Page:The Olive Its Culture in Theory and Practice.djvu/56

46

The situation suitable for the olive in one locality, will not always answer in another. A southerly exposure, where there is a good, free circulation of air, is generally the most desirable, especially as one goes northward. In any latitude, a southern exposure, is best calculated to receive the sunshine from early sunrise to sunset. It receives all there is to give. A northerly exposure receives the sun's rays obliquely, and then only after it has risen high in the heavens; and so, as the sum total of heat is less, the fruit ripens late, and in some cases not at all. An easterly exposure has the full force of the sun all the morning, but after noon, there is either no sunshine, or feeble, slanting rays, so that at the very time when the sunlight is strongest, an easterly position is deprived of its warmth altogether. Of course a westerly exposure is just the reverse of this, and after a morning passed in the shade, the tree is suddenly overwhelmed with sunlight at a time of day when the temperature is the highest. In summer, the variations of temperature in half an hour's time, may be from sixty to ninety-eight degrees. This sudden change is as harmful to plants as to animals. The more perpendicular the sun's rays are, naturally, the more heat they give; so also the farther north one goes, the more oblique they become and lessen in warmth. Therefore the higher the latitude, the greater the necessity of a hillside to receive the sun perpendicularly. A well-protected situation, with a southern exposure, may be considered equal to a point one degree farther south. The influence of a protection, be it a mountain range, a fence, or a hedge, is felt for a distance equal to eleven times its height, but at the point where the protecting influence is lost, the wind has greater power than if the shelter did not exist. Strong and impetuous winds injure the olive, especially sea winds, on account of their vapor and saline properties.