404 THE MONTHLY BULLETIN. 



municipal abattoir was used. "We did not learn of the use of any kind 

 of commercial fertilizer in the orange groves, except in the municipal 

 experimental farm where some tests of artificial fertilizer were being 

 tried. Under the system of little and shallow cultivation we found that 

 the fine root system was distributed in the soil from the surface to a 

 depth of about twenty inches. Most of the small roots were found near 

 the surface, this tendency being particularly marked in the heavier soils. 



CARE OF TREES. 



The pruning of the orange trees is mostly confined to the occasional 

 removal of dead branches. "We did not observe any particular method 

 in this matter. 



Tree renewal, by cutting off the main limbs of dead or dying trees, 

 near the tree trunk, or by cutting back the entire tree to a point just 

 above the original bud insertion, is universally practiced. New tops 

 are successfully grown by this method which in three or four years bear 

 profitable crops. "Where the entire tree is cut off, the stump is frequently 

 covered with trash, leaves or branches in order to protect the young 

 sprouts. No other care of cut-back trees was observed. We were told 

 that the fruits borne by the renewed trees is of superior quality to that 

 borne by trees not so treated. We could not confirm this opinion. The 

 orange orchards are not made up of uniform trees such as we frequently 

 find in California, but are somewhat irregular in appearance due to the 

 common tree renewal practice. 



Another method observed for replacing poor trees is to set a new tree 

 two or three feet from the older tree. As soon as the new tree begins 

 bearing fruit the other one is removed. Still another method of effecting 

 this result is to alloAv a root sprout to grow near the undesirable tree. 

 This sprout is budded at the proper age and as soon as this bud develops 

 to a productive size the other tree is cut out. 



TREE PESTS. 



The navel orange trees, as well as other citrus trees, we found to be 

 attacked by many kinds of scale, the white fly, several kinds of ants and 

 other insect enemies. All of the insects attacking the citrus trees in 

 California with which the members of the expedition were familiar, as 

 well as other unknown kinds, were found in the Bahia district. Samples 

 of all kinds were collected for identification by the United States Bureau 

 of Entomology. Ladybirds were also very commonly found, and in 

 some cases observed feeding on various scales. As fumigation, spraying 

 or other methods of artificial insect control are not practiced, except in 

 the treatment of any colonies, it is evident that the ladybirds and other 

 natural parasites perform an important function in the control of 

 certain of the insect enemies of the orange trees. The most serious 

 damage due to insects seemed to be the defoliation of the trees by the 

 Brazilian ants. We found that certain men have adopted the profession 

 of any colony extermination which is effected in several ways such as by 

 fumigation, destruction of the colonies by digging, and by burning. 



Of the many fungous diseases attacking the navel orange trees, the 

 most destructive kinds are the group of diseases included under the 

 heads of gummosis, scaly bark and dieback. When the orange trees 

 become unproductive from any of these causes, the tree renewal or 



