136 Pecan-Growing 



period of twenty years after it is planted. Growers, however, 

 are more likely to measure up to these yields for the first 

 thirteen years because most trees are planted too close to- 

 gether and will begin to crowd long before they are twenty 

 years old. In addition, the average grower who gives his 

 trees good care during the first five or six years of their bear- 

 ing life does not fully realize their growing demands for 

 plant-food, moisture, and space for development and for the 

 production of increased yields. Many growers apply very 

 little more fertilizers to a twenty-year tree than to one only 

 twelve or fourteen years old. 



Another important factor is that young trees are more 

 easily protected against insects and fungous diseases as they 

 can be sprayed more readily than the older and larger speci- 

 mens. Also, some varieties grow and produce well for several 

 years and then develop a degree of susceptibility to certain 

 diseases that greatly reduces their productiveness. 



In large commercial plantings of pecans there are almost 

 invariably a sufficiently large number of low-yielding trees 

 each year to keep the average production very much lower 

 than those previously stated. Kecords from a number of 

 large commercial orchards, where the trees range from twelve 

 to fifteen years of age, show that the average yield to a tree 

 each season rarely exceeds six pounds through the fifteenth 

 year after planting. The highest yielding trees of these or- 

 chards, however, are in strong contrast with the average 

 yielders. 



The question of varieties, as previously mentioned, has a 

 very important bearing on the yield of pecan nuts. The 

 Stuart and the Schley are planted possibly more extensively 

 than any other two varieties of pecans. In some regions in 



