Determination of fruit bearing zones in California citrus trees

In almost every plot studied, most citrus fruit was produced on the south half of the tree. The exceptions were the navel and Valencia groves at Woodlake, where most fruit was produced on the east half of the tree. Of the fourteen plots counted, six showed that the southwest quadrant had significantly more fruit.

These results indicate that maximum production would be obtained from trees planted so that any crowding or shading does not affect the south canopy. In most areas, crowding of the southwest quarter of the trees should be avoided, if possible. To expose the section of the tree with the most fruit-bearing capabilities, trees should either be planted far enough apart so that there is no crowding and shading, or close-set rows should be planted in an east-west direction. Best plantings theoretically, would be in rows from northwest to southeast, with trees in each row offset from the adjoining row.