Influence of Fertilizer on Swollen Stem Formation (“Bulbing”) and Vitamin C Content in Different Kohlrabi Cultivars
Kohlrabi is a vegetable crop that is found in Brassicaceae family and it is rich in antioxidants such as vitamin C. Vitamin C helps in body tissue repair and keeps the immune system strong, so exploring vitamin C sources is potentially a great contribution to improve human health. Studies have confirmed that applying fertilizers on the kohlrabi will increase its yields and quality. However, there are no comparisons of those effects by using different fertilizer levels in different kohlrabi cultivars. The purpose of this study is to determine if fertilizer application affects Kohlrabi yield in terms of the swollen stem (edible part) and the vitamin C content and if those effects are the same in different kohlrabi cultivars.
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[00:00:00.000]Hello, welcome to my presentation
[00:00:02.840]about the Influence of Fertilizer
[00:00:05.300]on Swollen STEM Formation
[00:00:06.850]and the Vitamin C Content
[00:00:08.600]in different Kohlrabi Cultivars.
[00:00:11.400]My name is Mark Iradukunda.
[00:00:12.980]I am a Junior in integrated science major.
[00:00:16.490]This research was supervised by Dr. Paul Reed
[00:00:19.230]in the Department of Agronomy and Horticulture
[00:00:21.860]at the University of Nebraska Lincoln.
[00:00:24.420]This is Kohlrabi.
[00:00:25.530]Kohlrabi is a vegetable crop that is found
[00:00:27.610]in Brassicaceae family.
[00:00:29.450]The edible part is this swollen STEM, though
[00:00:31.880]other people eat leaves.
[00:00:33.160]We will focus more on the soil in swollen STEM.
[00:00:36.010]Kohlrabi can grow faster, transport it easily
[00:00:39.330]and can be used in the various dishes.
[00:00:42.520]It is reaching antioxidants
[00:00:44.150]like vitamin C and nutrients like a Potassium.
[00:00:46.500]But in our study, we will focus more on vitamin C
[00:00:50.640]unfortunately many people in America and all
[00:00:52.820]over the world have vitamin C deficient issues
[00:00:55.440]and that can lead to fatigue, bleeding gum,
[00:00:58.083]scurvy and even worse cancer.
[00:01:00.380]And that is because vitamin C helps
[00:01:02.930]in body tissue repair keeps the immune strong.
[00:01:06.230]And so exploring vitamin C sources like Kohlrabi is
[00:01:10.620]potentially a great contribution to improve human health.
[00:01:15.210]Nitrogen containing fertilizers have been found to
[00:01:17.890]improve the size and the quality of swollen stem,
[00:01:22.140]but there are no comparisons between application rates
[00:01:25.810]in different, in different cultivars
[00:01:27.680]and the effects into the vitamin C content.
[00:01:31.110]The purpose of this study is to determine
[00:01:34.080]if the application affects the Kohlrabi yield
[00:01:36.820]to terms of soil and swollen STEM in a vitamin C content.
[00:01:39.920]And if those effects are the same
[00:01:43.310]different Kohlrabi cultivars.
[00:01:45.460]So we asked three questions
[00:01:48.380]does the Kohlrabi growth increase as the
[00:01:51.140]fertilizer level increases?
[00:01:52.870]Does the vitamin C content increase
[00:01:55.840]as the fertilizer level increases?
[00:01:58.520]If that's true are these effects the same
[00:02:01.040]in different Kohlrabi cultivars to test
[00:02:03.210]that to be we selected four common cold Kohlrabi cultivars.
[00:02:07.800]in each cultivar, we took a group
[00:02:11.360]of plants and treated them with a recommended fertilizer.
[00:02:14.350]The rule of thumb says two tablespoons per gallon.
[00:02:17.430]So made the double of that one half of it.
[00:02:20.430]And another group of plants
[00:02:22.390]we treated them with no fertilizers.
[00:02:24.570]We repeated the process four times in,
[00:02:26.990]in, within the cultivar
[00:02:30.410]and repeated that process in all four cultivars
[00:02:33.354]and distributed our plants in, in the teaching greenhouse
[00:02:38.475]of agronomy and horticulture on east campus.
[00:02:43.350]And our design was a completely randomized block.
[00:02:47.807]Every day we, watered our plants and just
[00:02:51.610]scouted for anything.
[00:02:53.390]And on, on, on Fridays, we fertilized
[00:02:57.700]were, each plant received 15 milliliters of fertilizer
[00:03:02.270]and those plants that didn't receive fertilizer
[00:03:04.406]received the same amount of water.
