Hort120 Final Exam

hot temperature adaptations

Rolled leavesLeaves more upright/verticalHeat shock proteins to help prevent denatured proteinsChange composition of cell walls

cold temperature adaptations

Freezing resistance through extracellular ice formationShort (appropriate) growing seasonSmall habitShaped to shed snow

very wet adaptations

Leaf drip tipsAerial rootsFloating stems or leavesRot-resistant wood

dry adaptations

Losing leaves in dry seasonThick, waxy leavesTap roots and/or shallow rootsWater storage structuresSmall leaves to reduce evapotranspirationThorns or spikes

Increased temperatures means increased transpiration

When the temperature is higher, the "bucket" of relative humidity gets bigger, so plants lose water more quickly. CO2 "fertilization" from climate change will probably help plants grow bigger and better as long as they aren't limited by nitrogen or water (or other things).

threat of climate change to water quantity and quality

Earlier snowmelt, reduced water supply, more intense and frequent drought, degraded water quality, excess soil moisture, and greater flooding, all of which will alter crop and animal production

ways to help protect water quantity and quality

Target existing programs to support water issuesBuild resilience by enhancing soil healthInvest in water management infrastructure and adaptive irrigation systems

threat of climate change to vulnerable communities

Socially disadvantaged, low-income, minority, and rural populations are more likely to be vulnerable to the impacts of climate change.

ways to help protect vulnerable communities

Engage meaningfully with impacted and vulnerable communitiesEvaluate programs and activities for risks to communitiesProvide assistance and resources

threat of climate change to increased natural disasters

More frequent and intense disruptive events including hurricanes, floods, drought, and fires, which can have significant impacts on agriculture and forestry.

ways to help protect against increased natural disasters

Update vulnerability assessmentsUse monitoring tools to build resilienceBuild forest and grassland resilience through management, planning, and responsesStrengthen disaster assistance and relief programs

horticultual climate change call to action

Freeze Agriculture's FootprintGrow More on Farms We've GotUse Resources More EfficientlyShift DietsReduce Waste

freeze agriculture's footprint

Trading tropical forest for farmland is one of the most destructive things we do to the environmentMost of the land cleared for agriculture in the tropics is used to produce cattle, soybeans for livestock, timber, and palm oil.

use resources more efficiently

precision agricultureaquaponics

shift diets

55% percent of the world's crop calories are fed to people directly~36% are fed to livestock~9% are turned into biofuels and industrial products

reduce waste

About 25% percent of the world's food calories and 50% of total food weight are lost or wasted before they can be consumed.Combat food waste by serving smaller portions, eating leftovers, and encouraging cafeterias, restaurants, and supermarkets to develop waste-reducing measures.

ecosystem services

the direct and indirect contributions of ecosystems to human wellbeing, and have an impact on our survival and quality of life.the equivalent of $125 trillion in services per year

ecosystem services provided by plants

regulatingprovisioningculturalsupporting

regulating services

Plants help control floods, diseases, pests, and the climate, and provide for water purification and pollination.

supporting services

Plants form the critical base of food chains in nearly all ecosystems.

cultural services

Plants are valuable to human cultures for recreational, spiritual, and healthful uses.

provisioning services

Plants provide products such as food and resources, including wood, oil and medicines

plant propagation

The reproduction or duplication of a plant from a sourceSexual - propagated via seedAsexual - propagated vegetatively (clones)

cultivation

the act of caring for or raising plants

domestication

the process whereby wild plants have evolved into crop plants through artificial selection

when to select asexual propagation

Some plants produce few viable seedsWant highly uniform plantsOutcrossing plants produce highly variable progenyAble to combine favorable traits into one plantSeeds can have complex dormancies

when to select sexual propagation

Requires specialized resourcesGenotype dependentTime and energy intensiveIncreasing chance of infection with ageLong life cycle may show new somatic mutations

sexual propagation - self pollination

The transfer of pollen grains from the anther to the stigma of the same flower or another flower on the same plantOffspring are similar to parents*May not be possible*

sexual selection - cross pollination

The transfer of pollen grains from the anthers of a flower to the stigma of a flower on another plant of the same speciesOffspring are not true to type but may be better than their parents

