Horticulture bro #3

Hardpan

A layer in soils that is occasionally present. A layer of compacted soil that slows or stops movement of water and air and the growth of roots into lower layers. When air is lacking, roots are susceptible to disease organisms in soil, and weakened/killed. Form naturally or as a result of heavy equipment ( to fix it, dig through it with a post hole digger or construct raised planters). It is accompanied by poor drainage and can be identified by filling a planting hole with water and waiting for it to drain away. If water remains after a half, then it is still present

Earthworms

Feed by passing soil containing organic matter through their bodies, it is subjected to digestive enzymes and grinding action. Material that has passed through the earthworms body is called casting. Castings are higher in organic matter and nutrients. Earthworms are most abundant in moist clay or loam soils rich in organic matter, earthworms burrow increase soil aeration and drainage. After the first cold snap, earthworms acquire cold Tolerance and migrate deeper into soil

Understanding CEC is important in fertilizer application because

Fertilizers need to be applied less frequently to soils high in cation-exchange capacity. Because there is less run-off. Of the three commonly applied fertilizer elements- nitrogen, phosphorus, and potassium- both nitrogen and potassium leach readily in soils with low CEC and mist be applied frequently. Fertilizer can be reduced in high CEC soils by using fertilizers with nitrogen and ammonia form, such as urea or ammonium nitrate

How are fruits different

They are different in appearance by whether the fruits splits and releases the seeds at maturity

Tropical/ subtropical

Do not experience frost and freezes. The true tropics lie between the tropics of cancer and Capricorn with negligible temperature variation through the year

When does dormancy occur

During periods not suitable for plant growth, and is usually seasonally related (winter dormancy is found in areas of distinct wet and dry seasons, such as California or Texas)

Parasitic wasp

Eats: caterpillars, grub, worms, and other pest

12 foods that are fruits

Eggplants, avocados, squash, corn kernels, nuts, sunflower seeds, cucumbers, olives, pea pods, peppers, pumpkins, tomatoes

Scientist researching plant hormones encounter a # of opportunities

- hormone mutant plants - synthetic or extracted hormones to study - hormone analysis -collaboration with other scientists -GFP ( green fluorescent protein)

Scientist researching plant hormones encounter a number of difficulties

- effects of hormones are not the same species to species - slight changes in hormone concentrations can alter their effects completely - two or more hormones are frequently found together (it is difficult to determine which chemical is responsible for a particular effect)

What all does ethylene do

- ethylene is a retardant, with use dates to Chinese practices of ripening fruits in incense-filled rooms (later determined to be ethylene gas given off in the fumes that caused the accelerated ripening) -ethylene is also produced by the ripening fruits themselves, wounded plant parts or by cut flowers (it can be manufactured) - ethylene also ages plant parts such as flowers, causing them to abscise, and induce de flowering in limited number of species

Gibberellins are used in greenhouses to

- form tall tree-form fuchsias and geraniums from cuttings -increase the size of grapes by elongating flower parts - substitute the vernalizing azaleas and fruit trees in the south

Hormone summary

-auxin (root growth) -gibberellin( elongation) -cytokinin( above ground growth) -ethylene( ripening) -abscisic acid(drought signaling) -salicylic acid( resistance to pathogens) -jasmonic acid( regulating plant responses to pathogens and stresses)

Types of precipitation

-condensation occurs above freezings( dew point is above 32°) -drizzle: water droplets less than .5mm -rain: water droplets greater than .5 mm -condensation occurs below freezing -snow: water condenses below freezing directly into small, loose ice crystals

The rhizosphere: soil-plant interface

-dynamic and active environment -influencing plant health -nutrient uptake, soil chemistry, water, and inputs

Growth flush includes

-leafing our of trees -emerging and blooming of bulbs -blooming and fruit setting in fruit trees -new shoot growth in shrubs

Hormones and growth-regulating chemicals

-plant hormones are chemicals -made within the plant -produces changes in growth -plant growth regulators are synthesized chemicals like plant hormones, which have the same effects (may be chemically quite similar to hormones but they do not occur naturally) -nine groups of plant hormones have been identified

Heat symptoms

-scorch -failure of flower buds to open -bleaching of leaves to a paler color -failure to grow at a normal rate -or failure to produce fruit may all occur (leaves may drool even though the plant is receiving regular watering; plants may also become more attractive to insects)

Flower to fruit

-seed -young plant -mature plant -flower -fruit

The growth patterns of plants very widely from seasons to season depending on plant types

-some are spring bloomers, others don't flower until fall -some begin to grow as soon as snow has left the ground ( asparagus) -others produce no growth until all chance of frost is gone (lilies)

The baseline temp below which very little growth occurs is established for each crop

-subtracted from the average temp for a given day •these daily measurements can then be added and compared to an established standard for that crop to determine when the crop will mature

Addition to amendments

A soil amendment is a material added to the soil to improve physical properties such as drainage, CEC, aeration, and water retention. It may or may not supply nutrients, addition of amendments for soil improvement will greatly influence gardening success. The best amendment is chosen by considering the problem to be corrected, it's seriousness, properties of amendments available and cost

