Minecraft 1.10.2 - Botania R1.9 339 (Most Recent) - Forge 12.18.3.2185 (Most recent)

Attempting to make an automated tree farm with Botania and Vanilla blocks, nearly identical to the one in this video but in modern version: https://youtu.be/pswTgkR-LDA

Bug: Grass colored with a pasture seed used as target for planting blocks for the Rannuncarpus; changes into dirt when tree is grown on top and pulled back by piston at the same time. It does not seem to change when only a block is placed on top, or when only pulled by a piston, only with a combination of the two.

Screenshot highlighting the problem block: http://imgur.com/a/pY2Y0

FML Log: http://pastebin.com/mXSiQBDG

Reproducing the issue seems to have the block change into dirt each time. The tree is grown on top of the pasture seeded block, the redstone signal fires through the log block into the following circuit, triggering the piston to retract the block.

it's a vanilla thing.
not sure when it changed, but according to the vanilla code, vanilla saplings always set the block below them to dirt when growing
I'm not sure there's anything botania can do code-wise.

I know normally with vanilla dirt, growing a sapling will change it from grass to dirt. However I tested the Botania colored grasses and growing trees on top of them normally (without piston mechanisms or the like) does not change them. They stay their respective color of grass. Which I'm assuming is the intended way for them to work since they're for redstone mechanisms that need plant-able dirt. So I'm thinking it's a small bug, but if it is a change with vanilla somewhere between 1.7 and 1.10 that causes it then it might also be worth a look at since mechanisms like this are somewhat the functional point of these grass types.