Post by Dean Hoffman
That's true of all plants... over watering (and too frequently) is far
worse than underwatering. Corn needs a good amount of moisture when
first starting out but once it's root system begins to develop it's
far better not to water but only occasionally and deeply... with corn
especially too much water will cause the plants to rot and mildew.
Anyone not comatose who has ever observed a corn field would have
noted that the corn planted close to culverts and roadside ditches
quickly dies... you cn actually see teh progression of dead plants to
stunted plants that eventually are normal sized healthy plants as they
are furher from the wet soil. Corn doesn't require much water once it
reaches about 3', it's foliage is so dense that the sun can't easily
penetrate to the ground (except at the noon hour) so it stays moist
for a long time even through protracted dry spells. It's only with
newly planted fields where corn really suffers from lack of
moisture... once corn is taller than a man it's best it doesn't rain
until after harvest. Most home gardeners have little luck with corn
because they plant too widely spaced (not enough shade and poor
pollination) and then to add insult to injury they over water (and
water incorrectly by wetting the foliage). A lot of novice gardeners
over water, so the plants never develop a proper root system, probably
why so many think corn has shallow roots.
Sweet corn water use pretty much matches field corn water use.
The irrigation section is a bit over 3/4 of the way down.
Field corn uses a lot of water after it's shoulder high. There's a
water use chart here: http://tinyurl.com/yolyyc The local paper
publishes a water use chart almost daily. The highest use per day I
remember was about .35".
The pattern you suggest would deprive the plant of the water it needs at
the most critical time of production.
As much as it absolutely pains me to defend anything that Sheldon has ever
written, I don't believe that what he wrote above really conflicts with the
information which is given in the cite you provide. (Which is most
interesting - thank you for posting the cite). I guess we could quibble
about the sentence about once it's as high as a man it's best if it doesn't
rain till harvest, but it's close to harvest then anyway and what he means
by 'rain' may be different to what I (or you) mean by rain. For my
conditions 'rain' means a shower of up to an hour if I'm lucky, but for him
it could perhaps mean days of rain. I am told that there are still some
places in the world where such a rain pattern still happens although I am
begining to have doubts about that.
He does mention the use of infrequent but deep watering but that corn hates
waterlogging. He didn't use that term but that is what I took him to mean
from the example he gave.
So long as soil moisture levels remain sufficient for the corn to keep
growing strongly and taking up nutrients, there is no need to water on a
daily or even frequent basis unless the soil is not moisture retentive.
Soil with a high sandy content may be one situation where daily watering is
required. It is doubtful that this would apply though in home gardens where
keen home gardeners know about building up humus content. Humus (and its
retention and increase) is usually more of a problem for broadacre farmers.
Post by Dean Hoffman
I work for an irrigation company in Nebraska. Irrigation season
usually starts for real about the third week in June. Corn will be
somewhere between waist and shoulder high then. The crop canopy should
be close to shading the ground by then depending on the row spacing.
Irrigation will be heavy through about the first week in August then
tapers off. Crop consultants usually tell farmers to irrigate through
the first week in September. That's usually when the black layer forms
at the kernel base. http://tinyurl.com/2bc29o
We had a good rain here about ten days ago. Some of the crop was in
but wouldn't come up due to the soil crusting. The cure for that is
more rain or irrigation. Some irrigation systems were running because
The seed companies here usually plant 4 or 6 female rows to every male
row for their seed corn production. I don't see how pollination would
be a problem for the home gardener. Each plant has it's own tassle and
silk for pollination purposes unlike the seed corn.
The difference between seed company production of ears and home gardeners is
that the the former will have huge fields of corn and given that corn is
'wind' pollinated, there has more chance of being pollinated where there is
a huge field rather than in a smaller plot where there is a lesser chance of
pollination happening. Home gardeners would usually do some basic
calculation on how many ears they would eat between crops and how many
plants it would take to get that number of ears and then to figure out how
much space they can spare and how mcuh they can freeze. Thsi year we
overplanted in amajor way and although I have a moutnain of corn in the
freezer, I ended up giving huge amounts of cobs to the chooks.
Home gardeners are advised to plant in close set blocks for this reason as
the closeness of planting combined with the dropping of pollen from above or
nearby can take advantage of even the slightest zephyr of breeze. Many home
gardeners now have much more limited vegetable growing space in their home
gardens and in their freezers than they might like. I know one set of
friends who grow what I consider to be a piddling amount of corn (10-20
plants) so in their minute garden that is the space they can spare and they
like to have a small amount of fresh corn each year.
Post by Dean Hoffman
Why is wetting the foliage on a corn plant a bad thing? Pivot
irrigation systems get the foliage wet whenever they're running.
It can be a bad thing where heat levels are not high enough for excess
moisture to evaporate from the leaves and forming cobs or where high
humidity levels cause moulds/mildews/fungal growth to set in.