Soil layers

A-topsoil b&c- horizons are the subsoil ( low in organic matter and relatively infertile. Progressively lighter in color than topsoil) roots grow in A&B horizons and sometimes big trees in C horizons

Gibberellins

Activity associated with: stem elongation; breaking dormancy of seeds, buds, and tubers; increases in flower, leaf, and fruit size; inducing flowering in plants that normally require vernalization or a specific photoperiod

During cool periods of outdoor microclimates

Additional warmth speeds up or prolongs growth, but if a wall faces south it may be excessively hot in summer and damage can occur. At night when temp drop, objects begin losing heat to the cooler night air (heat radiating from the ground can protect plants from frost and extend the growing season)

Water In soil

Adhesion holds water iN the soil rather than allowing it to flow through. At the same time water is adhering to soil particles, it is also cohering to other water molecules. In addition to moving down in soil, water may also move sideways and upward (due to combined forces of adhesion and cohesion called capillary water) analogous to water that moves upward in a straw placed in a glass of water

Climate and seasons

All parts of the U.S. and Canada are considered temperate zones (with normal seasons: summer, fall, winter, spring) seasons are sometimes classified as wet or dry

Relative humidity

Amount of water vapor in air expressed as a percentage of the amount of water vapor that could be held at saturation

Specific humidity

Amount of water vapor in air expressed as grams water per kilogram of air (g/kg)

Vapor pressure

Amount of water vapor in air expressed as the downward pressure exerted by the water vapor present in the atmosphere

absolute humidity

Amount of water vapor in air expresses as grams water per cubic meter of air (g/m3)

Humidity

Amount of water vapor in the air

Cytokinins

Are believed to work in conjunction with light to increase cell division and enlargement -have also been shown to prevent chlorophyll degeneration and break axillary bid dormancy. Their only commercial horticulture use is in tissue culture, where they stimulate callus growth

Fruit

Are classified based on the appearance of the fruit tissue. Primary differences is the fruits are fleshy or dry

Clay soils

Are often referred to as heavy soul, composed primarily of platelike clay particles. The small size and flattened particle shape are responsible for the properties of clay soils. Because they are flat they are able to lie close contact with one another. They have the ability to hold large amount of water, slow movement of water and air in the soil, small and numerous pore spaces, good ability to attract and hold nutrients(cation-exchange capacity). Water movement through pores determines whether drainage is good( fast) or poor(slow). Plasticity( sticky and moldable while wet)

Microclimate

Are small areas w/ slightly different climate characteristics than the surrounding land. May be less windy, shadier, moister, warmer, or in any other way different from the typical climate. These differences affect plants, sometimes helping and sometimes hindering growth. Microclimates May be either artificial or natural. They can be formed by the natural terrain & vegetation ( or unintentionally created by structures, fences, and roadways

Vitamins

Are sold occasionally as stimulants for plant growth and for use after transplanting ( the same sole for human use but act more as hormones for plants, particularly B vitamins) vitamin effectiveness hasn't been determined fully ( when used on bean seed, limited experiments have shown improved germination rates and decrease the time from seed sowing to harvest. Increases in yield have been reported on some species)

Fleshy fruits

Are those that contain appreciable amounts of water. Most eating fruits. Most vegetables from which the fruit is eaten( cucumber, squash, eggplant)

Partial shade

Areas that receive direct sunlight for about one-third to 1/2 of the day •East and west facing walls of houses • under small/finely foliaged trees that admit filtered sun

Full shade

Areas where the sun rarely shines directly • northern sides of house, narrow areas between houses • under large trees & other areas shaded most all day

When will annual plants begin senescence

At flowering and will die soon after seed formation is complete

Plant hormones effect on roots

Auxin is essential for early root development, promotes root elongation at [very low], inhibits [higher], promotes lateral root formation. Abscisic acid promotes elongation, especially under drop stress. Ethylene inhibits elongation

Why does light intensity affect photosynthesis

Because, in general, the brighter the light intensity, the more photosynthesis occurs. Moderate to bright light intensities are most beneficial (latitude will alter intensity)

At high elevation adaptive strategies

Both cold and drying winds become factors in plant survival (the term tree line refers to the elevation at which trees can no longer grow due to climate extremes) in growing conditions w/out much sun, leaves of plants are very large to expose the maximum amount of leaf area to the available sunlight

How is senescence characterized

By dramatic changes in metabolism: increased respiration, decreased photosynthesis, breakdown of larger molecules into smaller ones (proteins, fats, and carbohydrates)

How else are fruits classified

By the position of the seeds relative to the fruit

Cation-exchange capacity

CEC of a soil is the relative capacity of a soil to attract and hold nutrients (cations) on the surface of the soil particles. Soil/ organic matter particles have negative charged and they attract positively charged ions from the soil water and hold them against the surface of soil particle

Heat

Can break dormancy in some seed. Forest fires destroy existing trees, but also trigger the germination of dormant pine seed. Only intense forest fire heat will weaken seed costs of some pine seeds that are woody and thick. Most seeds require less drastic measures to break dormancy

