In August of 2015 we planted 210 walnut trees in to red loam soil with a clay base. The trees where fertigated in September, November and early January with 6L/Ha of Guano Liquid Gold®. The product was applied via 4L/Ha drippers two at each tree.
In mid-December and again in early February we had two heatwave events of three days over 40 degrees including two consecutive days over 42 degrees with a top temperature of 43.6 degrees. Over the cause of December through to Mid-February we had a run of 55 days over 30 degrees and little rain.
While the plants showed signs of stress we only lost 20 trees in conditions when we expected to lose more than half.
In March 2016 as the trees recovered I under took a tissue test on the trees and the leaves had high levels of silica. The assumption is that the elevated silica has thickened the trees epidermis and assisted in tolerating the heat stress.
Robert Drewitt, 02.08.17
Walnut Tree Grower