Crop Protection

• Variability - is the property of an organism to change its characters from one generation to the other.
• Mutation - is any heritable variation that occurs spontaneously or as a result of exposure to mutagens, which may be physical (e.g., radiation) or chemical agents (e.g., pesticides).
• Recombinant DNA Technology - involves the isolation of specific gene sequences from a donor organism, their insertion into a vector molecule, and transfer of this recombinant DNA construct into a recipient cell where it can be expressed.
• When a new plant cultivar is introduced and the existing population of pathogen show avirulence to the newly introduced cultivar then pathogen have to produce variability in order to survive.
• 1. Mutation - changes in the genetic sequence, and they are a main cause of diversity among organisms. 2) Recombination - process by which pieces of DNA are
  2. broken and recombined to produce new combinations of
  3. alleles.
  4. 3) Heterokaryosis - refers to the presence of two or more
  5. genetically distinct nuclei within the same cell.
  6. 4) Parasexualism - process that forms an offspring cell from
  7. more than a single parent, bypassing standard meiosis and
  8. fertilization.
  9. 5) Heteroploidy - existence of abnormal chromosome number
  10. that deviates from the normal diploid number of a given species
• At least 40% global crops lost to pests every year: FAO
• Pre-IPM Era: 2500 BC- use of insecticide by the Sumerians (sulphur compounds to control insects and mites); 1500 BC-manipulation of planting dates as cultural control; 1200 BC- mercury and arsenical compounds to control body lice, botanical insecticides were used as seed treatments by the Chinese
• Pre-IPM Era: 950 BC-burning (cultural method); 500 AD- all the general types of control measure available today- insecticides, host plant resistance, biological and cultural control; - had already been developed and used by one civilization or another; 1732 farmers first begin to grow crops in rows to facilitate weed removal
• Pre-IPM Era: 1752 - Linnaeus - that "Every insect has its predator which follows and destroys it"; 1880 - first commercial spraying machine; 1912-U.S. Plant Quarantine Act; 1930-introduction of synthetic organic compounds for plant pathogen control
• The Era of Pesticide (1939-1975)


  The use of synthetic pesticides in the US began in the 1930s and became widespread after World War II. By 1950, pesticide was found to increase farm yield far beyond pre-World War II levels. Farmers depend heavily on synthetic pesticides to control insects in their crops.
• DDT


  A highly toxic synthetic insecticide, first made in 1874, discovered in 1939 by a Swiss chemist, Paul Hermann Müller, a contact poison that apparently exerts its effect by disorganizing the nervous system
• During the 1950s and a large number of other popularly used organophosphates and 1940 Bacillus popilliae and B. lentimorbus were named and described as etiological agents of a naturally occurring disease of Japanese beetles, referred to as milky disease. Late 1940s (post WWII): the advent of "chemical" pesticides including 2,4-D (/st hormone-based herbicide 1944) 1948-Warfarin registered as a rodente de
• Green Revolution


  The great increase in production of food grains (such as rice and wheat) due to the introduction of high-yielding varieties, the use of pesticides, and better management techniques
• The new varieties require large amounts of chemical fertilizers and pesticides to produce their high yields, raising concerns about cost and potentially harmful environmental effects
• 1959-Introduction of concepts of economic thresholds, economic injury levels, and integrated control; 1960- First insect sex pheromone isolated, identified, and synthesized (gypsy moth); 1960- First Bacillus thuringiensis (Bt) product registered
• Learning Guide Questions


  • What are the categories of techniques employed in IPM?
  • Which IPM technique is considered as the 'first line of defense'?
  • What is that insect management method considered to be among the most environment-friendly insect pest control methods ever developed?
  • Regulatory control is being implemented by the government. Which particular government agency acts as the regulatory arm on aspects of quarantine regulations?
  • List down the categories of host plant resistance.
  • What are biopesticides? Three major classes of biopesticides?
  • Distinguish between regenerative agriculture and permaculture

