UNIVERSITY OF CALIFORNIA COLLEGE OF AGRICULTURE AGRICULTURAL EXPERIMENT STATION BERKELEY 4, CALIFORNIA WHEN TO PLANT SMALL GRAINS IN CALIFORNIA C. A. SUNESON 2 and F. G. PARSONS Timely seeding is among the most important good husbandry practices known to the efficient small-grain producers of California. An adjust- ment in planting date, furthermore, does not ap- preciably affect the labor or power required to produce a crop on a given acreage, though it can materially affect the yield. In the interest of maximum wartime efficiency in producing grain, accordingly, this leaflet will review the experi- mental data accumulated at Davis from comparisons of three seeding periods over a term of years. For this purpose the production of several barley, wheat, and oat varieties has been averaged, as shown in table 1. It should be emphasized that these results were obtained on well-drained lands, relatively free from wild oats, canary grass, or mustard. According to this table, November or December seeding is most productive, especially with wheat ; and in most seasons very severe yield re- ductions result from delaying seeding until Feb- ruary or March. Sometimes, however, early plant- ing is out of the question. Very often a delay until after the rainy sea- son starts is necessary in order to permit kill- ing a weed crop or improving the seedbed before seeding. The farmer must then wait until rain has germinated the weed seeds in the surface soil so they can be killed by cultivation. Under these circumstances, he should plant as early as practicable, in December or January. Occasion- ally the use of selective sprays on the growing crop for weed control 4 will prove more economical and wiser than repeated winter tillage for weed control before seeding. Obviously, farmers operating on soils that are poorly drained or sometimes flooded may have to plant late or else risk having to replant a badly thinned or weedy crop. With these soils, plant - 1 Based on cooperative experiments by the Division of Agronomy, University of California, and the Division of Cereal Crops and Diseases, Bureau of Plant Industry, Soils, and Agricul- tural Engineering, Agricultural Research Ad- ministration, United States Department of Agriculture . p. Agronomist, United States Department of Agriculture . Associate in the Experiment Station, Di- vision of Agronomy. described in: Ball, W. S. , A. S. Crafts, B. A. Mad son, and W. W. Robbins. Weed control. California Agr. Ext. Cir. 97: 1-111. 1940. ing often is postponed until after the heavy rains, Where such delay is necessary, one should observe the following precautions: (1) have a firm and weed-free seedbed; (2) drill the seed into mois- ture, using about one fourth more seed than for earlier sowing; (3) avoid late-maturing varieties; (4) avoid rust-susceptible varieties of wheat and oats. liariout barley, especially California Mari- out , is particularly suited to spring planting on such soils. TABLE 1 Effect of Date of Seeding on the Average Yields of Barley, Wheat, and Oat Varieties at Davis for the Years Shown Crop year Number of varieties grown Acre yield in bushels from various dates of seeding November or December January Barley (48 pounds per bushel) Wheat (60 pounds per bushel] March 1928 5 44.6 41.0 21.5 1929 5 36.5 33.6 23.5 1930 5 76.7 88.6 23.4 1939 3 72.2 .... 65.9 1941 10 68.3 54.8 • • • • 1942 9 85.3 28.9* 1928 5 29.4 27.1 6.6 1929 5 28.9 24.7 12.3 1930 5 38.4 35.7 5.8 1938 2 42.9 .... 4.0 1939 3 52.5 39.3 1941 15 34.1 24.3 .... 1942 12 54.2 17.7* Oats (32 pounds per bushel) 1928 2 42.5 53.0 21.0 1929 2 65.3 65.1 24.0 1930 2 96.7 105.0 16.0 1939 3 86,5 . • . . 45.0 1941 5 53.2 34.0 1942 3 102.6 .... 27.8* K Results from seeding February 16, 1942. [1] Early seeding is desirable in most of the grain- growing regions of California. Seeding in Novem- ber or December results in a crop that matures earlier and is therefore less liable to suffer from droughts, hot winds, or certain diseases and insects. In planting early, the farmer should observe a few precautions. If he seeds too soon in dry soil, he may encounter early rain, which will germinate the seeds but will not be followed quickly enough by later rains to permit saving of the crop from the intervening dry spell. October or early-November plantings of early-maturing varieties, such as Ramona wheat and Vaughn barley, should be avoided because of possible frost damage at heading time the next spring. In most sections of California, frosts never injure grain except at heading; but at that stage the pollen and other flower parts may be killed by even light frost. Bunyip wheat is not well adapted to early seed- ing because it is often attacked by septoria leaf spot, a disease most apt to be serious in prema- ture plantings. Atlas barley runs into the same difficulty, being susceptible to scald and sub- sequent loss of leaves. Growers in the northern or mountain counties, where temperatures are severe, must seed as early as possible and yet must avoid frost injury at the heading stage. They must work out their planting dates to suit local conditions, inasmuch as the climate varies greatly outside the larger grain-producing sections. [2] 5m- 12, '43(8775!