Fog and mist

Can influence plant growth greatly. In coastal climates, the moisture from fog and mist is absorbed by plants, supplementing not enough rain. At the same time this vapor slows loss of water from leaves

Precipitation

Can take many forms including rain, snow, hail, and sleet (rain is the greatest value to outdoor plants) lack of rainfall is a limiting factor to plant growth (particularly in western U.S. where irrigation is essential to grow plants)

Sloping terrains

Can vary in temp by several degrees from the top of the slope. Cool air is heavier than warm air, will flow down the slope and collect at the bottom, a phenomenon called air drainage. Plants growing higher on the slope are less likely to be damaged by cold than those at the bottom

Seasons

Caused by the unique tilt of the earth and orientation to sun

Sodium and ammonium amendments

Certain amendments are high in these chemicals. In drier parts of the hemisphere, rainfall is often insufficient to wash away the salts, resulting in salt toxicity to plants. Manure often contains high levels of ammonia salts and will burn plants if used in large quantities. Ash content often contains high levels of ammonia salts and will "burn" plants if used in large quantities. Ash content also refers to the amounts of mineral matter present in the amendment. In organic amendments, low quantities of ash are usually undesirable, as ash does not improve the soil. Leaf molds and manures and composts often contain large amounts of ash

Terrain( topography)

Changed in terrain alter climate, particularly rainfall. Most rainstorms move from west to to East in North America. The narrow range of hills, west facing slopes often receive much more rainfall than east facing slopes. Heaviness of the water in rain clouds prevents them from passing over mountains until most of the precipitation has been released. The drier region on the eastern slopes often referred to as rain shadow

Elevation

Changes in elevation can give areas only small distance apart completely different climates for plant growth. Higher the elevation of an area, the cooler the average year-round temperature. Every rise of 300 ft caused an average temp decrease of 1°f

How breaking dormancy works

Chemical scarification can weaken the seed coat, such as through the swallowing of seeds. Acid of the stomach eats away the seed coat, and the seed is deposited along with the feces of the animal (a sort of built-in fertilizer)

Pinching agents

Chemicals are used commercially to kill terminal vegetative buds (to promote branching and a more bushy, attractive plant: Offshoot-0 and Atrimmec are mainly used for this purpose

Maturity

Color changes result from the breakdown of chlorophyll and accumulation of other pigments. Chlorophyll decreases and other pigments increase intensity

Types of condensation: fog

Condensation of water into small droplets that stay suspended in air close to the earths surface

Types of condensation: cloud

Condensation of water into small droplets that stay suspended in air high in the atmosphere

Types of condensation: dew

Condensation of water onto solid surfaces

Seeds are "dormancy"

Conditions needed to break dormancy and start germination are specifically geared to ensure seedling survival. Many seeds require winter vernalization

Seed coat

Consists of one or more protective layers that encase the seed

Follicle (split)

Contains one locale that splits along one or more suture. (Larkspur, sweet gum, magnolia)

Legume or pod (splits)

Contains one locale that splits along two structures (bean, pea, peanut, mimosa)

Capsule (split)

Contains three or more locales that split along three or more sutures. (Okra, golden rain tree, tallow tree)

Condensation

Conversion of water vapor to liquid or ice; condensation occurs when the temp drops below the current dew point

Soil crusting

Crusting refers to the formation of a thin, hard soil layer at the soil surface that impedes movement of water and air and may physically impede the germination of seed. Most common in soils deficient in organic matter, seldom a problem where organic matter is returned to the soil

Winter solstice

Dec 21 or 22, when earths axis is tilted 23 1/2 away from the sun -colder due to: suns rays spread over larger area - suns rays pass obliquely through thicker layer of atmosphere -shorter days

Senescence of perennial plants is frequently called

Decline: asparagus is a perennial that suffers from decline. The productive life of asparagus plants is generally 20 to 25 years. As plants reach this age, yield drops off and the bed is replanted

How can humidity determine how well a plant will grow

Defined as the amount of water the air contains relative to the amount capable of holding at that specific temp. * often higher humidity improves plant growth by reducing the rate at which plants lose water*. Low humidity will not seriously hinder growth of most outdoor plants is there is adequate water around the roots. Indoor plants in cold winter climates are commonly damaged by insufficient humidity

American horticultural society heat-zone map

Divided the US into 12 heat zones. By the average number of days per year the areas experience temperatures over 86°f. The range is from 0-210 heat days per year. Heat tolerance rating is listed next to USDS cold hardiness number. Stress that will independently and together alter ability of a plant to grow with in specific heat zones: light deprivation, microclimates, soil characteristics, plant nutritional status.

Soil testing

Establish a grid pattern over the area being sampled and take a small sample from each grid intersection. Each individual sample can be best taken by digging a hole 6" to 8" deep and skimming a small slice of soil off, from the top to the bottom of the hole. At least a dozen samples should be combined in a plastic bucket and mixed thoroughly.

