Transcript Preventing Disease, Weed, and Pest Problems

Preventing Disease, Weed, and
Pest Problems
Vegetable Gardening for Beginners
Introduction: What did we learn last time?
 Our role as gardeners: assist plant growth by careful addition and subtraction of positive
and negative factors.
 For each problem, there may be more than one solution!
 What is your personal gardening style or philosophy?
Introduction: Know Thine Plantes
 Keep up with your gardening work. The earlier you fix a problem, the better.
 An unfixed problem will, literally, grow.
 Visit your garden as often as possible (once a day)
 Get familiar with how your plants look when healthy!
Looking for Changes
 If you’re attentive, you will be able to figure when a plant is beginning to encounter a
disease or pest problem, before the problem becomes serious.
 What are we looking for?
The Obvious Signs
 Holes in leaves: Something is probably
munching on these leaves!
 Look for bugs or caterpillars.
 Larvae and adults can be equally
voracious.
This is a cabbage worm, larvae of the White
Cabbage Butterfly. The butterflies are pretty, but
boy do their children cause damage.
The Obvious Signs
 Leaves changing color to yellow
 Or leaves oozing sap
 Small hard spots on leaves or fruits
 This means you have aphids or other bugs
with sucking mouthparts
More bug pictures
Another species of aphids. Occasionally you will
see some aphids “farmed” by ants.
The squash bug family will cause damage not
only to squashes but to tomato fruits.
Obvious Signs
 Leaves turn brown or black and curl up
 Leaves have brown spots
 Probably a fungus such as late blight
One more type of attack
 If the whole plant seems to wilt at once,
with the leaves curling up, your plant may
be affected by a virus.
 Viruses are a more common problem
once we get to trees and bushes.
 Tobacco Mosaic virus can affect
members of the Solanum family
Of course, nothing is ever simple.
 Plant diseases can cause damage that looks like pest damage.
 Nutrient deficiencies can cause problems that look like a disease.
 Two steps:
 Prevention is important, and
 Never treat with a chemical until you’re sure what you’re treating.
Nothing is simple: A mimic
 Iron chlorosis is a condition where your
plant is not getting enough iron for the
chlorophyll to function normally, but it
looks like your plant has a disease!
 If you think you have this, take a soil
sample to the extension agent, and
follow their advice to add amendments
to the soil.
Nothing is simple: Easily preventable
 Tomatoes need calcium and magnesium
almost as much as they need NPK
 This picture shows blossom end rot.
Prevention and Treatment
An ounce of prevention is worth a pound of cure!
Prevention is a healthy plant
 Plants that are already healthy are much less likely to be subject to major damage from
pests, fungus, or disease.
 Add the correct amendments to your soil, as indicated by a soil test.
 Keep a high level of organic matter and carbon in your soil.
 Keep soil biodiversity high by adding compost and not using strong chemicals.
Diagnostics
 This class is too short to effectively look at the many kinds of diseases and pests, except to
touch on the most common kinds.
 Many online materials exist to use as guidebooks.
 Take a sample of affected leaves/ branches with bugs and put them in a plastic baggie.
Take the baggie to the extension office and have them identify it.
Fungus Prevention
 Fungus resides in the soil.
 Apply mulch around the base of plants when they are young.
 Stake up plants like tomatoes and cucumber vines so that they don’t sprawl on the
ground.
 If you water your plants from overhead, don’t do so at night.
Fungus Treatment
 Copper Sulfate: good for grapevines and tomatoes.
 Raise the plant, let it air out, and let nature get rid of it.
Many pest problems: Prevention
 Keep your plants healthy!
 Mix up your plant species and families so that bugs have to travel farther to look for foodincreases predation.
 If you have had a perennial problem with certain plants, you may have to choose a
resistant variety or leave them out altogether, substituting another plant family to do the
job.
Many pest problems: Treatment
 Handpick small amounts of pests
 Organic treatments: pyrethrin, Bacillius thurenginis, soap, neem oil
 Wait for nature to do the trick!
 Inorganic pesticides: follow instructions exactly to minimize toxicity.
Virus problems
 Prevention: Choose resistant varieties, and keep your plants and soil healthy as many
viruses are spread by bugs.
 Treatment: Remove as much of the infected plant as possible and burn it or throw it away.
Section 2: Weeds
“A weed is just a flower that hasn’t been recognized yet”
Weed prevention
 Garden design: Use permanent beds and pathways rather than rows.
 The Seven-Day Rule
Weed prevention
 Organic material: straw, leaves, lawn clippings
 Biomass production areas and green or living mulches
 Landscape paper on top of soil- replace yearly
 Plastic mulches
 Comes in black, red, or other colors
 Cheap but not durable.
I already have weeds!
 Big weeds are a problem. Use a weed
eater or hire a local teenager.
 Chop them to the ground, then cover
with cardboard and mulch.
 Change your perspective and put the
edible weeds in your salad!
Summary
 Healthy plants
 Prevention
 Observation
 Right treatment for the right problem
Questions?