Territory Stories

Technical annual report 2000-01

Details:

Title

Technical annual report 2000-01

Collection

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

Date

2001-10

Description

Made available via the Publications (Legal Deposit) Act 2004 (NT).

Notes

Date:2001-10

Language

English

Subject

Agriculture -- Northern Territory -- Periodicals; Fisheries -- Northern Territory -- Periodicals

Publisher name

Dept. of Primary Industry and Fisheries

Place of publication

Darwin

Series

Technical bulletin (Northern Territory. Dept. of Primary Industry and Fisheries) ; no. 295

ISSN

0158-2763

Copyright owner

Check within Publication or with content Publisher.

Parent handle

https://hdl.handle.net/10070/223369

Citation address

https://hdl.handle.net/10070/687151

Page content

Department of Primary Industry and Fisheries 142 Results and Discussion: Planting 1 The average yield of the scion/rootstock combinations ranged between 45 and 104 kg. The average fruit weight ranged between 277 g and 584 g. An interesting point was that the lightest fruit were from the cultivar Ray Ruby on the C35 but the heaviest fruit were from the same cultivar on the rootstock trifoliata. It is stressed that results should be interpreted with caution due to the small number of replications of each combination (Table 1). Table 1. Estimated total yield and average fruit weight for Planting 1 Rootstocks C35 Swingle Trifoliata Cultivar Yield (kg) Average weight (g) Yield (kg) Average weight (g) Yield (kg) Average weight (g) Flame No trees No assessment No trees Henderson No trees 103.7 448 83.8 367 Ray Ruby 45.7 277 89.6 489 56.1 584 Rio Red No assessment No assessment No trees Star Ruby No assessment No assessment No trees The values are an average of one, two or three trees depending on the combination. The current market standard for grapefruit is a juice content above 33% (NSW Grading, Packaging and Labeling Requirements). The readings for all cultivars/rootstocks combinations were above this standard when determined in "late March". Some combinations had juice content levels higher than 40% when measured in "Late March" but all combinations, except Ray Ruby on C35, had levels higher than this in "early May" (Table 2). Table 2. Juice content (%) at various sampling times for Planting 1 Rootstocks C35 Swingle Trifoliata Cultivar Late March Early May Late March Early May Late March Early May Flame No trees 42.1 - No trees Henderson No trees 39.5 44.7 42.35 46.25 Ray Ruby 33.1 37.5 40.4 43.5 36.05 43.75 Rio Red No assessment 39 - No trees Star Ruby No assessment 30 - No trees The current market standard for grapefruit is a brix:acid (sugar/acid) ratio of 4.5:1 (NSW Grading, Packaging and Labelling Requirements). The brix:acid ratio was above 6:1 for all cultivars/rootstocks combinations when determined in "late March". When measured in "early May" the ratios were higher than the "late March" values for all combinations (Table 3). Table 3. Brix:acid ratio at various sampling times for Planting 1 Rootstocks C35 Swingle Trifoliata Cultivar Late March Early May Late March Early May Late March Early May Flame No trees 8.6 - No trees Henderson No trees 7.3 7.6 6.7 7.1 Ray Ruby 6.6 6.8 6.6 7.2 7.4 7.6 Rio Red No assessment 8 - No trees Star Ruby No assessment 8.2 - No trees Planting 2 The average yield of the scion/rootstock combinations ranged between 2 and 105 kg. The trees are still recovering from heavy pruning in 1999. It is expected that the trees will be more productive in the 2002 season. The average fruit weight ranged between 455 g and 1,223 g. The heaviest fruit were produced by