Stress management
This presentation is the property of its rightful owner.
Sponsored Links
1 / 48

Stress Management PowerPoint PPT Presentation


  • 77 Views
  • Uploaded on
  • Presentation posted in: General

Stress Management. Outline. What is stress and how does it affect potato plants? How does stress impact external tuber quality? How does stress impact internal tuber quality? How can you avoid or manage stress?. What is Stress?.

Download Presentation

Stress Management

An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -

Presentation Transcript


Stress Management


Outline

  • What is stress and how does it affect potato plants?

  • How does stress impact external tuber quality?

  • How does stress impact internal tuber quality?

  • How can you avoid or manage stress?


What is Stress?

  • Any condition (moisture availability, temperature, fertility, etc.) that is above or below the optimum for plant growth and tuber production

  • The “ideal” temperature for growing potatoes is 77oF in the day and 54oF at night.

“Therefore, potatoes grown in all regions experience temperature stress every year”


What is Stress?

  • The impacts of stress tend to be cumulative

    - 10 days of heat stress is more damaging than 5 days

    - Two stresses together (ex. heat and water stress) tend to cause more damage than a single stress


Moisture Stress and High Soil Temperatures Combine to Cause Damage

No Stress

Hot Soil

Heat cables increase soil temperature by 6 to 9 F

Source: Kleinkopf, 1988


Environment (uncontrollable)

Sources of Stress

  • Heat/cold/frost

  • Drought/excess rainfall

  • Hail/lightening

  • Air pollution


Management (controllable)

Sources of Stress

  • Soil moisture deficits or excesses

  • Nutrient deficits or excesses

  • Poor stand establishment

  • Compaction/root pruning

  • Physical damage to tubers


Water Stress

  • Low moisture availability

  • High demand (heat, wind, excess N)

  • Low capacity (poor root system)


Heat and Water Stress Occur Together

  • As temperatures increase, so does water use by the plant


Effect of ET rate on level of soil moisture that can be used before development of stress

High

Low

Data for a sandy soil in Egypt


Stress–related problems

Internal

  • Hollow heart / Brown center

  • Internal brown spot (IBS)

  • Sugar ends

  • Vascular discoloration

External

  • Tuber size

  • Malformation

  • Second growth

  • Chain tubers

  • Growth cracks

  • Greening

  • Enlarged lenticels

  • Heat sprouts

  • Black heart

  • *Blackspot /shatter bruise

  • Low starch

  • High sugars

  • *Frost

  • *Chilling injury

  • Pressure bruise

*Immediate


From Hiller, WCS 19:169


Stress-related problems

Requirements for Expression

  • Susceptible variety

    +

  • Stress conditions

    • Weather or environment

    • Management mistakes


Common DefectsTriggers

MalformationsHeat, drought

Growth cracksMoisture stress, erratic growth

Sugar endsHeat

Hollow heartCold soil, low tuber set

Stem end??

Low solidsHeat, early death

Net necrosisPLRV

Russet Burbank


Outline

  • What is stress and how does it affect potato plants?

  • How does stress impact external tuber quality?

  • How does stress impact internal tuber quality?

  • How can you avoid or manage stress?


  • During stress low availability of sugars and the imbalance in top/tuber growth can temporarily stop tuber growth. When growth resumes, it occurs at the site of most active cell growth. The end result is malformed tubers that may have knobs

Around the eyes and bud end is where growth resumes


1. How does stress affect sugar development - Energy production and use

  • The temperature optimum for Photosynthesis (energy production) is around 65o to 75o F,Respiration (energy use) continues to increase with temperature

Source: Winkler, 1961


Plants Continue to Produce Sugars on Hot Days

Temperature (F)

  • There is a period during the morning where photosynthesis reaches the optimum, even on very hot days

6182 93 86

“Mid-day depression”

Source: Dwelle, 1983


Dry matter partitioning – two temps

APJ 69:653

Harvest Index = .5 to .7

Harvest Index = .2 to .7


Outline

  • What is stress and how does it affect potato plants?

  • How does stress impact external tuber quality?

  • How does stress impact internal tuber quality?

  • How can you avoid or manage stress?


  • During stress there is less sugar available, and the tuber has a harder time converting sugar into starch. The tuber becomes a weaker sink, and the end result is lower specific gravity and more sugar ends

Stems

Sugar

Starch


Carbohydrate metabolism in potato tubers

During normal tuber growth, metabolism is driven towards the production of starch. Stress (in-season or in-storage) changes enzyme activity and membrane function


Effect of temperature on specific gravity of potatoes

Air Temperature (oF)

Cool (77/54)

Hot (100/82)


Comparison of soil temperatures at Oakes, ND

High sugar ends


Kincaid et al., 1993

R2 = 0.42

Irrigation Frequency

“Soil temperature was directly related to percentage of sugar end tubers”


E

0”

W

36.6%

50.4%

4”

63.4%

8”

75.7%

Impact of row orientation on Russet Burbank quality

Percentage of 10 Tuber Sample with Sugar Ends


Row Width Can Influence Sugar Ends

Source: Shock, 1988


  • The damage that occurs to the starch production system early in the season is permanent – The symptoms usually develop when the tubers are exposed to cold

Storage at 48 F

End of stress

Harvest

Source: Sowokinos


Effect of a single water stress event on the incidence of disorders in Russet Burbank

Source: Shock, OSU


Stress event

High or erratic N availability

Pattern of hormone changes during tuber growth and storage


Outline

  • What is stress and how does it affect potato plants?

  • How does stress impact external tuber quality?

  • How does stress impact internal tuber quality?

  • How can you avoid or manage stress?


Principles of Stress Avoidance and Management

  • Maintain uniform and optimal conditions throughout the plant growth and tuber bulking growth phases

  • Minimize environmental stress

  • Avoid added management stress

  • Plant resistant varieties


Don’t Contribute to Environmental Stress with Management Stress!

  • Poor root development

    • Compaction and late cultivation

  • Poor vine development

    • Erratic stands and early stress

  • Excess vine development

    - Too much N

  • Disease


Plant root systems 21 days after emergence extracted from: compacted soil (left)uncompacted soil (right)


By row closure a healthy potato root system extends more than 3 feet down and across the entire furrow

Source: Modified from Weaver (1926)

1 ft

2 ft

3 ft

Root Pruning

Compact layer


How does a stand like this impact row closure and soil temperature?


Excess Nitrogen Fertility Can Lead to an Imbalance in Vine and Root Growth

Vines with too much N

Roots with too much N


Stress (water, heat, nutrients, pests) can lead to premature plant death


Impact of Resistance on Stress Management

Intensity of Management Required

Resistance LevelInput Level

HighLow

ModerateModerate

LowHigh


Sugar End Susceptibility by Variety

Parma, ID - 1994


Varieties With Stress Resistance

Heat and Drought Stress

Ranger Russet Gem Russet

Russet NorkotahClearwater Russet

Umatilla Russet


Water Use Efficiency (WUE)

18 cwt/ in of water

15 cwt/ in of water


Varieties With Stress Resistance

Defoliation Stress

Ranger Russet Alturas

Gem RussetBannock Russet

Summit Russet

Russet Norkotah (affects yield)


Varieties With Stress Resistance

Stresses Conducive to Hollow Heart

Ranger RussetAlturas

ShepodyUmatilla Russet


Ask questions – gain some wisdom!


  • Login