Ethylene

Ethylene involved in ripening fruits. Also ages plant parts such as flowers causing them to abscise

Plant hormones

Ethylene, auxin, cytokinins, jasmonic acid, brassinosteroids, gibberellins, abscisic acid, salicylic acid

Too much precipitation

Excessive rain or rain occurs g out of season can be as detrimental to plants as lack of rainfall ( excessive rain can kill plants adapted to dry areas) unseasonable rain near harvest can make strawberries watery-tasting, and split unpicked apples and grapes. Frequent rains spread plants disease by splashing microorganisms from one leaf to the next, triggering the growth of dormant disease organisms present in plants

Pericarp

Exocarp, mesocarp, endocarp

Fall

Fall is a transitional season for plants that live year-to-year and the end of life for those living one season. - those surviving the winter engage mechanisms to ensure their winter survival:dropping leaves and stopping new growth (nearly static state to await favorable growing conditions) -plants that live one year have produced seeds capable of sprouting in the next growing season ( and must have dispersed those seeds throughout the area by their own unique evolutionary means)

Winter

For most plants, winter time is waiting (when temp are below freezing, water is solid and cannot travel readily throughout the roots and stem) -lack of water and leaves drastically slow biochemical processes in the plant -until the return of favorable growing season (except for evergreen plants such as pines, spruces, firs, and junipers) -it is advisable to water evergreens during periods of thaw when souls is able to take moisture( this can help avoid unsightly winter burn)

Minimum winter temps limit areas where many plants live

For some plants lack of cold prevents survival (fruit trees, flowers) for temperate zone fruits, an adequate number of cold days per winter, the chilling requirement, is essential for normal growth and fruit production ( apples and cherries) each types of fruit and variety of fruit has its own specific requirement. Each crop also needs a certain number of adequately warm days in order to mature, the growing degree-day requirement

Spring

For the majority of plants in temperate zones, spring is when yearly growth takes place ( some plants such as grapes, make all new growth for the year during this 1-2 month period; others like lawn grasses, continue to produce new growth as long as the weather is favorable)

Full sun

Found on the south side of houses or with no trees, shrubs, or structures to block light •full sun can also be on the west side of houses in western U.S. as the afternoon sun in these areas can be very strong.

Frost

Frost can be one of two types radiation and hoar frosts. When plants are covered by a barrier blocking flow of heat to the sky, frost can often be prevented. Clouds form this barrier, and radiation frosts seldom occur on cloudy nights. On clear, protection by layers of newspaper, cloth, smoke, or plastic film can serve the same function. Sprinkler irrigation of plants is also used to prevent frost.

Berry

Has one or more seed in a soft fleshy covering (grapes, tomatoes, raspberries, and blackberries)

Drupe fruits

Have a fleshy exterior and a single seed encased in a hard covering (peaches and plums)

Indoor microclimates

Have varying temperatures, light, and humidity. Light microclimates are easy to detect, being governed by the size and location of windows.

What can growth retardant be used on

Headed and lawns to slow growth and decrease maintenance. They can also be used to maintain bedding plants in a compact size, giving plants a neater appearance in formal landscapes

Challenges in soil

Home gardeners often in position of trying to garden in areas where developers have removed topsoil during construction, leaving only subsoil. Due to the inherently infertile nature, a successful garden takes extensive use of soil amendments and management

Water in soil saturation

If enough water is added to the soil, it will becomes completely saturated. After any excess (gravitational water) has drained away, the soil is said to be at field capacity. As water evaporates or plants absorb it, the water content drops until none is left that plants can use (called the permanent wilting point, the only water left in the soil is hygroscopic, held too tightly together by soil particles for plants to remove) available water for plants growth is between field capacity and permanent wilting point

Indehiscent

If they do not split (pods such as beans and peas)

Dehiscent

If they split

Summer solstice

June 21 or 22, when the earths axis is tilted 23 1/2 towards the sun - warmer due to: suns rays concentrated over smaller area - suns rays travel through thinner layer of atmosphere - days longer

Salicylic acid

In the fourth century BC, willow leaves/bark extracts were used to relieve fever and the pain of childbirth. It plays a role in the resistance to pathogens. Involved in plants growth and development, photosynthesis, transpiration, ion uptake and transport

Dry fruits

Include sunflowers, pecans, and others that contain very little water

Organic matter in sandy soils

Increase the action exchange capacity: water and nutrient holding capacity

Endocarp

Inside

Stratification

Involves storing moist seeds at temperatures near freezing for one or more months. (Peach and apple seeds are stratified before planting)

Abscisic acid (ABA)

Is a growth retardant that may induce abscission and does induce dormancy and inhibit seed germination - it's action can be counteracted by growth-inducing chemicals such as auxins, gibberellins, and cytokinins -VERY INVOLVED WITH STRESS RESISTANCE

Carotene

Is a pigment that gives orange color to fruits such as oranges and persimmons

Dormancy

Is a stage of plant development where growth slows or stops, affecting all life stages from seed to maturity (important in adapting plants to environment and ensuring survival)

Acidification in soil

Is generally accomplished by using sulfur or aluminum sulfate, or organic amendments like oak leaves, pine needles, or sphagnum moss. Overuse of aluminum sulfate can result in aluminum toxicity and when using organic amendments , large quantities are needed and change very slow. Fertilizers like ammonium and potassium are also acidic and acidify soils.

