Monsanto (MON) investors may have started to get a little jittery about the company's future. The seed giant is set to report its second-quarter numbers this Wednesday, and Street estimates run high. But the stock hasn't kept pace with the optimism, giving up nearly 4% gains over the past three months. The market is clearly paying closer attention to the war against genetically modified crops that appears to be heating up.

Dow Chemical's (DOW) Enlist E3 soybeans may have moved closer to receiving the U.S. Department of Agriculture's approval, but major U.S. grain exporters refused Syngenta's (NYSE: SYT) Agrisure Duracade GM corn trait last month following China's rejection even as the FDA approved the trait last year. Meanwhile, France is mulling a revival of its ban on GMO crops, and news is pouring in that Brazil may even suspend Monsanto's glyphosate Roundup herbicide.

Source: Monsanto.

The pressure's building up on Monsanto, but a slowdown in the company's seed sales because of all the noise against GMOs is the last thing that investors want to see. Will Monsanto's upcoming earnings report be a harbinger of tougher times ahead?

Near term looks safe
The second quarter is traditionally Monsanto's most important quarter since it coincides with the peak selling season ahead of the U.S. spring planting. Monsanto ended its first quarter with higher year-over-year prepays (advance payments) from customers in the U.S., indicating robust demand for its seeds. DuPont (DD) also projects higher sales from its agriculture segment for the first half of the year, backed by a strong North American season.

Analysts expect Monsanto's Q2 revenue to climb 6% year over year, and see its net profit improve a good 13%. So Monsanto's profitability is actually improving, irrespective of all the opposition to its products. The company hopes to improve gross margin from its seeds and genomics by 3% to 4% this year. If its Q2 margins trend higher, Monsanto could easily meet its target.

What you should watch for
In its upcoming report, check how Monsanto plans to boost its revenue and profits when farmers are increasingly opting for soybeans over corn. Farmers are paying more attention to soybeans after the sharp jump in the crop prices in recent months. Farm Futures even expects to see a "significant shift" in acreage from corn to soybeans in the U.S. Department of Agriculture's crop report scheduled for release this week.

Lower corn acreage isn't good news for Monsanto since corn is a major growth driver -- it made up roughly 65% of its seed sales during its financial year ended Aug. 31, 2013. Soybeans contributed nearly 16% to its sales during the period.

But given that Monsanto's Roundup Ready soybean trait already covers nearly 90% of the soybeans acres in the U.S., an increase in soybean acreage should not hurt Monsanto as much as archrival DuPont, which has to license much of its genetically modified soybean traits from Monsanto and has a much smaller footprint in the soybean market. Dow Chemical hopes to edge out the Roundup Ready weed control system once its Enlist E3 goes online, but that story could take several years to unfold.

More importantly, both corn and soybeans are near-equally profitable for Monsanto. Their contribution to the company's gross profit during the last financial year matched their respective percentage contribution to its sales. So the company may be able to balance out the weakness in one product portfolio with strength in another.

Intacta RR2 PRO soybeans. Source: Monsanto.

Plans at risk?
With competition intensifying, look for details about Monsanto's planned launches for 2014 in its upcoming earnings call. Five products are ready to go online this year, including the Intacta RR2 PRO soybeans.

Remember, the company is very excited about Intacta RR2 PRO, and is betting on it heavily to gain traction in the key Latin American market. But any negative publicity out of the ongoing glyphosate-based herbicides issue in Brazil could serve a major blow to Monsanto's dreams. So make sure you don't miss the company's upcoming earnings call that could provide some valuable insight.

The Foolish bottom line
While growing concerns about GMOs is worrisome, Monsanto investors may have a real problem in hand if the company downgrades its earlier 2014 projection of at least 10% upside on its earnings per share. I don't see that coming, though, but even a small hint of doubt in management's words could send the seemingly vulnerable shares down. But before you decide to act, make sure to check back at Fool.com for detailed analysis on Monsanto's earnings and plans for the future.