Assessing morphological characteristics of elite Cocoa accessions (Theobroma cacao L.) in Makira Island, Solomon Islands

Characterization in Theobroma cacao L. based on the suggested Australian Center for International Agricultural Research(ACIAR) guidelines is observed to be important to encourage fine quality Cocoa production, and to realize remunerative income. Hence, 40 Cocoa accessions collected from fields distributed under different wards of Makira Island of the Solomon Islands were characterize for nine quantitative and qualitative morphological traits. Among the identified Cocoa accessions,Principal Component Analysis (PCA) grouped all the traits into three major Principal Components (PC) accounted 46.2% of total variation. PC axis one accounted for 23.1% of total variation explained by pod weight, pod circumference, cotyledon length, pod length, cotyledon width, pod external thickness, mature pod ridge color (anthocyanin), pod surface texture, pod surface shape and pod shape. The 12.2% of total variation in PC axis two was considerably attributed by the qualitative traits cotyledon color, pod surface texture , mature pod ridge color (anthocyanin), pod surface shape, cotyledon width, pod shape and tree vigor. While, PC axis three accounted for 10.9% of total variation referred to traits pod neck, pod surface shape, pod surface texture, pod length, tree vigor, pod internal thickness, weight of the bean per pod, pod external thickness, number of beans per pod, pod weight and reaction to black pod. Unweighted Pair Group Mean with Arithmetic Average (UPGMA)classified the 40 accessions in to three clusters. Under Cluster 1, 95.5% of identified accessions were grouped by traits such as cotyledon length and cotyledon width, red pods tree. While, Cluster 2 made up of 5% of total number of accessions with traits least pod weight, least pod external thickness, least cotyledon length and red podded trees. A single accession in Cluster 3 characterized by longest pod and constituted only 2.5% of the total accession. The frequency distribution of the nine qualitative traits confirmed that, 90% of identified accessions exhibited pod surface texture as smooth and slightly rough, 97% with pod surface shape as slightly furrowed with medium furrows and 85% with Amelonado pod shape. Most of the identified Cocoa accessions, grouped into three pod apex shapes traits such as Mammelate, Acute and Obtuse,accounting for 44, 25 and 20%, respectively. Of the total accessions studied, 63% had no anthocyanin on the mature pod ridge. Each of 72% measured as the strength of the accessions to withstand Phytophthora palmivora, and vigorous. The Shannon Weaver Diversity Index characterized and suggested that the Cocoa accessions in Makira Island mainly resemble to Amelonado (bulk) type, usually classified as Forasterio variety

Nutrition management of tropical fruits grown in North Queensland, Australia

The wet tropical coast and drier elevated tablelands of tropical north Queensland are major production areas for tropical and sub tropical fruits including durian, longan, lychee, mangosteen and rambutan, offering important economic diversification opportunities for sugar cane and tobacco farmers. An understanding of nutrition management and its effects on production has been a key area of research over the last five years. Yield versus fertiliser inputs were examined and the use of nutrient budgets to manage fertiliser inputs is discussed. The project was unable to identify any direct links between tree nutritional status, fertiliser inputs and yield. This suggests that within the range of nutrient status observed, other factors than fertilisation, such as pruning practices and climate, play a more important role in flowering and subsequent yield and/or that the method for measuring nutrient status does not reflect nutrient supply mechanisms appropriately. Leaf and soil nutrient concentration guidelines have been developed to assist growers to manage fertiliser inputs appropriately. This paper describes the grower survey methods used to quantify the guidelines

Commercialising cocoa growing in North Queensland

What the report is about? The report is about the commercialisation of cocoa (Theobroma cacao) growing, including harvesting, fermenting and chocolate manufacture in far north Queensland. The work is important because it is another step towards the development of a small and stable cocoa industry of regional importance in far north Queensland. Who is the report targeted at? The report is targeted towards government R&D agencies and potential growers/producers of cocoa. Where are the relevant industries located in Australia? The industry is located in far north Queensland on the wet tropical coast from Daintree to Kennedy. There are approximately a dozen growers, three in the Innisfail to Kennedy region and the remainder in the area around Mossman. The study documented the issues involved in establishing and producing cocoa in a Cadbury Schweppes funded seedling scheme initiated in 2007. The project also established protocols for successful fermentation and drying of cocoa bean in a cool wet tropics environment. New growers entering the industry will benefit from the learning and outcomes of this research

Collation of health literature for tropical and exotic fruits and extracts

This report collates data on the nutrient and phytochemical content of tropical exotic fruits, the evidence for health effects from consumption of these fruit and the use of extracts from edible and non-edible parts of these plants. The knowledge of Australian fruit compared with that grown overseas is presented together with opportunities for future work by Australian researchers. Opportunities for developing commercial extracts for use as food or nutraceutical uses are also presented

