MY VISION of the world after the holocaust is this: A sterile pile of rubble, warmed by relentless sunshine unbroken by shade. There is no sound except the wind. The world is painted in neutral shades of ash and stone and dust, except for a few tentative sprouts of green around the edges of heaps of destruction.

Poison ivy.

It is a survivor, a strong competitor, say the scientists. It will regenerate itself from bits of vine or from seeds long left dormant. It will choke out neighboring plants. It is frequently a vine, but give it nothing to climb on and it climbs on itself, building into a bush. You can hack it to death or poison it with herbicides, but given a tree and a couple of birds in the neighborhood, you will have it again. You destroy every last bit of it in the baseball field and every tendril wrapping itself around a utility pole. It is lurking in the woods.

There is, to be sure, an entomologist in California experimenting with Japanese insects that might eat the noxious weed. Or killer bees might be the answer, suggested a friend. Insects which would prey on the plant might help control poison ivy and its relatives in the woods, but introducing foreign insects is a ticklish business, and the insect hasn't been discovered yet.

There are long lists of home remedies and more modern palliatives for poison ivy, and volumes of advice on how to avoid it, but there's nothing surefire about poison ivy except growing it.

"It's got what it takes to survive under all conditions," said Dick Hammerschlag, chief of the ecological services laboratory for the U.S. Park Service.

There are some limited good things you can say about poison ivy. "It's a very beautiful plant with very shiny glossy leaves," said Dr. Dayton L. Klingman, chief of the Weed Science Laboratory at the Beltsville Agricultural Research center, and a poison ivy expert. "As far as I'm concerned it's beautiful - if it's at a distance. But we have other beautiful plants that could take its place," he said.

"Poison ivy is really good bird food," according to Tom Woodward, grounds manager at the Washington Audubon Society's headquarters in Chevy Chase, where the weed grows unmolested. "That's the way it's spread," he said. "The seeds are unaffected by the birds' digestive systems . . . It's almost impossible to control because you can't control the flight of birds."

The waxy white berries that appear in the fall are not the only food available to the birds. But with a berry that hangs on after other foods have disappeared, poison ivy serves as "stress food" for birds, said Woodward.

"In a hard winter like last year, the birds would probably take anything they could get," he said. If they couldn't get their usual foods, they could make it through on poison ivy. The bird lovers of America should praise poison ivy," he said.

Poison ivy, poison oak and poison sumac are fairly widespread around the United States. Poison ivy grows almost everywhere, although it thrives better in moist areas like our own. "We certainly have lots of poison ivy. Ivy and oak are found most widely in the humid eastern and southeastern part of the United States and on the west coast," said Klingman. "I've lived in Wyoming, Missouri, Nebraska and here. I'd have to say there's more poison ivy here than any other location I've lived in."

As Klingman pointed out in Farmers's Bulletin No. 1972, published by the Agriculture Department, poison ivy and oak are neither ivy nor oak. They belong to the cashew family.Poison ivy is the most widespread. Poison sumac tends to grow in swampy, marshy areas.

It is a native plant and one with which North America appears to be uniquely blessed, although there are related plants in Japan. Captain John Smith of the Jamestown Colony discovered "a poison weed, being in shape but little different from our English yvie, but being touched causeth redness, itchings, and lastly blisters . . ."

As the forest was cleared, poison ivy may have spread it. It prefers sunshine, although, in its competitive way, it will grow in shade if it must. "I doubt if it does well in dense forest," said Klingman. "It's possible that when man first came here we had less poison ivy in this area. To this extent, man and his activities may have increased the problem, but you couldn't live in this country if we didn't have anything but climax forest."

In 1969, the last year for which there are figures available, there were an estimated 1.5 million cases of poison ivy, with 152,000 work days lost, according to the Public Health Service. For some workers, it is a serious occupational hazard. California firefighters wading into billows of poisonous smoke from brush fires where Pacific poison oak is burning can contract miserable cases, said Dr. Harold C. Baer, director of the allergenic products branch of the Food and Drug Administration Bureau of Biologics. Firefighters, agricultural workers, telephone linesmen and others all work in some jeopardy from it.

As for killing it, there are two baisc approaches, with a third in the offering. One approach is physical violence. You can mow it, grub it out with a hoe or pull it up by hand. There are short-comings in the last method.

The other approach is poison. An old method was to douse plants with a solution of three pounds common table salt to a gallon of slightly soapy water, dabbing it on the plant in June, catching the leaves just as they are full grown.

"The simplest and best control methods include the use of herbicides," according to Klingman. Amitrole, silver, ammonium sulfamate and 2, 4-D can all be used, he said. Treat the poison ivy selectively, said Klingman. "If you are in your yard, yoy have to be careful not to hurt the ornamentals."

Klingman said the herbicides are "about twice as poisonous as table salt. We use them on range land. They're much less poisonous than most insecticides." Killing the weed will probably take more than one attempt.

