Academic literature on the topic 'Tropical commodities'

This comprehensive handbook on economic entomology for Australian field crops and pastures is the first of its kind. It encompasses pests and beneficial insects as well as allied forms of importance in Australian agriculture.
 Organised by commodities – such as cereals, sugar and tropical pasture legumes – it examines all the pest species for a particular commodity across Australia. Identification, distribution, damage, host range, biology, risk period and monitoring techniques are described for each entry, accompanied by useful illustrations. The book also describes introduced biological control agents that effectively control crop pests.
 Pests of Field Crops and Pastures will be a useful tool in crop management for progressive farmers, agronomists, agricultural consultants and academics alike.

AbstractThis chapter shows that hygiene had profound practical and material consequences for people in both West Africa and Europe. Hygiene was more than a metaphor used to encode religious virtues, scientific imperatives, cultural values, social interactions and colonial anxieties. It was a practice that materialised itself in and on individual bodies, and crucially depended on material aids such as drugs, medical equipment, sanitary articles and specific clothing. The Basel Mission actively engaged with these tools of hygiene, from an early interest in natural remedies in West Africa to the establishment of a thriving commodity culture surrounding tropical hygiene around 1900. Remedies and commodities circulating through missionary networks shaped bodily practices, while images produced and propagated by the Basel Mission left a visual legacy that informs our understanding of purity, health and cleanliness to this day. Examined critically, these material and visual sources reveal the profoundly interactive nature of missionary encounters and testify to the conceptual, practical and material exchanges between people in West Africa and Europe.

AbstractThe introduction explores the books’ main themes, protagonists and goals. The aim is to extend the history of hygiene in two ways: firstly, beyond scientific and secular narratives by showing that religious stakeholders crucially participated in producing and promoting hygienic knowledge between 1885 and 1914; and secondly, by analysing how hygiene was shaped by colonial entanglements. The introduction offers a brief research review highlighting the connected histories on which this history of hygiene is built: mission history, particularly mission medicine; the history of science, with a focus on tropical medicine; and colonial history, specifically the knowledge produced in colonial entanglements. To do so, it introduces the concept of “spaces of knowledge” as an analytical lens to demonstrate how different discourses and practices of hygiene overlapped, differed and influenced each other. These spaces of knowledge are examined through an extensive body of sources, including archival material, publications, images and commodities, which are briefly presented and critically discussed with regard to their limitations and challenges.

AbstractBanana and plantains are among the most valuable agricultural commodities in the world. Banana Fusarium wilt, caused by the soil-borne Fusarium oxysporum f. sp. cubense (Foc), is one of the most devastating diseases of banana globally. In the 1990s a new strain of Fusarium oxysporum called tropical race 4 (TR4) emerged in Southeast Asia that affected commercial Cavendish plantations. The development of resistant cultivars is an effective strategy for management of the disease. Field-based screening to identify Foc-resistant plants is time-consuming, expensive and is often challenged by variable environmental conditions. Here we present an early selection protocol enabling evaluation of the disease under in vitro conditions. This method provides a preliminary screening and allows evaluation of a large number of in vitro plantlets. Using this method, within a short time and in a small laboratory, breeders can evaluate thousands of banana plantlets, produced via irradiation. Subsequently, putative, disease-resistant mutant lines can be identified and evaluated in the field.

AbstractCoffee is a perennial (sub)tropical crop and one of the most valuable commodities globally. Coffee is grown by an estimated 25 million farmers, mostly smallholders, and provides livelihoods to about 125 million people. The Coffea genus comprises over 120 species. Two species account for nearly the entire world coffee production: C. arabica L. (Arabica coffee) and C. canephora Pierre ex A. Froehner (Canephora coffee) with the former supplying about 65% of the world’s consumption. Arabica coffee is a self-pollinated, amphidiploid species (2n = 4x = 44) whereas other Coffea species are diploid (2n = 2x = 22) and generally cross-pollinated. Induced mutagenesis using physical and chemical mutagens has been a successful strategy in producing over 3,300 mutant varieties in over 220 crop species with global impact. Spontaneous Arabica coffee mutants of significant economic importance have been found since the early 1900s, following the spread of Arabica coffee cultivation across the globe. However, Arabica coffee has so far not been improved through induced mutagenesis and studies on coffee mutagenesis are scarce. In this chapter, principles and practices of mutation-assisted breeding along with current breeding limitations of Arabica coffee are briefly reviewed, as an introduction to subsequent protocol chapters on mutation induction, advanced cell and tissue culture, Leaf Rust resistance screening and the application of novel molecular/genomics tools supporting mutation-assisted improvement and genetics research of Arabica coffee.

