I know of several 1790 owners with liquid fertilizer coulter setups where the dealer or whoever setup the liquid system "forgot" to put orifices in the fertilizer lines ahead of the openers.

This causes an extreme variation in the amount of fertilizer put down on each row - usually the rows near the center of the planter get way too much often burning them while the rows on the outside ends get way to little, starving them.

The confusing thing is that the piston pump put out the right amount of total fertilizer per acre so consumption looked right but the distribution across the planter was all wrong.

There needs to be an orifice in each row unit line small enough to keep the same pressure at the end rows as in the center rows.

This is not a shortcoming of the 1790 but of the liquid system installation.

Sounds like this may have been your problem also. What fertilizer and how much were you trying to put down?  The stock JD openers are usually about 2" from the seed center if the mount is centered on the row unit as I recall but checking this just involves looking on the ground ahead of the row unit - can't blame the planter for someone not checking the distance. Again maybe setup error.

There was lots of very good corn raised with 1790's in the last few years. I don't think you can blame a particular model planter for fertilizer rate issues. What you are describing can happen on any planter. The setup man needs to know what he is doing regardless of color. jmho.

Jim at Dawn