Abstract:
Rice is a staple crop in Sri Lanka, where rodent
damage is an increasing threat. This study
examined the effect of weed density and standing
water level on rodent damage in rice fields. The
experiment was conducted in selected farmer
fields in Kurunegala district with four replicates
following a standard statistical procedure. For the
study of weed density, three experimental plots
were demarcated, each measuring 50×50 m.
Three treatments were weed-free, conventional
farmer weed management practice, and un
weeded. For the study of standing water level, four
separate experimental plots were demarcated
each measuring 50×50 m, and treatments were no
standing water, farmer practice (based on water
availability), 5 cm of standing water, and 10 cm of
standing water. Damaged and undamaged tillers
were recorded in two-week interval before
harvesting. Accordingly, un-weeded (minor
season – 20.56%, major season - 52.51%) and no
standing water (minor - 15.33%, major -16.00%)
treatments were given the highest rodent damage,
while weed-free (minor - 1.81%, major – 1.48%)
and 10 cm of standing water (minor - 0.67%,
major – 1.00%) treatments were given the lowest
damage. Meanwhile, weeds were collected from
each transect by using a quadrate (36×36 cm),
and their dry weight was measured. A positive
linear relationship was observed between rodent
damage and weed dry weight. Data were arcsine
transformed and analyzed using ANOVA (SAS
9.1.3), with means compared using the LSD test at
P < 0.05. These studies indicate that effective
weed management and adequate water
availability reduce rodent damage in rice fields.
