12 



REPORT OF THE FIRST SEMI-ANNUAL MEETING 



on account of one or two instances of frost damage unless these 

 facts have been taken into consideration. The original tree of the 

 Meserve avocado was frozen back more or less severely in the 

 winter of 1912-'13, but practically everyone is agreed that the dam- 

 age was due to the sappy condition of wood induced by copious 

 watering of the asparagus bed near which the tree is growing. 



Another point which may be emphasized is the maintenance of 

 healthy growth in the tree by proper cultivation and judicious fer- 

 tilization. There is little, if any, evidence to show that an avocado 

 and a citrus tree require any different fertilizing elements. Since 

 the foraging power of the roots is dependent upon the physical 

 condition of the soil, the importance of keeping it well supplied 

 with humus and of maintaining a good soil texture cannot be over- 

 emphasized. For young trees as well as for old trees the basin- 

 mulch system seems practicable. By keeping the basin well supplied 

 with strawy manure and other decaying vegetable matter, both the 

 humus content and the proper texture of the soil can be econom- 

 ically maintained. Experiments in other countries have shown 

 that the avocado tree responds to judicious fertilizing, although 

 excessive amounts of nitrogen appear to increase the fiber content 

 of the fruit. Liquid coav manure has been found good for seedlings. 

 AVester, in the Philippines, uses the following formula for many 

 kinds of tropical plants, applied at intervals of two or three weeks : 



Nitrate of Soda.... 275 grams 



Sulphate of potash, 49 per cent 125 grams 



Acid phosphate, 16 per cent 350 grams 



Water 100 liters (105 qts.) 



AVe frequently receive complaints and specimens of a leaf 

 trouble in Avhich the leaves begin to turn brown and die back at 

 the tip and along the edges, and occasionally the twigs are affected 

 in a similar manner. Specimens received for examination ordinarily 

 show no fungus present, but in a moist chamber there develops an 

 organism, determined by Mrs. Flora Patterson of Washington, 

 D. C, as Colletotrichum gleosporioides, the same fungus which 

 attacks mango, avocado, and citrus trees in Florida and the AVest 

 Indies. In California this fungus appears to be of little practical 

 importance, for although it has long l^een present in the citrus 

 districts, it very rarely attacks healthy trees as an active parasite, 

 although it may cause tear-staining and decay of the fruit. On 

 senile leaves or younger leaves weakened by sunburn, frost or oth- 



