Shelf Planting and Light Intensity

Shelf Planting and Light Intensity
5/26/2018
Looking at the cups of plants of my 2018 planting, I again question the intensity of light on the different areas of the shelf.

2018 planting seed cups.

 

The cups of plants in the middle are getting more of a dose of light.

The cups of plants on the edge aren't getting light from the reflective curve portion of the light apparatus.

I had these thoughts for last year's 2017 Planting. It seems the plants on the edge of the shelf are green and grow tall. They may be taller because they are reaching for light. They may be green in order to process as much light that does hit them.

Sarracenia flava var rugelii x Sarracenia flava var atropurpurea variety Waccamaw seedling positioned to get less of the light from the grow lights.

The plants in the middle, under more light, seem to remain dwarf, are more red rather than green, and don't grow as tall. Maybe not having to reach for light, no need to grow tall. Maybe since they are getting a lot of light, no need to produce as much chlorophyll (green) to process as much light that does hit the plant.

Sarracenia flava var rugelii x Sarracenia flava var atropurpurea variety Waccamaw seedling positioned to get a lot of light from the grow lights.

 Although smaller, the plants in the middle seemed to have more pitchers.

Removing the affect of positioning of the 2017 not pictured here: Cups of plants the 2017 Planting were placed randomly on the shelf, a system that required a random number generator (this is different from me just hap haphazardly picking a cup and putting it where I felt like). The random placement was chosen to remove differences that could be caused by positioning. For the Portulaca Planting, I randomly moved plants every week in order to prevent any affects of their area on the shelf. I did not remove the affect of position in reference to the light in this 2018 planting, light I believe has an influence.

Different species: Last year I had so many different species. Different species will grow differently. This time I have the same type of seeds in all cups being tested.

Last year (2017) I cross pollinated one of my most vigorous plants, a Sarracenia flava var rugelii (purchased from Meadowview Biological Research Station on March 19, 2016) with a Sarracenia flava var atropurpurea variety Waccamaw (purchased from Meizzwang on February 15, 2017). I bought the Waccamaw plant as a flowering size plant, and for the cost, it came with a flower. Since my Rugelii had flowers, why not? Lets see what happens. From the Waccamaw flower, the pod was recently transplanted and may not have been 100% giving me just 36 seeds. From the Rugelii flower, it grew well under the conditions of a grow-light, inside an apartment, and I obtained 263 seeds. Note this was in the middle of the Appalachian Mountains of Pennsylvania. Light is poor and temperatures get cold. Haha, being so high on the mountain you might think well I was closer to the sun it should be warmer and sunnier, hahaha I joke because it doesn't work that way.

2017 Partial Plant Collection Grown Inside an Apartment. R = Rugelii. W = Waccamaw. Flowers are circled. Cross pollinated sweet plant love~

Fast forward to the 2018 planting (Planted February 25, 2018), I planted all the seeds from the cross. From the Waccamaw flower (Waccamaw the mother, Rugelii the father), 1 of 36 (3%) seeds germinated. That 1 seedling later died. From the Rugelii flower (Rugelii the mother, Waccamaw the father), 127 of 260 (49%) seeds planted germinated. Of the 127, 86 survived (68%)  to the end of Week 13.

Back to the question of light intensity, since I had so many seeds and planted so many cups, and the cups not shuffled or randomly placed to avoid the affect of positioning, I can then analyze cup positioning related to light.

Cup positioning. Numbers represent plants. The yellow rectangle represents the positioning of the light apparatus.

I counted the plants, the numbers of pitchers on the plants, and decided my own light intensity categorization on the plants. The light intensity categorization ranged from 1 to 4. 4 being directly under the lights. 3 getting some direct and some neglect. 2 on the edge of the shelf away from the light. 1 being on the corner... I felt like it.

Light intensity under grow lights base on cup positioning on the shelf keeping in mind the edge, edge of darkness.

Then I made a table. "Number" is the cup number, a label rather than a measurement. "Plants" are the number of plants in the cup. "Pitchers" are the total count of pitchers on the plants in the cup. "Pitcher/Plant" is the number of pitcher divided by the number of plants in a cup. "Light Intensity" is a light assignment number I chose based on positioning of cups to the shelf in reference to the light and the edge of the shelf, 1 is the least light, 4 is the most light.

Then I do what I do for most of my analyses:

Data Analysis

Light category represents the light intensity. The numbers in the light blue represent the samples. Count is the number of samples for the light intensity. Average is the average of the samples for each light intensity. StDev is the standard deviation and StdError is the standard error for each of the light intensity categories. StdDev is calculated using the =stdev function in Excel. StdError is calculated by dividing the StDev by the square root of the count, example: =StDev/(SQRT(count)). Note the blue text is not part of the function, rather the cell selection.

This now reduced table is all I need to make a graph. The category is there, the average for the bar, the StdError for the standard error bars.

The graph on the x-axis represents the light categories from 1 to 4. The y-axis indicates the average number of pitchers per plant. The number inside the bar are the number of samples used for the bar average. The error bars are 1 standard error of the samples for each category. Note the error bar for light intensity 1 is 0 because both samples were 2, no error... variation/noise to say. The graph reveals the potential for more light intensity may cause the seedlings to grow more pitchers. The bigger bar of light category 4 has no overlap in error bars with the other light intensity categories. It averages nearly half a pitcher more than the other category nearest category. I need to run a statistical test to confirm what I see in the graph, but I am too lazy today and might do it later. When I do, I will lists the instructions on how to do it. The graph was easier to see than reading the positioning chart:

Are more pitchers a good thing? Is more light a good thing? I like the more pitchers because I think it is the plant struggling for nutrients from insects.

Thanks for reading!
Questions or comments let me know!
 Have a Great Holiday Weekend!