1 / 29

Pecan Fertility and Orchard Floor Management

Pecan Fertility and Orchard Floor Management. Lenny Wells UGA Extension Horticulture---Pecans. Leaf Sampling. Sample trees between July 7th and August 7th.  Use terminal shoots exposed to the sun.  Collect leaflets from all sides of the tree. 

flo
Télécharger la présentation

Pecan Fertility and Orchard Floor Management

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Pecan Fertility and Orchard Floor Management Lenny Wells UGA Extension Horticulture---Pecans

  2. Leaf Sampling • Sample trees between July 7th and August 7th.  • Use terminal shoots exposed to the sun.  • Collect leaflets from all sides of the tree.  • Avoid leaflets damaged by insects and diseases.

  3. Leaf Sampling • Abnormal trees or trees not representative of the area should be sampled and sent separately.  • Sample trees of the predominant variety in a given block. • Immediately upon collection, wipe leaves (entire surface, boh top and bottom) with a damp cellulose sponge or cheese cloth to remove dust and spray residue.  • Do not allow   the leaves to come into contact with rubber or galvanized containers.  • If recent soil test data is not available, it would be advisable to collect a soil sample and have it sent to the Soil Testing Laboratory.

  4. Soil Sampling • Useful for pH and toxicities • Late Fall/Winter • Sample uniform area • 1 pint/sample (15-20 cores) over large area • Sample to 8” depth

  5. Nitrogen • N absorption by roots is driven by demand • Demand is regulated by growth of leaves or fruit, and production of proteins. • Flowers may be aborted if leaf N is deficient the previous summer

  6. Nitrogen Leaf Concentration: 2.5-3.3% (Apply when less than 3) 10 lbs N/100 lbs expected crop Shoot growth should be 8-12”

  7. Nitrogen • In well managed, irrigated orchard soils, N can move more readily and leach out of the effective root zone before it is taken up by the tree. • Initial spring N used by developing foliage comes from storage pools within the tree. • N demand will be greatest for “on” trees bearing a heavy crop load, since expanding leaves, shoots, and fruit create the greatest demand.

  8. Nitrogen • General Recommendation: • 75-100 lbs N applied mid-late April • Examine Crop in June/July • “On Year”---50 lbs around August 15 • “Off Year”---0 lbs around August 15 OR IF NO AUGUST APPLICATION • 75 lbs N in March/April (March after “on year”) • 25-75 lbs in late May/Early August • Most of the N taken up during the kernel-fill stage will supply the N storage pool needed for early spring growth. • Timing of fertilizer application for non-irrigated or run-down orchards will be different

  9. Nitrogen Dry-Land /Neglected Orchards • 75 lbs N in March • 25 lbs in late May Young trees • Year 1: 1 cup ammonium nitrate in June if growth is good (2-4’ terminal growth) • Year 2: 1 cup in April, 1 in May, and 1 in June • Year 3-4: 2 cups in April, May, and June • Year 5-7: 4 cups in April, May, and June + • Year 1:1 lb 10-10-10 fertilizer distributed in a 25 sq. ft. area around the tree(apply in June if growth is good) • After Year 1:4 lbs of 10-10-10 fertilizer for each inch of trunk diameter (measured one foot above soil surface). Do not place fertilizer within 12 inches of the trunk • 1 lb zinc sulfate per tree for the first three years following planting.

  10. Nitrogen • Fertilizing on a per tree basis • Mature trees • 1 lb amm. Nitrate/inch of trunk diameter in late March before bud break. Water in promptly • If lawn is concern, bore holes in ground and pour in, then water area + • 4 pounds of 10-10-10 for each inch of trunk diameter (measure 4 1/2 feet above soil level) up to 25 lbs/tree. This fertilizer should be applied in late March before bud break. Zinc needs are best determined by analysis of leaf samples taken in late July or early August. (Max 2 lbs/tree)

  11. Clover as a Source of Nitrogen • Crimson – 100 lbs N/A • 10 lbs/A seeding rate • 1.00-1.50/lb • White Clover--103 lbs N/A • 4 lbs/A seeding rate • 2.00-2.50/lb • Use mixture • Allow clover to re-seed • Apply Poast in February

  12. Potassium (K) • K is transported to nuts at leaf’s expense • 50-100 lbs K applied in February/March • During “on” year apply additional 30 lbs K in mid August • 1.25-2.5 ppm in leaf analysis • Manage N/K ratio to 2:1 • Manage Mg---(No Dolomitic lime above .45% Mg) • Deficiency most common on Desirable and Schley

  13. Basal Leaf Scorch • Usually occurs in June/July • Results from imbalance between N/K • More susceptible to winter injury • Defoliation • Occurs on basal leaves of shoot and moves upward • Scorched areas circular or oblong/ dime size

  14. Basal Leaf Scorch • Maintain adequate K levels • When K level is marginal or deficient, N level should be reduced until K is corrected • Foliar K can help, but does not replace soil applied (Potassium Nitrate: 3 lbs/100 gallons)

  15. Zinc • Necessary for shoot elongation, leaf expansion, and yield • Apply when Zn in leaf is below 50 ppm • 2 lbs Zinc sulphate + 3 lbs Potassium Nitrate/100 gallons • Begin 2 wks after budbreak until shoot elongation complete

  16. Mouse Ear • Nickel Deficiency • Zinc Management • Nickel lignosulfonate • Apply 1 pt/A in spring (April) while canopy is developing (parachute stage); • 2nd application: 1 pt/A 30-60 days after 1st appl. • Third application of 1.5-2 pts/A in late Sept.-early October before leaf fall to prevent mouse ear in the spring flush.

