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Greening Up the Greens - Transpiration Application Scenario: Greening up the Greens Patricia Hain Department of Agronomy and Horticulture at University of Nebraska-Lincoln, USA Roch Gaussoin Department of Agronomy and Horticulture at University of Nebraska-Lincoln, USA 2005 This scenario accompanies the online lesson, "Transpiration - Water Movement Through Plants", and is designed to allow you to apply the concepts learned in that lesson to a real-life problem. Lesson Navigation Tips: - To answer questions, select the button next to the correct answer and then select 'check it' to see if you are correct. - To review concepts from the Transpiration - Water Movement Through Plants lesson, click on the link below each question. - Click once on figures to see enlarged versions. Scenario You are a student intern for the summer at Fall Oaks Golf Course in eastern Nebraska. After working there for a month you notice that the greens are not in the greatest condition. In the morning the greens are a lush green color, but then during the middle of the day areas turn bluish-green to brown. The greens seem to recover their green color later in the day, but the plant density (thickness of the greens) has been steadily decreasing since you started working there in early June. The other intern, who worked there last summer, comments that it sure didn’t look like this last year! Greens under heat stress turn bluish-green to brown in color and plant health decreases. (Roch Gaussoin, 2005) You decide to impress your boss by taking the initiative to determine how to correct the problem. Before you can make a recommendation, though, you need to gather some information to figure out what the problem is and how it can be remedied. Your first step is to find out more about the management practices for the greens. You can ask your boss, a Certified Golf Course Superintendent, any of the following questions. How much is the golf course used? What are the greens like? Are the greens fertilized regularly? How is pest control addressed? Are the greens receiving enough water? What was the temperature in June & July of 2004? What was the temperature in June & July of 2005? Question : Based on the information you have so far, what do you think is the most likely cause of the problem? lack of fertilizer disease insects water stress heat stress foot-traffic from golfers Question : What is happening to the environment around the grass plants as the air temperature increases (providing no other conditions change)? the water holding capacity of the air increases the relative humidity of the air is less than the same air sample at a lower temperature the driving force for transpiration increases all of the above To review this concept click on the link Transpiration - Factors Affecting Rates of Transpiration. Question : How do the grass plants cool themselves? transpiration sweat stomata close all of the above To review this concept click on the link Transpiration - What and Why. Question : In addition to cooling the temperature of a plant, transpiration is important to a plant for many reasons. Which of the following is NOT an important result of transpiration? enables the plant to access nutrients in the soil carbon dioxide entry allows toxins to exit through open stomates. water uptake for biochemical process and turgor To review this concept click on the link Transpiration - What and Why. Question : When the transpiration rate is extremely high, plants are highly susceptible to __________ . wind light cavitation excess water uptake To review this concept click on the link Traspiration - Major Plant Highlights. Question : The creeping bentgrass plants on the greens protect themselves from losing too much water by… opening stomates to increase transpiration opening stomates to stop transpiration closing stomates to increase transpiration closing stomates to stop transpiration To review this concept click on the link Traspiration - Major Plant Highlights. Question : If the grass plants are not transpiring, what will happen to them? wilt heat up, causing proteins to break apart and cell death stop photosynthesizing stop biochemical processes requiring water all of the above To review this concept click on the link Transpiration - What and Why. Question : Why do the greens seem to recover in the evenings and mornings? less foot traffic allows the plant to rebuild cells the air temperature decreases and transpiration can resume to cool the plant the grass plants have more water available in the soil because that’s when the greens are watered stomates are closed at night allowing the plant to store up water and green up To review this concept click on the link Traspiration - Major Plant Highlights. Question : How could you get the greens to recover during the day? cool the temperature of the air and plants heavily irrigate during the day to get more water to the roots restrict foot-traffic on the greens all of the above To review this concept click on the link Traspiration - Major Plant Highlights. Describing your findings to your boss, he recommends a management technique called “syringing” be done to the greens in mid-afternoon. He describes “syringing” as a light application of water that is sufficient water to wet the green surface but move minimally down into the soil. Syringing a green. (Roch Gaussoin, 2005) Question : Why would this be effective when the roots are not receiving much moisture? the relative humidity would increase encouraging the stomates to open and transpiration to resume the water would cool the temperature of the plant and the air temperature around it even a little additional moisture for the roots is better than nothing when it is so hot, plants can take in water through the stomates To review this concept click on the link Traspiration - Major Plant Highlights. As a result of your accurate assessment and consultation with your boss, you begin syringing the greens. Over the next few days you see a marked improvement in their appearance. Healthy greens on a golf course. (Roch Gaussoin, 2005) Development of this lesson was supported in part by the Cooperative State Research, Education, & Extension Service, U.S. Dept of Agriculture under Agreement Number PX2003-06237 administered by Cornell University, Virginia Tech and the American Distance Education Consortium (ADEC) and in part by the New Mexico and Nebraska Agricultural Experiment Stations. Any opinions,findings, conclusions or recommendations expressed in this publication are those of the author(s) and do not necessarily reflect the view of the U.S. Department of Agriculture. Take Quiz