Mulching

• When to Apply:
  Apply mulch after your first full irrigation. Use decomposing straw or bark chips around the stem or across the entire “bankie”.
• Benefits of Mulching:
  • Controls weed emergence
  • Decreases soil re-compaction
  • Moderates soil temperature
  • Increases water penetration
  • Boosts biological activity
  • Preserves soil moisture content
• Application Tips:
  • Keep a hand-width space around the trunk to prevent contact with wet mulch, reducing the risk of Phytophthora infection.
  • If mulch is limited, prioritize:
    1. Soils with a surface crust that impedes water penetration (e.g., where clay is on the surface or top soils are bleached grey-white).
    2. Soils with very low water holding capacity (e.g., coarse sandy soils, soils with a large coarse fraction, or shallow-rooted orchards) to buffer against drying out.
• Important:
  Do not apply mulch if the orchard has high nematode counts. First treat the nematodes, then prioritize mulch application. Many product active ingredients react with organic material, reducing their efficacy.

Drainage

• Options:
  • Cut-off drain: Perforated pipe below the soil surface to remove subsurface water.
  • French drain: Like a cut-off drain, but rocks are placed above the pipe up to the soil surface, intercepting both surface and subsurface water. More effective on heavy soils with poor infiltration and surface run-off.
  • Open trench: A 1.2m deep open furrow to intercept water before it enters a block from higher areas or to remove water collected by other drains.
• Best Practices:
  • Install drainage during the dry season and after soil preparation.
  • Consult a soil scientist or irrigation specialist for drainage design.

Irrigation

• Refer to the September Timely Hints for an irrigation monitoring strategy.
• Most cultivars are now in the rapid fruit growth stage; manage soil moisture carefully.
• Allow only 45% extraction of readily available water to maintain a buffer in case of pump failure or hot weather.
• If irrigating on a roster (e.g., 2 hours on Monday, Wednesday, Saturday), consider shortening both the waiting period and irrigation length. The total water volume may remain the same, but stress from drying out is reduced.
• Avoid over-irrigation when making adjustments.

Nutrition

• Nutrition, after irrigation and pest management, is the most influential factor on fruit size and quality.
• Adjust your fertilizer program to support the set crop. Redo your yield estimate and communicate with your consultant/agent to adjust fertilizer and foliar feeds as needed.
• Consider both yield and tree vigour.

Potassium (K) Application

• Importance: Adequate K is crucial for fruit size due to its role in water movement and turgor pressure.
• Foliar Application:
  • Potassium Nitrate (KNO₃ 390 formulation): 1000g/100L water (also increases shoot growth).
  • Potassium Sulphate (K₂SO₄ 429 formulation): 920g/100L water (use if vigour is too high).
  • Apply 1 to 5 sprays from pip hardening, waiting 14 days between applications.
• Other Sources: K fertilization can be done through many products; KCl is the primary source due to its availability and high K content (50%).

Nitrogen (N) Application

• If vigour is lacking, increase N through fertilizer or foliar application to ensure adequate new growth for next season’s bearing positions.
  • Urea (LB) as foliar: 500g/100L water.
  • Apply 2 to 4 sprays where vigour is poor, waiting 7–10 days between applications.
  • Start application at 100% petal drop.
  • Do not apply if vigour is adequate to strong.

Harvesting Tips for Stone Fruit

Your exporter will provide guidelines for the required maturity standards for export. The Department of Agriculture, Land Reform and Rural Development (DALRRD) applies maturity standards for export, monitored and verified by the Perishable Products Export Control Board (PPECB). Below are practical tips for harvesting various stone fruits.

Apricots

• Maturity Standard: Use the “wring test”—cut the apricot in half and wring the halves apart. The pit should be loose from the flesh. If loose, the apricot is mature enough to harvest.
• Firmness: Check exporter-specific firmness guidelines. Over-mature, soft apricots will be rejected.
• Harvesting Tips:
  • Provide pickers with cotton gloves to reduce nail injuries and emphasize careful handling.
  • Avoid torn stems or stem injuries to the fruit.
  • Most injuries occur when lifting the fruit against the branch; give a slight twist when harvesting, but avoid injuring the shoulders.
  • Pick according to the desired colour standard—typically green, lime, or yellow.
• Export Requirements: Apricots for the EU must complete phytosanitary registration and implement the Fruit Fly Management System. Contact your exporter or HORTGRO for details.

Dessert Peaches

• Maturity Standard: Check with your exporter. Peaches are harvested based on flesh firmness, which determines the correct background colour.
• Harvesting Tips:
  • Handle with care to avoid injuries, especially to the fruit’s shoulder.
  • Over-mature fruit is problematic; harvest at least three to five times per season.
  • For early varieties, harvest into trays and keep the tip upright.
  • Consider spraying ReTain (3-Buteoic Acid Hydrochloride) to delay harvest and produce firmer fruit with fewer soft tips (consult your exporter and spray representative).
• Export Requirements: Peaches for the EU require phytosanitary registration and implementation of the Peach and Nectarine FCM Management System. Contact your exporter or HORTGRO for details.

