WEED CONTROL

What is a Weed??

What is a Weed? A weed is a plant growing where it is not wanted. Ex. Red rice, Giant Ragweed

How do weeds affect us?? 2-Brainstorm….What are some affects of weeds on our everyday life?

6 Ways Weeds affect Humans Housing pest Impurities in crops Poisonous Allergies Costly Aesthetic Impure seed products

6 ways weeds affect humans Housing insects and disease. Impurities in agriculture products. – Ex.-red rice causes lower yields. Poisonous to livestock. Allergic reactions-common ragweed

Why do weeds cost $$? Competition for water and nutrients. Competition reduces crop yields. Expense of herbicides. Contamination of seeds Aesthetics

How do weeds compete with crops? Uses nutrients intended for crops. Competes for growing space. Interferes with harvest. Crowds out crops and allows for crop loss.

Review Define weed The effects of competition on the crop or yields The effects of weeds on humans and livestock The aesthetic effects of weeds in home yards and public areas The economic effects on crop yields.

Identifying Weeds Weeds can be classified based upon their: – Lifecycle – Persistence – Leaf Structure

Weed Lifecycles Annuals- – Grow from seed and complete their life cycle in one growing season Biennials- – Complete their life cycle in two growing seasons Perennials – Require two or more years to complete their lifecycle

Persistence Common Weeds: – These are more persistent and may or may not be vigorous. – Cause serious problems to farmers because they reoccur so often – Mostly annuals Noxious Weeds: – Most undesirable – Persistent growth makes them hard to control Leaf Structure: – Grasses – Broadleaf

Identifying Common Weeds Weed ID Project – You must collect 15 different common weeds – Label each weed, identifying their: lifecycle Persistence leaf structure.

Review Major Weed Categories: – Lifecycle Annual Biennial Perennial – Persistence Common Noxious Leaf structure – Weed ID Project

Student Learning Objective Describe the methods of weed control. Determine the use of chemicals to control weeds. Explain alternative methods of weed control. Describe methods of weed management.

Methods for weed control 1. Mechanical: hand pulling, hoeing, tractor cultivation, etc. 2. Biological: using parasites, predators, genetic engineering, etc 3. Cultural: cropping practices, host resistance, sanitation, varying planting dates 4. Chemical controls: use of herbicides. Herbicides are classified as either: -Selective - kill only certain types of plants - Nonselective - kill all plants they come in contact with - Herbicides are classified further according to the time they are applied. -Pre-emergent -Post-emergent

What is the most common control practice? Why? Chemical control is still the most popular form.

What information must be listed on a pesticide label?

Brand, trade, or product name Ingredient statement Manufacturer Registration number Establishment number Classification statement Directions for use Signal words and symbol Precautionary statements

What information must be listed on a pesticide label? Statement of practical treatment Environmental hazard statement Re-entry statement Storage and disposal statement

Mixing and Loading Pesticides Follow all instructions provided on the pesticide label. The most serious pesticide poisonings occur during mixing and loading.

Protective Clothing and Equipment Refer to the pesticide label to determine the proper protective clothing and equipment to use. Look for the signal words on the label. – Caution – Warning – Danger

Applying Pesticides Some pesticides require extra personal protective equipment. This is why it is important to follow all information provided on the label.

Alternative Methods of Weed Control Hoeing and hand weeding Use of mulch to smother weeds Cultivating Mowing Burning

Disadvantages of Alternative Weed Control Labor intensive Unrealistic for large crops and pastures

Integrated Pest Management (IPM) Used to: – Manage crop diseases – Managing insect pests – Managing weeds

What information must be listed on a pesticide label? Brand, trade, or product name Ingredient statement Manufacturer Registration number Establishment number Classification statement Directions for use Signal words and symbol Precautionary statements

What information must be listed on a pesticide label? Statement of practical treatment Environmental hazard statement Re-entry statement Storage and disposal statement

Weeds Classed According to Lifecycle Annuals Biannuals Perennials

Weeds Classed According to Plant Type Grasses Broad Leaves Sedges

Weeds Classed According to Persistence Common Weeds Noxious Weeds