Project Number: 5325-42000-036-03
Project Type: Trust

Start Date: Sep 01, 2007
End Date: Jul 31, 2009

Objective:
1) Determine if there is value in adding arbuscular mycorrhizal (AM) fungi inoculum, particularly at planting. 2) Determine if pre-plant fumigation impacts the extent and nature of AM fungal populations in the soil and is this of consequence? 3) Characterize the AM fungi populations present on field grown nursery stock vs. potted plants at the time of planting and the resulting tree performance.

Approach:
Nonpareil almond trees on Nemaguard rootstock will be planted in Spring 2008 at USDA Parlier. Plot strips will be fumigated in the fall of 2007 and non-fumigated plot strips will be used as comparison. An assessment of the extent and nature of AM fungi populations present in the soil/residual roots after fumigation but before planting. At time of planting and before any inoculation, there will be an assessment of the extent and nature of AM present on tree roots. Tree performance data to be collected will include: (1 Trunk circumference: initial and final yearly. (2 Annual pruning weights; Nutrient status-characterize nutritional deficiencies if and when symptoms arise. 3. At end of trial: Whole tree top weight, trunk diameter, etc. Annual assessments will be made of the extent and nature of AM fungal populations on tree roots.