xiii, A. 4 Reinking: Philippine Economic-Plant Diseases 193 



become brown. Often some of the largest leaves of the bud 

 fall over (Plate V, figs. 1, 2, and 3). This diseased central 

 portion is surrounded by older leaves, on the outside, which are 

 perfectly healthy and remain upon the tree until they drop off 

 naturally. Trees are more commonly affected when they first 

 come into bearing. The young nuts, on bearing trees attacked 

 by the disease, remain small and fall off prematurely. Trees 

 are affected most generally in regions of great moisture and 

 in overcrowded areas. 



Internal symptoms of diseased trees are very characteristic. 

 A longitudinal section of the bud shows, in new cases, that the 

 disease may start in the young leaves, at a point where they 

 begin to unfold (Plate VI, fig. 1). At this point a spotting of 

 the leaf is first noticed, then the organism works downward, 

 causing a soft rot and browning of the group of unfolded leaves. 

 The upper exposed portions of these leaves die and turn brown, 

 due to the rotting beneath. The rot advances downward through 

 the young leaves to the growing point and then spreads into 

 the soft tissue below. From here it invades the woody tissue, 

 usually not penetrating farther than from 5 to 10 centimeters. 

 In the early stages of the disease no discoloration is produced 

 in the growing point and cabbage, but a dark red to brownish 

 ring always limits the advance of the disease in the wood on 

 bottom and sides (Plate VI, fig. 4) . The disease does not 

 penetrate readily into the old leaf sheaths surrounding the young, 

 tender, developing leaves (Plate VII, figs. 1, 2, and 3). 



The rot is checked, as a rule, when it reaches the firmer tissues 

 of the trunk, penetrating, in advanced cases, about 20 centi- 

 meters (Plate VI, figs. 2 and 3). The softness of the affected 

 portion in the trunk is shown by the fact that the finger can 

 be pushed into the diseased part. A vile, somewhat sour odor 

 accompanies the disease. The most advanced stages of the dis- 

 ease are characterized by the white cabbage changing into a, 

 semiliquid mass with an ill-smelling odor. The diseased portion 

 of the trunk becomes a mass of fibers and a semiliquid. 



The disease spreads very rapidly from tree to tree, but the 

 manner of spread is not fully understood. Insects are undoubt- 

 edly one of the factors to be considered in its transport from 

 infected to healthy trees. In one barrio under observation, 

 fifty-eight new infections appeared within one year after an 

 inspection in which all trees found with the disease were cut 

 down and burned. Infection must have started from one or a 

 few trees unobserved during this first inspection. These trees 

 are located in the upper extremity of the coconut region on the 



