44 STATE BOA ED OF HORTICULTURE. 



I am thoroughly convinced that the tree is above the average 

 in vitality, and that there is no justification for the belief that 

 it is to become nonproductive as it grows old. 



It is a fact which cannot be denied that many of the oldest 

 orchards are yielding light crops, and that their foliage lacks 

 that dark rich .green characteristic of the thoroughly healthy 

 orange tree. But I am satisfied that the fault is not with the 

 tree, but with the owner. It is true that the young bearing 

 orchards average better crops than do the old ones. But it is 

 also true that the very best trees, the richest foliaged and 

 heaviest bearing, are the oldest in the valley. These facts 

 seem to point clearly to causes outside the tree itself for the 

 unsatisfactory condition of many orchards; and, having satis- 

 fied myself that many of the oldest orchards are the best, I 

 have thought it well to endeavor to discover why it is that 

 orchards adjacent to those which are most healthy and prolific 

 are sometimes either a burden to their owners, or, at best, 

 return but very moderate dividends. 



It cannot be doubted that to three or four causes is due the 

 failure of many groves. I do not mean absolute failure in all 

 cases, but failure as compared to the best. I do not think the 

 average orchardist will admit his fault in the matter. I find 

 a majority deny conditions in their groves which are apparent 

 enough to an unprejudiced investigator. I am convinced that: 



First — We do not feed the trees sufficiently. The Navel 

 bears every year, and sooner exhausts the soil of the essential 

 elements than such trees as rest from time to time. 



Second — We do not stir the soil to a sufficient depth, nor do 

 we take all the pains we should to pulverize it finely. In rich, 

 red, clayey soil, most prized because it produces the highest 

 colored and best keeping fruit, there is invariably a tendency 

 to form a crust of somewhat impervious soil below the depth 

 regularly reached by the plow and cultivator. This is hardly 

 "hardpan," such as is found in some sections. It will allow 

 the roots to penetrate, and softens into cultivable shape if 

 irrigation is long continued. But it is sufficiently hard to pre- 

 vent the penetration of ordinary irrigation, and to prevent the 

 soil from receiving the full benefit of the soluble fertilizers 

 applied. It prevents the aeration of the soil, without which 

 the essential process of nitrification is impossible. In nine out 

 of ten of the orchards examined I find evidence that its 



