Maize & other Cash Crops

Domestication of Maize - process through which wild plants are turned to useful crops.

Maize “Corn” uses:

  • Animal Feed: pig feed

  • Food source: corn syrup, flour, and cereals

  • Fuel: ethanol

Origin of Maize

Lack of relatives makes it’s origins somewhat a mystery. Fossils dating back 6000 y.a

Discovering Teosinte

  • A type of grass from Central America, genetically similar to Maize.

  • George Beadle provided evidence that Teosinte is the ancestor of Maize

    • Through hybridization experiments

Beadles Experiment (Crossbreeding) - identify how many genes distinguish maize from teosinte

  • 1st Generation: Hybrid between maize and teosinte

  • 2nd Generation: Further crosses of the F1 plants to determine genetic differences.

    • Conclusion: 1/500 F2 plants resembling teosinte or maize suggested approximately four to five genes control the major differences.

Balsas River Region: Key area where maize was first domesticated (9,000 years ago)

  • Archeological Evidence:

    • Plant Grinding Stones: Used by ancient people to process maize.

Disease Resistance to Teosinte

  • Species discovered before 1977, later named Diploperennial was resistant to 7 viruses.

  • Scientists attempted to crossbreed it with maize to transfer resistance genes.

    • ❌ No fertile hybrids were produced.

Genetically Modified Maize

  • Modern maize has been genetically engineered to resist pests: BT corn

  • It contains a bacterial gene producing a protein toxic to certain insects.

Cultivated Crops

Starchy Crops

  • Potatoes

    • Origin: Peru (Andes Mountains)

    • Ex. Russet, gold, red, purple, and fingerling potatoes

    • Important tuber crop (stores starch underground).

  • Cassava (Manioc)

    • Staple in South America (Brazil) + Africa.

    • A root, not a stem.

    • Contains Cyanide (HCN)

      • Detoxification methods: Extract juice to remove toxins. Roast, dry, or ferment to make cassava flour.

  • Peanuts (Legume Family)

    • 2nd Southern Cash Crop promoted by George Washington Carver

    • 50% oil and 30% protein

    • Flowers pollinate → fruits develop underground.

    • Peanut Butter: at first a medical product. Major US food product.

Spices

  • Parts used: roots, bark, seeds, fruits, flower buds.

    • Cinnamon: inner bark of the cinnamon tree.

    • Black pepper: dried berries.

    • Nutmeg & mace: both from the nutmeg seed and its aril.

    • Cloves: dried flower buds.

    • Saffron: From the stigmas of Crocus sativus flower.

      • Expensive and Labor intensive to harvest  

      • Used for flavoring and yellow coloring in foods (saffron rice)

      • Artifacts depict trained monkeys harvesting saffron.

  • New World Spices

    • Vanilla: from Mexican orchids.

      • Labor-intensive; requires hand pollination.

      • Most modern vanilla flavor is synthetic (vanillin).

    • Hot peppers: Capsicum species (New World origin).

      • Capsaicin — causes burning sensation.

      • Scoville test: measures pepper “heat.”

Herbs

  • Mint Family (Lamiaceae)

    • Thyme, Basil, Oregano, Sage, Marjoram.

    • Contains aromatic oils (distinct flavors and smells).

    • Fresh herbs release more flavor w/ longer cooking times.

    • Often used in Italian dishes (pasta, pizza).

  • Parsley/Carrot Family (Apiaceae)

    • Parsley, Dill, Cilantro (Coriander), Fennel, Caraway.

    • Flowers are compound umbels.

    • Cilantro: some people perceive a soapy taste due to genetics.

  • Mustard Family (Brassicaceae)

    • mustard seeds, horseradish, and wasabi.

    • Glucosinolates (oily sulfur compounds) → sharp, sinus-clearing effect.

    • Wasabi: Derived from rhizomes grown in Japan’s riverbeds.

      • Rare & expensive; most “wasabi” sold is colored horseradish.

  • Onion Family (Alliaceae / Amaryllidaceae)

    • Onion, Garlic, Chives.

    • Release sulfur compounds → tear-inducing & antimicrobial.

    • Have medicinal uses and culinary importance.

Others

  • Sugarcane - #1 global crop by tonnage (main source of table sugar).

  • Bananas

  • Palm Oils + Waxes

  • Chocolate

    • Pods contain pulpy seeds → fermented, dried, and roasted. Processed into: Cocoa powder, Cocoa butter, Chocolate liquor

  • Rubber

    • Natural rubber from the Hevea tree (Brazil).

    • Today, much is synthetically produced.

Top Sources of Calories in Human Diet

  1. Wheat – bread, cereals.

  2. Rice – feeds over 2 billion people globally.

  3. Maize (Corn) – starch and protein source.

  4. Potatoes – tuber crop.

  5. Cassava (Manioc) – root crop.

  6. Sweet Potatoes – unrelated to potatoes (in morning glory family).