The third approach, still in the offing, is predatory insects.

Dr. Carl B. Huffaker of the division of biological control of the Department of Entymological Sciences at the University of California at Berkeley, is exploring the possibilities. "We have one insect that looks rather promising, but we will have some other testing to do before we can bring it into this country," he said.

He has found a family of insects that live naturally on plants of the genus Rhus, to which poison oak and ivy belong, and has been surveying them for potential predators on poison ivy and oak.

The family Rhus includes the small Japanese lacquer-tree (Rhus verniciflua), a source of Japanese black lacquer. People who are extremely sensitive to the chemical in poison ivy which causes all the grief have been known to develop a rash from handling Japanese lacquer-ware.

The poison is a group of substances called pentadecyl catechols, also called urushiol, a Japanese name. They act through an immunological reaction called delayed contact sensitivity, said Baer. "People are probably never reactive the first time they come into contact with it. The first contact includes the sensitivity," he said. "It takes time to build up all the sensitive cells."

In subsequent exposures, the reaction itself may be delayed by as much as one to five days after contact with the plant. Urushiol is an oily saplike fluid. It seeps through the skin.

If you get it on your hands and scratch your forehead, you are likely to break out on your forehead.

Some people become increasingly sensitive, while others become less so, said Baer.

Baer is working on a new approach to treating and preventing poison ivy. "The procedure would be to try to take people who have never had poison ivy and see if they can be kept from getting it," he said. "It may take a year to find out whether we have accomplished anything."

The principle of shots now available for poison ivy is to "reduce sensitivity of people already sensitive," he said. Commercial shots are now being reviewed by an efficacy committee at the FDA.

"The best thing, of course, is to keep away," said Baer. "If you get it, if it isn't too severe, just itch," he said. Soothing lotions, such as calamine, may help. The Potomac Trail Book is big on soaking in tubs full of cool water laced with cornstarch.

For severe cases, doctors may prescribe steroid creams or even pills or shots of steroid hormones such as cortisone.

Several people swear by something called Rhus-Tox, a poison ivy derivative sold by a pharmacy that specializes in homeopathic drugs - cures derived from the source of the ailment.

Woodward is of a more philosophical bent. "Once you've got a case, you may as well let it run its course. It's a matter of will power," he said. It's like a lot of physical discomforts. You just have to live with it." On the other hand, in his last job Woodward decided he liked living with rattlesnakes. "They were fascinating."

If you can't kill it, and you can't cure it, then the advice that everyone starts out with - avoiding it - makes sense. But avoiding it isn't easy, either. Generally speaking, the leaves do come in clusters of three. Woodward said that the hairs along the stems are the best identifying mark to distinguish it from other less harmful plants with clusters of three leaves. The forms are quite variable, so recognizing poison ivy in one of its incarnations doesn't necessarily protect you against oak or sumac or poison ivy in another shape.

"The great range of variation in the shape of lobing of the leaflets is impossible to describe," said Klingman and Donald M. Crooks, in their opus on the subject for the Agricultural Research Service. Woodward has found poison ivy on the grounds of the Audubon Society that looks so different from the textbook examples that he can't persuade people to leave it alone. He has fun, too, with the leaves of young box elder trees, which look similar. "I say, 'Hey, do you know what this is?' and hand it to them. It freaks them out."

More than most people, Woodward is tolerant of the plant, but he has his limits. "I'm not an advocate of growing poison ivy in the yard. The Audubon Society had a greenhouse plant sale in April, and one man asked for a poison ivy plant, Woodward said. The man had a hole in his fence and wanted to foster poison ivy around the hole to keep the neighborhood kids out. "I refused to sell it to him," said Woodward.

The poison ivy I contracted last November was bad enough. The other irritations were worse.

First, there were the people who acted as if poison ivy and free will existed in the same world. "Ah," they would say disapprovingly when they noticed my agony. "You scratched, didn't you?"

Then there were the Coasters. Dating back to my preteen days when my older sister Laura told me that the Coaster's "Poison Ivy" was a metaphor about veneral disease, I have known all the lyrics.But I haven't always had them running through my mind without ceasing. There I was, trying to act in the office is if my mind was on my work and not poison ivy. And there were the Coasters, in the background. "It's gonna take an ocean . . . of calamine lotion . . . You'll be scratching like a hound . . . etc."

Then there was my own complete, inexcusable stupidity, for which I was paying. I had read, or heard, somewhere that poison ivy was primarily a danger in the spring and summer when the poisonous sap was rising. Something like that, anyway. Like a sap, I rose to the wrong conclusion - that it was no danger in the fall and winter. With my bare hands, I began ripping out the vines among which morning newspapers had landed all summer.

I was scratching like a hound . . . a week after I started to mess around, with . . . poison ivy.

Earthman Henry Mitchell is on vacation, reading seed catalogs, averting his eyes from the weeds and zinnas and dreaming of May. He'll return with a full report.