distance about as great as the diameter of 

 the spot. Similar masses of discoloured tissue are sometimes scattered through the flesh nearly 

 to the core of the fruit, but the trouble is usually confined within a quarter inch of the surface." 



Again, Wortmann (97) remarks—" On cutting across spotted apples, the spots are rarely 

 found more than two-fifths of an inch from the surface, and quite isolated. What generally occurs 

 is this, that the spots in the interior of the fruit always originate more or less near the surface, and 

 then are continued to the skin, gradually blending with one another and forming larger spots, 

 according to the duration of the formation." 



Sorauer, also, in his " Atlas der Pflanzenkrankheiten," shows the brown spots directly 

 beneath the skin. 



While the Bitter Pit is thus found in its early stages immediately beneath the skin in the zone 

 of the vascular network, it is also well-known that it may occur scattered through the flesh, and 

 extending even to the core. This will depend upon the stage of growth of the apple when the 

 disease begins, as in the specimens of Pomme de Neige from Orange (Fig. 47), the brown spots 

 started at an age when the core formed the principal part of the fiuit. It will also depend on the 

 continuance of the conditions favorable to it, when it extends along the vascular bundles towaids 

 the core. 



WHEN IT ORIGINATES. 



The earliest appearance of Bitter Pit in the apple was specially followed in the Burnley 

 Horticultural Gardens, where there are 672 different varieties of apple trees under observation. 

 Only vague answers were given by the orchardist as to the stage of growth of the fruit when the 