fertilization

the union of gametes, an egg and a sperm to form a zygote

seed

a mature ovule of a flowering plant

seed storage

in their original packaging in a cool (below 50 degrees Fahrenheit), dark place where their moisture (

seed viability

percentage of seedlings that develop from the number of seeds planted

tetrazolium test

based on the presence of dehydrogenase activity in viable seed tissues during the respiration process.Dehydrogenase can catalyze the colorless 2,3,5 triphenyl tetrazolium chloride solution into a red dye formazanTherefore, living tissues of seeds that imbibe tetrazolium chloride will be stained red, while dead tissues will retain their natural color

seed dormancy

The failure of viable seed to germinate under adequate environmental conditionsSurvival mechanism in the wildMany prairie seeds have dormancy

seed coat dormancy

Imposed by the seed coatNeed scarification to breakSurface is mechanically scratched or rupturedHeat treatment - typically boiling waterAcid - concentrated sulfuric acid

physiological dormancy

imposed by the embryoneed stratification to breakChilling temperatures (1-7℃)MoistureAdequate oxygenPeriod of time

seed certification

Created to protect and maintain the genetic quality of cultivars (cultivated varieties)costs more but assures quality

asexual propagation

Reproduce plants with the identical genotype of the parent plant○ Flower, foliage, fruits, disease/pest resistance, etc.○ Not possible through seed propagation\***Clones can become infected with viruses that are passed along the daughter plants\***

asexual propagation - cutting

A piece of vegetative tissue that when placed in the proper environment regenerates the missing parts and develops into a self sustaining plant

totipotency

a single plant cell has the genetic potential to grow into an entirely new plantStem, Leaf, Leaf-bud, Root

factors influencing rooting with cuttings

Source of material and time of yearYounger and nonfloweringEtiolation - absence of lightTreatment with AuxinMisting - need near 100% humidityBottom heat - roots 6℃ above shoots

asexual propagation - grafting

Art of joining the scion and rootstock together so they will unite and continue their growth as one plantPropagate plants that are difficultto rootProvide disease resistance to asusceptible but desirable cultivarTo rapidly increase the numberof a desirable cultivarTo repair a damaged plantTo change plant size

asexual propagation - layering

Instead of severing the part to be roots it is left attached and receives water and nutrients from the motherAfter stem (layer) has rooted it is cut form the mother plant e.g. rhododendron, honeysuckle, boxwood, azalea, and wax myrtle

asexual propagation - runners

Some plants grow a rosette crown with runner (stolons) arising from the crownNew plants arise from nodes at intervals along the runners

asexual propagation - suckers

Some plants produce adventitious shoots or suckers from their horizontal root system.Individual shoots with a piece of old root can be dug out and replated.E.g. blackberry and raspberry

asexual propagation - separation

A number of herbaceous perennial plants have structures like bulbs, corms, tubers, and rhizomesIn bulbs and corms the newly formed plants break away from the mother plant naturally

asexual propagation - division

A number of herbaceous perennial plants have structures like bulbs, corms, tubers, and rhizomesIn tubers and rhizomes they can be cut apart

asexual propagation - micropropagation

Using very small pieces of plant tissue or single cells, grown on sterile media, to regenerate new plantsTotipotency: a single plant cell has the genetic potential to grow into an entirely new plantExplantsCallusPollen grains

benefits of using plant tissue culture

Store large number of varieties in relatively small footprintControlled environment, protect from transmission of disease & pestsAbility to remediate pathogen infectionsPathogen-indexed stock remains cleanNo pesticide use/limited antibiotic use

costs of using plant tissue culture

High initial setup costSkilled labor is necessary; incorrect sample handling has long-term costsLonger time than traditional clonal propagation systemsHave to plan further ahead than most other propagation systems

ecosystem

Interacting living organisms + non-living environment(Interacting Biotic + Abiotic)

agroecosystem

Managed organisms + non-living environment(Cropping System + Abiotic)

cropping system

The crop(s), their sequence(s), arrangement(s) and management

crop succession - continuous cropping

Cultivation of a single crop to be the most profitablePros: Specialized - less equipment; High efficiency; Simple managementCons: Limited to suitable soils; High erosion; High fertilizer input; High water demand; High risk; Lower yields

