What do you mean by "lack of proper lighting"? I know we had a lamp above the experiment, but the experiments set up in our classroom had lamps directly overhead, and the lighting was probably also more concentrated/powerful. Or is it a different type of lighting that was used, or did the overhead lamp that we used light only some of the plants and not all? 

I feel that the plants of other groups were given a lot more room to grow, and we planted three seeds per canister, which is, like, 1/3 of the space that the other teams' seeds had. Could this also be a reason that our plants mostly grew "up" and not "wide" (i.e. they don't have true leaves and are very thin and feeble)?

I also thought that Fast Plants are very versatile and can grow in many different conditions. Does Mr. Roche or someone know the temperatures of the research lab? There are other experiments taking place in there too, some of which probably also involving plants, so I don't know if low temperatures really affected the growth of our plants that much. Did we perhaps do something wrong in our procedure that hindered the growth, or is it simply an accumulation of all these possible factors?

Emily - For lack of proper lighting, I meant that we only used a small circular lamp, whereas the other groups in Mr. Roche's room had fluorescent lights that stretched across many groups. In addition, the temperature was lower in the research lab, so that would make the growth slower. However, I think that you're right in that the main reason that our plants did not develop properly was the lack of space that they were given. Another problem may have been the wicks that we used; we reused wicks from a previous experiment, and it is possible that they were not sufficient in soaking the soil with water. 

Hours would be appropriate since you used half hour time lapse images. Looking forward to seeing the results!

Since this is a video of a video, it's a little hard to see clearly... is there any way to upload the actual video onto here? Or if that might be too inconvenient, does the actual time-lapse video appear clearly enough for us to know when the plants germinated or reached a certain height? (I mean, that's all that we need for our data.)

I don't think our time-lapse camera could see when each plant germinated through the soil, so we were planning on seeing when we could first see the plant--basically, when it first broke through the soil.

Selena - I think that's what Mrs. ArchMiller meant. As in, we will use whenever we can detect germination through the soil.

Right- I'm pretty sure that the plants grew to at least 3 cm before becoming lopsided or toppling over. That way, we can measure when germination can be detected through the soil, and when it reaches a certain height (to calculate approximate growth rate) around 3 cm, and anything that happens to the plants after that won't matter anymore.

As long as we have a clear view of the seed germination, I think it should be fine. We should try and record the data from the video first to see.

It looks like you'll be able to at least estimate when germination happened through the soil. I'm excited to hear about the results once you analyze the data! Good job everyone!

Sure, that should be fine. With the time-lapse camera, we'll be able to see when the plants reached certain heights (and then we can finally collect our data!).

So, just to confirm, we're doing averages for each test group, right? And measuring the dependent variable as the growth rate?

Ms. ArchMiller - 

One of the plants has fallen, and I am not sure why. When we planted, we sprinkled only a small amount of fine potting soil over the seeds. Is this something that we should be concerned about? Will it greatly affect the seed's growth? Thanks :)

Hi - this is the progress of the growth as of 11/3. If the time lapse camera doesn't work, or the data looks funny due to errors in our method, Mr. Roche said that we could redo the experiment. What do you guys think? We have around 20 more days, and it took about a week to perform this. 

Also, I'm a bit confused about our operational definition - would rate of sprouting/growth just be the average of the growth each day, or is there a more precise way to measure the rate?

Is it 20 more days for just the experiment part or for finishing the entire thing? If it's the first one, we should be able to do it, but if it's the second, I guess it depends on what else we have to do after this (observations, conclusions, and anything else). Also, I'm not really sure about our operational definition either. According to Mr. Roche, it would be hard to use the time-lapse to figure out exactly when the plants crossed a certain point, so I'd say we should probably decide once the experiment is over and we can look at the data from the camera.

I think it's 20 days to finish the entire thing. But the "entire thing" basically means to finish those simple observation and conclusion questions. I don't think it would take us that long to complete.

If we can't figure out exactly when the plants crossed a certain point, maybe we could just use the total height of the plant at the end.

Because we still aren't sure of how to operate the time lapse camera, redoing the experiment may not be the best idea. In addition, with the plant setup that we have, I don't think that there is an angle at which there'd be no distortion, especially for the plants furthest away. Therefore, I think that we should just go with the data that we have right now. I am afraid that if we do the experiment over again, we'd end up with the exact same problems (or maybe even more) than we had to begin with. If we can, however, find a good angle for the time lapse camera, a second experiment could be viable. 

Here's the overall set up of our experiment. The light source is located at the top, and the time lapse camera is to the left, angled down at the fast plants.

Sorry that it's sideways... don't know how to fix that. As you can see, our plants have actually grown quite a bit, some of them already at 5 cm (where we drew the last tick marks on the sticks)! I haven't seen them since they were planted, so I guess we can only use the time-lapse camera to determine their growth rate.

The other teams in our class/grade gave the plants more... sideways room when they planted them. Their plants have much wider leaves but are also quite short. Our plants are taller than most others that I've seen, yet the leaves are pretty tiny. Does this have to do with the amount of horizontal space that the seeds were given? 

The plants look good! It's more likely that you have smaller leaves and taller plants because the light quality and amount reaching the seedlings is better for photosynthesis (i.e., photosynthesis efficiency is higher) than the other groups. When plants are grown in shady conditions, for example, they tend to grow wider leaves that can capture more sunlight than other plants in more full sunlight conditions. That's just a thought. I'm hopeful that your time-lapse photography worked! 

