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London, Ohio

i have never used calcium on my pumpkins except for gypsum in the fall is it neccesary to get a big one or has big ones been growed with just gypsom that has been applied to the fall patch
thanks, dan

7/12/2005 12:38:20 PM

Ontario, Canada.

Calcium in the Plant.

Calcium uptake is by mass flow. Calcium contained in the soil solution moves into the root system with the influx of water and is carried in the transpiration stream to the various plant organs. Usually those areas with the greatest activity receive more water and therefore more calcium. Calcium uptake is generally genetically controlled. One of the restrictions is the fact that only newly expanding unsuberized root caps can absorb calcium. Any environmental factor that limits root expansion limits the uptake of calcium predisposing plants to physiological disorders.

7/12/2005 1:28:22 PM

Ontario, Canada.

Calcium and Nitrogen Regulation

Nitrogen plays a very important role in crop production the appropriate rates of N promotes fast vigorous growth and high yields. However too much in particular too much nitrate nitrogen can cause increased susceptibility of disorders and predispose plants to pathogen infection. Environmental concerns arise with excessive nitrates available to potentially leach to ground water.

Nitrate nitrogen tends encourage soft succulent vegetative terminal growth at the expense of reproductive growth. Ammonium Nitrogen uptake alters the plants sugar metabolism. This encourages not only more sugar production but a greater rate of export out of the leaves to the roots and on the way to the roots, fruits and storage organs can grab the sugars and enhance growth, yield and quality and decrease the susceptibility to diseases.

If plants can utilize 50 % of their N as ammonical forms the crop can use more Nitrogen to produce more yield and quality. Nitrogen Use Efficiency is increased when a crop can produce more yield with the same N level.

Nitrate nitrogen tends to accumulate in the leaves and increase organic acid production, which increases the demand for Calcium to neutralize the acidity, if this calcium is in short supply calcium may be mobilized from the roots. This movement of calcium from roots is the demise of the root integrity and can lead to leaky roots and ethylene production signaling the plant to shut down.

7/12/2005 1:29:22 PM

Ontario, Canada.

Work done at Texas A & M Extension Service by Sam Feagley and Llyod Fenn demonstrated the value of urea fertilizer combined with soluble calcium to enhance yield. The addition of calcium chloride enhanced more ammonium N uptake, potassium, phosphorus, magnesium, copper, and zinc in the crops. The rates that were used were 1 pound of calcium chloride for each pound of urea.

In the case of onions within 30 hours of an application bulb weights increased 50 %. However the entire plant weight did not increase as much as the bulbs demonstrating that more sugar was disproportionately deposited in the bulbs.

Timing of application is best done in the spring. The authors do recognize the need to fertilize later in the season and calcium ammonium applications worked as well foliar later in the growing season. They worked so well they suggested that a foliar application may be a way to extract more latent nitrate nitrogen out of a soil and enhance crop yields and reduce nitrate carry over. With Nutrient Management Planning pending and ground water quality issues this needs to explored.

http://www.agtest.com/

7/12/2005 1:31:21 PM

Midwest

I use Biomin Calcium as a foliar every week. I plan to use it on the fruit soaked in a towel and around the blossom end and stem.

7/12/2005 1:32:05 PM

Ontario, Canada.

I hope this helps.

Good Luck and Good Growing.

Russ Landry

7/12/2005 1:32:55 PM

London, Ohio

thanks for the replies
dan

7/13/2005 3:22:19 PM