Post on 28-Apr-2022
1
How Different Liquids Affect the Growth
of Mung Beans:
A Science Fair Production
Emilie Beaupain
2/24/21
Science
2
Research Question -
In this science fair project, I researched which liquids are best for the growth of
mung beans. I always wondered if different liquids could boost the growth of plants to
increase their harvest. Now, I tested that out to see which of the liquids, coffee-water,
sugar-water, salt-water, garlic-water, lemon-water, or regular water, would of these liquids
would make the mung beans grow the most.
Hypothesis -
If I add lemon water, garlic water, coffee water, sugar water, salt water,
(independent variables) and regular tap water to mung beans, then the sugar water will
make the beans grow the fastest, with the regular water coming in second because of
the following:
1) Salt has high amounts of sodium and chloride which is toxic to plants, and
also prevents water from coming up through the roots.
2) Coffee has nutrients but will make it harder for the plant to start growing as
a seed. Coffee also changes the pH of the soil.
3) Garlic water has no negative effects (unless over-used) and barely any
positive effects.
4) Lemon water is acidic and can lower the pH, which is not good for mung
beans, and it can burn the leaves if they are touched by the solution.
5) Sugar water will grow the most because it can give more energy to the plant
to help it grow faster.
6) Regular water will grow second-fastest because it will help the plant grow
at a normal pace.
If my hypothesis is correct, then people can increase their harvest of mung beans
by using sugar water to grow the mung beans the fastest. If my hypothesis is correct,
there is still the question of whether it affects the taste of the bean. Also, will it mold? If
so, there might be another liquid that elicits the same growth as the sugar but doesn’t
mold, which makes it safer to eat.
3
Research -
First, I researched how sugar water could affect plants. According to a Garden
Tools & Instruments article, How Does Sugar Water Affect a Plant's Growth?, sugar
water can give more energy to the plant to help it grow faster because when the plant
drinks sugar water, the plant's porous plant cell membranes (plant membranes with
pores/very tiny holes) let in water because of their high sugar content. The plant stores
sugar for roots so the roots can grow, so it is believed that adding a bit of sugar gives
roots extra food to grow faster. I think that adding sugar to tap water will make the beans
absorb additional amounts of sugar and use that extra energy to grow the fastest.
Second, I researched how the pH level of different liquids would affect plants.
Different liquids in the soil can change the pH of the soil, can affect or give different
nutrients going into the plant, and can deprive the plant of nutrients. Coffee Cup
Science’s article, Growing Plants with Caffeine - our Ultimate Guide, says that
watering a plant with coffee can stunt and distort the growth of a mung bean and may
make the plant stop growing entirely because the chemicals in coffee may alter the pH of
the soil. Salt can “affect the germination of mung bean plants'' because a...
“high concentration of salt in the soil can interfere with a plant's ability to take
up and hold water in its roots. High amounts of sodium and chloride are toxic to
plants as well. Saline soil can also reduce the amount of micronutrients that are
available, and this leads to mineral deficiencies.”
In other words, this quote states that salt will affect the nutrients and beneficial microbes,
leading to a plant that won’t grow.
Furthermore, as stated by Garden Guides’ website Why Does Salt Affect the
Germination of Mung Bean Seeds?, lemon juice can alter the pH because of the high
acidity, and lemon juice on the leaves can “cause them to shrivel, compromising the
plant's ability to perform photosynthesis.” Lemon juice will be negative for plants except
for those plants that like acidity.
On the other hand, garlic is not harmful to plants and doesn’t affect the plant’s
growth or vigor, according to Dengarden’s post How to Make and Use Garlic Water
Pesticide for Plants. “While the solution effectively eliminates pesky garden infestations,
it can also negatively affect beneficial soil microbes if used too often.”
To summarize, this research shows that almost all the liquids except sugar water
and tap water will have a negative effect on the mung beans, so the mung beans watered
with tap water and sugar water will produce the most growth.
4
Procedure -
1. Prepare habitat by placing half of a paper towel, folded into four layers, at
the bottom of each cup
2. Prepare all liquids by adding 1/16 cup of each IV (sugar, salt, etc.) and add
¼ cup of water.
3. Let sugar and salt dissolve into the water, coffee cool, and garlic steep for
1 hour before watering ¼ cup of each liquid into the adjacent cup.
4. Take pictures each night after watering and repeat the process for 6 days
Variables -
Independent variables (the types of liquids I watered my mung beans with):
lemon water, garlic water, coffee water, sugar water, salt water, and regular water
Dependent variable: the growth, measured with a ruler
Control variables: the habitat and the mung beans.