Dew

Is most likely to occur when air is warm and humid. (After sunset, air temp drops, and the atmosphere is unable to contain the water it held during the daytime. Water precipitates out, in the small droplets called dew) although it's effect on most plants is not great, it can be a factor in the spread of disease in turf grass. It is also an important water source for plants that absorb water readily through their leaves

Lime

Is one material used to raise the soil of pH. Ground limestone or calcitic limestone is most common and least expensive. Dolomitic limestone also provides magnesium. It will take 3-6 months to accomplish pH change due to the slow speed at which lime dissolves (finely ground lime mixed thoroughly in soil can speed change. Surface applications of lime are only minimally effective in raising the pH below the soil surface.

Organic matter in soil

Is relatively small quantities (a few percent). However, greatly influenced soil properties: -responsible for half of cation-exchange capacity -in sandy soils, organic matter increased water and nutrient holding capacity -in clay soils it improves drainage and air movement and decreases compaction and plasticity

Anthocyanin

Is the pigment responsible for the red color of ripe strawberries and apples

Wind

Is the the 5th climatic element governing growth. Ocean wind limits the number of plants that can be grown near shoreline (by salt spray, which browns plant leaves; by intensity, which whips and breaks leaves and branches) hot desert winds increase the rate of moisture loss from the soil and plant leaves, intensifying drought conditions. Subzero winds in cold northern areas damage evergreens by removing moisture from foliage, freeze-drying it

Simulated vernalization

Is used to break dormancy (commercial nursery crop production)

As permanent wilting point approaches

It becomes more difficult for the plant to absorb water, until the plant is unable to remove any water from soil. The relative amounts of the soil water that are available to a plant: the difference between field capacity and permanent wilting point. Because soils predominantly clay and heavy are capable of holding more water, their available crop is greater.

Classification the soil texture triangle

It combines and converts relative percentages of each major component( measured by weight) into a textural class or name

why is the duration of daily light a plant receives is important

It determines the period of time it can manufacture the carbohydrate necessary for growth. Duration of night also affects the start of some plant processes, such as flowering.

Bodies of water

Large bodies of water exert strong effects on the climate of nearby land. The enormous volume of water absorbs heat in summer, making adjacent land cooler, and gives it off in the winter, raising the temperature. Growing plants near water in warmer winters has a positive influence on plants

High CEC (clay)

Large quantity of nutrient can be held by each soil particle. when a fertilizer is added, a large amount of the nutrient will be held in the soil. Absorbed nutrient can't be leached out of soil by watering- they are stored for future plant use

Acidifying soil pH

Large scale acidification can't be done due to high cost, instead soil immediately surrounding and acid-loving plant is adjusted. Agricultural sulfur is common acidifying agent and less costly than aluminum sulfate, but greater quantity is required and effect is slower. Souls with high buffering capacity will require larger quantities of pH-adjusting materials than with those of low buffering capacity

Light duration

Light duration, intensity, and quality affect growth of outdoor and indoor plants (may control flowering and growth rate) -light duration depends on distance from the equator and season( at the equator day and night are equal length all year) -north and south of the equator, days become longer in the summer and shorter in winter (the further from the equator, the greater difference between longest summer day a shortest winter day)

Sandy soils

Light soils, can be thought of as possessing the opposite properties of clay soils. Don't retain moisture well nor expand and contract. Cation-exchange capacity of sandy soils is very low, so nutrients wash away readily when water drains through. Inability to hold water, rapid movement of air and water in the soil( good drainage), large and fewer pore spaces, does not expand or contrast as result to water, poor ability to attract and hold nutrients for plant growth, no tendency toward compaction, not plastic when wet. Irregular shaped and don't pact tightly.

How have evergreen leaves adapted to minimize water loss in dormancy

Limited surface area

sleet

Liquid rain droplets fall through a layer of freezing air and then freeze

Hail

Liquid rain droplets fall through a layer of freezing air and then freeze; air currents carry the frozen droplets back up into the upper atmosphere; they pick up more water, then freeze upon falling through the layer of frozen air

Relationship between humidity and temp in precipitation

Loss of atmospheric water; occurs when condensation is extensive enough that water or ice coalesce to form droplets/crystals that fall from the atmosphere due to the force of gravity

Winter light intensity

Lower because of distance through the atmosphere the rays must travel (lesser amount of light signals plants become dormant. For evergreens, lower light intensity of winter is sufficient to continue photosynthesis and sometimes growth.) Indoor plants can be seriously retarded by the decrease in light, as many are already growing at subsistence light levels

Soil biology- fauna( animals)

Macrofauna (large animals): gophers, mice, burrowing insects, grubs, spiders, ants, sow bugs, centipedes, earthworms, slugs, snails. Their tunneling brings subsoil to the surface continuously

Verbal or spring equinox

March 20 or 21, when earths axis is oriented/ tilted neither towards or away from the sun

