ee 
LONCHOCARPUS, DERRIS, AND PYRETHRUM CULTIVATION 17 
Sievers.* In the Far East the plant is grown as a supplementary cash. 
crop by native subsistence farmers and has been tried as an estate 
enterprise by a few of the larger agricultural companies. It has also 
been interplanted as a catch crop on new rubber and kapok plantations. 
Mature stem cuttings, usually between 8 and 14 inches in length, are 
used as propagating material, and a common practice is to place them 
in nursery beds of sandy soil for 3 to 6 weeks to develop roots before 
setting them out in the field. 
Among some growers it is customary to set cuttings directly in the 
field without previously rooting them in nursery beds, although weed- 
ing expenses are said to be higher under this system, since a longer time 
elapses until vine growth covers the fields and aids in suppressing weed 
competition. When either rooted or nonrooted cuttings are planted 
in the fields, they are usually spaced approximately 2 by 2 2 feet to 3 by 
3 feet. This task is perfor med during a rainy season, and one or two 
cuttings may be set in each location. Land preparation in Perak, 
Federated Malay States, is accomplished by chopping and burning 
off high bush where it exists and by burying any weeds and lalang 
grass that may be present by loosening the soil to a depth of 18 inches 
and turning them under (22). 
cr ellising on poles is sometimes practiced in the Netherlands East 
Indies, where it is said yields are thereby increased about 30 percent. 
One method of pole trellising consists of making tripods by crossing 
two stakes of one row of plants with one stake of an opposite row. 
Three plants then grow on the tripod for support. Trellising involves 
the expense of cutting poles and training plants to grow on them, but 
it prevents stems from rooting at nodes, which they would do if they 
were left in contact with the ground. The tendency of trailing derris 
to root from stem nodes results in the production of many fine rootlets, 
which are difficult to recover at harvesttime, whereas roots concen- 
trated at the base of trellised plants are more easily dug (fig. 11). 
Where trellised plants are involved, vine clearing preparatory to 
harvest consists of severing main stems and stacking them aside, but 
in cases where fields have been left to grow in a prostrate manner the 
job of cutting the matted vines and rolling them away in preparation 
for harvest is a laborious and expensive task (25). It is often 
remarked that trellised derris requires more weeding and that trailing 
derris suppresses competitive growth after the first year. 
In many places where derris is grown, the top growth of trailing 
plants never quite succeeds in suppressing the competition of vigorous 
grasses. The resulting weeding costs may easily be greater than if 
the plants were trellised, since the decumbent vines must be lifted 
aside so that grass underneath them and growing up through them 
can be cut back. Adequate experimental trials for the purpose of 
comparing the relative costs of root production by trailing and by 
trellised plants remain to be made. 
Apparently one of the most critical factors involved in successful 
derris culture is the selection of the proper soil, which should be some- 
what sandy, or at least completely friable, so that root digging will be 
*Srevers, A. F. THE PRODUCTION AND MARKETING OF DERRIS ROOT. U. S. 
Bur. Plant Indus., 24 pp. [Mimeographed copy in U. S. Dept. of Agr. Library, 
Washington, D. ey] 