Hey Mary (and others),

I don't think it's that worrisome that we haven't seem germination yet, since only one team in our class saw germination the day after planting. It's been 2 days after planting for us, which is still a reasonable time for the plants to not be sprouting. (Also, they might have germinated, but we might not be able to see it above the soil yet...?) If we still do not see germination/sprouting on Monday, that might be a problem, since these are "fast" plants...but maybe the relatively cold temperature of the research lab, compared to the environment that the other projects are in, has something to do with that.

Where is everyone else planting?

Hi Ms. Archmiller,

Most other groups are planting in our biology classroom. There's probably about one other group also planting in the research lab, and I'm not sure if they've seen results yet either. 

Any sprouts yet?

Yup!! Will attach photos/descriptions soon.

That's ok, this happens *all the time* in experimental biology. You just try to do your best to do things right, then if something goes wrong, you adapt. The most important thing to do is keep track of everything like you have here. Good work!

So... when we're collecting our data, do we just average the 11 seeds in the B group and the 12 seeds in everything else, or do we discount all of the seeds in pot 5 and only take the data for 11 seeds in each group?

I'm not an expert, but I think we should just take the average and leave n/a for the missing seed in the data table. Just because we have one piece of data missing, I don't think we should take away two other pieces of data, too.

Correct Emily, it would be a shame to miss out on the data from that whole canister just because of one missing data point. :-)

Technically, the analysis for a randomized complete block like you have is more challenging than just averaging over all canisters or "blocks" by treatment. However, unless you've taken some statistics, this may be beyond what Mr. Roche would want me to try and explain through PlantingScience. If you're curious, though, I can do my best to try and explain the more correct--and challenging--approach to analyzing your data. :-)

Half an hour should be just fine. Let's hope it worked! :-)

I don't think so, the soil is still probably plenty moist to last the weekend. But I am glad that you all are so considerate of all the things that might affect your experiment!

Almost forgot to mention, we are using a lamp clamped on an overhead bar as a source of light energy for the plants. 

Looks good!  I would certainly mark each seed treatment. Otherwise, this looks good. 

If we rotate them every day, we'll have to leave them to sit in the same position for two days on the weekend. Should we change the days between rotations, then, or just let it sit over the weekends? If we do make the rotation intervals longer, we should make sure there is enough time for us to rotate it at least three times. Ms. ArchMiller, do you know about how long the Wisconsin fast plants normally take to sprout?

(Also, Mary, I think you meant 120 degrees for each canister.)

I am not sure about Wisconsin fast plants. This is something that you might be able to find online or ask your teacher. I am happy to see you all thinking about these different issues! 

Sounds great. Good luck planting today!

Hmm, these links don't work for me...

I uploaded an experimental design diagram of our experiment, but I was a bit unsure about the exact measurements of our controls. 

Wait... what do you mean by that? Why would marking the locations of A make sure that none of them are rotated? Should we instead stagger the orientation so that the seeds facing a certain direction cycle (A, B, C, A, B, C, A, ...) so that we always know if we've rotated the canisters exactly once?

I agree with Emily--I think staggering the orientation in an orderly fashion would be the best. We'd always know how much they should be rotated.

Mr. Roche said that we would be planting in class on Thursday.

Just a change -- we are actually planning to plant on Monday, and prepare on Thursday, because on Monday we would be more likely to be in school around the time the seeds sprout. 

Hi Ms. Archmiller,

Thank you so much for your suggestions! Mr. Roche was thrilled that you shared the randomized complete block system.

a) We decided to use the randomized system using 12 film canisters, planting three seeds (one seed from each treatment) in clockwise order. We can change the orientation of the film canister to make the treatment randomized. We can also line the 12 canisters in a circle, and then rotate it every couple of days. (We will attach a drawing with a representation of this system.)

b) Hi Ms. Archmiller, how will we make sure that there is the same volume/mass of soil in each pot? Does that mean that we should use a mass scale to ensure that each pot gets the same amount of soil?

Also, do you think that packing the soil would be a good idea? After all, since un-packed soil would come in all different densities, that might affect the growth/germination of the plant. If we pack the soil, how would we pack it (with what)? 

I've never planted stuff before, so to everyone- how deep do you think we should plant the seeds beneath the soil? Would 1 cm or 1 inch be enough/too much?

The experimental design sounds great! 

I would put the pot on a scale, tare it (which resets it back to zero) and then add some amount of soil to a set weight. You might want to fill the first one, record the weight and then fill the rest to the same weight. Then, to try to make the densities similar, if they have the same volume and you lightly pack (with fingers) them to the same height in the container, then the average density will be consistent throughout the soil. This is because density is mass/volume. If you set the mass using the scale to be the same and try to keep the volume the same in each container by lightly packing them to the same height in the container, then the density should be equal too!

I would ask Mr. Roche if the seeds come with planting guidelines. Seed depth is usually specific to the seed types, and so I imagine that the seeds come with some advice for planting. You could also try to find some planting guidelines for Wisconsin Fast Seeds on the internet. 

I guess to make sure all of the seeds are planted at the same depth, we'll have to pack the soil into the pot(s), level it off so it's all the same height, sow the seeds, and then cover them with another layer of soil, and level that off too with something flat.

If we do put all of our plants in one pot, it has to be not only wide enough for all the plants to fit but also deep enough for there to be space for their roots. Unless we drill holes in the bottom of it to let the roots grow through and submerge it in water, which would also solve our watering problem. It's just a thought; I don't know whether it would work. What are your thoughts?