Abstract This chapter reviews the findings, outputs and outcomes of research on multidimensional crops in the tropics, focusing mainly on cereals and grain legumes. Specifically, the chapter addresses the: (i) establishment of crop residues (CRs) as traded commodities and their changing valuation as the impetus for multidimensional crop improvement; (ii) trait identification and development of infrastructure for quick and affordable phenotyping for CR fodder quality; (iii) exploitation of existing cultivar-dependent variations in CR fodder quality; (iv) targeted genetic enhancement for multitrait food-feed-fodder cultivars; (v) trade-offs between CR fodder traits and primary traits, notably grain and pod or straw yields; and (vi) outcomes of multidimensional crop improvement and future work.

Abstract This chapter explores the role of knowledge circuits as a category of analysis in the techno-scientific developments of tropical products within the history of science and environmental and commodity histories. It uses the terms ‘domestic knowledge circuits’ and ‘tropical scientific knowledge’ to understand the intimate connection between the advances of science and the clearly practical and productivist objectives of knowledge applied to basic goods. This suggests complex and changing dynamics within the chain and life cycle of goods and illustrates areas of encounter, negotiation, and hybridity in the production and circulation of knowledge. This is exemplified with a case study of the control and eradication of the sugar cane mosaic virus in Cuba and Puerto Rico, highlighting the necessary interconnections between local and global strategies for the generation of new scientific knowledge. The chapter concludes with suggestions as to how such analytical frameworks may further research into the knowledge circuits of commodities.