Pome fruits

Mature from multiple-seed ovary (apples and pears)

Mesocarp

Middle

Outdoor microclimates

Natural examples is a frost pocket: colder, possibly moister due to water runoff (suitable for moisture-loving plants not easily damaged by cold) another natural microclimate is found under trees: shadier/cooler in summer, good for shade-loving plants or growing indoor foliage plants outdoors in summer

Factors modifying climate

Natural factors include distance from equator, elevation, terrain, and nearby presence of large bodies of water

No water in dormancy means

No photosynthesis

Radiation frost

Occurs when the air is cool and calm and skies are clear (warmth from the sun accumulated by soil and plants in the day is lost at night as heat radiating upward) if the day was warm and night only slightly below freezing, heat in soil and plants may last all night and offer frost protection, if not then frost damage will result

Samara (not split)

One or two seeded with pericarp flattened into wings (maple,ash)

Achene (not split)

One seeded fruit with seed free from pericarp (sunflower)

Caryopsis or grain (not split)

One seeded fruit with seed fused to the pericarp. (Wheat,corn,grain)

Organic matter in clay

Organic matter in clay soils is to cause aggregation. When organic matter decomposes, resulting humid acid acts as glue, causing clay particles to clump loosely. They form a structure of much larger particles that functions more like sand. When clay soils are worked while wet, aggregates are broken apart, resulting in poorer structure. Clay soils should never be distributed until they are dry enough to let soil crumble easily in the hand. Another beneficial effect of soil organic matter is decreased tendency of soil to crust

Classification ( organic soils)

Organic soils ( include I gotta muck and pear) contain predominantly decaying organic matter- with smaller amounts of mineral components. Generally found in small pockets in north central and northeastern sections of US and Canada. Organic souls are very fertile, but do not respond the same as mineral soils

Exocarp

Outside

Climate modification by humans

People can modify climate intentionally/unintentionally. Among the most widespread unintentional cause of climate change are air pollution and consequent smog. Smog affects plant growth by temp modification acting like an insulation layer, preventing heat from escaping. Particulates settle into leave and decrease light reaching plants. Smog affects plant growth through foliage injury by toxic gases entering leaves, causing them to partially brown and sometimes to die. Plants classified at intolerant cannot be grown in smoggy areas

Summer

Period of maturing plants. -tomatoes and corn have their flowering period -fruit trees enlarge/ ripen fruits -new tender leaves toughen to leathery texture •many plants accumulate energy in the summer to enable them to live through the long winter (during which it will have no leaves and be completely dependent on the food stored in its roots and branches)

Wind in outdoor microclimates

Plants by a wall will receive wind protection unless it is directly in the path of prevailing winds. When two walls are parallel, a wind tunnel can be formed and wind conditions will be worse there than in a completely unprotected area.

Adaptive strategies of plants for climate tolerance

Plants have evolved adaptive strategies to cope with adverse environmental conditions. The most common is winter dormancy. Plants in desert areas develop the ability to store water in their leaves, making leaves fleshy and thick.

Frost hardy

Plants that are able to survive temps lower than freezing. They vary widely in tolerance to sub freezing temperatures. In some cases woody portions or root system may be frost-hardy but not flowers or leaves. Some garden flowers die to the ground in fall but grow back from the roots the following spring. some houseplants and many tropical plants suffer chilling injury at temperature less than 50°f

Reducing erosion

Prepare individual planting holes for shrubs or ground covers, is better than tilling the entire area. If disturbed the area then plant immediately after preparation (the soil surface should be mulched to stabilize to soil and reduce water loss) do not over water (match irrigation rate with soil type so run off doesn't occur) where extensive bank areas are to be planted, commercial hydro seeding is a good option

A colorful show of leaf senescence occurs during

The fall when trees turn color. Shortening of day length in fall and cooler temperatures trigger this senescence

Classification ( mineral soils)

Primarily by the size and quantity of mineral particle present in soil (from clay particles, to silt, to sand) the properties of silt are intermediate between those of clay and sand. Basic understanding of soils can be obtained by considering mainly the properties of clay and sand.

Loam soils

Process qualities of both sand and clay proportional to the relative amount of clay or sand particles in the loam soil. Considered ideal for most plants because the do not have extreme properties of either sands or clays. Loam soil will absorb a large quantity of water and not require frequent irrigation, yet be dry enough to be workable faster than clay soil. Loams also hold more nutrients than sandy soils, yet not prone to become if cloudy and compacted.

