Influence of Nonpermanent Netting on Foliar Spray Deposition, Insect Pest Prevalence, and Production of ‘Nadorcott’ Mandarin (Citrus reticulata)

in HortScience

This study aimed to determine the effects of different types of nonpermanent netting (NPN) on foliar spray deposition, insect pest prevalence, and production and fruit quality of ‘Nadorcott’ mandarin (Citrus reticulata) trees in a commercial orchard at Citrusdal (lat. 32 32′31″S, long. 19 0′42″E), Western Cape, South Africa. The deposition quantity (FPC%) of foliar spray volumes of 3500, 7000, or 15,000 L·ha−1 was greater for leaves of control trees compared with leaves treated with NPN during summer (January) (8.8 vs. 6.1; P = 0.0055) and winter (June) (4.8 vs. 3.1; P = 0.0035). Deposition uniformity (CV%) was better for control leaves during summer (64.9 vs. 75.2; P = 0.0062) and winter (59.6 vs. 80.5; P = 0.0014), and deposition quality (ICD%) was better during winter (79.4 vs. 84.2; P = 0.0393). There were no differences in FPC%, CV%, and ICD% for fruit when foliar spray volumes of 3500 and 15,000 L·ha−1 were used for the control and NPN treatment groups during winter. However, with a foliar spray volume of 7500 L·ha−1, fruit from the control treatment group had greater FPC% (19.3 vs. 6.1; P = 0.0262), CV% (70.3 vs. 50.9; P = 0.0484), and ICD% (57.1 vs. 79.9; P = 0.0157). There were no differences in macronutrient concentrations between the leaves of trees subjected to control and NPN treatments, but leaf zinc (<81%; P = 0.0317) and iron (<78%; P = 0.0041) concentrations were lower with the NPN treatment. During short NPN treatments, fruit yield was reduced by ≈37% compared with that after control treatment, and longer NPN treatments had no effect on fruit yield. The reduction in fruit yield with NPN was not related to the effects of NPN on foliar spray deposition or to lower leaf micronutrient concentrations. The lower fruit yield during short NPN treatments was most likely caused by fruit drop that was exacerbated by the removal of the NPN. In the long NPN treatment group, fruit damage caused by sunburn was reduced by 17%, but the outer canopy fruit experienced increased wind damage or scarring. Except for the lower titratable acidity content with the shortest NPN treatment and the higher Brix°:TA ratio with two NPN treatments, NPN did not impact other fruit quality attributes. The use of NPN excluded male wild false codling moths (Thaumatotibia leucotreta) (FCM) males; however, it was still possible to capture a very small amount of mass-released sterile FCM and wild fruit flies under the NPN.

Contributor Notes

We thank CP Mouton and Conrad Vorster for allowing access to their orchard at Houtkaprug in Citrusdal, and Citrus Research International (Pty) Ltd and the Department of Science and Technology (SIF-RCE) for financial support. We also express our appreciation to Drape Net SA (Pty) Ltd for providing the nets.

Corresponding author. E-mail: jakkie@sun.ac.za.

Article Sections

Article Figures

  • View in gallery

    The average number of (A) released (sterile) male false codling moths (FCM) (Thaumatotibia leucotreta), (B) wild male FCM, and (C) fruit flies (Ceratitis capitata) catches per trap per week for control and nonpermanent netting (NPN) treatments from Dec. 2017 to July 2018.

  • View in gallery

    Effects of different nonpermanent netting (NPN) treatments on the distribution of different commercial fruit size calibers (SC) on the yield of ‘Nadorcott’ mandarin.

  • View in gallery

    Wind damage of fruit from (A) inside and (B) outside tree canopies of control and nonpermanent netting (NPN) treatments at the time of commercial harvest in July 2018.

  • View in gallery

    Effects of different nonpermanent netting (NPN) treatments on sunburn of ‘Nadorcott’ mandarin fruit.

Article References

  • AgustíM.ZaragozaS.BleiholderH.BuhrL.HackH.KloseR.StaubR.1997Adaptation de l’échelle BBCH à la description des stades phénologiques desagrumes du genre CitrusFruits52287295

    • Search Google Scholar
    • Export Citation
  • BarryG.H.2006The quest for seedless Citrus fruitProc. Intl. Soc. Citricult.1346

  • BedfordE.C.G.1998Thrips wind and other blemishes p. 170–183. In: E.C.G. Bedford M.A. van den Berg and E.A. de Villiers (eds.). Citrus pests in the Republic of South Africa. 2nd ed. Institute for Tropical and Subtropical Crops Agricultural Research Council Nelspruit South Africa:

  • CohenS.RavehE.LiY.GravaA.GoldschmidtE.E.2005Physiological responses of leaves, tree growth and fruit yield of grapefruit trees under reflective shade screensScientia Hort.1072535

    • Search Google Scholar
    • Export Citation
  • De NettancourtD.1977Incompatibility in Angiosperms. Springer Berlin Germany

  • Department of Agriculture Forestry and Fisheries (DAFF)2015Export standards and requirements: Part 2 soft citrus

  • Du PlessisS.F.KoenT.J.1992Leaf analysis norms for lemons [Citrus limon (L.) Burm.]Proc. Intl. Soc. Citricult.2551552

  • Du PlessisS.F.KoenT.J.OdendaalW.J.1992Interpretation of Valencia leaf analysis by means of the N/K ratio approachProc. Intl. Soc. Citricult.2553555

    • Search Google Scholar
    • Export Citation
  • Du ToitW.J.1998Fruit flies p. 229–233. In: E.C.G. Bedford M.A. van Den Berg and E.A. de Villiers (eds.). Citrus pests in the Republic of South Africa. 2nd ed. ARC Institute for Tropical and Subtropical Crops South Africa

