Technical annual report 2000-01
Dept. of Regional Development, Primary Industry, Fisheries and Resources technical annual report; Department of Regional Development, Primary Industry, Fisheries and Resources technical and annual report; Reports; PublicationNT; Technical bulletin (Northern Territory. Dept. of Primary Industry and Fisheries) ; no. 295
Made available via the Publications (Legal Deposit) Act 2004 (NT).
Agriculture -- Northern Territory -- Periodicals; Fisheries -- Northern Territory -- Periodicals
Dept. of Primary Industry and Fisheries
Technical bulletin (Northern Territory. Dept. of Primary Industry and Fisheries) ; no. 295
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Department of Primary Industry and Fisheries 152 A national project, which is funded by the Rural Industry Research and Development Corporation, has been established to introduce red fleshed selections and a white fleshed low acid cultivar, Oroblanco, into established citrus production areas and those areas with potential for citrus development throughout Australia. Commercial selections of red fleshed varieties were introduced into Australia in 1986. Participation in a national trial has enabled these selections to be made available for commercial assessment in Central Australia. The South Australian Research and Development Institute is coordinating this project. Method: Arid Zone Research Institute (AZRI) Seven clones consisting of Marsh, Oroblanco, Ruby Pink, Henderson, Ray Ruby, Rio Red and Star Ruby on two rootstocks, Carrizo Citrange and Swingle, have been planted. They are arranged in single tree plots with four replicates of each in a random design. Preparation for the planting commenced in the middle of April and planting took place in July 1995. There are 56 trees, with a surrounding guard row consisting of lemon and orange cultivars. Ti-Tree Research Farm and Murray Downs Station Demonstration plantings have been established at these locations. The plantings at Ti-Tree Research Farm (TTRF) and Murray Downs consist of one tree of each cultivar on each of the two rootstocks (Carrizo Citrange and Swingle). Results and Discussion: AZRI Data collected included fruit maturity, which includes recording of Brix and Brix/ Acid ratios, fruit characteristics, juice percentages, counts, weights, diameters, seed counts, and rind thickness. A summary of the 2001 yield data for each of the seven varieties planted at AZRI can be seen in Table 1. The table shows that Oroblanco and Rio Red had similar yields. However, because of Oroblancos large sized fruit, Rio Red is seen to have a far superior crop. Star Ruby has again performed below average with the lowest yield. In 2001 there was no difference between the rootstocks used. Table 1. AZRI fruit counts and weights per tree for 2001 Swingle Carrizo Citrange Variety Fruit No Average fruit weight (g) Average yield per tree (kg) Fruit No Average fruit weight (g) Average yield per tree (kg) Marsh 557 460.3 64.1 730 473.8 86.5 Oroblanco 673 557.7 93.8 460 548.5 63.1 Ruby Pink 642 462.9 74.3 696 507.6 88.3 Henderson 624 383.1 59.8 577 436.7 84.0 Ray Ruby 620 386.1 59.8 727 391.1 71.1 Rio Red 797 470.3 93.7 700 479.0 83.8 Star Ruby 394 476.8 47.0 285 577.8 41.2 Maturity of citrus is determined by calculating the sugar/acid ratio of the fruit. The National Standards state the minimum sugar/acid ratio for grapefruit is 4.5 to 5.0:1 and minimum juice percentage of 33%. A summary of the 2001 brix sugar/acid data for AZRI can be seen in Table 2.