The objectives of this project were to develop nondestructive methods for detection of internal properties and firmness of fruits and vegetables. One method was based on a soft piezoelectric film transducer developed in the Technion, for analysis of fruit response to low-energy excitation. The second method was a dot-matrix piezoelectric transducer of North Carolina State University, developed for contact-pressure analysis of fruit during impact. Two research teams, one in Israel and the other in North Carolina, coordinated their research effort according to the specific objectives of the project, to develop and apply the two complementary methods for quality control of agricultural commodities. In Israel: An improved firmness testing system was developed and tested with tropical fruits. The new system included an instrumented fruit-bed of three flexible piezoelectric sensors and miniature electromagnetic hammers, which served as fruit support and low-energy excitation device, respectively. Resonant frequencies were detected for determination of firmness index. Two new acoustic parameters were developed for evaluation of fruit firmness and maturity: a dumping-ratio and a centeroid of the frequency response. Experiments were performed with avocado and mango fruits. The internal damping ratio, which may indicate fruit ripeness, increased monotonically with time, while resonant frequencies and firmness indices decreased with time. Fruit samples were tested daily by destructive penetration test. A fairy high correlation was found in tropical fruits between the penetration force and the new acoustic parameters; a lower correlation was found between this parameter and the conventional firmness index. Improved table-top firmness testing units, Firmalon, with data-logging system and on-line data analysis capacity have been built. The new device was used for the full-scale experiments in the next two years, ahead of the original program and BARD timetable. Close cooperation was initiated with local industry for development of both off-line and on-line sorting and quality control of more agricultural commodities. Firmalon units were produced and operated in major packaging houses in Israel, Belgium and Washington State, on mango and avocado, apples, pears, tomatoes, melons and some other fruits, to gain field experience with the new method. The accumulated experimental data from all these activities is still analyzed, to improve firmness sorting criteria and shelf-life predicting curves for the different fruits. The test program in commercial CA storage facilities in Washington State included seven apple varieties: Fuji, Braeburn, Gala, Granny Smith, Jonagold, Red Delicious, Golden Delicious, and D'Anjou pear variety. FI master-curves could be developed for the Braeburn, Gala, Granny Smith and Jonagold apples. These fruits showed a steady ripening process during the test period. Yet, more work should be conducted to reduce scattering of the data and to determine the confidence limits of the method. Nearly constant FI in Red Delicious and the fluctuations of FI in the Fuji apples should be re-examined. Three sets of experiment were performed with Flandria tomatoes. Despite the complex structure of the tomatoes, the acoustic method could be used for firmness evaluation and to follow the ripening evolution with time. Close agreement was achieved between the auction expert evaluation and that of the nondestructive acoustic test, where firmness index of 4.0 and more indicated grade-A tomatoes. More work is performed to refine the sorting algorithm and to develop a general ripening scale for automatic grading of tomatoes for the fresh fruit market. Galia melons were tested in Israel, in simulated export conditions. It was concluded that the Firmalon is capable of detecting the ripening of melons nondestructively, and sorted out the defective fruits from the export shipment. The cooperation with local industry resulted in development of automatic on-line prototype of the acoustic sensor, that may be incorporated with the export quality control system for melons. More interesting is the development of the remote firmness sensing method for sealed CA cool-rooms, where most of the full-year fruit yield in stored for off-season consumption. Hundreds of ripening monitor systems have been installed in major fruit storage facilities, and being evaluated now by the consumers. If successful, the new method may cause a major change in long-term fruit storage technology. More uses of the acoustic test method have been considered, for monitoring fruit maturity and harvest time, testing fruit samples or each individual fruit when entering the storage facilities, packaging house and auction, and in the supermarket. This approach may result in a full line of equipment for nondestructive quality control of fruits and vegetables, from the orchard or the greenhouse, through the entire sorting, grading and storage process, up to the consumer table. The developed technology offers a tool to determine the maturity of the fruits nondestructively by monitoring their acoustic response to mechanical impulse on the tree. A special device was built and preliminary tested in mango fruit. More development is needed to develop a portable, hand operated sensing method for this purpose. In North Carolina: Analysis method based on an Auto-Regressive (AR) model was developed for detecting the first resonance of fruit from their response to mechanical impulse. The algorithm included a routine that detects the first resonant frequency from as many sensors as possible. Experiments on Red Delicious apples were performed and their firmness was determined. The AR method allowed the detection of the first resonance. The method could be fast enough to be utilized in a real time sorting machine. Yet, further study is needed to look for improvement of the search algorithm of the methods. An impact contact-pressure measurement system and Neural Network (NN) identification method were developed to investigate the relationships between surface pressure distributions on selected fruits and their respective internal textural qualities. A piezoelectric dot-matrix pressure transducer was developed for the purpose of acquiring time-sampled pressure profiles during impact. The acquired data was transferred into a personal computer and accurate visualization of animated data were presented. Preliminary test with 10 apples has been performed. Measurement were made by the contact-pressure transducer in two different positions. Complementary measurements were made on the same apples by using the Firmalon and Magness Taylor (MT) testers. Three-layer neural network was designed. 2/3 of the contact-pressure data were used as training input data and corresponding MT data as training target data. The remaining data were used as NN checking data. Six samples randomly chosen from the ten measured samples and their corresponding Firmalon values were used as the NN training and target data, respectively. The remaining four samples' data were input to the NN. The NN results consistent with the Firmness Tester values. So, if more training data would be obtained, the output should be more accurate. In addition, the Firmness Tester values do not consistent with MT firmness tester values. The NN method developed in this study appears to be a useful tool to emulate the MT Firmness test results without destroying the apple samples. To get more accurate estimation of MT firmness a much larger training data set is required. When the larger sensitive area of the pressure sensor being developed in this project becomes available, the entire contact 'shape' will provide additional information and the neural network results would be more accurate. It has been shown that the impact information can be utilized in the determination of internal quality factors of fruit. Until now,