90 MISC. PUBLICATION 650, U. S. DEPT. OF AGRICULTURE 
eround level. In applying fertilizer, about 2 inches of soil was firmed 
over the cuttings; then the fertilizer was scattered and covered up 
with the remaining earth. When fertilizer was not applied, the 
cuttings, with the exception of the protruding vine stumps, were 
covered with soil in one operation. 
Figure 12.—Rooted cutting of Derris elliptica in nursery ready for transplanting 
to field. 
Weeding and Trellising 
Because local conditions may determine whether or not it is more 
or less profitable to trellis derris rather than to let it trail on the 
eround, Moore makes no specific reeommendation as to this practice. 
His experiments have shown that weeding expenses increase when 
plants are trellised and that the rotenone content of roots is reduced 
one-eighth as compared with that of prostrate plants. However, 
root yields of trellised plants increased 75 percent over those not 
trellised. If the ground is properly cleared in the first place, trailing 
plants may be kept clean by mechanical cultivation for the first few 
months until there is danger of damaging tender young stems; then 
hand weeding with hoes, or machetes, becomes necessary. 
Mulching 
Keeping trailing derris weed-free for the first year or so, until it is 
somewhat capable of suppressing competition by the density of its 
own foliage, is a major production expense. As the result of mulching 
studies at the Puerto Rico Experiment Station, White, Pagan, and 
