PT ET | IY I ET TT NL HT 
WINTER GREEN-MANURE CROPS. 17 
In February, 1908, at Redlands, Cal., which is representative of the 
citrus sections, plantings of vetch made in September, 1907, were from 
12 to 15 inches high and in afine condition to turn under. Plantings 
made in October, 1907, from a month to six weeks later, were but 
6 inches high. During the past season similar results were noted. 
The rate of seeding varies from 40 to 60 pounds per acre. Forty 
pounds per acre has been more generally recommended, but the 
heavier seeding is giving much better crops and more than makes up 
for the difference in the cost of the seed. 
Early as well as heavy seeding is quite commonly recognized by 
growers as necessary for obtaining the best results, and a deeper 
seeding has also been found essential where the plantings are early. 
In northern California under irrigation, vetches should be sown about 
the first of October. They will then make sufficient growth to be 
turned under in February or March. This later season of planting 
in the northern part of the State is desirable in both citrus and 
deciduous orchards on account of the heavy winter rainfall, which 
does not permit turning under the crop as early as in the southern 
section. Later planting in the deciduous-orchard sections is also 
desirable on account of the possible injury from frosts when an early 
succulent growth is made, as would be the case with earlier plantings. 
Experiments and observations have shown that vetch will make 
but little growth by February or March when sown in the fall without 
irrigation. 
CANADA FIELD PEAS. 
The field pea was among the first crops tried in California for green 
manuring and was the first one extensively used for this purpose. 
Its early use was partly due to the fact that seed was readily obtain- 
able. At the present time it still holds a prominent place as a green- 
manure crop, and next to common vetch is most extensively used 
(see fig. 4). 
Like the common vetch the field pea is adapted to varied conditions 
and has succeeded wherever green-manure crops have been grown. 
For making a growth during cool weather there is no other crop 
known that equals it; but it has other characteristics that make 
it less desirable for green manuring, especially in citrus orchards. 
The root system of the field pea, which is very extensive, consists 
of a central or main taproot from which radiate the many finer 
laterals. The roots extend quite deep, and for this reason the crop is 
favored by many orchardists for breaking up ‘‘ plow sole.” 
The vines, which are succulent and tender, are greatly damaged by 
the trampling necessitated during the harvesting of most citrus fruits; 
and on account of their making so much new growth during cold 
weather they are often severely injured by frost. Usually as the 
§2810°—Bull. 190—10——3 
