Monday, October 8, 2007

Module 7 - Watering (Irrigation) DUE Tuesday, Oct. 23

Automatic Irrigation System for Hanging Baskets

INTRODUCTION
This module consists of three subject areas that overlap. First, by reading the textbook you should develop an understanding of the importance of irrigation and the biological functions that water drives in plant growth and development.

Second, you will take a look at the many different types of irrigation systems that are now available for greenhouse growers to choose from. These range from the trusty watering wand to high-tech automated watering systems like the one shown in the image here that combines a hanging basket conveyor with a two tiered water water delivery system.

Finally, you will examine the impact of automation on the greenhouse industry.

LEARNING OBJECTIVES
  • Explain why a plant needs water
  • Understand how water is taken up and moved through plant structures
  • List the effects of too much water on the growth of plants
  • Discuss how moisture stress affects plants
  • Describe several ways that water may be applied to crops
  • Discuss the current trends in greenhouse automation and speculate on what the future may hold.
Ebb and Flow benches can help reduce foliar diseases, but create other management issues.

TERMS TO KNOW
absorption
alkalinity
reverse osmosis
Moisture Probes
hard water
diffusion
hose watering
softened water
flooding
low volume watering
acidifying water
transpiration
trickle irrigation
chlorine
guttation
drip tube
fluorine
surfactants
moisture stress
spray stakes
wetting agents
soluble salts
boom irrigation
tensiometer
ebb and flood irrigation
capillary mat

READING ASSIGNMENT
  1. Read Chapter 8: Watering in your text. pages 257-301
Ebb and Flow system adapted to the entire floor of a greenhouse.

ACTIVE LEARNING EXERCISES
  1. Watch Audio PowerPoint Lecture on Greenhouse Irrigation (approx. 40 minutes). Depending on your Internet Connection Speed this may take some time to download.

  2. Search the Digital Greenhouse Repository using the keyword "irrigation"; study the pictures and read the abstracts when available.

  3. Watch the short video clips showing automated hanging basket and boom irrigation on display at a trade show. Write a paragraph explaining how these systems would not only save labor but could improve plant uniformity, quality, and health. (20 pts).

  4. Briefly explain (based on plant biology) why transpiration rate directly correlates with the rate of photosynthesis in a plant. (10 pts). You may have to do a little searching to answer this one.

  5. Choose 5 "irrigation" images from your search in #2 that show 5 different irrigation methods/systems and describe the advantages and disadvantages of each one. (20 pts). Create a new Google Document Presentation to answer this question. (It's like using PowerPoint, contact your instructor if you need assistance)
Poinsettias on sale in a small-scale production/retail center. Note all the drip tubes, during peak production times there are just as many poinsettias hanging from the frame as are on the benches.

STUDY QUESTIONS (Answer in complete sentences)
  1. Discuss the three rules of irrigation as covered in your textbook. For each rule explain its significance and give an example of what can go wrong if the rule is not followed (10 pts).

  2. Compare and contrast pH and alkalinity. Which is arguably more important for greenhouse crop production? Give two examples of how alkalinity and pH can interact to present special challenges for greenhouse crop production. What corrective steps can be taken to correct for water with high alkalinity? (10 pts)

  3. What is water harness actually a measure of? How does water hardness come into play when trying to maintain the proper balance between calcium and magnesium? What are some general rules of thumb to maintain the balance between these two nutrients? (10 pts)

  4. Compare and contrast 3 different containerized plant watering systems (you can choose). Make sure you indicate the advantages and disadvantages of each. (10 pts)

  5. Some growers insist on hand watering to save costs and maintain irrigation control. Support or argue against this practice with information you learned during this module. (10 pts).
Extra Credit (5 pts). Develop a summer and winter production calendar (dates to transplant) for the hydroponic lettuce system highlighted in the video below.


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