Acting on panic never helps investors, but it's still a good idea to question why you're really buying individual investments.

Consider seed giant Monsanto (NYSE: MON). Though the global agriculture sector holds tremendous promise, you'll find that a few of the 3,065 Motley Fool CAPS members who weigh in on the company offer reasons to be bearish.

Here at The Motley Fool, we like to consider both the good and the bad sides of an investment, so in this article, I'm highlighting three of the main bearish arguments on Monsanto. Be sure to read the bullish side as well, and then weigh in with your own comments below or rate Monsanto in CAPS.                                              

1.  Unhappy customers
Monsanto has experienced backlash from some of its customers, who have complained of high seed prices and lower-than-expected yields on certain products. While rival DuPont (NYSE: DD) has been able to raise prices recently, Monsanto has lowered prices and unbundled product offerings to appease unhappy customers, leaving some investors concerned about the possibility of eroding margins.   

2. Competitive threats
Monsanto faces serious competitive threats on several fronts, threats that could continue to pressure the stock. Cheaper generic Chinese glyphosate weed killer is killing its Roundup sales, as companies like Origin Agritech (Nasdaq: SEED) get in on the action. And some seed missteps have opened the door for rival DuPont to steal market share in North American corn and soybean seed sales.              

3. Earnings struggle
In their most recent quarters, Mosaic's (NYSE: MOS) and PotashCorp's (NYSE: POT) profits more than doubled on strong fertilizer demand, and Roundup lawn products marketer Scotts Miracle-Gro's (NYSE: SMG) profit increased by 19%. But Monsanto's aforementioned woes led to a 45% drop in fiscal-third-quarter earnings, and management cut its full-year earnings estimate. With Deere (NYSE: DE) recently forecasting strong farm equipment sales, some investors see better ways to play the agriculture sector.

To see details of what CAPS members are saying now about Monsanto, just click on over to Motley Fool CAPS and have a look -- or add your own thoughts directly to this story in the comments box below.