Sweet Corn

I normally wouldn't do this but this post is a direct cut and paste from a Harris Seed Company email sent to customers and potential customers.  I love sweet corn and couldn't write this better.  Here is plagerism except I am giving credit.  Even got the author's picture. 


Sweet Corn Genetics

Customers often ask about the different genetic types of sweet corn we offer. Here I will try to give you a quick lesson in sweet corn genetics. There are five basic genetic types of sweet corn we offer: normal sugary (su), sugary enhanced (se), synergistic se (sy), supersweet (sh) and augmented supersweet (shA).

Normal Sugary (su) is the standard sweet corn and is the one you've known from many years ago. These varieties have good corn flavor, and their quality is best if picked and eaten the same day. When picked at full maturity the quality is good, but it soon depreciates after full maturity has been reached. Most normal sugary varieties germinate quite well at soil temperatures over 55° F and grow with good vigor. The only (su) variety we still offer is Silver Queen.
Isolation note: Normal sugary varieties should be isolated from supersweet varieties (sh and shA), field corn, popcorn and ornamental corn. They may be planted beside sugary enhanced (se and sy) varieties.

Sugary Enhanced (se) varieties have elevated sugar levels, better tenderness, and higher kernel moisture levels as compared to (su) varieties. The result is a sweeter, tenderer kernel with good corn flavor that will retain its eating quality longer than a normal sugary variety. Most (se) types prefer slightly warmer soils (above 60° F) for germination. Synergistic se (sy) types are very similar to the (se) types, but the breeders have incorporated some supersweet kernels into the ears to give the varieties an extra punch of sweetness. As a whole, these types tend to have a tenderer kernel and will hold slightly longer at full maturity than the standard (se) types.
Isolation note: (Se) and (sy) varieties should be isolated from supersweet varieties (sh and shA), field corn, popcorn and ornamental corn. They may be planted beside each other and normal sugary (su) varieties.

Supersweet (sh) varieties have a shrunken gene, so named to describe the lightweight, wrinkled seed of this type. This gene raises the original levels of complex sugars and extends their flavor by slowing the conversion to simple sugars and finally to starch. Supersweets' kernel moisture is retained longer, and their ears have a much longer holding period after they reach full maturity, both on the plant and after harvest. The earlier introductions of this type had a kernel texture that was noticeably crunchier and firmer than other genetic types. However, with the introduction of Augmented Supersweet (shA) varieties, breeders have improved the tenderness considerably from what it used to be. Supersweets do not normally germinate well under less-than-ideal conditions. Wait for ideal growing conditions (soil temperatures of at least 65° F and moderate soil moisture) before planting supersweet varieties.
Isolation note: Supersweet varieties (sh and shA) may be planted beside each other but need to be isolated from all other genetic types of corn, including (su), (se) and (sy) sweet corn, field corn, popcorn and ornamental corn.

* Because corn is wind pollinated, isolation as discussed above can be achieved by separating varieties by: 250 feet of distance, an effective wind break, or 12-14 days difference in maturity time

Fertilizing a garden

April 12, 2011

Proper fertilization of a garden takes some effort.  If you are like most people you buy a bag of mixed fertilizer like a 12-12-12, or 19-19-19 and spread it over the garden.  During the summer many then water the garden with a soluble fertilizer like Green Light’s Super Bloom or Miracle Gro.  Most of the nutrients are probably wasted.  Please fertilize correctly, the wasted nutrients end up in our wastewater, streams and eventually in the ocean.  This causes local, state, and federal governments to enact rules that make it very difficult for fertilizer companies to get products to the market.  The EPA ends up getting involved with increased regulations.

The nutrients plants need are:

Nitrogen – produced quick growth and has numerous functions.

Phosphorus – is a component of proteins, phospholipids and nucleic acids.

Potassium – supports fruit development and regulates opening and closing of stomata.

Calcium – strengthens stalks and stems and influences cell membranes.

Magnesium – is essential in the chlorophyll molecule and for photosynthesis.

Sulfur – is essential in several amino acids that make proteins and enzymes.

Iron – is required for chlorophyll formation and other biochemical processes.

Manganese – influences photosynthesis and chloroplast structure and oxygen evolution.

Copper – is essential to photosynthesis and for respiration as part of cytochrome oxidase.

Zinc – is essential in NADH dehydrogenase and other photosynthesis enzymes.

Molybdenum – is required for nitrogen use, it helps transform nitrates to amino nitrogen.

Boron – regulates carbohydrate metabolism & helps cells determines cell differentiation.

Chlorides or chlorine – is required for photosynthesis.

Cobalt – A new addition to the required elements, helps legumes fix nitrogen.

Sodium – is involved in osmotic regulation and can or may do what potassium does.

Some plants use silica and selenium.  Silica may strengthen cell walls, stems and stalks.

An average crop needs about 150 units of nitrogen per year, plus a similar amount of phosphorus and potassium.  Most crops need about 20 lbs of calcium, magnesium and sulfur.  Only a few ppm are needed of the other nutrients usually called micronutrients.  Most soils can supply everything except nitrogen, phosphorus and potassium. 

