Corn Zea mays L.

2. Corn (Zea mays L.) 3rd most productive cereal worldwide. 1st in production and area in the U.S. Wide Adaptation Broad Utilization High Yield Potential High Feed Quality

3. High average yields Crop grown in favorable environments Relatively small area produced in stress environments Mostly hybrid production and fewer op landraces

4. Area � stable over past 40 years Yields � consistent improvement in yield Genetic Improvement Water management Weed Management Pest Management (Bt) Fertilization/Cultivation

7. Leading States North Central US Favorable Environment Texas Panhandle Temperate Environment Irrigated High Yield (150 bu/acre) South/Central Subtropical Environment Rainfed (high stress) Low Yield (75 bu/acre)

15. World Corn Exports

16. Examples of Uses of Corn Feed Grain Beef Pork Poultry Food Grain Masa for tortillas, chips Flour, baking Grits for cereals, brewing High Fructose Corn Syrup Corn Oil Industrial Ethanol Starches (food and industrial) Forage - Silage - 2009 Data 5,605,000 ac in U.S 108,209,000 tons produced at 35% moisture average yd: 19.3 tons/ac

20. Diploid Genetics 2n = 2x = 20 Chromosomes Annual Little to No Tillering Diecious � Separate male and female flowers on the same plant Naturally outcrossing, but moderately tolerant of self-pollination Modern cultivars are single cross hybrids

21. Monocot Cereal Grain, seed is a caryopsis i.e., mature fruit of grasses in which the seed coat firmly adheres to the pericarp such as in rice, wheat, barley, sorghum, and corn in SCSC 306 C4, warm season adaptation C3 plants include more than 95 percent of the plant species on earth. (e.g. cotton, soybean, peanut in SCSC 306.); while C4 plants include such crop plants as sorghum and corn. C4 are the second most prevalent photosynthetic type. There is 1 other photosynthetic type called CAM Photosynthesis : (Crassulacean Acid Metabolism); CO2 is stored in the form of an acid before use in photosynthesis. During the first steps in CO2 assimilation, C3 plants form a pair of three carbon-atom molecules. C4 plants, on the other hand, initially form four carbon-atom molecules. important difference between C3 and C4 species C3 species continue to increase photosynthesis with rising CO2 (may be important with �climate change.� C4 plants have reduced photorespiration because the C02 released during respiration can be re-captured within the leaf and recycled through the photosynthetic pathway.

22. In C-4 plants carbon dioxide is actively pumped into the mesophyll cells and fixed to a three carbon compound. The now four carbon compound is sent to the bundle sheath cells where the C-4 compound gives up the carbon atom to the normal Calvin-Benson cycle. Advantages C-3 vs C-4. In warm climates C-4 plants have an advantage because during the day they can keep their stoma closed thus conserve water. The C-4 adaptation allows oxygen to build up to much higher levels without seriously affecting the rate of carbon fixation. In cooler climates, C-3 plants have the edge because it takes less energy for them to fix carbon dioxide.

23. Corn Growth and Development

24. Corn Growth and Development