  17. Magnesium • 0.35-0.6% leaf • Deficiency occurs on acid soils (pH <5.5) • High K or Ca • Use Dolomitic lime • Maintain pH of 6.0-6.5 • OK to use calcitic lime when Mg above 0.45% • If pH adequate, apply foliar Magnesium Sulfate at 5 lbs/100 gallons (4” shoot growth to July)

  18. Chicken Litter • Have sample analyzed • Typically 70 lbs N/ton; 35 lbs P; 40 lbs K; 0.6 Zn • Nutrients are organically bound • Organic matter adds tilth/water-holding capacity to soil • Apply between late February and early June • Use BROILER litter and NOT LAYER litter • Ca/Mg

  19. Water Split • Occurs in August/September on Certain Varieties (late water stage/early shell hardening) • Split occurs along ½ length of fruit and may penetrate shuck and shell • Rapid influx of water • Rain/Irrigation/ High humidity/Low solar radiation

  20. Water Split • Occurs w/in 24 hrs of heavy influx of water to soil • Most split occurs in upper 1/3 of canopy • Split occurs in pre-dawn hours • Fruit falls from tree within 7 days of splitting

  21. Managing Water Split • Maintain soil moisture 2-3 wks before shell hardening (limited) • Fruit thinning • Avoid excessive N • Micronutrients? • B, Ni, Cu

  22. Orchard Floor Management • Mature Trees • Early Spring Pre-Emergence: • Simazine—2-4 qts/A Control of Annual Broadleaf weeds and some ann grasses Use low rate on sandy soil OR • Surflan 2-4 qts/A + Simazine—2-4 qts/A Broader Spectrum • Karmex 2-4 LBS Do Not use on sandy soil; Do not graze • Spring Post: (Can be mixed with pre-emerge applications) • Gramoxone Max 1.75-2.7 pts or Boa 2-3 pts 20 GPA Volume improves control Add 1 gal crop oil /100 gal spray mix Broad Spectrum of Annual weeds when small and succulent Do NOT contact foliage, green bark or allow animals to graze OR • Poast 16 oz/A-----Clover release

  23. Orchard Floor Management • Summer Burndown Herbicides: (Do NOT contact foliage or green bark) • Roundup (Glyphosate) 1-2 qts/A OR • Roundup+Karmex 2-4 lbs Use low rate on sandy soil OR • Gramoxone Max 1.75-2.7 pts • Rely 3-6 qts/A Better on perennials

  24. Orchard Floor Management • Eliminate grass and weed competition under orchard trees • Non-Bearing Trees • Pre-Emergence (after soil settles) • Surflan 2-4 qts/A • Surflan+Simazine (At least 2 yrs old) • Prowl 2.4-4.8 qts (after soil settles) • Solicam 2.5-5lbs. (after soil settles) • Post-Emergence • Roundup (Glyphosate) 1-2 qts/A • Rely (Glufosinate) 3 -6 qts/A • Poast 16 oz/A OR Fusilade 16 oz/A 1 qt crop oil low spray volume (10 GPA) increases activity (no broadleaf activity) Do NOT contact foliage or green bark

  25. Basic Needs of the Pecan Crop • Light • Water • Leaf Retention • Management of Crop Load • Pollination

  26. Pecan Irrigation • 71,031 Irrigated Pecan Acres in GA (~50% of crop) based on UGA Farm Gate & Irrigation Surveys • Average Amount Applied/Year = 15.5” • Average Cost/Year = $64.50/A • 18,254 Acres irrigated by solid-set • 52,777 Acres irrigated by drip

  27. Irrigation Schedule for Pecans MONTH SPRINKLER DRIP Inches/A % cycle April 0.5” 60 May 0.75” 70 June 1” 80 July 1.25” 90 August 1.5” 100 September 1.5” 100 October 1” 90 November 0.5” 60

  28. Pollination • Desirable (I) – April 23-May 4 • Cape Fear (I) – April 22-May 4 • Stuart (II) -- April 22-April 29 • Sumner (II) -- April 22-April 28 • Elliott (II) – April 19-April 30 • Schley (II) – April 19-April 27 Pistil Receptivity Pollen Shed • Desirable (I) – April 23-April 28 • Cape Fear (I) – April 23- April 30 • Stuart (II) – April 28-May 7 • Sumner (II) – May 1-May 7 • Elliott (II) – April 27-May 3 • Schley (II) – April 23-May 3

More Related