Soviet Premier Nikolai Ryzhkov warned Saturday of economic disorder spreading through the country and said the potato crop must be harvested within three weeks to avoid a hungry winter for the masses.

Ryzhkov, in a nationally televised interview, depicted a crumbling economy, with promised shipments of food, medicine and other necessities going undelivered, and "economic warfare" being waged among cities and regions."I don't want to dramatize things. I don't want to frighten anyone. I have no right to do that," Ryzhkov said.

"But laws are not obeyed, decrees are not obeyed, resolutions are not obeyed. There are massive violations, to say nothing of criminal violations," he said. "It's been a long time since we had such a situation in this country."

Ryzhkov has been pushing for a more moderate economic reform than that endorsed by Soviet President Mikhail S. Gorbachev, who has backed a plan to move from central planning to a market system in this nation of 290 million residents.

The Soviet parliament has been unable to enact a coherent reform plan, and last week bestowed extraordinary powers on Gorbachev to direct the economic transition. Gorbachev's first step was a decree threatening fines against suppliers who do not make promised deliveries.

That decree, and Rykhkov's televised warning, came amid media reports that the harvest was going poorly, especially for potatoes, a staple of the Soviet diet.

This week, factory workers, soldiers and city dwellers swarmed to the countryside to help farmers pull potatoes from rain-soaked fields in an effort to fend off hunger this winter.

"In some industrial regions, people are going to the fields despite the difficult weather conditions, and the Army helps," Ryzhkov said.

He referred to a resolution by the Council of Ministers on Wednesday aimed at "saving the harvest, especially vegetables and potatoes."