crop succession - crop rotation

Series of growing different crops in the same area-Increased biodiversity-Plant nutrition-Soil structure-Pest and disease prevention-Improved water quality-Weed suppression-Less risk

crop succession - fallow

Land parcel that is left unplanted for a growing season
Wind or rain carry away the topsoil of a bare fieldCover crops can protect against this

fallow syndrome

a drop in the yield or health of a crop grown on a previously bare field

cropping pattern - monoculture

Advantages:-Easy to harvest-Targeted pest control-Targeted nutrient management-Specialized crop varietiesDisadvantages:-Heavy chemical pest control-Heavy synthetic fertilizer-Lower biodiversity-Increased risk

cropping pattern - polyculture

Growing 2+ crops on a single land parcel in the same year-Benefits: Reduce risk: spread among crops; Reduce pests; Lower overall inputs; Reduce erosion; Promote soil health; Income diversification-Disadvantages: Difficult to mechanize: many types of machinery are needed need or custom planting/harvestingDifficult to manage - time consuming and a lot of record keeping; Crop choices are critical: poor choices can lead to increased pests, erosion, competition and nutrient loss

cropping pattern - companion cropping

Planting different crops in close proximity for:Pest controlPollinationProviding habitat for beneficial insectsMaximizing use of spaceIncrease crop productivity

cropping pattern - living mulch

Any plant that is used to:Cover an area of soilAdds nutrientsEnhances soil porosityDecrease weedsPrevents soil erosion

cropping pattern - cover crop

A crop grown to benefit the soil rather than yieldProtect soil from erosionAbsorb excess nutrientsEnhance soil fertilityReduce weedsControl soil moisture

cropping pattern - relay crop

A second-planted crop is planted into an established cropCrops share a portion of the growing season, increasing solar radiation and heat available to each

cropping management - industrial/conventional

Heavily utilized synthetic inputs for nutrients and pest managementFocused on profits onlyDegrades the land/soil

cropping management - sustainable

"Able to be maintained at a certain rate or level"Utilize some synthetic inputsFocused on profits over soilNeutral impact on the land

crop management - organic

Specifies production practices that must be followed to be "certified organic"How is it regulated?-National Organic Standard (NOS)-NOS Board-Volunteers: farmer, industry, science, consumer advocates

cropping management - regenerative

Zero synthetic inputsFeeds the soil while profitingConstantly improves the land

inorganic fertilizers - feed the plant

Synthetic fertilizers are water-soluble and can be taken up by plants almost immediately.May burn plants!

organic fertilizers - feed the soil

Remains or by-products of plants or animalsRelatively low nutrient contentsContain micronutrientsSlow release - low burn potentialImprove soil health

irrigation methods

Flood - flow downslope, must be flatFurrow - confined to furrow, plants in raised bedsSprinkler - overhead applicationDrip - apply water more precisely

precision agriculture

Use of information and technology to improve management capabilities and sustainability

Benefits of Precision Agriculture

Increased crop production and qualityImproved management costs and efficiencyMore performance measuresIncreased sustainability

barriers of precision agriculture

Additional education, knowledge and experience needed"Big Data" privacy issuesEquipment compatibility/capabilityIncreased costs to startNegative past experience

environmental modification

Walled gardensIrrigationWeed removal (competition)TerracesMulches

Growing environment efficiency

field < high tunnel < greenhouse

crop pest

any organism capable of causing damage to crop plant

recent pest threats

-spotted lanternfly: feeds on grapes, hops, fruit trees and many other crops, plants and trees.-emerald ash borer: killed hundreds of millions of ash trees in North America. Cost municipalities, property owners, nursery operators and forest products industries hundreds of millions of dollars.

