The Effect of Distance from Fruit in Donald Wyman Leaves


Is there a difference between chlorophyll content in leaves that range in distant from the fruit that it provides?

The research hypothesis was that the leaves in closer proximity to a crabapple (1-5 cm) fruit would have different phi II, SPAD, and LEF values than the leaves that were distant (25 to 30 cm) from the crabapple fruit.

We will be testing 3 Donald Wyman Flowering Crabapple (malus 'Donald Wyman') trees. We have developed a detailed protocol to gather data in an efficient and random manner. Our materials include a metric ruler, the multispeq device, and an android tablet or smart phone. The ruler is to measure the distance of sample leaves from the fruit. When measuring the tree we will start in the northwest quadrant and measure 5 leaves that are close to the fruit and 5 leaves that are distant from the fruit. We will repeat this in a clockwise manner for the other three quadrants (northeast, southeast, and southwest). We will also repeat this process for the other two trees so that we will have 120 readings per each time we measure data. The measurements we are interested in are chlorophyl content (SPAD) and photosynthetic efficiency (ΦII).

During the experiment, each collaborator spent 2 hours on 3 different occasions collecting data on the Donald Wyman leaves. A restriction present was that only one collaborator was allowed to take measurements within a 24 hour time period. Another restriction present was the weather; it must not be raining in order to collect data in order to preserve the MultispeQ and android device.

Each collaborator collected a total of 40 samples per tree on 4 different occasions over the course 4 weeks of research for a total of 1440 samples. Each person collected a total of 480 samples, 120 samples per tree of the same 'Malus' species.

There will be an analysis for each variable including LEF, PQ SPAD, and PSII. The first test will be a one-way ANOVA that includes all 3 trees of the same species that tests the distance of the fruit from the leaves. The two distances include 1-5cm and 25-30cm for each quadrant sampled. This will be a total of 6 one-way ANOVAS. The second analysis is also a one-way ANOVA that tests the tree comparison for all possible quadrants for all 3 trees. For all 3 trees we will be combining all possible quadrants for the 1-5cm distance range. In addition, all possible quadrants for the 25-30cm distance range will be done. A total of 24 ANOVA tests will be done.

A final statistical comparison is a graph with means displaying a 95% confidence interval for Malus close (1-5cm) to fruit versus the Malus farther (25-30cm) from fruit in a two-tailed t-test.



Leaf Photosynthesis - MultispeQ Beta ONLY

Measures photosynthesis-related parameters in <15 seconds, including: Phi2, PhiNPQ, PhiNO, NPQt, qL, LEF, and SPAD. In addition, measures PAR (photosynthetically active radiation), ambient temperature and relative humidity.

Works with the MultispeQ Beta device only


  1. What quadrant was sampled? (Multiple Choice)
  2. Portion of Tree (Multiple Choice)
  3. Number of Fruit Around Leaf (Multiple Choice)
  4. What is the tree code? (Multiple Choice)
  5. Distance from the Fruit (Multiple Choice)



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