zryteg

Best times of year to fertilize pistachio trees At a glance Time fertilization to the tree’s growth stage, not just the calendar. Split doses through the season (fertigation) and adjust with soil and leaf tests. Depending on climate, each window may shift by 2–4 weeks. Suggested pistachio fertilization calendar - Late winter to bud swell (Esfand → early Farvardin; roughly late Feb → early Apr) - Objective: Prepare the soil and start nutrition gently. - Actions: Soil amendments (gypsum on sodic soils, elemental sulfur, organic matter), base phosphorus or phosphoric acid placed near the root zone, Fe-EDDHA chelate in soil, and a gentle start of N with the first irrigations. Foliar Zn/B only if tests show need. - Budbreak to bloom (Farvardin → Ordibehesht; ~late Mar → late May) - Objective: Support early growth without provoking lush, excessive shoots. - Actions: Light, split N and P via fertigation; avoid heavy N right around bloom. Targeted foliar Zn/B only if needed. - Post-pollination to shell hardening (Ordibehesht → Khordad; ~late May → late Jun) - Objective: Supply most of the season’s N and P to secure set and young nut growth. - Actions: Apply the main share of N in several splits + begin K; add calcium if needed (e.g., calcium nitrate). Prefer low-chloride sources. - Shell hardening to the start of kernel fill (Khordad → Tir; ~late Jun → late Jul) - Objective: Prime the tree for peak K demand. - Actions: Increase K supply (KNO3 or K2SO4) and continue light, steady N. - Peak kernel fill (Tir → Shahrivar; ~late Jul → late Sep) - Objective: Maximize kernel fill and quality. - Actions: Maintain K and steady irrigation; keep N limited to avoid late vegetative flush. Under high salinity, foliar K can complement. Supply Mg/Ca if symptoms appear. - After harvest to pre–leaf drop (Shahrivar/Mehr; ~late Aug/Sept → Oct) - Objective: Rebuild reserves for next year. - Actions: If leaves are still healthy and active, one light N+K application. Avoid heavy N. Foliar micronutrients only with proven deficiencies. - Autumn and winter dormancy (Mehr → Bahman; ~Oct → mid‑Feb) - Objective: Soil correction and salinity management. - Actions: Organic amendments/compost, gypsum for sodic soils, periodic leaching irrigations if needed, and band/place P near the root zone. Avoid large amounts of soluble N in this window. Key notes - Testing: Base decisions on soil tests (autumn/winter) and leaf analyses (mid-summer, mid-shoot leaves from non-fruiting shoots). Track results year to year. - Salinity and water quality: In saline water/soils use low-chloride sources (K2SO4/KNO3) and split doses. - Alternate bearing: In on-years, slightly raise N and K; in off-years, reduce N to avoid excessive vegetative growth. - Young trees: From early season to mid-summer, provide split N to build roots and canopy, then taper gradually toward season’s end.