Pastures for Florida


 WEED CONTROL

 Weeds are detrimental to pastures because they retard the
desirable pasture plants by shading and competing for moisture
and plant nutrients. Weeds are most common on newly pre-
pared or mismanaged pastures. The mowing machine is con-
sidered the most effective weed cutting device; however, rotary
choppers are frequently used because they are more satisfactory
for rough land and woody plants and are operated with less
breakage (Fig. 18).
 Annual weeds which are propagated by seed can be extermi-
nated generally by mowing during the bloom stage to prevent
seeding. Prostrate perennial weeds such as match weed (Phyla
nodiflora (L.) Green) which commonly infests pastures in
southern Florida are difficult to control. It is generally neces-
sary to disk pastures during a dry period to kill the match weed,
and then replant the pastures.
 Weed eradication experiments on a permanent pasture in-
fested with dogfennel and field thistles show that mowing con-
trols these 2 weeds. Close cutting during the early bloom stage
prevented reseeding and also killed these weeds (Tables 9 and



















 FIG. 19.-CHOPPERS AID IN WEED CONTROL.
 Foreground, thistles chopped 3 times with a rolling chopper; back-
ground, thistles not chopped. Rotary choppers with closely spaced blades
would reduce the number of choppings required for control. Mowing
machines generally give better weed control because close cutting prevents
seeding.