Sunburn protection for newly-grafted Payne walnuts

Abstract

Because scions and rootstocks are sensitive to heat, they sunburn readily following grafting. When walnut rootstock is grafted, either the year planted or the following year, ordinary whitewash or a 50% solution of interior latex paint and water have commonly been applied for sunburn protection. In orchards where these sunburn treatments have been applied, erratic growth and poor grafting frequently occur, suggesting the whitewash treatment might be responsible. The experiment reported here was conducted to determine the influence of a sunburn protection treatment on growth of newly grafted trees.