Nectarines

• Maturity Standard: Determined by flesh firmness; confirm with your exporter.
• Harvesting Tips:
  • Some red varieties colour before maturity—do not pick based on colour alone.
  • Loss of glossy shine and a dull haze on the skin often indicate correct maturity.
  • Larger fruit are usually more mature, especially in early picks.
• Export Requirements: Nectarines for the EU require phytosanitary registration and implementation of the Peach and Nectarine FCM Management System and the Fruit Fly Management System. Contact your exporter or HORTGRO for details.

Yellow Cling Peaches

• Maturity Standard: Determined mainly by colour, especially for canning. Canners do not want green fruit.
• Quality Note: South African canned peaches are prized for their excellent yellow colour.

Plums

• Maturity Standard: Determined by flesh firmness and % TSS (Total Soluble Solids). Confirm with your exporter.
• Harvesting Tips:
  • Most varieties are picked using colour as a guide. As a rule, when you think it’s time to pick, wait two more days.
  • The first pick should be at least 20% of the crop; if not, you are picking too early.
  • For Laetitia: First pick is ¾ red fruit and redder; second pick is half red and redder; third pick is a strip pick.
  • Injuries and rub marks are common—pick into plastic bins or use liners, and avoid picking in the heat of the day.
  • Larger fruit ripen first.
  • For yellow plums like Songold, a single (strip) pick is possible if blossom was even.
  • Use plastic buckets (20L) for picking to reduce rub marks; transfer gently to bins.
  • When transporting, cover bins with a 150mm polyethylene sponge mattress and tie down to prevent fruit movement and rub marks.
• Productivity: A picker should harvest about 450kg of plums per nine-hour day (50kg/hour); for strip picking, at least 75kg/hour.
• Export Requirements: Plums for the EU require phytosanitary registration and implementation of the Fruit Fly Management System. Contact your exporter or HORTGRO for details.

Pest and Disease Control

• Crop Stage: Latest flowering cultivars are approaching final thinning; earliest cultivars have been harvested.
• Residue Compliance: Ensure compliance with required withholding periods to prevent chemical residues on fruit. Exporters may have stricter requirements than industry standards.
• Market Requirements: Some products approved locally may be prohibited for EU/UK markets. Know your target market and comply with their requirements.
• Monitoring: Thorough scouting and monitoring for fruit fly (all stone fruit) and FCM (plums, peaches, nectarines) is essential for EU/UK access.
• Fruit Fly Control: Spray Devipan @ 100ml/hl with a 14-day safety window when pests are noticed. Note: Devipan (organophosphate) is not allowed by many discerning markets.
• Other Pests: Refer to September and October Timely Hints for control strategies for powdery mildew, thrips, OFM, fruit weevil, brown rust, freckle, gum spot, scale, fruit fly, and post-harvest decay.
• False Codling Moth (FCM):
  • Mainly affects cultivars maturing after mid-December.
  • Mating Disruption (MD) is effective—use Isomate FCM @ 600 disruptors/ha (5–6 months coverage), hung from early November in the top 0.75m of trees, on the south-eastern side.
  • Alternatively, use Checkmate FCM-F every 21–28 days (based on heat), 110ml/ha as a bait application in 50L water/ha.
  • Monitor FCM activity both outside and above dispenser height in the orchard.
  • FCM Virus Cryptex/Gratham: Apply 10–14 days after peak moth catch at 60ml/ha, repeat every 14 days at 35ml/ha until under control. Apply in late afternoon/evening. Maintain pH 5–8 for efficacy.
  • Broadband or Eco Bb (Beauveria bassiana): Apply with a wetter-sticker (Biodew or Villa 51 @ 6ml/hl). Apply a series of 3 sprays. Suppresses red spider mite.
  • Marksman: Needs to be positioned early in the control programme for best efficacy.

Registered Products for FCM Control

Fruit Damage Assessments

• Must be done according to Hortgro’s FF and P/N FMS Management Systems.
• Assess 6 and 4 weeks before expected harvest and within 10 days of harvest.
• Inspect 10 fruit per tree on 25 marked trees per 2ha block.

Contributors

• Soil, Irrigation, and Nutrition
• Thinning and Newly Planted Trees
• Pest and Disease Control

Disclaimer

This document is issued by HORTGRO (Pty) Ltd (Reg no. 2005/010343/07). All care has been taken in the provision of the information, but it is provided without liability. The information is in good faith and not intended as advice. Some information may be from third parties and is not guaranteed for accuracy. HORTGRO and its affiliates disclaim liability for any loss or damage from using or relying on this information. Please consult a technical advisor for personal analysis before making orchard practice decisions.