alsike clover and red clover are grown — in South Carolina only 375 acres. The largest areas of white clover in the southern states are found in Mississippi, Louisiana, and northeastern Texas. In northwestern Arkansas and the bottom-lands of the rivers in the eastern part of the state white clover is valuable in favorable seasons. In the great Limestone Valley of Virginia west of the Blue Ridge Mountains, and in the smaller limestone valleys of southwestern Virginia, when the summer temperature is not high, it is abundant and a fair honey plant.
Over much of the region west of the Mississippi River white clover will not grow, as the climate is too dry, and over a large area too hot. In the semi-arid regions of Wyoming, Colorado, New Mexico, Utah, Nevada, Arizona, and Texas there are less than 4000 acres of clover alone under cultivation. In the eastern portions of the Dakotas, Nebraska, and Kansas white clover is frequently reported as a source of nectar. Both white and alsike clovers grow sparingly in the river valleys of Montana. White clover is abundant in northern Idaho, and at Moscow furnishes the larger part of the surplus. West of the Cascade Range in both Washington and Oregon it is increasing in abundance; but after July it often dries up. It is reported to yield nectar less freely than in the Mississippi Valley. White clover is rapidly extending over northern California; and, as it is a dependable source of nectar, this section will probably soon offer excellent localities for the production of honey.
THE SECRETION OF NECTAR
In order to obtain a large surplus from white clover, it is not sufficient that the plants produce a profusion of bloom. “As an actual fact,” writes an experienced beekeeper, “the amount of clover honey is not measured by the quantity of bloom; for I have seen the fields white with an abundance of it, with only a fair crop. I remember one year when there was a great scarcity of bloom, and yet there was a good crop of clover honey. I have also seen fields white with clover, but no honey.” In England white clover is usually a good honey plant, but “in France and Switzerland,” according to C. P. Dadant, “one may travel for several kilometers and not see a bee on the flowers. At Rouen, France, during one day of white-clover bloom a hive on scales actually lost 300 grains in weight.”
Nectar secretion in white clover is largely influenced by temperature, soil, rainfall, and winter protection. The relation of temperature to the distribution of white clover in the United States has already been briefly discussed. At Clarinda, Page County, Iowa, J. L. Strong carefully recorded from day to day for 29 years, from 1885 to 1914, the weight of one hive on scales and the weather conditions. White clover is the most important honey plant in this locality. According to an analysis of these statistics by L. A. Kenoyer, the largest amount of honey, or 46 per cent., was secured on days when the temperature was between 80 and 90 degrees F., while 17 per cent, was stored on days when the temperature was less than 80 degrees, and 37 per cent, when the temperature was over 90 degrees F According to the above figures a high temperature is less unfavorable to nectar secretion in white clover than is commonly supposed; and it is not difficult to understand how large crops in certain seasons may be obtained in localities much farther south. Days with a wide range of temperature are best. A very cold spring may cause a failure of the crop, even if there is a normal rainfall. In 1907 in parts of New York the average temperature of May and June was four degrees below the respective means for these months in other years, and there was no white-clover honey.
A second important factor influencing nectar secretion is the character of the soil. As has already been pointed out, white clover as a honey plant is restricted to limestone soils. On the calcareous glacial soils of the north-central states it is more abundant and yields a larger surplus of honey than in any other section. On an acid soil it can not be grown successfully. Vigorous plants secrete more nectar than those which have been stunted by a sterile soil.
A cold rain no doubt checks the secretion of nectar; but clearly the quantity of nectar brought in by the bees can not be regarded as an index of the amount