Lack of nutrients generally causes stunted plants.  Shortages of certain nutrients cause color streaking in the leaves and improper flower and fruit formation.  As important as having a shortage of nutrients is not to have excessive amounts.  Excessive nutrients are wasted and can cause damage to the plant.  Too much taken up by the plant often causes leaf burn in the plant.  Soils with excessive nutrients often have a white crust develop on the surface after heavy rains dry up.  The nutrients come to the soil surface as water evaporates leaving the salt on the soil surface. 

A good rule of thumb on a garden is to add about 10 lbs of fertilizer for 1000 sq ft of garden.  Then a similar amount can be added either with irrigation or again sprinkled on the surface a couple of months later when plants really start to produce fruits and flowers.  Additional nutrients will only be wasted.  Fertilizers should contain a good amount of nitrogen to support good vegetative growth early in the season.  Later when plants are starting to bloom or produce fruit a higher amount of phosphorus and potassium may be needed.  Grass type crops such as lawns and sweet corn need more nitrogen throughout the whole growing season. 

Certain soils will be short of some micronutrients.  Iron and zinc are the most common micro nutrients that are short.  When these are needed, it is usually because the soil has too high of a pH.  This may be alleviated with additions of iron in products like Green Light’s Iron and Soil acidifier or Ironite.

As important or more important as adding fertilizer is to have the correct soil pH.  PH is a measure of the acidity of the soil.  A good soil pH is 6.5.   Low pH soils can be raised with the addition of calcium, usually in the form of lime.  Powdered lime will influence the soil faster than aggregates of lime.  Pelleted lime is easy to apply but needs to be in a form that the pellets will dissolve in water leaving a powdered lime.  Gypsum can be added to get sulfur and calcium but it neither raises nor lowers the soil pH.  Sulfur will lower soil pH but lowering pH usually takes longer and is less critical than raising the pH.

How to plant a garden and what do I need to add at planting?

April 6, 2011

How to plant a garden and what do I need to add at planting?

Where can I get information on how to plant a garden?  Most extensions bulletins are available on line, so the trip isn’t even needed.  If you are truly interested in gardening attend a Master Garden Meeting and set a goal to be a Master Gardener.  Keep reading The Garden Doc for additional information throughout the year. A few weeks ago I wrote about when to plant.  Read that first.  What do I plant was also written a few weeks ago. 

How to plant a garden?  Remember to lay out the garden on paper leaving plenty of room for plants to grow.  Carrots and beets, don’t take much room, potato plants can individually take about 9 sq ft., squash and pumpkins may have vines that run for 20 or more feet, pole beans will grow well over 6 feet high.  Lay out the garden so one plant doesn’t shade or get over run by another plant.  Leave the room at planting.   Plant the seeds with this rule of thumb; plant to a depth 4 times the size of the seed.  This means corn and beans should be planted about 1 to 1/12 inch deep potatoes about 6 inches deep but in a hill, small seeds like carrots about ¼ inch deep.  Cover with loose soil.  The biggest problem during the growing season will be weeds.  Remember hand weeding takes a lot of time.  You may want to keep the garden a manageable size.

What do I add when I plant my garden?  If you have a good soil and it is moist, add nothing.  Just plant and let the soil and nature do what they are supposed to do.  If you need fertilizer, see below.  There are some interesting new products on the market that you may be interested in trying.  Plant Starter from Advanced Biological Marketing is a micro organism mixture that may benefit plants by colonizing the roots with good microorganisms.  I bought a package at Menards.  These organisms can live in a symbiotic relationship providing nutrients to the plant and in return get sugars from the plant.  Because they colonize the plant roots they may protect the plant from deleterious microorganisms that may cause plant disease.  Inovate is a product that provides miccorhizae that do the same as above.  The only place I know to purchase this item is at Summer Winds Nursery in Arizona and Colorado.  Microorganisms that may be used are miccorhizae, bacillus, and trichoderma.  Trichoderma has been sold as T-22 in the farm and horticulture market. Look on the website of BioWorks for a trichoderma source.

Another type of product used extensively is humic or fulvic acid.  There is a lot of scientific evidence that these products work, but they don’t work in all circumstances.  If humic acid is over applied it can limit plant growth.  The American Society of Agronomy holds a meeting once a year jointly with the Crop Science Society of America and the Soil Science Society of America.  The meeting in Pittsburgh in November 2009 held a day long symposia on humic acid and microbial additives to agriculture.  Dr Rene Scoresby, formerly of LignoTech, a Borregaard company, showed a long list of studies that indicated a 5 to 10 % yield increase could be obtained using humic acid.  The conclusions showed, each soil type would need the ideal humic acid rate figured out, and that soils with problems usually showed the best response to humic acid.  Some of the data presented was produced by the USDA and Universities, others by private researchers with nothing to gain from good data.  For a gardener 1 quart is about the right amount, but each humic acid source has a different concentration. 

Next blog will be about fertilizer and how much to use.