Biology Key Words
Grasses
1 narrow upright leaf at germination, parallel veins, fibrous root system, growing points near the surface
Grass Terms
 Grass parallel veins |  Fibrous grass root system | undefined grass seedling 1 leaf at germination |  Grass growing point |
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Broadleaf
2 leaves at germination, leaves with netted veination, coarse root system, growing points at surface and other parts of plant
Broadleaf terms
 Broadleaf netted leaf veins |  Coarse broadleaf root system |  Broadleaf - 2 leaves at germination |  Broadleaf growing points, |
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Woody Trees and shrubs – deciduous or conifers
Stages of Development
Seedling – Small succulent; – Most easily controlled
Vegetative – Rapid growth
Reproductive – Flowers and seeds
Maturity – Post reproductive
Life Cycles
Annual – all stages occur in less than 1 year
Winter annual – germinates in the fall and matures and dies in the spring. Fall is the best time to control winter annuals.
Summer annual – germinates in the spring and dies in the fall. Spring is the best time to control summer annuals.
Biennial – lives for 2 years
1st year – Vegetative stage – rosette is the best time for control
2nd year – Matures and seeds
Perennial – multiple years
Best time to control a weed is as a seedling.
Root systems
For Persistent roots, for effective control you must kill the roots.
Simple – spreads by broken bits
Creeping – stolons, roots at joints, horizontal stem at surface
rhizomes – underground horizontal stems
Bulbous – tubers, bulbs, nutlets
Biology
Xylem – moves herbicide, water, and nutrients up
Phloem – moves herbicide and plant food from foliage to roots
Grasses have vascular bundles which contain xylem and phloem
Trees and shrubs
Bark – phloem
Woody – xylem
Cambium – area between xylem and phloem, responsible for increases in tree diameter
Herbicide works best when plant is actively growing
Environmental Factors – Water, Soil, Temperature
1. WATER – Transport medium to move nutrients and herbicides from root to leaf
Sugars and foliar applied herbicides move from leaf to roots.
Water is key in photosynthesis
Rain carries herbicide to root zone
2. SOIL
Soil texture depends on percentages of sand, silt, clay
Coarse or light soil is high in sand
Fine or heavy soils are high in clay
Dark soils are high in organic matter (OM), decaying plants and animals.
CLAY
As clay increases – Adsorption increases – Leaching decreases
Herbicide use or application rate increases
ORGANIC MATTER (OM) is like CLAY
As OM increases – Adsorption increases – Leaching decreases
Herbicide use or application rate increases
SAND
As sand increases – Adsorption decreases – Leaching increases
Herbicide use or application rate increases
3. Temperature
As temperature increases
Plant activity increases
Speed of herbicide effect increases
As soil temperature increases – persistence of herbicide decreases