Apple (AAPL) got hit with a pair of downgrades Monday as analysts see a weaker consumer taking a big bite out of the computer-maker’s growth rate.

RBC and Morgan Stanley analysts slapped Apple with neutral ratings, down from buy, on concerns that the slumping economy will put a chill on sales of Mac notebooks and desktop computers.

Citing a IQ/Changewave survey, RBC noted that 40% of consumers questioned said they “plan on spending less on electronics in the next 90 days,” RBC analyst Mike Abramsky wrote in the note. This is the weakest outlook ever measured in these surveys, Abramsky wrote.

Apple shares fell 16% in morning trading Monday in the wake of the reports, as investors get a sobering view of how popular consumer devices can lose momentum in a faltering economy.

The growing credit crisis has helped deflate consumer confidence and force delays in purchases of items like new computers and flat-screen TVs. The problem for Apple, writes Kathryn Huberty in a downgrade of Apple to neutral Monday, is that not only is PC sales growth slowing but the one area shrinking less is the under-$1,000 price range where Apple is absent.

Add the slowdown in PC sales to the higher costs of iPhone production, and Huberty says there will be a dramatic drop in Apple’s profit growth. Huberty cut her Apple earnings growth projection for the year to 6%, well below the 9% analysts’ consensus average.

Apple is not recession proof, RBC’s Abramsky writes.

Not surprisingly, investors have taken flight from stocks in some of the stronger players as the market jitters spread across nearly all sectors. Apple shares are down 35% and smartphone rival Research in Motion (RIMM) is down 47% in the past month.

RIM’s disappointing outlook Thursday confirmed that the once hot smartphone segment is cooling just as the larger mobile phone market grinds into slow gear, not just in the U.S., but globally as Nokia (NOK) recently pointed out.