MONTREAL (Reuters) - Fertilizer fever, surging oil prices, banks on the defensive and a downbeat central bank forecast for the Canadian economy are just some of the key issues that will dominate the Toronto stock market in the weeks ahead.

Investors wondering whether Canada's Big Six banks have dodged the worst of the global credit crunch may also be wishing they had hedged their investments by stockpiling potash in their backyards.

With spot prices for potash, the raw material for potassium-based fertilizers, at $750 a tonne on the spot market this summer and by some estimates headed for $1,000 afterward, the pink mineral has taken on a rich glow.

Demand for fertilizers, driven by growing global food consumption, and depending on your point of view, the incongruous emergence of a market for biofuels, is behind potash's burgeoning popularity.

Potash Corp of Saskatchewan, which raised its profit outlook for the year by almost 50 percent, finished the week on a 7 percent upswing Friday to close at C$210.40. The stock, which traded below C$50 until late 2006, surged to a high of C$218 earlier this month, and some analysts, short sellers aside, figure it is headed for C$250 and higher.

Potash Corp is the world's largest publicly traded producer of fertilizer, has potash reserves that stretch out 100 years, and can ramp up production to meet growing worldwide hunger for crop nutrients.

"We expect rising fertilizer prices and increased earnings to result in a valuation for Potash Corp's shares that is well above current levels as reflected by our target price of C$300," RBC Capital Markets analyst Fai Lee wrote in a research report.

The upswing in fertilizer prices would also help Agrium , which reports first-quarter results on May 2.