On September 26, Siena College released a poll for the New York gubernatorial race. The results: Democratic incumbent Andrew Cuomo 56%; Republican Rob Astorino 27%; Green Party nominee Howie Hawkins 7%; undecided or other 10%. See more detail here. Scroll down to question 24.
Based on these results, it seems likely that the Green Party will have the third line on the ballot after the election. In 2010, the Conservative Party, which now has the third line, got 4.99% for Governor (cross-endorsing the Republican, as usual) and in 2012 it got 3.72% for Mitt Romney for President. Thanks to Gregory Koch for the link.