2/29/12

E-Mail - FEMALE FLOWERS

Happy Leap Day!
I have gotten a few E-mail’s about female and male flowers, so I thought I would post some general information about flowers. Please see my post on determining seed sex if this topic interests you.
Not all plants have flowers, but many that live on planet Earth today do. The flower, which is generally the showiest part of the plant is for sexual reproduction. Fragrance and color are devices to attract pollinators that play an important role in the reproductive process. (See my post on pollination)
Parts of the Flower --The flower can contain the male parts to produce pollen and/or the female ovule plus accessory parts such as petals, sepals, and nectar glands.
The pistil is the female part of the plant. It is generally shaped like a bowling pin and located in the center of the flower. It consists of the stigma, style, and ovary. The stigma is located at the top, and is connected to the wide base (ovary) by the style. The ovary contains the eggs which reside in the ovules. After the egg is fertilized the ovule develops into a seed.
The stamen is the male reproductive organ. It consists of a pollen sac (anther) and a long supporting filament. This filament holds the anther in position so the pollen it contains may be disbursed by wind or carried to the stigma by insects, birds or bats.
Petals are highly colored portions of the flower. Not all flowers have petals, like the spinach flowers above for example. The petals collectively are called the corolla. The number of petals on a flower is often used in the identification of plant families and species.
Types of Flowers-- If a flower has a stamen, pistils, and petals, it is called a complete flower. If one of these parts is missing, the flower is considered to be an incomplete flower. If a flower contains functional stamens and pistils, it is called a perfect flower. (Stamen and pistils are considered the essential parts of a flower.) If either of the essential parts is lacking, the flower is imperfect.
Pistillate (female) flowers are those which possess a functional pistil(s) but lack stamens. Staminate (male) flowers contain stamens but no pistils. There are plants which bear only male flowers (staminate plants) or bear only female flowers (pistillate plants). Species in which the sexes are separated into staminate and pistillate plants are called dioecious. There are a few plants like this, from my forestry classes I know holly, mulberry and pistachio trees are dioecious; Spinach, hops and asparagus are also dioecious; therefore, to obtain fruit from these plants, it is necessary to have female and male plants in the same area. Monoecious plants are those which have separate male and female flowers on the same plant. Corn plants and pecan trees are examples. Some plants bear only male flowers at the beginning of the growing season, but later develop flowers of both sexes; examples are cucumbers and squash.

I always enjoy getting E-mail questions about plants and growing, If you still have a question after doing a search on the blog feel free to E-mail me!

Good Growing,
Dr. E. R. Myers

2/23/12

How to Improve Growth with Scientific Experiments

One reason I like to write this blog for HTGSupply.com is because they approached me for a scientific way to find the best LED  The first product I tested was the Tri-band LED.  If you have read other posts you know I have often suggested that good growers experiment with different fertilizers and  grow mediums for seed germination or even lights. I want to take the time to talk about what a scientific approach is because so often people fall victim to advertising that seems to be scientific but in fact is not.

I tried this product and it really made my plants grow great…
Ever heard that? If you add a product to all your plants you don’t know how it is affecting plant growth, even if the growing seems different from past years. Why? Because you need to compare plants with the product to those without the product growing in the same medium with all environmental conditions exactly the same. If you don’t COMPARE plants that are growing in the same area you really can not say if the fertilizer is making a difference or some other factor is…

HOW TO CONDUCT A SCIENTIFIC EXPERIMENT: To do to scientifically based test on a fertilizer* for example you need to use it on some plants, and NOT use it on others. You are creating two groups to COMPARE. You need to be able to compare the difference between plants that are exactly the same in all ways accept one, in this example the fertilizer. The group that gets the fertilizer is called the experimental group. An experimental group is the group in a scientific experiment that is exposed to what you want to test. The group that does NOT get the fertilizer is called the control group. Comparing the control and experimental group is the only way to know if the fertilizer makes a difference. Without this comparison it is just speculation, which makes a great commercial, but will not make you a better grower.
Having multiple plants in a group will help rule out alternate explanations of the experimental results, like the plants directly under the light grew better, or you watered some of the plants more or less etc. The easiest way to compare the groups is to compare the average (called the mean in statistics) of the group. Measure the height, or yield of the plants after harvest and compare the groups. There are a lot of other statistics you could do, but this will be a good place to start… I don’t want to get too into statistical analysis (:

Other than the fertilizer (or whatever you are testing) you need to make sure both groups have everything else the same. The same exposure to light, you can’t have on group next to the fan and the other on the other side of the room. All environmental conditions need to be the same, that is how you can scientifically say a fertilizer improves growth or not.

