Lecture 7 - Cotton & Integrated Pest Management - Bio 2217

Biol 2217B: Cotton and Integrated Pest Management

Three Meanings of Fibre

  • Fibre Cells:

    • Long and narrow sclerenchyma cells that support plant structure.

  • Dietary Fibre:

    • Portion of plant-derived food not completely broken down by digestive enzymes.

  • Fibre Filament:

    • Natural or synthetic filament (e.g., cotton, wool, nylon) capable of being spun into yarn or material.

    • anything that’s capable of being spun into thread

Key Example: Gossypium hirsutum

  • Also known as upland cotton or Mexican cotton.

  • Taxonomy: Eudicot, Family: Malvaceae (mallow family).

  • Growing Conditions:

    • Warm-weather crop that thrives in full sun, requires a long frost-free season, and abundant moisture.

    • warm weather crop

    • most of it comes from mexico

  • Wild Growth:

    • Typically a woody shrub up to 3 m tall; cultivated as an annual about 1.5 m tall.

    • bigger grown in the wild

    • flower has single stigma and several stamen branching off the stigma

    • bracts

  • Fruit:

    • Produces a boll containing 25-50 seeds (3-5 mm) with fibres growing from the seed coat.

    • fruit is called boll

    • seeds of cotton is dispersed by wind

    • each seed has many fibers coming out of it tigons make hair like things

  • Related Plants:

    • Same genus as 1 of 4 commercially grown cotton species (90% of global production).

    • Related family members include cacao and okra.

  • Pollination:

    • Primarily self-pollinates; fibres are known as single-celled trichomes.

  • Domestication:

    • First domesticated ~4000 to 7000 years ago in multiple regions including Arabia, India, and Peru.

  • Leaves and Morphology:

    • 3-5 lobed, rough, dark green leaves.

Main Points of Cotton Production

  • Cotton seeds are the primary source of plant fibre for cloth manufacturing.

  • The harvesting and ginning processes are labour-intensive and pivotal to world history since the 1600s.

  • Integrated Pest Management (IPM) serves as a framework for managing agricultural pests, including cotton pests like the boll weevil and cotton bollworm, with varying levels of success.

Evolution of Cotton

  • 10 Million Years Ago (MYA):

    • Ancestors of cotton species evolved in Africa.

  • Dispersal:

    • Seeds spread to new continents leading to distinct species evolution.

  • 1 to 2 MYA:

    • Seeds reintroduced to Mexico from Africa and hybridized with local plants.

  • Domestication:

    • Initiated ~4000 to 7000 years ago.

  • how do we get these plants that are pretty similar ending up all over the world even before humans started domesticating it

    • believed that originate from africa(not sure if its like todays plant)

    • seed became very efficient at dispersale…. cross major oceans and continents, allowing for the spread of cotton species through natural means such as wind and water currents, as well as animal activity.

    • type of polyploidy is particularly relevant in cotton, as many cultivated varieties are the result of ancient hybridization events that have led to increased genetic diversity and adaptability in various environments.

Development of Cotton Bolls and Seeds

  • Composition of Fibres:

    • Made of cellulose.

  • Types of Fibres:

    • Long fibres referred to as lint (up to 7 cm long) and short fibres as linters.

    • wild cotton is shorter fibers that domesticated ones

      • we want longer fibers so that its easier to spin

    • shorter fibers are called linters

      • domestication = less linters more lint

Processing Cotton

  1. Harvesting

  2. Ginning:

    • Separates fibre from seeds and other plant materials.

  3. Spinning:

    • Converts fibres into yarn.

  4. Weaving:

    • Yarns are woven into cloth.

History of Indian Cotton Production

  • India has a long history (over 2000 years) of cotton exports.

  • 1526-1847:

    • During the Mughal Empire, cotton productivity increased significantly.

    • india is very powerful Britain not so much and right now are trading for goods

    • shift in 1700 where cotton starts being produce in britain

  • Technological Advances:

    • Inventions such as worm gear roller cotton gin and spinning wheel accelerated production.

