Horticulture Exam 3

Why gorw interior plants?

• aesthethics

• personal wellness

• hobby

• air purifucatio

• cultural significance

• food

• “something to care for”

Case Study: Aroid Craze

Environmental Factors to consider:

llight - measured by “footcandle” or how much light is cast by a candle on white room

, temp, relative humidity

-sunbleaching and decidng what windows is best - direction of windows greatly influence quality plants

• if we have an eastern facing window, the plant will get lots of light throughout the ENTIRE day, or a southern window!

Cannot changge just temp or heat, need to chanfe both

reduced humidity environments = plants transpire more since air is hotter

plants with hairy leaves should not be sprayed with water becasue the hairs will grab onto it and could lead to leaf rotting

Nutrition:

some are heavy feeders or light feeders

the more ligth = more photsynthesis = more nutrition needs to be provided - also dependent on plant species

soil/growing media:

qualities aof a good growing substrate: well drsined, erll aeratd, approprairw water goldign capacity and suitable pH

to increase pH

to neutralize: limestone to add Ca + Mg to reduce acidity

field soil (dirt from your yard) is not appropriate for house planrs or 99.9% of container production.

perlite = volcanic glass expanded like popcorn, inert and neutral pH and increase porosity

vermiculite = heat- expanded mica, sterile, inert, neutral pH, increase soil porosity + airspace annd very very lightweight and ideal for plants being shipped, often used ogt new seedinfs, can compact and increase ability to hold water

peat = mined from ancient bogs in sub-artic, organic by natuee, highly acidic and can decmpose over time and increade water holding capacity - nonrenewable

coconut coir - believed to be renewable., made from husks of coocnuts, sligthly less acidic than peat moss but more aeratd and less water holding capacity than peat

• pine bark

acclimation = adaptiion of plant to a new environment and it is very imortant of yhe heralth and growth of indoor plants

• two methods : start plant growth at acclimation conditions or slowly acclimate plant over a 4-6 week period

• light con=mpensation point = the light intensity in which the rate of photosynthesis is equal to the rate of respiration

containers:

plastic and ceramic pots better for plants that requires lots of water

plants that like a drier soil settinf and lots of gasa exchange do petter in terracotta plants which are more porous

• container with holes in the bottom are always goingto be better than those with no holes

-acclimization is important for transpiration

• differences between temp, humidity and light in production vs indoors:

  • temp is higher in production because of supplemental

  • indoors are cooler darker and dryer

what is an orchid?

-flowering monocots in the same family ‘Orchids’

• parallel leaves, flower parts in multiples of 3 (3 petals, 3 sepals)

• grown predominantly for their flowers

over 800 species

• there are monopodial orchids - one plant and do not spread just start at a single point and just grow up

Terrestrial orchids - orchids that grow out of the soil like other plants

-Lithophytic = orchids that cling to rock faces and crevices, obtaining nutrients from both the rock surface and the rain or air.

-Epiphytic = orchids clinging to other plants or their remnanta, and get most of their nutrients from the air/rain.

• velamen = spongy tissue on the outer root that absorbs water

• pseudobulbs = fleshy stems that store water and nutrients, not true bulbs usually made out of stem or leaf tissue instead of root tissue

• Epiphytic + lithophytic orchids are typically grown in large bark and charcoal or are mounted to wood planks

  • terrestrial; orchids can be grown in fine bark, sphagnum moss, or peat-based mix

• temps + humidity can vary from cool-damp to hot-dry

know : orchids have 3 petals and 3 speals and one of the petals is a modified peytal that is the labellum or lip which is where pollinators can land on and pollinate plant.

orchid flowers often come on long stems that are compunded

• sympodial orchids can grow through runners

Micropropagation Pathway:

1. explant

2. dmd

3. md

4. smd

5. final step

protocorm-like bodies

shoot tip culture = not appropraie for monopodial orchids because we need the shoot tip and if culture is unsuccessful, then we have lost the monopodial plants bc it can no longer grow upwards and out.

intergeneric hybridization = orchids can produce offspring wiht species from other genera

Things to kow: wjhat is inflourensence

niches, 2 main growtrh habits, organ modifications uniqiue to orchids, primary propagation style ( tissue cultue) , what is an intergeneric hybrid?

Lecture 4/14- Weed Control

allelopathy = plants secreting toxic chemicals substances to interfere with the growth of other plants around it

mechanical weed control:

-milling

-mulching

-soil solarization = clear plastic creates greenhouse effect and heats up soil which can kill weed seed in summer or can induce growth of weeds in spring for early termination and removal

-cultural control of weeds

-biological control of weeds:

• use of living organism to contril weeds : inscrts, fungi, goats/ other anikals that grazw

Mycoherbicides = fungal herbicides ( may be applyng the spores of a fungus or even through sprays ) , difficult to work with or more harder to intergate because they are a bit slightlhy complicated to keep ., species specific, usually more expensive

-chemical control of weeds

How weeds are classified:

-habitat

• aquatic, terrestrial, or aerial environments

-life cycle

• growth habits

  • prostrate growth habit = plants grow straight across ground

  • climbing - twining growth habit in which twining plant stems grow in a spiral pattern

  • erect growth habit

• cylces:

  • annuals

    • winter annual (c3 plants)

    • summer annual (c4 plants)

  • perennials

  • ex: mugwort

-taxonomy

• Broadleaf (dicots)

• monocots

• grasses

  • differentiating grasses:

    • ligule

    • auricle

• sedges/kyllingas

-physiology

Lecture 4/21/25

germplasm = sum total of a plant’s genes