Crop physiology

Crop physiology - Crop physiology Yield: Measured as the...

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Crop physiology Yield: Measured as the amount of the material (grain, dry matter, pods) a plant produces per unit area Commonly measured as a volume (bushels) of grain per unit of area or as weight such as kilorams per unit of area. Forage yield is typically measured on a weight basis using tons per unit of area, bales per of area Calculating: o Kernels/ear X g/kernel X pounds/g X plants/acre X ear/plant -> bushel o Heads/area X seeds/head X weight/seed Two types of yield: o Economic (agricultural)- any portion of the plant (seeds, leafy material, fleshy stems) that has marketable value and is sold for uman or animal consumption or used as seed o Biological- all cry matter that the plant produces, including stems, leaves. Seeds, root material, reproductive structures Rate of growth: Plant growth curve o Logarithmic growth phase Germination Vegetative o Decreasing growth phase Flowering Seedfill o Steady state phase Physiologica maturity Plant growth regulators o Auxins – like indoleacetic acid (IAA) stimulate cell elongation and can cause plants to be tall and spindly
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o Gibberellins- like gibberellic acid (GA) act similarly to auxins to stimulate cell elongation o Cytokinins (kinins)- are regulators that stimulate cell division and cell differentiation o Growth inhibitors- Chemicals lik abscisic acid (ABA) and phosphon prevent budding, seed germination, as well as some types of vegetative growth o Ethylene- a gas, considered an inhibitor commonly used to ripen fuit, allows producers to harvest when fruits are less susceptible to damage Regrowth: o Red clover damaged by frost can regrow from lateral or apical buds. o If the growing point of corn is below the soil surface, it will regrow after frost damage o Plant growth and regrowth occurs from meristematic tissue at the apica (tip) and axillary (lateral) buds, and for some plants, such as grasses, meristematic tissue located at the base (crown) area of the plant Photosynthesis: o Over 90% of all plant dry matter yield is the result of photosynthesis o Going into photosynthesis Sun CO2 H2O o Being made C6H12O6 ATP Amino acids Lipids Carbs o Coming out O2
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CO2 H2O o Photosynthesis occurs in the chloroplasts of plant cells, solar energy is captured in the chlorophyll of green leaves and is temporarily stored in adenosine triphosphate (ATP) and nicotinamide adenine dinucleotide phosphate (NADPH). CO2 enters the stomata from the air and H2O is delivered to the leaf from the soil through the xylem. Using ATP and NADPH, CO2 and H2O, enzymes manufacture sugars and oxygen is
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This note was uploaded on 09/19/2011 for the course AGRON 114 taught by Professor Staff during the Spring '08 term at Iowa State.

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Crop physiology - Crop physiology Yield: Measured as the...

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