*Since plants need fertilizer maybe you don’t have to have a group with no fertilizer, you could have two or more groups each with different amounts of fertilizer. This would still allow you to COMPARE groups so you know if more or less fertilizer is changing plant growth. This may be a good way to find the optimal or best amount of fertilizer to add to your plants. You could also use two different fertilizers and compare the groups too. Basically, you can’t just add a fertilizer and draw any conclusions, you will always need something to compare, otherwise it is just your opinion and not science.

I am comparing  products containing beneficial bacteria and I posted the results here..

I have also tested mediums for seed germination.

Good Growing,
Dr. E.R. Myers

2/14/12

E-mail – Recomended LIght for Starting Some Tomato Plants

For someone that just wants to start some tomato and pepper plants, what do you suggest for grow lamps so that these can be started indoors with no windows?

Hello,
I would read my post on what you need to grow indoors.
If you just want to start plants you can start out with standard 4 foot fluorescent tubes, you can get a 2 light shop light ballast and use cool white tubes. You can get all this for about $20 at any hardware store. Keep the lights about 1 inch from the plant tops. This is fine for seedlings if you want to start plants indoors and then move them outdoors but once the plants get bigger (over a few inches tall) you will need to get either a high out put fluorescent T-5 from HTGSupply.com or I have recommended that if you only want to use one light use an HPS (High Pressure Sodium). The HPS is the best light if you are looking for flowering and fruiting. The higher the wattage the more plants you can grow and the bigger your yields will be, but you will need more space and you will have more heat. If you use a 250 watt you can grow in a 3x3 area, 400 watt 4x4 and 600 watt would be for a 5x5 square foot area. If you use an HPS, you will have to think about venting the heat. I used to grow in a large closet 10 feet by 4 feet by 8 feet high. I used a 400 watt HPS and did not have any problems with heat in this space. If you are growing in a smaller closet or grow tent, you will need to think about venting the heat.
Another option is to use an LED light. I helped HTGSupply.com develop their triband LED lights, they work great, do not produce as much heat an an HPS and last for many many years.
I hope this helps, Let me know if you have any other questions

Good Growing,
Dr. E.R. Myers

2/2/12

Buffers and Minimizing pH Changes Using Phosphorus and Potassium

Happy Ground Hog Day! Phosphorus is required in large amounts by plants, especially when plants are seedlings, after transplanting and during flowering. Potassium is a good all around nutrient that has been shown to increase plant immunity. I recommend to use it in all stages of plant growth. Good growers know there are at least two forms of fertilizers containing both K and P - KH2PO4 mono-potassium phosphate (MKP) and K2HPO4 di-potassium phosphate. Just as I suggested you can control your pH by using two forms of nitrogen You can affect pH by using a higher proportion of K2HPO4 which will increases pH. MKP can be used to lower the solution pH. I worked in a greenhouse that used MKP containing the equivalent of 52% P2O5 and 34% K2O, this fertilizer was labeled 0-52-34.
Buffers are solutions which resist pH change and are used with some pH testing devices to calibrate pH electrodes. Buffers can be added to nutrient solutions in an attempt to maintain pH stability. Each buffer will have a set point, a pH that it maintains, so not all buffers are good for hydroponics. One such buffer is called 2-(N-morpholino) ethanesulfonic acid look for it abbreviated as MES. Many hydroponic nutrients add MES to their product to help stabilize the pH of your hydroponic system.
Good Growing
Dr. E.R. Myers