KABUL, Afghanistan - The campaign for Afghanistan's first national elections in five years got off to a subdued start yesterday, shadowed by security fears and marked by the chronic disorganization that characterizes most large-scale endeavors here.

None of the three main presidential candidates made a public appearance on the first official day of the two-month campaign. Out in Afghanistan's hinterlands, many candidates for provincial and national assemblies stayed home, saying that traditional campaign activities such as rallies would be too dangerous.

In Kabul, the capital, campaign workers were out before dawn, plastering walls and utility poles and the city's few trees with campaign posters. By midday, many of the posters had been torn down, defaced, or papered over with a rival's image.

The ballot for the Aug. 20 vote is laden with 41 presidential candidates, most of whom are considered to have little chance to win. The only qualifications for running for president are holding Afghan citizenship and being at least 40 years old.

Last week, when the final list of candidates was compiled, the head of the election commission told reporters he was "ashamed" that lawmakers had failed to set basic requirements for seeking the country's highest office, such as the ability to read and write. Some candidates, he said, were illiterate.

Providing a secure environment for the vote will be an enormous challenge for NATO and U.S. forces in a country where the burgeoning insurgency has rendered large swaths of territory unsafe for travel, particularly in the south.

In Helmand, the country's largest opium-producing region and the scene of heavy fighting between coalition troops and the Taliban, officials said this week that five of the province's 13 districts were outside the government's control.

Western commanders have described election security as a key undertaking, and President Obama's decision to deploy 21,000 extra U.S. troops over the summer was driven in part by the desire to safeguard the vote.

Afghan President Hamid Karzai, who has led the country since 2001, is the front-runner. However, his popularity has slid sharply over the last two years, and polls suggest he might have trouble winning 50 percent of the vote. If he does not, a runoff would be held in the fall.

Karzai's campaign manager, Haji Din Mohammed, dismissed a poll released Monday by the International Republican Institute indicating the president's voter support had fallen to 31 percent. Other surveys have pointed to disenchantment among the populace, citing corruption, pervasive violence, and inefficient governance.

"These polls are not neutral," Mohammed said. "No other candidate has his [Karzai's] standing."

That same poll by the IRI, a nonprofit group funded by the U.S. government, put the level of support for Karzai's two main challengers in single digits.

Each is a former cabinet minister who had a falling-out with the president: Abdullah Abdullah was a foreign minister, and Ashraf Ghani previously served as finance minister.

The Afghan leader rattled many in the international community when he picked a former warlord, Mohammed Qasim Fahim, as one of his two running mates. Fahim has been accused of serious human-rights abuses, and the United Nations and a number of foreign diplomats had entreated Karzai not to put him on the ticket.