  • El-OtmaniM.Jr. CogginsC.W.AgustiM.LovattC.J.2000Plant growth regulators in citriculture: World current usesCrit. Rev. Plant Sci.19395447

    • Search Google Scholar
    • Export Citation
  • EmbletonT.W.MatsumuraM.KhanI.A.1988Citrus zinc and manganese nutrition revisitedProc. Intl. Soc. Citricult.6681688

  • GambettaG.GravinaA.FasioloC.ForneroC.GaligerS.InzaurraldeC.ReyF.2013Self-incompatibility, parthenocarpy and reduction of seed presence in ‘Afourer’ mandarinScientia Hort.164183188

    • Search Google Scholar
    • Export Citation
  • GravinaA.GambettaG.ReyF.GuimaraesN.2016Mejora de la productividad en mandarina ‘Afourer’ en aislamiento de polinizacion cruzadaAgrociencia Uruguay.202228

    • Search Google Scholar
    • Export Citation
  • GroutT.G.MooreS.D.2015Citrus p. 447–499. In: G. L. Prinsloo and V. M. Uys (eds.). Insects of cultivated plants and natural pastures in Southern Africa. Entomological Society of Southern Africa South Africa

  • HouX.JonesB.T.2000Inductively coupled plasma/optical emission spectrometry p. 9468–9485. In: R.A. Meyers (ed.). Encyclopedia of analytical chemistry. John Wiley & Sons Ltd Chichester UK

  • LovattC.J.2013Properly timing foliar-applied fertilizers increases efficacy: A review and update on timing foliar nutrient applications to citrus and avocadoHortTechnology23536541

    • Search Google Scholar
    • Export Citation
  • ManjaK.AounM.2019The use of nets for tree fruit crops and their impact on the production: A reviewScientia Hort.246110122

  • MesejoC.YusteR.ReigC.Martínez-FuentesA.IglesiasD.J.Muñoz-FambuenaN.BermejoA.GermanaA.Primo-MilloE.AgustíM.2016Gibberellin reactivates and maintains ovary-wall cell division causing fruit set in parthenocarpic Citrus speciesPlant Sci.2471324

    • Search Google Scholar
    • Export Citation
  • MooreS.D.HattinghV.2012A review of current pre-harvest control options for false codling moth in citrus in southern AfricaSA Vrugte J.118285

    • Search Google Scholar
    • Export Citation
  • MupambiG.AnthonyB.M.LayneD.R.MusacchiS.SerraS.SchmidtT.KalcsitsL.A.2018The influence of protective netting on tree physiology and fruit quality of apple: A reviewScientia Hort.2366072

    • Search Google Scholar
    • Export Citation
  • NadoriE.B.2006Nadorcott mandarin: A promising new variety. Proc. Intl. Soc. Citricult. (2004):356–359

  • NewtonP.J.1998False codling moth Cryptophlebia leucotreta (Meyrick) p. 192–200. In: E.C.G. Bedford M.A. van Den Berg and E.A. de Villiers (eds.). Citrus pests in the Republic of South Africa. 2nd ed. ARC Institute for Tropical and Subtropical Crops South Africa

  • OteroA.RivasF.2017Field spatial pattern of seedy fruit and techniques to improve yield on ‘Afourer’ mandarinScientia Hort.225264270

    • Search Google Scholar
    • Export Citation
  • PérezM.PlazaB.M.JiménezS.LaoM.T.BarberoJ.BoschJ.L.2006The radiation spectrum through ornamental net houses and its impact on the climate generatedIntl. Symp. Greenhouse Cooling.719631636

    • Search Google Scholar
    • Export Citation
  • RavehE.CohenS.RazT.YakirD.GravaA.GoldschmidtE.E.2003Increased growth of young citrus trees under reduced radiation load in a semi-arid climateJ. Expt. Bot.54365373

    • Search Google Scholar
    • Export Citation
  • SmithP.F.1966Citrus nutrition p. 174–207. In: Childers N.F. (ed.). Temperate and tropical fruit nutrition. Hort. Pub. State Univ. New Brunswick NJ

  • StampsR.H.2009Use of colored shade netting in horticultureHortScience44239241

  • SwietlikD.1996Responses of citrus trees in Texas to foliar and soil Zn applicationsProc. Intl. Soc. Citricult.8772776

  • Van ZylJ.G.FourieP.H.SchutteG.C.2013Spray deposition assessment and benchmarks for control of Alternaria brown spot on mandarin leaves with copper oxychlorideCrop Prot.468087

    • Search Google Scholar
    • Export Citation
  • WachsmannY.ZurN.ShahakY.RatnerK.GilerY.SchlizermanL.SadkaA.CohenS.GarbinshikofV.GiladiB.FaintzakM.2014Photoselective anti-hail netting for improved citrus productivity and qualityActa Hort.1015169176

    • Search Google Scholar
    • Export Citation
  • WrightG.C.2007Pollination of W. Murcott Afourer mandarins. Citrus Res. Rep. 12–13

  • ZhouK.JerszurkiD.SadkaA.ShlizermanL.RachmilevitchS.EphrathJ.2018Effects of photoselective netting on root growth and development of young grafted orange trees under semi-arid climateScientia Hort.238272280

    • Search Google Scholar
    • Export Citation

Article Information

Google Scholar

Related Content

Article Metrics

All Time Past Year Past 30 Days
Abstract Views 145 145 145
Full Text Views 39 39 39
PDF Downloads 18 18 18