HORT lab quiz 1

mist is what

a thin layer of water from a pressurized irrigation system

mist does what?

cools the atmosphere, provides a thin layer of water on plant to reduce transpiration

transpiration prevents what

dessication

what is the most crucial part of propagation?

preventing dessication

what are the 2 ways misting reduces transpiration

it cools the leaf temperature, and maintains high humidity conditions at leaf surface

what are the two common types of mist nozzles

orifice and impingement

orifice nozzle

liquid is forced through a very small hole at high pressure breaking it up into droplets

impingement nozzle

a solid stream of fluid impinges on a pin breaking it up into small droplets

misty mist

deflection nozzle; 6 foot spray pattern at 5 feet high

pin perfect

deflection; 10 ft diameter spray pattern at 5 feet high

phyto mist brass nozzle

deflection; flat circle of fog

what are ways to control your mist system

electronic leaf, timers, integrated control units

electronic leaf with electrode

as water evaporates, the sensor switches to open position triggering irrigation event

solenoids do what

shut off, release, dose, distribute, or mix fluids

electronic leaf with balance

large pad acts with digital leaf surface, the sensor being weighed down with water triggers solenoid to turn off flow, when leaf rises with evap. as water evap. the leaf rises triggering solenoid to start irrigation event

timers consist of what

frequency, and duration of misting

head to head coverage

when the water flow pattern overlaps between misters

air currents in the greenhouse can

affect uniformity in misting patterns

higher water pressure affects size how

smaller the droplet size

higher water pressure affects droplet number how

higher droplet number

with a taller riser

the diameter of water spray is larger

with a shorter riser

the accumulation of water in the cups is greater

what three substrates were used for the substrate physical properties experiment?

sand, Vermiculite, and Commercial Mix (promix)

what did we calculate with our substrates and the water drainage?

bulk density, total porosity, air space porosity, and volumetric moisture content

bulk density

the dry mass of a substrate per unit of volume

total porosity

the percent by volume of substrate that is occupied by water and/or air

how do you calculate total porosity

volumetric moisture content + air filled porosity

volumetric moisture content

the % volume of pore space filled with water at container capacity

what equipment should be used for a proper stem cutting

sanitized, sharp shears/knife

cuttings should be __ until stuck in substrate

kept hydrated

why should cuttings be a standard size?

uniformity

what were the types of PGRs used in the stem cutting experiment?

liquid quick dip, talc/powder dip

what is the quick dip concentration for an herbaceous stem cutting?

500-1250 ppm

general process of stem cutting propagations

make uniform cuttings, treat with PGR (and water before if needed), stick to proper depth/spacing, keep hydrated.

basal cut

cut at an angle to promote surface area for adventitious root formation

herbaceous cuttings typically

produce no woody tissue (lignification)

terminal cut

contains a terminal bud

medial cut

contains no terminal bud