Weed control program should be environmentally benign and
cost-effective so that reduced herbicide use can help meet these goals.
Field trials were conducted to assess the bio-economic and qualitative
impact of reduced doses (25 and 50% of label dose) of a postemergence
pyrimidinyloxybenzoic acid herbicide (bispyribac-sodium) applied alone
or in combination with multipurpose tree (eucalyptus [ Eucalyptus
camaldulensis Dehnh.], mango [ Mangifera indica L.], and mulberry [
Morus alba L.]) water extracts in direct seeded rice ( Oryza sativa
L.) fields. The label dose of bispyribac-sodium and penoxsulam along
with weed control were included for comparison. Tank mixing of
multipurpose tree water extracts with reduced herbicide doses accounted
for > 55% suppression in weed density and > 75% in dry weight;
they were quite higher than those recorded for the same herbicide doses
used alone. A combination of these extracts with 50% reduced dose of
bispyribac-sodium improved rice yield and quality attributes similar to
the label dose of this herbicide. Despite the higher net benefits
associated with label herbicide dose, the maximum marginal rate of
return was achieved with a tank mix of 25% label herbicide dose with
multipurpose tree water extracts