Page 58 - Ilmu Tanah

The Chemistry and Fertility of Soils under Tropical Weeds 45

For example, the resistence of Setaria viridis on herbicide trifluralin (Beckie et
al., 1990). The method is also used in allellopathy research. For example, the
use of bioassay to evaluate the allelochemicals of sweet potato (Ipomoea
batatas) at inhibiting the growth of Cyperus esculentus (Harrison dan Peterson,
1994) and Cyperus rotundus (Peterson dan Harrison, 1995).

200
Dry-Weight (g/pot/3 months) Bobot Kering (g/pot/3 bulan) 160

120
80

40
0
IC PC SP AG BA CO CL LC MM MP WS
JENIS GULMA
Weeds

Fig. 3.4. The increase in soil biomass as affected by weeds (IC Imperata
cylindrica, PC Paspalum conjugatum, SP Setaria plicata, AG Asystasia
gangetica, BA Borreria alata, CO Chromolaena odorata, CL Crotalaria
lappacea, LC Lantana camara, MM Mikania micrantha, MP Mimosa pudica,
and WS Widelia sp. (Sembodo et al., 2012).

3.4 Methods of Weed Control

Weed management comprises every aspects used to make sure that the
negative effects of weeds are minimum. The negative effects may relate to crop
production, crop quality, and other aspects of human activities. Weed control may
refer to the method to eliminate or decrease the population of weeds in a
particular land. This means that weed control, which is intended to decrease the
weed population, is only one important component of weed management. As
pointed out by Bridges (1999), weed management must include the following

Abdul Kadir Salam and Nanik Sriyani – 2019