Integrated Pest Management (IPM) Chapter 14

Agricultural Methods 1.Slash and Burn – Clear small area – Burn trees and brush  releases nutrients – Farm a mixture of plant species a season or two – Usually done in tropical areas

Agricultural Methods Benefits – Less chance of insect plagues – Not much erosion – Having a variety of plants benefit eachother (some N- fixing, others are nat. insect repellants Drawbacks -Not efficient - Long recovery time before area can be used again

Agricultural Methods 2. Manual Labor Farming Usually done in 2 instances: A.Site doesn’t allow for machinery (mountainous area) B.Crop doesn’t allow it (planting paddy rice or harvesting fruit) – Fairly common in poorer/less developed parts of the world (Africa, Central/South America, Asia)

Agricultural Methods 3. Mechanized Agriculture – Common in N. America, Europe, parts of Russia and S. America where money and large tracts of land are available – Machines and fossil fuel energy do work of humans – Results in monocultures

Problems with Mechanized Agriculture If planting different crops, efficiency decreases Large tracts of land are left uncovered, increases erosion Removes most of organic material each year, increases need for fertilizers Reliant on hybrid seeds with little genetic variability, pest control can be major issue Planting same crops year after year depletes soil minerals and increases growth of insect and fungus pests. Increases need for fungicides and insecticides

Benefits of Mechanized Agriculture Increases productivity Leads to more research in genetic engineering and other forms of biotechnology (i.e. pest resistant strains, drought resistant strains)

Fertilizer Can be a substitute for labor Responsible for 25% of world’s crop yield Chemical fertilizers are tied to the price of oil; therefore, as oil prices increase, the price of fertilizer increases and subsequently the price of food increases as well

Fertilizer Replaces nutrients to soil that are lost when plants grow Some nutrients C, H, O are easily replaced from air and water

Fertilizer Three Primary Soil Macronutrients (required in large amounts) 1. Potassium 2. Phosphorus 3. Nitrogen * Common ingredients in chemical fertilizer

Fertilizer Micronutrients- required in small amounts for proper plant growth Ex: boron, zinc, manganese

Pesticides Chemicals used to kill or control populations of unwanted fungi, animals (including insects), or plants (“weeds”)

4 Categories of Pesticide 1.Insecticides- kill insects 2.Fungicides- kill fungal pests 3.Herbicides- kill plants/weeds 4.Rodenticides- kill small mammals (mice/rats) Could be called “biocides” b/c they kill many living things including humans– don’t just kill target species (i.e. kill pollinating insects too)

Problems with Pesticides 1.Kill more than target species 2.Take a long time to break down 3.Bioaccumulation (DDT- first synthetic organic insecticide, 1942) DDT worked well at first, then targeted species began building a tolerance to it

Why are Pesticides so Widely Used? 1.Increases amount of food that can be grown. Pests consume about 33% of crops in U.S. and 35% worldwide. 2.Economic- more profits for farmers and making pesticides is big business 3.Health reasons- kill insects that transmit disease

Organic Farming Relies on animal manure as fertilizer and crop rotation to restore nutrients to soil Slightly less profitable, but when adjustments are made for $ spent on fertilizer and fuel, profits almost balance

Drawbacks of Organic Farming 1.Will not be able to produce enough food for the ever-growing world population 2.Have to plant clover, alfalfa, or other legumes to replace nutrients 3.Cattle must be a part of any organic farming operation

Benefits of Organic Farming 1.Less chemicals in the environment or consumed by humans 2.Less erosion

Integrated Pest Management (IPM) Using a variety of methods to control pests other than pesticides alone Must have an understanding of plant metabolism, life cycle/biology of pest, and interactions between pests and predators to be successful Main drawback is that it takes a long time to learn this info, and the research is done at universities and government labs-- have to get information to the farmers

IPM Strategies 1.Sex attractants- spray pheromones or place pheromones in traps (gypsy moths) 2.Male sterilization- release sterile males 3.Release natural predators/parasites- ladybugs kill aphids, mites, scale insects. Bacteria are used to kill gypsy moths and mosquitoes

IPM Strategies 4.Development of resistant crops- Green Revolution 5.Use of natural pesticides- Marigolds (soil nematodes) and garlic (Japanese beetle) 6.Modification of farming practices- plowing under and crop rotation 7.Selective use of pesticides- only in small doses and at precise times in pest’s life cycle