RESEARCH: SUPER DWARF CROP
AND BREEDING OF DWARF CROPS The Crop Physiology
Laboratory has a long history of identifying, characterizing, and
hybridizing “Super-Dwarf” germplasm of the crop plants. In 1996,
we released "USU-Apogee" an early maturing, dwarf
wheat plant developed for use in the confined environments of
spacecraft. "USU-Apogee" wheat was grown to maturity on the
Russian space station MIR in 1998, and was used in a series of studies
on the International Space Station in 2002. We
recently completed the development of a new wheat cultivar, "USU-Perigee", which has a
similar yield to "USU-Apogee", but is only half as tall (25 vs. 45 cm
In cooperation with colleagues at
the Chinese Academy of Agricultural
Sciences in Beijing, we are using mutation breeding to develop an
improved version of the rice cultivar "Super-Dwarf".
We are continuing to characterize "Triton"
pepper, and "Micro-Tina" tomato.
We recently added two more lines to our cultivar list: 'Hoyt'
Soybean and 'Earligreen' Pea. Research
continues on all of these cultivars - visit back soon for more
These early flowering, super-dwarf
lines are important for studies in space, and as model crops for
genetic engineering. For more information, see the article
“Engineering Plants for Spaceflight” published in the bulletin of the
American Society of Gravitational and Space Biology.
--- CLICK THE CULTIVAR TO VIEW CULTURAL RECOMMENDATIONS and RESEARCH ---
Small is Better: The Advantages
of Super-Dwarf Crop Plants in ALS Research
Support and Biosphere Science - 2000
Extremely dwarf genotypes of most of our major crop
plants exist, but they have not been utilized for ALS research. When
these plants are less than about 20 cm tall at maturity we have called
them SUPER-DWARF CROP PLANTS. Their yield in field studies is only about
25% of their tall counterparts; however, their yield increases to
about 50% of taller cultivars when grown at high plant densities in
near-optimal controlled environments. When yield is expressed on a
unit volume basis, these cultivars often exceed all other genotypes.
Multiple plants can be grown in small plots in small plant growth
chambers. In some cases, the size of a plant growth chamber can be
reduced to a 30 x 30 cm plot area, 30 cm tall. This size means that
multiple small chambers can be accommodated in a larger plant growth
chamber, thus facilitating replicate chambers of environmental
treatments. Edge effects must be rigorously controlled with reflective
foil around the perimeter in these small chambers. This talk will
summarize our work with super dwarf tomatoes, rice, and wheat. The
potential to use super dwarf cultivars of other crop plants will also
Growing Dwarf Plants Under Electric Lamps in the Classroom
1. Start by
getting a bag of potting soil and some pots at a garden store. The
pots should be at least 15 cm tall, and 20 to 25 cm tall would be
better. Be sure the pots have at least one drain hole in the bottom.
If you are
unfamiliar with centimeters, get a ruler with centimeters (cm) on it
and bring it with you to the store. One of the things you will learn
in the process of measuring plant growth is how to use the metric
system. You may not be able to explain your metric measurements to
your grandparents, but you will be able to communicate to research
scientists and to all the rest of the people in the world.
2. Get a small container of house plant fertilizer and use it
according to the directions on the label. Miracle Gro is a good
fertilizer because it has all of the micro-nutrients needed for plant
growth, but other brands also work well. It is best to water with a
dilute solution of fertilizer every time you water. Be careful not
to put on too much fertilizer! Everyone gets tempted to add extra
fertilizer in the hope that it will make their plants grow faster.
Fertilizing too much will make your plants sick - like over feeding a
cat or a dog. If you have a 2 liter watering can you will only need
to add a gram of fertilizer per container (2 liters) to have ample
nutrients for plant growth.
METRIC CONVERSION: a teaspoon
of fertilizer is about 5 grams, so a quarter teaspoon of
fertilizer (1.25 grams) per 2 liter container provides plenty of
nutrients for plant growth
3. Fill the container with the potting soil. Do not pack the soil in
the container because roots need air to grow properly. Plant the
seeds about 1 cm deep and about 5 cm apart. Water with fertilizer
solution to get things started.
4. The seeds should start to come up in 3 to 6 days.
5. Providing light for growth. The most difficult part of
growing excellent crops is getting the plants enough light. Our eyes
adjust when we go outside, so we don’t realize that outside light
levels in the summer are 200 times brighter than a well lighted office
or kitchen. House plants have been selected to grow in the low light
levels of a house, but crop plants do not have a low gear and will not
grow their best in the low light levels of even a south facing
window. The solution is to use electric lights. Cool white
fluorescent lights work well for growing plants. DO NOT buy Grow
lights, (Gro Lux or any other brands). These lights are expensive
and they do not work as well as standard fluorescent lamps. A 120 cm
long (4 foot), two tube fixture works well. High output (HO)
fluorescent lamps put out twice as much light as standard fluorescent
lamps and the plants will grow twice as fast, but they are twice as
Keep the light
within about 15 cm of the top of the plants so that the plants get as
much light as possible. Either raise the light or lower the pots to
keep the tops of the plants close to the lights. Try not to let the
leaf tips touch the light bulbs because the leaf tips will get too hot
and die. Our research at Utah State University has shown that wheat
plants never need to sleep so keep the lights on for 24 hours a day
for wheat. This give the plants more light and they will grow faster.
If the lights are on for 24 hours a day they will grow twice as fast
as if the lights are on for only 12 hours a day. Tomato and pepper
plants need to “sleep”, however. You will need a time clock set so
that the lights are off for 8 hours at night. This will give the
plants 16 hours of light each day.
6. The other environmental conditions are much less important than
high light. The temperature should be a comfortable room temperature,
which is between 20 and 25 degrees Celsius. Cooler air temperatures
are better since the plant leaves will be warmed by the heat of the
lights. Get a thermometer and put it with the plants under the
electric lights. If the temperature gets above 25 C, get a small fan
and blow air over the plants to help them stay cool. The best
temperature is 23 C until the plants flower (24 to 30 days after
planting), then the optimum temperature is about 17 C.
7. The plants should flower about 4 weeks after planting and the
plants should be ready to harvest 10 weeks after planting. If the air
temperature is warmer the plants will be ready sooner, but the seed
number and seed size will be smaller.
8. Keep the soil moist, but not soggy. It is best to let the surface
dry out a little bit before watering again. When you add water, make
sure to add water until it starts to drip out the drain hole in the
bottom of the pot. Put a saucer under the pot to catch the water that
comes out. Pour the excess water down the drain so the bottom of the
pot stays dry because the roots at the bottom of the pot need air too.
9. Keep records of plant height each week and number of leaves. It
helps to record observations on a calendar so you can keep track of
the date when things happen.