Tropical tree crops and current research at the Department of Primary Industries, North Queensland

The Center for Wet Tropics Agriculture (CWTA) was established to provide service to argriculture. Today, the facility accommodates the Departments of Primary Industries and Natural Resources. Banana and papaya are the major tree fruits under considerable research, with increasing effort into rambutan, mangosteen, and durian research. Cacao research has also been initiated recently

Low temperatures decrease CO2 assimilation and growth in the tropical rambutan

In glasshouse experiments, high temperatures increased vegetative growth in the tropical rambutan (Nephelium lappaceum L. seedlings of cv. Rapiah). In absolute terms, there was generally a greater response to night temperature (day/night temperatures of 32714°C vs. 32728°C) than to day temperature (22714°C vs. 32714°C), and better growth at 32728°C than at 32722°C. The effects of temperature on nutrient concentrations were small, whereas average leaf water potential (ΨL) during the day was -1.5 MPa at 32728°C, 0.1 to 0.4 MPa higher with nights of 14° or 22°C, and 0.7 MPa higher at 22714°C. Average net C02 assimilation rate (A) was 5.3 μ-mol m−2 s−1 at 32722° and 32728°C, 50% lower at 32714°C and 80% lower at 22714°C. When seedlings of cv. Rapiah were grown in water baths, the two critical root temperatures at which 90% of maximum plant weight occurred were similar for leaves and stems (about 24° to 30°C), but lower for roots (19° to 25°C). There was only a small effect of temperature on the concentration of most nutrients, and on average day time ΨL, whereas average A was 4.5 (μmol m s−1 at 28°C, 30% lower at 20°C, and 80% lower at 15° and 38°C. These experiments show that rambutan growth was strongly reduced when night or root temperatures fell to 14° or 15°C. The main effect was through lower Co−2 assimilation, whereas the changes in water and nutrient status were relatively small. Areas where night or root temperatures remain at or below 14°C for prolonged periods should be avoided for rambutan production

DigiHort: Digital Twins for Innovation of Future Orchard Systems

New orchard systems of the future feature unconventional layouts and narrow canopies with fruit walls under intensive pruning and training practices. The development of such systems is not only time- and - labour consuming, but also faces other challenges in potential overuse of chemicals, in maintenance of fruit/nut quality and in response to climate change. Our DigiHort solution is to address those challenges via development of Digital Twins powered by High Performance Computing and Artificial Intelligence. It includes two components: LIGHT and SPRAY. The LIGHT component allows its users to have 3D digital twins of their orchard designs and pre-evaluate how different factors such as row orientation, tree spacing, canopy size and terrain could affect the potential orchard light environment. This can help decision makers optimise their orchard designs in silico before creating/reconfiguring real orchards in situ. Using the SPRAY component, the growers can operate their sprayer digital twin within their orchard digital twin, configure the virtual sprayer with different nozzle types and directions, adjust vehicle speed and/or flight height, simulate spray operations with explicit droplets, evaluate wastage and coverage, and then figure out the optimal instructions to guide their real-world practices. The ultimate purpose is to develop these two technologies into adoptable, affordable and easy-to-use decision-support tools for tree crop growers and horticulturalists to optimise orchard light quality, minimise spray wastage, narrow the range of investigations, and accelerate the innovation of future horticultural systems with better yield, lower cost and less pollution

Plantation crops

Plantation horticulture is an important part of the economic landscape of many tropical countries. Plantations were developed in association with colonial expansion and the original models were based on the production of monocrops which had a ready export market, using cheap or slave labour. Plantations in the twenty first Century are less likely environments for exploitation of human and environmental capital. They are however, linked to crop production on a large scale for produce to be sold, at profit, for export to distant markets rather than local sale. A range of crops can be broadly categorized into plantation crops. Plantations continue to be effective models for efficient agricultural production and will evolve in response to the continued demand for food, fruit, fibre, oil crops and timber from a growing populatio

Sapindaceae production and research in Australia

Australia has an abundance of native Sapindaceae, with a few species that are considered to have an edible aril. A number of these have minor 'bush food' status but have limited commercial potential. Longan, lychee and rambutan were introduced into Australia from the mid 1800s. Serious commercialization of these crops began from the 1970s when farmers in sub-tropical and tropical regions of Australia were seeking new commercial horticultural opportunities. Currently the value of these industries is in the vicinity of $35 M with lychee the predominate crop followed by longan and rambutan respectively. Despite Australia being a minor producer on the world scale it has contributed significantly to the scientific and production developments through the combined efforts of researchers and innovative growers. This paper details the development and status of the commercial Sapindaceae in Australia and highlights production and research activities