EPTC and amidochlor

Reduce growth or flowering but can't stop it completely

Maleic hydrazide and mefluidide

Reduce growth or stop flowering

Jasmonic acid

Regulating plant responses to pathogens and stresses. Flower development and leaf abscission. Tuner formation in potatoes and yams. Response to wounding of plants. Systemic squired resistance

Soil mineral components

Sand particles- 2.0-.o5 mm silt particles-.05-.002 clay particles- smaller than .002

Top portions of herbaceous perennials and bulbs senesce annually, but the root system remains alive

Senescence

Fall equinox

Sept 22 or 23, when earths axis is oriented to but neither towards nor away from the sun

Different environmental conditions in outdoor environmental conditions for plants living near the house

Shielded from rainfall by an eave, so the soil will be drier. The wall may afford protection from cold or drying winds. radiates warmth from the heated dwelling

Nut (not split)

Similar to an achene, but one seeded by abortion and partially enclosed (acorn) or entirely enclosed by a husk (pecan, walnut)

The importance is snow

Snow cover plays an important role in plant survival in areas with cold winters. protects low-growing plants from low-temperature damage due to the chill factor or drying injury due to sublimation of the frozen water from plants

Maturity- over-ripening

Softening of fruits is the result of the breaking down of compounds called pectic substances, which strengthen cell walls and cement cells together. In over-ripening, mushiness occurs because too much pectic substance has been lost

Other things that affect soil health

Soil biology and soil pH

Microorganisms in the soil

Soil contains a vast, ever-changing population of microscopic, plants, fungi, bacteria, and animals. These animals affect soil and higher plants by improving drainage and aeration, assist in decomposition of organic matter, aid in plant nutrient and water uptake, and cause disease, or feed on plants, insects, or pathogens. Included are such animals as earthworms, insects, nematodes, mycorrhizae fungi, algae, and bacteria.

Classification

Souls seldom contain only one type of particle. ( they contain several types in varying percentages) soil is classified to the type of particle that predominates

Endosperm

Source of stored food consisting primarily of starches

Inorganic amendments

Such as vermiculite and perlite are usually too expensive to be used in soils. Though they are commonly used in potting soils. Sand is sometimes used but must be used in large quantities to be effective. Inorganic amendments often cause permanent effects, whereas organic amendments must be added periodically

Growth retardants

Synthetic and natural growth retardants are sold under the trade names A-Rest, B-Nine, Bonnie, Sumagic, and Cycocel. Used on florist crops such as poinsettias and chrysanthemums (they slow elongation of stems, making them sturdier, fuller plants) on fruit crops they improve color, firmness, and storage life.

Auxins

Synthetic auxins, available in garden centers, have a # of practical home use (powders sold to encourage rooting of cutting are composed of manufactured auxins in a talcum base; 2/4D sold to control lawn weeds, is an auxin which kills many plants at high concentrations, but at low concentration it is a growth enhancer; high auxin concentrations can prevent fruit on ornamental trees when it is an undesirable feature) In commercial agriculture, synthetic auxins defoliate plants before harvest, prevent sprouting of potatoes in storage, and prevent premature orchard fruit drop.

Temperature

Temp largely determined the geographical range over which a plant will grow( particularly minimum winter temperature) the lowest temperature that a plant can withstand is called cold hardiness or cold tolerance. For many plants 28°f is the minimum because at this temperature the liquid contents of the plant cells freeze and the plant dies( these plants are designated as frost tender)

Senescence

The aging of a plant or any of its parts. Natural part of life cycle of the plant or as a result of environmental factors

The amount of amendments

The amount depends on the material chosen and severity of soil problems (usually used in large quantities and as a general rule, 25% of soil volume) usually spread over the surface of the soil to a depth of several inches, then spade or rototill it into the soil. Large quantities of amendments are added, the process is best repeated several times. A 2-inch layer of amendment incorporated each time.

Due to elevated differences

The appearance of frost in some areas but not in other areas close by. Cold air is heavier than warm air and flows down to the lowest area

Climate

The average atmospheric conditions over a long period of time

Soil improvement and soil testing

The best way to determine the pH and nutrient content of a soil is to have it professionally tested. In most of the US a soil test can be performed for a small charge by the cooperative extension service and in other areas in commercial soil testing labs. The most important step in soil testing is taking a sample, which must be representative of the area being tested or it'll be meaningless. To obtain a representative sample, a combined sample is taken from the area.

Breaking dormancy

The change over from dormancy to active growth. Normally results from changing environmental conditions

Weather

The current and temporary atmospheric conditions

Abscission

The dropping of plant parts (involves hormones and the formation of a sone of abscission)

Elements of climate

The elements combining to make up climate include primarily: temperature, precipitation, humidity, light, and wind (each has a wide range of variation and dramatic effect on plant growth)

Auxin(IBA)

The first hormones discovered: promotion of rooting, formation of underground tubers and bulbs, prevention of fruit formation (defoliation), prevention of abscission of leaves and fruits, auxins promote juvenility, auxins made in the terminal bud is responsible for suppressing the sprouting of axillary further down the stem of a plant

Erosion

The movement of soil particles from one place to another. A process detrimental to the fertility of the soil (water and wind are usually the agents) it is most likely to be a problem on steep banks where water erosion will result in the moving of soil from the top of the bank to the bottom

Experiencing frost

The northern parts of the U.S. and almost all of Canada experience freezing of the ground during winter. In unseasonably cold years many plants may "freeze out" as a result of the temperature around the root zone being to cold for the plant to survive. Freezing of the soil causes water contained in it to expand, and may cause frost heaving ( soil pushes up around the roots of plants leaving cracks over the root area, exposing them to dry winter wind.) gardeners frequently lay a thick layer of mulch over root areas of plants they know to be borderline cold-hardy