crop pest types

Vertebrate (birds and mammals) and Invertebrate Predators (Insects) - cause damagePathogens (Bacteria, Fungi, Viruses, Nematodes) - cause diseaseWeeds (plants) - cause competition

insects

-Over 1.5 million species globally~80,000 species in North America6,000 considered pests but not economically harmful200 are considered "crop" pests-Insect structure3-segmented body - head, thorax, abdomenTypically 6 legsMost adults have wingsHard exoskeleton
Type of metamorphosis undergone is very important to pest identification and management

insect characteristics

-Small size: Infiltrate locations easily and undetected-Flight: Disperse rapidly; Cover great distances; Invade new areas easily-Rapid Reproduction: Most species have short life spans; Prolific reproduction; Some are asexual; Develop chemical resistance easily-Highly specialized body parts: Fill niches in the ecosystem

direct insect damage

Chewing - feed directly on or tunnel into plant tissues; Easy to identify if on outer tissueSucking/Piercing - puncture plant parts with stylet into the phloem; Injury symptoms include discoloration, leaf curling, plant stunting or deformities

indirect insect damage

-Insects can be vectors for disease: Carry disease from plant to plant; Create wounds for plants to infect-Insects often leave behind residue: Fungal spores stick to it and grow; Steals photosynthates from plants

detrimental effects of insects

-Tissue loss = loss of photosynthetic area if leaves-Stem/Stalk damag: Lodging occurs-Seed damage: Poor germination and stand establishmentPoor seed quality = less money-Disease vector: Carry disease from plant to plant-Root loss: Lower water and nutrient uptake; Lodging possible-Premature Plant Death-Higher Production Cost

favorable insect conditions

-Continuous crop on crop production: Same crop = same habitat; No genetic diversityNew Introduction: Could be problematic if no natural pests are around-Weather conditions: Conditions favor growth and rapid development; Ex. warm and wet weather-Reduction in natural enemy populations: Insecticides can kill beneficial insects

benefits of insects

-Pollinators: Plants with colorful flowers; Most fruit trees; Almost all cross-pollinated plants benefit-Products: Honey, Beeswax, Silk, Shellac, Pigments-Biological Pest Control: Lady beetles attack aphids-Food for Wildlife and Fish

plant disease

disturbal by a causal agent (pathogen) that results in abnormal physiological function that alters the structure, growth, function or other activities of the plant
may reduce yield and quality

Plant disease triangle

host, pathogen, environment

integrated pest management (IPM)

practice that utilizes all suitable pest management techniques and methods to keep pest populations below economically injurious levels
Each pest management technique must be environmental sound and compatible with producer objectives

IPM philosophy

Recognize there is no "cure-all" in pest controlDetermine and correct the cause of the pest problemRecognize that eradication of the pest is seldom necessary or even desirable, and generally not possible

principles of IPM

-Knowledge of the crop, pest and available resources-Requires advanced planning and organization-Maintaining good communication to acquire and disseminate knowledge-Balances cost/benefits of all pest control practices

IPM cultural control

Favor plant development and minimize pest activity-Regionally adapted plants-Irrigation practices-Crop rotation-Fertility management-Seed certification

physical/mechanical control

Prevent pest access to the host or area, or, if the pests are already present, physically removing them-Plastic mulch-Sticky traps-Row cultivation-Cleaning field equipment-Removal of pests/infested plants

IPM genetic control

Use pest-resistant plant cultivars-Plant breeding or GMO/gene editing-Examples (Mi locus in tomatoes, Bt transgene in corn)-Pyramiding resistance is a better long term practice

IPM biological control

Use predators, parasites and diseases of pests to suppress pest populations-Release of predators/parasites/disease of an insect or weed-Can be time consuming, expensive and difficult

IPM chemical control

Only when other control practices are not available, economical, or practical
Used with there is no risk of environmental damage or when benefits outweigh the risks
Must monitor pest populations in the field-Identify the pest-Is the life stage susceptible to pesticide?-Will the pesticide/herbicide/fungicide target only pest?

IPM regulatory control

Role played by government agencies in trying to stop the entry or spread of pests into an area or into the country
Inspection, quarantine, destruction of infested material, and other methods-EPA-APHIS

harvest

The final step of production: Digging, picking, cutting, lifting, separation, grading, sorting, cleaning, conveyance, loading-Care must be taken not to damage the product-Fresh market vegetables and fruits and nearly all cut flowers are still harvested by hand

transportation

Produce/products must be transported from where they are grown to where they are consumed-Truck: Haul the majority of all perishable goods; Dock to dock; Greatly impacted by fuel price-Rail: Maybe cheaper than trucks-Air: High-value, perishable crops (cut flowers, strawberries, pineapples)-Waterway: Efficient handling of containerized freight

storage principles

CoolingAppropriate moistureDehydrationCanningProcessing with sugarProcessing with salt