Fifty trees each of 1-year-old Paradox rootstock June-budded to `Chandler' walnut and 2-year-old Paradox whipgrafted to `Chandler' were planted in a 28 × 28-ft spacing on a Hanford sandy loam soil. Ten trees of each type were selected at time of planting and the number of roots, individual root diameter, trunk diameter, root dry weight, scion dry weight, and total dry weight were compared. All parameters, with the exception of root number, were significantly greater for the grafted 2-year-old rootstocks. Growth of the trees measured as trunk circumference 20 cm above the graft union was significantly greater for the grafted 2-year-old rootstocks following the first season. There was no significant different in trunk circumference between the 1- and 2-year-old rootstocks following the second or third growing seasons.
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