  
• Adverse Impacts of Pesticides

  • pesticide resistance
  • resurgence of insect pests
  • pesticide poisoning
  • environmental toxicity
  • elimination of predator species
  • negative outcomes for other non-target organisms
  • disruption in the food web
  • accumulation of toxins in the food webs
  • reduced crop yields

  
• Component Strategies in Pest Management

  • Regulatory Control
  • Host Plant Resistance
  • Behavioral Control
  • Biological Control
  • Genetic Manipulation of Pests
  • Chemical & Biopesticides
  • Physical / Mechanical
  • Cultural

  
• Regulatory Control


  Refers to the role played by government agencies in trying to stop the entry or spread of pests into an area or into the country via inspection, quarantine, destruction of infested material, and other methods
• Legislative measures in force now in different countries

  • Legislation to prevent the introduction of new pests and weeds from foreign countries (international quarantine)
  • Legislation to prevent the spread of already established pests, diseases, and weeds from one part of the country to another (domestic quarantine)
  • Legislation to enforce farmers to apply effective control measures to prevent damage by already established pests
  • Legislation to prevent the adulteration and misbranding of insecticides and determine their permissible residue tolerance levels in food stuffs
  • Legislation to regulate the activities of people engaged in pest control operations and application of hazardous insecticides

  
• Plant Quarantine


  The legal enforcement of the measures aimed to prevent pests from spreading or to prevent them from multiplying further in case they have already gained entry and have established in new restricted areas

  
• The regulatory arm of the Philippine Department of Agriculture when it comes to matters of import, export, domestic movement as well as market access of plants and plant products is the National Plant Quarantine Services Division (NPQSD)
• NPQSD is under the Bureau of Plant Industry (BPI)
• The Bureau of Customs stationed at the Ninoy Aquino International Airport on May 19, 2021 apprehended a total of 2,032 pieces of Live Ornamental Plants for failure to secure the required Plant Quarantine Permit prior to importation

  
• Host Plant Resistance


  It involves the use of pest-resistant and pest-tolerant varieties developed through traditional breeding or genetic engineering
• Categories of Host Plant Resistance

  • Non-preference (anti-xenosis)
  • Antibiosis
  • Tolerance
• Non-preference (anti-xenosis)


  Host plants that express non-preference affect the way an insect pest perceives the desirability of the host plant. Non-preference plants either provide stimuli that are unattractive to the pest (color, odor, texture such as downy hairs) or fail to provide stimuli that are attractive to the pest. In this way, non-preference plants affect the behavior of pests

  
• Antibiosis


  A type of resistance in which the host plant causes injury, death, reduced longevity, or reduced reproduction of the pest. Plants that express antibiosis affect the biology of pests
• Tolerance


  Host plants that express tolerance are resistant to pest damage because they can remain healthy and yield well despite the damage
• Behavioral Control


  The behavior of the pest can be exploited for its monitoring and control through baits, traps, and mating disruption techniques

  
• Semiochemicals


  Organic compounds used by organisms (like insects) to convey specific chemical messages that modify behavior or physiology
• Behavioral manipulation techniques


  • Pheromone
  • Kairomones & Allomones
  • Sounds and vibrations
• Behavioral manipulation techniques


  • Yellow sticky traps
  • Pheromone traps
  • Insect light trap

  
• Biological Control


  The reduction of pest populations by natural enemies and typically involves an active human role. It involves the protection, enhancement or introduction of natural enemies

  
• Natural enemies in Biological Control

  • Predators
  • Parasitoids
  • Pathogens
  • Antagonists
• Predators


  Predators capture and eat other organisms such as insects or mites
• Parasitoids


  Parasitoids are insects that parasitize other insects. The immature stages of parasitoids develop on or within its host, eventually killing it
• Parasitoids


  • Braconid wasp
• Pathogens


  Entomopathogenic fungi and insect viruses (nuclear polyhedrosis virus)
• Antagonists


  Microbial antagonists prevent infection of the host plant by the pathogen, or establishment of the pathogen in the host plant