  • British Influence:

    • The British East India Company started importing cotton from Asia into England in the 1600s, leading to the Calico Acts in 1700 and 1721, which restricted cotton imports to protect local markets.

  • Domestication:

    • The earliest domestication occurred in the Indus Valley (~5000 years ago).

    • cotton has been domesticated at least for times but india is one of the earliest not the only

Industrialization of Cotton Production

  • 1770s:

    • Advancements in spinning technology allowed for multiple threads at once and water-powered processes in Britain.

  • 1793:

    • Invention of the cotton gin in the US transformed cotton processing.

      • more efficient and ginning fabric

  • Growth Factors:

    • Cotton replaced tobacco as the leading cash crop in the US, heavily relying on slave labour until the late 19th century.

  • Production Data:

    • Throughout the early 1800s, US cotton production and export statistics reflect rapid growth, peaking significantly as the largest global producer.

    • tend to work in closed environments to keep moisture

Cottonseed Composition

  • Cottonseed contains:

    • Carbohydrates: Approx. 50%

    • Protein: Approx. 25%

    • Oil: Approx. 25%

  • Uses:

    • Cottonseed meal serves as livestock feed; cottonseed oil is used for cooking.

Pest Management in Cotton Production

  • Boll Weevil (Anthonomus grandis):

    • Adult pests feed on flowers and bolls; females lay eggs causing severe damage.

    • Known for 5 to 6 generations per year and significant yield losses upon infestation.

    • feed on the outside so don’t do that much damage… although the lay eggs in the buds of the fruit which is where most of the economic damage comes from bcs the larva eat from the inside out

    • short lifespan and lay many eggs so there may be few during plantation but could lead to a rapid increase in pest populations, necessitating the implementation of effective management strategies to mitigate damage. going through 5-6 generations and multiplying each time

    • BW comes into southern texas and over the years it has gone to all the other crops infecting them

      • this is a $20 billion cost

    • what did they do to stop BW

      • usee pesticide

      • developed more effective organic pesticides

      • use DDT (famous bcs its toxic to humans, toxic to pollinators, broad spectrum pesticide… will kill BW and a lot of other things, its persistent and doesn’t break down.. if animal eats near area it can build up in animal immune system and kill them creating a chain reaction to predator that eats pray and so on, resistant to metabolism)

        • DDT caused economic yield bcs BW still survive and develop resistance the DDT, DDT becomes less and less effective

      • Diapause (dormancy that insects go through)… how BW survives winter to lay eggs in spring

        • in order for pesticides to work they need to eat it so because the BW sleeps through it, they are not exposed to the pesticide during their dormant phase, allowing them to survive and reproduce once conditions become favorable.

      • put of traps for females with male sex pheromone allowing farmers to see when there are going to be larger families so they know when to spray pesticides

  • Pest Management Strategies:

    • Integrated Pest Management (IPM) is critical in controlling pest populations through various strategies such as setting action thresholds, regular monitoring, and prevention methods like crop rotation.

  • After the famine / controlling late blight

    • chemical fungicides introduced

    • phytosanitation

    • “seed potatoes

      • grow in sanitary conditions so that they insure there ins no fungi before plantation

  • Bollworm (Helicoverpa armigera):

    • Widespread pest laying thousands of eggs on plants and causing significant economic damage globally.

IPM Examples

  • Utilization of trap crops and biocontrol measures such as neem oil and nuclear polyhedrosis virus (NVP) to reduce pest populations and pesticide dependency.

  • Research and studies on natural enemies and parasitoids for biological control techniques illustrate innovative pest management approaches.

Readings

  • Required: Hancock, James (2017) "Plantation Crops, Plunder and Power: Evolution and Exploitation" (Chapter 3 on Cotton).

  • Background: EPPO datasheet on Helicoverpa armigera and other relevant academic articles.

  • Resources:

    • Access may require library login or searching mentioned titles.