Dry at 80°C until constant in weight :)

Yes it is not varied with crop to crop and most of the cases should be dried at Eighty degree centigrade until final weight

I used 80 oC and 72 hours for my in vitro plant species.

Yes that should be Eighty degree Centigrade until final weight.

I would also suggest 80°C for 72 hours but sometimes, depending on the stage of the plant material, there is still some water left. It is therefore necessary to go up to 96 hours or even 120 hours. But it is necessary to weigh to see if there is always variation of the mass before stopping.