pesticide application in a rice farm in sablayan
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Pesticide Application in a Rice Farm in
Sablayan, Occ. Mindoro
CHEM 185 CASE STUDYMangao, ArnoldusRamos, Ana Rose
FARM PROFILELOCATION: San Vicente, Sablayan, Occ. MindoroCROP PLANTED: Rice
CHARACTERISTICS:• Three cropping per year• Conventional Farming• Irrigated
FARM PROFILE
Problems and its extentPresence of plant-eating mollusk
Presence of grasses that compete with the crop
No significant effect to yield since these problems are addressed
Pesticide Being Used• MOLLUSCICIDE
Visocol WP 50
• HERBICIDENomineeTopshoot
Molluscide: Visocol wp 50• CHEMISTRY• Main ingredient: Niclosamide• MOA: inhibits glucose uptake and oxidative phosphorylation
O
NH
OH
N+
O
O-Cl
Cl
5-Chloro-N-(2-chloro-4-nitrophenyl)-2-hydroxybenzamide
Molluscide: Visocol wp 50Environmental Fate
• Degrades rapidly in natural water and sediment systems• Depends on microbial activity• Soil mobility: slow to medium (0-25 cm, depends on soil type and
pH)• Degrades rapidly with UV (photolysis)• Does not affect
Cost, effectivity and application• COST• Php 800 per hectare
• APPLICATION• Before direct seeding or transplanting• Applied early in the morning or late in the afternoon
• EFFECTIVITY• Kills almost all of the snails
Herbicide 1: NomineeNa+
O O-
ON
N
O
O O
N
N O
O
sodium 2,6-bis((4,6-dimethoxypyrimidin-2-yl)oxy)benzoateChemical Formula: C19H17N4NaO8
Molecular Weight: 452.35
• CHEMISTRY• Main ingredient: Bispyribac-Sodium• MOA: inhibits acetolactate synthase
(ALS)
• a selective post-emergence herbicide to be applied in rice in order to control annual grasses and broad-leaved weeds (including Echinochloa spp., Cyperaceae etc.)
Herbicide 1: NomineeEnvironmental Fate• Bispyribac sodium underwent a moderate degradation
when exposed to sunlight• has a log Kow of -1.03 and thus it is unlikely to
bioaccumulate in the aquatic organisms• dissipated readily under aerobic soil conditions with a
half-life of 18.6-19.1 days in one soil.• is classified as being of low to high mobility depending
on soil type
Cost, effectivity and application• COST
• Php 1500/ha
• APPLICATION• a selective post-emergence herbicide; best results, apply NOMINEE only when both, crop and
weeds are actively growing; drain field to expose weeds.
• EFFECTIVITY• displays excellent activity against emerged weeds, but has almost no pre-emergent activity
and will therefore not control weeds that germinate after application.
• SELECTIVITY• Nominee does not have phytotoxic effects on rice provided dose rate and application
conditions are respected.
Herbicide 2: TopShot• CHEMISTRY• Main ingredient: Metsulfuron Methyl• MOA: inhibits cell division in the shoots and roots of the plant
• A sulfonylurea compound used as a selective pre- and postemergence herbicide for broadleaf weeds and some annual grasses
O
O
S
O
ONH
O
NH
N
N
N
O
methyl 2-(N-((4-methoxy-6-methyl-1,3,5-triazin-2-yl)carbamoyl)sulfamoyl)benzoateChemical Formula: C14H15N5O6S
Molecular Weight: 381.36
Herbicide: TopShot• Environmental Fate
• The breakdown in soils is largely dependant on soil temperature, moisture content, and pH.
• degrade faster under acidic conditions, and in soils with higher moisture content and higher temperature
• It is rapidly taken up by plants at the roots and on foliage. The chemical is translocated throughout the plant, but is not persistent.
Cost, effectivity and application• COST
• APPLICATION• Apply at the time where weeds are actively growing
• EFFECTIVITY• works through the leaves and roots of the weeds, works rapidly after it is
taken up by the plant
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