[00:03:08.735]And on every week we,
[00:03:10.810]measured the length and the width of
[00:03:13.300]plants using the inch inch ruler
[00:03:15.346]and use the caliper to measure the diameter of swollen STEM.
[00:03:20.810]And then we got results.
[00:03:21.940]Our results shows that in all cultivars
[00:03:25.824]the increase in fertilizer lead to faster growth
[00:03:30.500]and they, and, and the bigger growth.
[00:03:34.400]And, and so, as you can see on this graph
[00:03:38.100]the starting point of our plants
[00:03:40.870]at the transplanting time was between 4 and 2 inches,
[00:03:45.860]but at the end, the plants that received more fertilizer,
[00:03:49.020]were six-inch larger than plants that didn't
[00:03:51.760]receive fertilizer and two inches bigger
[00:03:54.184]than plants that received the recommended rate.
[00:03:57.080]And this was within six weeks.
[00:03:59.310]And so the effect was true in all cultivars
[00:04:02.910]as you can see on the pictures.
[00:04:05.890]Just in more depth,
[00:04:09.550]our height increased as we increased
[00:04:11.920]the fertilizer and, and so this,
[00:04:15.240]this graph shows that when we
[00:04:17.030]we doubled our fertilizer, the height increased.
[00:04:21.190]And when we reduced the fertilizer
[00:04:23.304]our height was a lot less.
[00:04:26.150]And the same was true in all cultivars and this graph shows
[00:04:30.100]that we are very confident in our data
[00:04:32.270]that they increase in fertilizer increases the height of a
[00:04:35.613]of Kohlrabi and where ou R is about 0.97.
[00:04:41.332]So in with in all cultivars
[00:04:44.710]the increase in,
[00:04:47.015]in the fertilizer increase the weight of our plants.
[00:04:51.380]And this graph shows that we are very confident
[00:04:53.710]in our data where our R about 0.91.
[00:04:56.720]So we're very confident that increases in
[00:04:58.630]in fertilizer would increase the width, of our plants,
[00:05:03.660]and the same is true in all cultivars.
[00:05:06.360]About the diameter, it's the same.
[00:05:08.990]So, eh, when we doubled our fertilizer,
[00:05:14.465]our plants were a lot bigger
[00:05:16.780]and when we reduced the fertilizer
[00:05:19.240]our plants were a lot smaller
[00:05:21.190]like 60% smaller than the recommended rate.
[00:05:26.360]So everything was against recommended rate.
[00:05:28.500]So we had recommended ratw against one and a half
[00:05:31.970]against recommended, rate zero against recommended rate
[00:05:35.940]then double against recommended rate.
[00:05:38.330]So, but our studying was actually more focused
[00:05:41.140]on the vitamin C, but we don't have our data
[00:05:43.760]about vitamin C yet, but in a few weeks, we'll have data.
[00:05:46.170]And we'll be able to determine
[00:05:47.460]if the increase in the fertilizer does
[00:05:50.150]or does not increase the vitamin C content in Kohlrabi.
[00:05:56.540]But we can still confidently say.
[00:05:58.700]that they increase in the fertilizer, increases the Kohlrabi
[00:06:01.700]height, width and swollen STEM diameter.
[00:06:04.530]And the effect is the same in all the cultivars.
[00:06:07.850]We are more curious
[00:06:09.470]about how this affects the vitamin C content.
[00:06:13.881]These results are still helpful
[00:06:15.950]because they can help farmers apply,
[00:06:19.150]apply the appropriate amount
[00:06:20.730]of fertilizer economically, and environmentally friendly.
[00:06:24.380]We don't wanna people to apply for it
[00:06:25.920]fertilizers that would harm our environment.
[00:06:29.010]For future studies, people can work out more increments,
[00:06:33.330]so like triple quadruple
[00:06:35.680]and determine where the increase in the fertilizer.
[00:06:38.740]Doesn't no longer affect the vitamin C content
[00:06:42.580]or the growth of the plant.
[00:06:44.900]Also, it will be important to
[00:06:46.280]explore the fertilizer increase
[00:06:47.797]and the change in the nitrogen toxicity in our plants.
[00:06:51.190]We don't want to apply too much nitrogen
[00:06:53.350]that will affect people's health.
[00:06:58.050]This is, these are our references.
[00:07:00.520]So I thank ARD for funding this research
[00:07:03.600]I thank my supervisor, Dr. Paul Reed.
[00:07:06.480]I thank other faculty that helped me
[00:07:08.420]throughout this process
[00:07:10.920]and I thank my friends for their support.
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