Results -
For my results in experiment one, the mung beans didn't grow as much compared
to the mung beans in experiment two.
I did experiment 1, and the following happened: In experiment one, the coffee was
the longest and the mung beans watered with tap was second. Nothing molded, to my
surprise, but nothing grew too much either.
I did experiment 2, and the following happened: The mung beans watered with tap
water in experiment 2 grew much more than the mung beans watered with tap water in
experiment one. However, the beans watered with sugar grew about the same amount in
both experiments. The lemon-watered mung beans in the first experiment were equal to
the one in the second experiment, except for the fact that in the second experiment there
was lots of fuzzy blue and black mold on the beans. In experiment 2, it was the tap that
was longest, with the mung beans watered with coffee in second. The mung beans
watered with garlic came in third both in experiment 1, and experiment two.
5
Trial 1: Rate of Growth of Mung Beans in Different Solutions
(mm)
Beginning Length Ending Length Total Growth
Coffee Water 4 11 7
Salt Water 4 4 0
Sugar Water 4 4 0
Garlic Water 4 6 2
Lemon Water 4 5 1
Water (Control) 4 10 6
Trial 2: Rate of Growth of Mung Beans in Different Solutions
(mm)
Beginning Length Ending Length Total Growth
Coffee Water 4 8 4
Salt Water 4 4 0
Sugar Water 4 4 0
Garlic Water 4 6 2
Lemon Water 4 4 0
Water (Control) 4 63 59
6
Average Growth of Mung Beans in Different Solutions
(mm)
Ending Length :
Trial 1
Ending Length
: Trial 2
Average
Growth
Average
Growth
Coffee
Water 7 4 5.5
Coffee
Water 5.5
Salt Water 0 0 0 Salt Water 0
Sugar Water 0 0 0 Sugar Water 0
Garlic Water 2 2 2 Garlic Water 2
Lemon
Water 1 0 0.5
Lemon
Water 0.5
Water
(Control) 6 59 32.5
Water
(Control) 32.5
7
8
Conclusions -
My hypothesis turned out to be wrong: If I add lemon water, garlic water, coffee
water, sugar water, salt water, and regular tap water to mung bean plants, then the plants
watered with sugar water will grow the fastest, with plants watered with regular water
coming in second. Instead, ….. I think it was wrong because mung beans don’t have
roots, so the extra boost from the sugar for the roots is wasted. The plants watered with
tap water grew the most, most likely because, without the coffee, salt, sugar, garlic, or
lemon juice, it was not held back by those liquids’ negative effects.
One mystery is why the coffee water grew fast in experiment 1 but not in
experiment two. Next time, I would research this more to see if I can manipulate the
positive effects of the coffee. Another thing to research is how to prevent the mold from
growing on the mung beans when you water them with different liquids. This will make it
safe to eat and if it is safe to eat then I can experiment with the taste of the plants that are
watered with different liquids.
9
Appendix -
1st Experiment - Photographs
Coffee longest
10
Tap second
11
Garlic third
12
Lemon just sprouting, bleached
13
Sugar not sprouted yet, soon though
14
Salt still dehydrated and small
15
2nd Experiment - Photographs
Coffee sprout grows almost 2 cm
16
Salt same, doesn’t sprout or change in appearance
17
Sugar same, enlarged but not sprouted
18
Garlic past sprouting, sprouts about 1/4 cm
19
Lemon the same and fuzzy mold white
20
Tap is giant
21
Works Cited:
CK. Growing plants with caffeine - our ultimate guide. Coffee Cup Science.
(2019). Retrieved From:
https://coffeecupscience.net/caffeinefuelledseedlings/
Garden tools and Instruments. How Does Sugar Water Affect a Plant's
Growth?. (2018). Retrieved From:
https://www.youtube.com/watch?v=PJpRE3B-BKo
Harris. Rob. Can I Feed Lemon Juice to Plants?. SFGate. Retrieved From:
https://homeguides.sfgate.com/can-feed-lemon-juice-plants-104940.html
J. Lang Wood. Why Does Salt Affect the Germination of Mung Bean
Seeds?. Garden Guides. (2017). Retrieved
From:https://www.gardenguides.com/13406185-why-does-salt-affect-the-
germination-of-mung-bean-seeds.html
Zach. How to Make and Use Garlic Water Pesticide for Plants. Dengarden.
(2019). Retrieved From: https://dengarden.com/gardening/Using-Garlic-
Water-for-Plants