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ACIAR�HORT-2014-077�END OF PROJECT REVIEW

Citrus & Other Fruit Component

Adj. Professor John Chapman

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SCOPING CITRUS IN TONGA

  • First visit Tonga April 2016 with Dr L. Singh-Peterson (Social scientist)
  • Key Tongan project contacts:
    • Heimuli Likiafu, MAFFF
    • Soane Patolo, MORDI
  • Three (3) days reviewing citrus production and markets Tongatapu & Eua
    • Production opportunistic bush blocks and gardens – no tree orchards
    • Seedling based with consequent genetic run down in quality
    • Virtually no tree vegetative reproduction via grafting onto rootstocks
  • Decision made to import grafted trees

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SITE SELECTION

  • Key contract guideline was to:
    • Establish 3 or 4 citrus blocks &
    • Establish one other tropical fruit demonstration block
  • Eua Island 2 community citrus blocks - possibly one at Hango Agricultural College
  • Tongatapu 1 citrus block and other tropical fruit block at Nishi Trading
  • Criteria for block site selection on Eua: community land, good soil, irrigation potential, enthusiastic community support.
    • Communal school land targeted as many had large blocks alongside.
    • Eua consultation: Island Administrator, Eua Agricultural Council, District Officers Tuifio Finau (East) & Paula Vehi (West), Sione Dean Hango Ag College, Maloni Havea MAFFF
    • Community consultation at Houma and Ha’atua schools forming community work groups.
    • Thirteen (13) sites considered and eight (8)rated
  • Selection:
    • Houma (Western Division)
    • Ha’atua (Eastern Division)

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IMPORTING PLANT MATERIAL & FIRST PLANTING

  • Aust. Project Team 2016 Visits - Challenges required April, June & November
  • Importation of citrus trees in November 2016:
    • 60 Washington Navel,
    • 60 Valencia Orange,
    • 58 Imperial Mandarin,
    • 58 Emperor Mandarin,
    • 58 Afourer Mandarin,
    • 45 Ellendale Mandarin,
    • 14 Meyer Lemon, &
    • 14 Tahitian Lime.
  • Rootstocks Troyer citrange for all except Imperial and Emperor on Cox Mandarin Hybrid.
  • Planting:
    • Immediate planting at Nishi Trading, Eua sites land not cleared & prepared.
    • Push for planting at Eua April 2017 achieved with major community effort. Insufficient mounding at Ha’atua
  • Extensive training and community engagement workshop held during both November 2016 & April 2017 visits

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SITE 1 – NISHI TRADING

  • Planted: November 2016
  • Summer 2016/17 grew very poorly with unusual symptoms
    • Resolved as calcium deficiency despite very high CEC soils (47 me/100gm normal range 12-25) with very high soil Ca (32.9 me/100gm normal range 6-12)
    • Calcium leaf analysis oranges 2.04% normal range 3%-5.5% & mandarins 2.68% normal range 3%-5.5%
    • Immediate result via gypsum and every six months since
    • YarraCan Calcium Ammonium Nitrate (27%N) the best bet for nitrogen & growth
  • 2017 growth recovered brilliantly until early 2018 hit by cyclone Gita
    • Citrus twisted and leaning not uprooted so no losses but within days many trees with obvious yellowing & dying
    • Diagnosed as Phytophthora citrophthora from root sheath tearing
    • Solution two soil applications of Ridomill eventual follow up with Phosphorous Acid foliar spray
    • Cyclone induced Pink Wax Scale attack as well
  • Thus Nishi block has given many lessons for the later planted blocks on Eua

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SITES 2 & 3 – EUA - HOUMA & HA’ATUA

  • Planted: April 2017 (6 months after Nishi block)
  • Both sites Houma and Ha’atua have experienced variable management
  • Initially communities well engaged with monthly supervision by Heimuli, MAFFF
    • Heimuli Masters study, communities effort reduced and now managed by MORDI
  • Houma site: is most suitable but least growth due to variable management eg. poor weed control, irrigation and fertilisation management
    • Experienced some community resistance to herbicides and higher toxicity pesticides
  • Ha’atua site: better managed but concerns regarding drainage & mounding essential

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BOB BUSTER CITRUS - EUA

  • Bob Buster Eua citrus block coincidence
    • Over 200 trees
    • Planted 2016
    • Pruning training

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TROPICAL FRUIT DEMONSTRATION PLOT – �NISHI TRADING

  • Planted: November 2018
  • Citrus first priority other fruit second so later planting and getting established
  • Two tree imports required because of poor quality in first shipment
    • First shipment 2017 (Fitzroy Nursery, Pink Lily, Qld):
      • 16 Mango, 4 Avocado, 16 Lychee, 9 Guava, 6 Carambola, cuttings of 3 Dragon Fruit
    • Second shipment 2018 (various retail nurseries, Sunshine Coast, Qld):
      • 6 Avocado, 16 Lychee, 2 White Sapote, 2 Black Sapote, 2 Sapodilla, 3 Abiu. Mango considered low viability because of climate & Anthracnose

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SUMMARY

  • Considering challenges, very few losses:
    • Ca & Cu deficiency,
    • weed control,
    • Cyclones,
    • Pest problems.
  • Three (3) established blocks or four (4) with Bob Buster
  • Another three years take us:
    • Into extensive propagation training;
    • Into fruit quality and
    • Establishing value chain
  • Objectives of revitalised Eua Island citrus:
    • Dietary improvement and community economic benefit within our grasp