Lab Quiz #1 Flashcards
CEA
Controlled Environment Ag.
nutrient optimizes flowering, short, small leaves, roots grow to the bottom of the pot
Nitrates
nutrient makes softer, lush growth, leafy, tall with large leaves, roots only grow on the top of the pot; makes pH lower/more acidic
Ammonium and Urea
fertilizer composed of manure, fishmeal, or compost - releases NPK as it decomposes, need to add a lot more to get the same amount of nutrients
organic fertilizer
pH lower than 5 can cause…
Al3+ is toxic and becomes more soluble which stunts growth and prevents Ca uptake
how many essential nutrients
17 - 9 macro and 8 micro (C4 and CAM plant also require Sodium; sometimes doesn’t add sulfur)
Immobile nutrients
boron, Ca, Fe - symptoms seen in new growth
Mobile nutrients
Cl, Mg, N, P, K, and Sulfur - symptoms seen on old growth (apical meristem always has priority)
easy fix for micronutrient deficiencies
foliar sprays on symptom-showing leaves
optimal pH
5.7/5.8-6.3
Lime causes pH to…
rise - become more alkaline
citric acid causes pH to…
lower - become more acidic
ratio of NO3:K and Ca:Mg
3:1
optimal EC
0.75-2.5 uS
When do you want lower/higher EC?
lower - greens/leaves
higher - fruit
too high of this can cause plants to wilt even though they’re getting enough water
Electrical Conductivity
benefits of calcium
prevents blossom end rot; gives lettuce its crunch - in cell walls
How to add Ca
CaNO3 (calcium nitrate); CaCO3 (lime - raise pH); CaSO4 (gypsum - pH stays the same); egg shells or bonemeal for organic option
what causes plants to not be able to take up Ca?
humidity - not as much transpiration happening
NFT
nutrient film technique
goals of a hydroponics system
deliver water, nutrients, and oxygen to the plant
benefits of hydroponics compared to field production
yield is greater in weight, nutrients are sent directly to the roots (plants require less energy to uptake nutrients), requires less water, faster growth, no soil, less disease, less pesticides
when do you need an air pump?
when there’s no air gap in the water to add oxygen - when there’s no water falling
Flow rate
0.2-1 liter per minute
optimal slope for NFT
1”:50”
what does a lower slope cause?
algae blooms, stagnate water, hotter water, plants won’t get nutrients fast enough
causes of algae blooms
lower slope, oxygen depletion, stagnate water
most common soilless media
rockwool (volcanic rock and limestone) and perlite (neutral with lots of air space)
What causes the price of local food to become the same prices as shipped food?
the price of fuel - higher fuel price causes shipped food to be more expensive
optimal temperature for growth (most plants)
80-85 degrees
