Pest, Disease and Weed Management

Course Outline: 1. Learning Objectives 2. Definition of pest, disease and weed 3. Pest, Disease and Weed Management and

control

Prepared by: Andrew A. Ngadin - 2014

1. Learning Objectives

1. Recognize, define and distinguish the organic and integrated pest management approaches to managing insects, diseases and weeds.

2. Identify and classify insect pests, disease pests, and weed pests.

3. Describe and apply the six components of IPM for insect, disease, weed and vertebrate management: Prevention, pest identification, monitoring, tolerance levels and economic, control methods and evaluation.

2. Definition of Pest, Disease and Weed

What is a pest and disease? • An organism is considered a pest only when its activities start to

damage crops and affect yields.

• Pests can be insects or other arthropods such as snails, mites and slugs. Pests are also disease causing agents such as fungi, bacteria, viruses and nematodes. On the farm, the word pest is also given to weeds, birds, rodents and other vertebrates.

• Farmers are likely to encounter pests in the field, soil, and surrounding environment before, during and after crop production. Pest damage is a serious problem on the farm and requires the farmer’s careful attention. A farmer should establish an effective system of pest prevention and control in order to minimize crop damage and sustain a successful business.

Can you guess?

http://www.csrtimys.res.in/diseases-pests

Example of pests attack papaya • (Giant) African snail (Achatina fulica)

 as a parasite of papaya stems (1)  early stem injury (2) advanced stem injury (3)  plant death (4)  snail eggs at base of stem (5)  as a parasite of papaya fruit (6)  fruit damage associated with snails and Phytophthora palmivora infections (7)

1 2 3 4 5

6

6 7

Anthracnose (Colletotrichum gloeosporiodes, fungus)

 sunken lesions with pinkish spore masses on fruits (1)

 A typical symptoms (2) complete decay of fruit with spore masses (3)

 Petri plates with fungal cultures (C. gloeosporiodes) (4)

1

3

4

2

Black spot (Asperisporium caricae, fungus)

 spots on upper leaf surface (1)  spots on lower leaf surface (2)  early fruit symptoms (spots) (3)  mycoparasitism of Asperisporium lesions on fruit (4)  spores on leaf debris (5)

1 2 3 4

5

Powdery mildew (Oidium caricae, fungus)

 on upper leaf surface (1)  on lower leaf surface (2)  on fruits (3)

1 2 3

Ringspot (Papaya Ringspot Virus, PRSV)

 multiple symptoms (1)  ringspots on fruits (2)  ringspots on leaf (3)  leaf mosaic (4)  leaf shoestring (5)  PRSV virus particles (TEM) (6)

1 2 3 4

5

6

White peach scale (Pseudaulacaspis pentagona, insect)

 on fruit (1)  on stem (2)  Pseudaulacaspis pentagona (3)  Adult female white peach scale, Pseudaulacaspis

pentagona (Targioni), with eggs (4)

1 1 2 3

4

http://entnemdept.ufl.edu/creatures/orn/scales/white_peach_scale.htm

Ants – Phildris – cut cacao tree yields

Disease – Botrytis cinerea

• Fungus

• Papaya fruit

What is weed? • A weed is a plant out of place not intentionally

sown, whose undesirable qualities outweigh its good points. Some crop plants even can become weeds when they grow where they are not wanted. In contrast, a number of plants usually thought of as weeds may actually be helpful in controlling erosion or serving as food for wild animals and birds.

• Weeds are troublesome in many ways. They reduce crop yield by robbing water, light, space, and soil nutrients. Weeds can produce allelopathic substances that are toxic to crop plants. Weeds often serve as hosts for crop diseases; they also may provide shelter for insects and diseases. To plan an effective weed management program, a producer must be able to identify weeds present and understand how weed biology affects where weeds are found and their relative competitiveness.

Problem for Dragon fruit plantation

• There are few problems such as;

• Weed control is still a challenge and this is due to high cost in weedicides like BASTA..

• High cost of fertilizers. Agricultural inputs like fertilizers, pesticides, fungicides and other chemicals have risen very high to almost 50% increase.

IPM

• Integrated pest management (IPM) is an ecosystem-based strategy that focuses on long-term prevention of pests or their damage through a combination of techniques such as biological control, habitat manipulation, modification of cultural practices, and use of resistant varieties.

• Pesticides are used only after monitoring indicates they are needed according to established guidelines, and treatments are made with the goal of removing only the target organism. Pest control materials are selected and applied in a manner that minimizes risks to human health, beneficial and non- target organisms, and the environment.

A diagram outlining IPM strategies, where prevention is the basis of control

Intervention Toxicity

Prevention

Conventional Pesticides that kill on contact

soap, oils, baking soda, repellants insect growth regulators (IGR),

microbials

Biorational Predators, parasites,

nematodes

Insects: traps, barriers Weeds: weed, mulch

Diseases: prune

Site & plant selection, sanitation rotations

Biological

Chemical

Physical - Mechanical

Cultural

IPM for Pest of Crops, Lawn & Garden

3. Pest/ Disease Management and Control

• Diseases are another type of agricultural pest which severely threaten crop production and yield. The 5 components of the Integrated Pest Management (IPM) strategy can help to prevent or fight against disease infestation.

(A) Components of IPM for Pest/ Disease

1. Prevention. Smart management decisions can prevent susceptibility to pest/ disease.

2. Pest/ Disease Identification. It is critical to correctly identify a pest/ disease in order to confirm its cause and plan for the best solutions.

3. Monitoring. By identifying a pest/ disease and measuring damage, farmers can make better decisions about when and how to apply a control method.

4. Control Methods. When possible, use the least impactful cultural, mechanical, biological, and/or natural chemical controls to manage pest/ disease.

5. Evaluating the pest/ disease management program and improve it when possible. This requires keeping records so that one can learn from his or her mistakes and successes

• A successful disease management program requires careful thought in the crop production system in order to prevent and control disease development. Important disease prevention strategies are:

1. Starting with the selection of appropriate disease-free or resistant fruits varieties 2. Maintaining a healthy soil with good drainage. 3. Proper irrigation management 4. Having a fertilizer program that results in optimum plant/fruits growth 5. Appropriate ground preparation 6. Maintaining appropriate plant density to minimize disease infection and spread 7. Properly thinning and pruning or ‘canopy management’ can provide optimum air

circulation 8. Maintaining a transplant program which minimizes transplant shock 9. Ensuring a clean seedling production program 10. Conducting effective pest monitoring during the season 11. Knowing the harvest and shipping procedures that maximize shelf life and

produce quality

1. Prevention

2. Disease Identification

• The first step in disease management is learning how to identify a disease in the field. This requires the farmer to be knowledge about:

a) the disease,

b) the pathogen that causes the disease (fungus, bacteria, virus or nematode)

c) how the disease develops,

d) phases of disease development,

e) common signs and symptoms of each disease, and

f) disease management: prevention and control.

a) Disease:

• A disease is described as an organism that changes the normal state of the plant/ fruit by disrupting the functions of the plant/ fruit. Often a disease is caused by disease causing agents (pathogens), environmental factors, inherent defects of the plant/ fruit, or a combination of these factors.

b) Diagnose the problem: • Which of the four pathogenic microorganisms, fungi, bacteria, virus or

nematode, is causing the disease to prevent additional yield loss. Many times simple field observation is not efficient enough to determine the cause of the disease since these microorganisms are not visible to the naked eye; therefore, samples must be sent off for laboratory analysis

There are 4 types of pathoge