Walnut Production Manual

acre amendment amount applied black walnut blackline virus buds California walnut canopy cation catkins cells cost cover crops crown rot cultivars damage deficiency disease droplets dryer effective English walnut factors fertilizer Figure fruit graft union growers growing gypsum harvest hedgerow herbicides hindsii inches increase infected infiltration irrigation scheduling irrigation water kernel leaching leaf leaves loam mature ment meq/L microsprinkler nematode nitrate nozzles nutrients occur Payne percent Persian walnut pest photosynthesis Phytophthora Phytophthora species pistillate plant pollen Pomology pores problem production pruning reduce regia removed require result root and crown root growth root system root zone rootstock salinity sample scion season Serr shell shoot soil moisture soil pH soil surface soil-water spray sprayer sprinkler susceptible symptoms Table temperature tensiometer tion tissue toxic trunk UC Davis UC Davis Department varieties vigorous walnut orchards walnut trees weed yield