Dr. Scott Johnson’s stone fruit nutrient deficiency studies have led researchers to look anew at traditional nutrient analysis sampling methods and deficiency threshold levels. Based on his research, the recommended optimum range for some nutrients has been fine-tuned. Throughout the last 50 years, growers have been advised by horticulturists to take a summer leaf sample to analyze the nutrient status of their stone fruit trees. “We’ve now learned that midsummer is a lousy time to take samples,” the University of California Cooperative Extension pomologist said. Johnson and his colleagues are looking at whether or not dormant shoots are better indicators […]