Poor CEC (sand)

The number of cations each sand particle can attract is low. Due largely to small surface area of each particle

How many microorganisms

The numbers of each organism depend on soil conditions such as: moisture, aeration, organic matter content, and temperature, soil acidity and alkalinity, species of plants present

What determines the fruit structure

The ovary; fertilization of the egg starts fruit development. Ovary wall develops and differentiates into the fruit wall (pericarp)

Soil pH

The pH of soil is a measure of acidity or alkalinity which is measure on a logarithmic scale from 0-14. pH of 7 is neutral, above 7 is basic, below 7 is acidic. Optimum range is 6.5-7.0. The pH of 6 is 10x more acidic than of pH of 7.and pH of 5 is 100x more acidic than 7. Plants adapted lower pH are called acid - loving. A soil that is not optimum may be corrected by adding materials to the soil to change pH.

Where is the zone of abscission Formed in simple leaves

The point where the petiole connects to the stem

Where is the abscission zone in compound leaves

The point where the petiole reaches the stem ( individual leaflets may form abscission layers and drop)

Matrix potential

The potential energy of water in its attraction to soil. To extract water from the soil, a plant must overcome the matrix potential of the soil. In unsaturated soil, matrix potential comes from capillary and adhesion forces. Plants can absorb water through the roots easily when the matrix potential of the soil is high and soil is full of water ( field capacity). When the matrix potential is low (less water in the soil), plants can't absorb as easily

Addition of amendments

The quantity of nitrogen in an amendment, relative to carbon content (C:N ratio) is important and how rapidly it decomposes. If the amendment decomposes rapidly, with little nitrogen, soil nitrogen may be taken to supply needs for decomposing the amendment. The nitrogen is released when decomposition is complete, but in the meantime, nitrogen deficiency symptoms can occur in plants growing in the area. To counteract this, a fertilizer containing nitrogen should be added with the amendment

Plant growing zones in north america

The question of where in the country a specific plant can be grown is important. There is little worry in plants bought at local nurseries.

Hoar frosts

The second type of frost is caused by cold air mass moving into an area (carrying off heat from the plants, which are then frosted) frost often leaves ice crystals on plants and the ground in early morning, are called hoar frosts (called black frosts, because the first sign of their occurrence is the blackening of injured plants)

Achenes

The seeds can be born outside the juicy part (strawberries, dandelions)

Plants "yelling" for help

The smell of cut grass is the plants way of signaling distress. This summons beneficial insects to rescue

Soil biology

The study of soil organisms. It has revealed an interdependent population of organisms in the soil that makeup an interrelated ecosystem or food web

Dew point

The temperature where relative humidity equals 100%

Maleic hydrazide, melfluidide, EPTC, and amidochlor

These chemical must be used carefully and the results are not always predictable; unacceptable color loss, injury and lessened ability of the turf to recover from disease and pest problems can result

How can microclimates be used

To provide the specialized growing conditions favored by different plants. In some cases they make it possible to grow plants not normally considered cold-hardy in that area.

USDA plant hardiness zones

USDA has prepared maps showing zones of minim winter temps in the US and Canada. Eleven zones are outlined, ranging from completely frost free areas Florida, Texas, California. The map takes into account cold mountain climates in warmer zones as shown in Colorado.

To minimize erosion

Use appropriate plant materials to cover the bank. Extensive, fibrous root systems and spreading growth habits. The gardener should disturb the soil as little as possible

Air and water in the soil

Varying amounts of air and water are contained in soil. WHEN EITHER WATER OR AIR IS LACKING IN SOIL, PLANTS DIE. A good soil will provide a balance between both. In a sandy soil, lack of water commonly restricts growth and in heavy clay soil ( poor drainage), growth may be restricted by lack of oxygen for root respiration. Soil pore spaces are filled with either air or water. The balance between air and water is partially determined by the soil itself (pore size/number) and water supplied. Small pores hold water better than large pores.

Organic matter

Vegetative matter such as leaves and roots, and animal products like manure, returning to the soil and decomposing. Plants can be grow. In pure organic matter quite well

Adaptive strategies

Water loss from leaves in less severely dry climates can be reduced in two ways 1) by a wax layer the plant excretes to cover its leaves 2) a thick covering of silvery hair that reflects sunlight and also insulated the leaf from air

The seed coat eroded enough by _______ to permit germination

Weather; it can also be weathered artificially by scarification (Cutting, scraping, or otherwise injuring the seed coat enough to allow water absorption and germination)

Can photosynthesis happen at temperatures below freezing

Yes, however dry winter air can cause plant damage or death, especially if groundwater is frozen or unavailable

Embryo

Young multicellular organism before it emerges from the seed

Sleet, hail, freezing rain

•can be very injurious to plant health - sleet and hail tear leaves and bruise or knock of fruit - freezing rain often causes branch breakage of trees -heavy snowfall can cause breakage due to its weight