Weed Science and Crop Protection

Comprehensive vocabulary flashcards covering the classification, morphology, dispersal, competition, and chemical control methods of weeds based on lecture notes.

Weed Science

The study of weeds and their control, considered an offshoot of plant physiology evolved from the study of auxins and plant growth regulators.

$$2,4-D$$

A discovery in the 1940's that led to the evolution of Weed Science into a specific discipline.

Indigenous Weeds

Weeds that are native to the area where they are found, such as Cogon grass ($Imperata\,cylindrica$).

Exotic Weeds

Weeds that are not native to the area where they are found, such as Siam weed ($Chromolaena\,odorata$).

Sapsapon ($Crassocephalum\,crepidioides$)

A native weed traditionally eaten and used medicinally, considered a "weedy vegetable" in areas like Abra and Ilocos.

Agrostology

The scientific study of grasses.

Grasses (Poaceae/Graminae)

Plants with round/cylindrical stems (culms), narrow leaves with parallel veins, and distinct nodes and internodes.

Ligule

The membranous appendage arising from the inner surface of the leaf, found in most grasses except the genus $Echinochloa$..

Sedges (Cyperaceae)

Plants characterized by triangular stems, narrow leaves with parallel veins, no distinct nodes or internodes, and no ligule.

Broadleaf Weeds (Dicotylodenae)

Weeds characterized by expanded leaves, woody or succulent stems, and usually a tap root system.

Annual

A weed that completes its entire life cycle in one growing season.

Biennial

A weed that has a two-year life cycle.

Perennial

A weed that lives for more than two years and can persist and grow across many seasons.

Monocot

Weeds whose seeds have a single cotyledon, featuring parallel leaf venation and a fibrous root system.

Dicot

Weeds with two cotyledons in their seeds, featuring netted leaf venation and a tap root system.

Acidophile

Weeds that thrive in acid soils, such as Bent grass ($Agrotis\,spp.$).

Basophile

Weeds that grow in saline and alkaline soils, such as Dandelion ($Taraxacum\,stricta$).

Neutrophile

Weeds that thrive in neutral soils, such as Common purslane ($Portulaca\,oleracea$).

Hydrochore

A technical term for the dispersal of weeds by water.

Anemochore

A technical term for the dispersal of weeds by wind.

Biochore

A technical term for the dispersal of weeds by other living organisms.

Thalassochore

A technical term for the dispersal of weeds by the sea.

Intraspecific Competition

The struggle for limited resources between individual plants of the same species (e.g., Corn vs. Corn).

Interspecific Competition

The struggle for limited resources between individual plants of different species (e.g., Banyard grass vs. Rice).

Koline

An allelopathic substance produced by higher plants that is effective against another plant.

Phytoncide

An allelopathic substance produced by a higher plant that is effective against a microorganism.

Prevention

A management concept focused on hindering the introduction and spread of weed seeds or propagules into an area not yet invaded.

Eradication

The total removal of all plants and plant parts of a single species from an area.

DEVINE

A liquid formulation of chlamydosphores of $Phytophtora\,palmivora$ used to control milkweed/strangle vine in citrus.

COLLEGO

A wettable powder formulation of dried spores of $Colletotrichum\,gloeosporioides$ used for weed control via post-emergence spraying.

Selective Herbicides

Chemicals designed to kill specific plants while leaving others unharmed (e.g., Butachlor, Propanil, $2,4-D$).

Translocated/Systemic Herbicides

Herbicides that move inside the plant until they reach a specific site of action (e.g., glyphosate, pendimethalin).

Category I Pesticide Toxicity

Highly toxic and extremely hazardous substances marked with a Red color band and an Oral $LD_{50} < 50\,mg/kg\,BW$.