Fruit and nut trees use a recovery period of 10 years.
Since the trees died (no sale or salvage price) you would just remove 100 dead trees from the group of 1200. Then enter a new asset of 100 trees.
Example; If you originally entered a group purchase of 1200 @ $10/tree =$12,000 total cost. You will need to Edit this asset to reduce the tree count and cost. Now 1100 @ $10/tree=$11,000 total cost.
Then enter the new asset of 100 trees @ $15/tree=$1500 total cost.
TurboTax now has preselected categories of different farm assets to pick from for different recovery periods. Fruit and nut trees are included if you are using the Home and Business or Self Employed versions.
Please see the attached page snip below of farm recovery periods;
