Eight deserters filed slowly into the guerrillas' position, a stone-walled cattle pen on the heights above the beleaguered Afghan Army garrison of Puzhgur in the middle reaches of this strategic valley.

They ranged from mid-teens to late 40s, gaunt, unshaven and motley. They stood listlessly in tattered boots, hunched against the cold -- an improbable enemy.

The eight had fled their positions near the Soviet base at Bazarak, a key communist strong point in the valley, two days before. They said some had brought weapons to nearby resistance fighters, others had come empty-handed. They were now going to homes in northern Afghanistan.

As Afghan Army units in the Panjshir Valley crumble under an apparently nonstop stream of desertions that began with the war six years ago, such scenes have long since ceased to excite more than passing interest here. Guerrilla camps the length of the valley play host daily to government soldiers on the run.

According to rebel estimates, Kabul's forces in this center of anticommunist resistance number about 7,500 men, backed by 7,000 Soviet troops. But morale and professional standards appear to have ebbed in Afghan Army ranks.

The defectors and prisoners I saw daily during nearly three weeks in the Panjshir were more rabble than military.

All interviewed said they had been pressed into service during roundups by security forces in villages or on city streets. Mostly from peasant backgrounds, they described receiving one month's basic training before being posted to operational units.

On average, they had deserted within five months.

Army commanders' confidence in their troops has wholly evaporated, according to defector accounts. Troops in some front-line positions were issued weapons only after the beginning of a guerrilla attack. "We weren't allowed to carry a weapon when leaving our post to relieve ourselves or to fetch water," said Sahib Jan, 19, a conscript with four months' service. He said his 16-man post surrendered after a 10-minute exchange of fire.

"Mostly the soldiers were waiting for a mujaheddin attack and a chance to escape," he said, using the pervasive name, meaning "freedom fighters," for the rebels.

Several defectors explained that they had been unable to cross the lines earlier because of mine fields around their positions -- laid ostensibly to keep out the guerrillas.

Guerrillas give the deserters a cordial welcome, part of a general policy aimed at undermining Kabul's forces.

Troops are encouraged to cross the lines at the first opportunity, bringing with them a weapon if possible. But both deserters and rebel commanders stressed that stepped-up vigilance on the part of Afghan officers and military police had seen a reduction in the number of men defecting with their rifles.

Fleeing soldiers are provided food and given cash grants by local guerrilla commanders sufficient to cover basic expenses on what for most is the beginning of a long walk home. "This is done very much on a humanitarian basis," said Massoud Khalili, an aide to Panjshir commander Ahmed Shah Massoud. "But it's also a good investment as it underlines the difference between the treatment these men get from us and what they've had from the regime," he added.

In one recent incident, said Khalili, a defector wounded while escaping, reportedly after shooting six officers and bringing over several weapons, was given a reward worth $100 in Afghan currency by Massoud.

Kabul attempts to stem the front-line losses appear to have focused largely on pressing more men into Army ranks while increasing the ratio of officers to conscripts. According to diplomatic estimates, the Afghan Army today numbers -- on paper at least -- about 30,000 men, a drop of more than 50,000 from its strength at the outbreak of the Moslem insurgency in 1978.

As of this fall, conscription has been extended from three years to four for males 18 to 45. In 1982, when length of service was extended from two years to three, men who had already completed national service prior to the war were declared liable for call-up for a second period.

But while the measure provides legal grounds for extended press-ganging, many analysts believe it has accelerated desertion by confronting reluctant soldiers with dangerously long periods under arms.

The increase in the ratio of officers to other ranks has produced situations in the Panjshir in which posts are manned by six officers and 10 conscripts, with the officers apparently serving as guards in addition to leaders.

Some "production-line officers" receive crash promotions and additional political and military training after two years in the ranks. But in one group of six junior officers captured in early October, and interviewed by this correspondent, none had completed even six months in the ranks before being promoted. Two said they had served only two months before becoming officers.

In contrast to common soldiers, captured Army officers are viewed with suspicion and held under close guard pending investigations into their political loyalties and backgrounds. Conscripts formerly under their command often testify.

Rebel commanders admit freely that men with proven affiliations to the communist People's Democratic Party or the secret police may well be executed.

The unreliability of the Afghan Army and apparent Soviet failure to improve the situation have led to a growing emphasis on militia units organized on a local basis under Kabul's Ministry of Tribes and Nationalities. Stiffened by communist party activists, these units are now believed in diplomatic circles to outnumber the Army. They consist mostly of tribal or ex-rebel groups bought over en masse by Kabul.

"They are well-paid, know the terrain they operate in and often have some political motivation," said one western diplomat, adding that in many cases militia groups were fighting more effectively than the Army.

But the difficulties faced by Soviet authorities in relying even on militia forces have been illustrated in recent months by the defection of several leading militia chieftains. Most widely noted was Hasan Khan Karokhel, a tribal leader in the area east of Kabul who joined the resistance with some 3,000 armed followers.

Guerrilla commanders in the Panjshir argue that the most telling evidence of the failure of Soviet efforts to "Afghanize" the war has been the steady increase in Soviet troop strength in the country and the growing prominence of often elite Soviet commando units in combat.

Western diplomatic sources estimate current Soviet strength in Afghanistan at 115,000 men, an increase of 10,000 over the number during most of 1983. The Soviet "limited contingent" that moved into Afghanistan in December 1979 numbered an estimated 85,000.

An additional 40,000 airborne troops committed to the Afghan theater are based across the border in Soviet central Asia. Since the offensive against the Panjshir in April they have been increasingly deployed for specific operations south of the border, said the sources.