The War of the Roses Case Study 1, Part 2

When Jason went back to school he took a sample of leaves from his mother’s rose bush with him. “I’ll show these to Professor Jackson and Professor Perkins and see if they’ll tell me what’s up with the roses. I’m sure they’ll know, and they can tell me what Mom should do about it.”

Professor Jackson was out, but Professor Perkins was in her lab, where she was busy studying diseases that affect apple orchards. “Sure, I’ll look at it,” she said. “Apples are in the rose family, and there are some shared diseases.” When Professor Perkins looked at the rose leaves, she smiles. “Jason,” she said, “you should recognize this from your textbook. It’s a common problem of roses.”

“Um, really?” Jason asked. “What is it?” “Oh, no,” Professor Perkins replied. “I’m not letting you off that easy. I want you to tell me what it is. First, is it a disease, an insect problem, or something your mother is doing wrong?” Jason looked puzzled. “Well… since she’s treating all her roses pretty much the same, I don’t think it’s something she’s doing. But then again, if it’s a disease or an insect, wouldn’t all of the roses be affected the same way?”

“Not necessarily,” Professor Perkins replied. “As with most plants, some varieties are more disease- resistant. So how can we find out what is causing these spots?” “Look at them under the microscope?” Jason guessed. “That would be a good start. It might tell us whether we’re dealing with a disease, or very tiny insects.” Professor Perkins helped Jason take a small sample from the leaf surface and put it under a microscope.

Under the microscope

“So what do you see?” Professor Perkins asked. Jason pondered for a moment. “The cells of whatever is on the roses look long and stringy. Fungus cells look like that. Those smaller cells look like spores. Is it a fungus?” “That’s a good hypothesis,” Professor Perkins said. “How can you find out if you’re right or not?”

Question Set 2 1. Is the problem with the roses a disease, an insect problem, or something to with the way the roses were cultivated? How do you know? List at least three sources of information that support your answer. 2. Why is the problem affecting some of Mrs. Cook’s rose bushes, but not others? 3. Why is it more difficult to diagnose a plant disease than a human disease?

Write a summary Explain how the disease affects plant tissues, growth, and the transport of water and nutrients. If you were Jason, what steps would you recommend your mother take to solve the problem with her roses? List several measures that can be taken, and the advantages and disadvantages of each.

To turn in: Question sets 1, and 2 Plant disease sheet Summary Turn in by Wednesday, April 30