Browsing by Browse by SEO 2008 "820299 Horticultural Crops not elsewhere classified"

Despite widely reported trends of agricultural land abandonment across many parts of the globe, this land use change phenomenon is relatively new in the context of Nepal. In recent years, rural farming communities in the hill region are gradually reducing the intensity of farming, leading to underutilisation and abandonment of agricultural lands. Adopting a mixed methods research approach, this study investigated the extent of agricultural land abandonment, its underlying causal drivers and perceived impacts in the hill agro-ecological region of Nepal. A structured survey of 374 households and six focus group discussions were carried out in three districts. The study revealed that around 40% of agricultural lands in the hill agro-ecological region have been abandoned and 60% of farmers have left at least one parcel of agricultural land abandoned. It was found that biophysical drivers (distance from homestead to parcel, slope of the parcel, land fragmentation, land quality and irrigation availability) and socio-demographic drivers (family size, higher education of the household members, domestic migration and out-migration) were responsible for agricultural land abandonment. Negative impacts of land abandonment were observed on the rural landscape, human-made farm structures, socio-economic systems, local food production and food security. In line with global studies, this research suggest that marginal land quality, demographic changes and rising alternative economic opportunities elsewhere contribute to farmland abandonment. This study also discusses land management approaches and policy implications to address the issue of agricultural land abandonment.

Phytophthora root rot (PRR) disease is a major threat in avocado orchards, causing extensive production loss and tree death if left unmanaged. Regular assessment of tree health is required to enable implementation of the best agronomic management practices. Visual canopy appraisal methods such as the scoring of defoliation are subjective and subject to human error and inconsistency. Quantifying canopy porosity using red, green and blue (RGB) colour imagery offers an objective alternative. However, canopy defoliation, and porosity is considered a 'lag indicator' of PRR disease, which, through root damage, incurs water stress. Restricted transpiration is considered a 'lead indicator', and this study sought to compare measured canopy porosity with the restricted transpiration resulting from PRR disease, as indicated by canopy temperature. Canopy porosity was calculated from RGB imagery acquired by a smartphone and the restricted transpiration was estimated using thermal imagery acquired by a FLIR B250 hand-held thermal camera. A sample of 85 randomly selected trees were used to obtain RGB imagery from the shaded side of the canopy and thermal imagery from both shaded and sunlit segments of the canopy; the latter were used to derive the differential values of mean canopy temperature (Delta T-mean), crop water stress index (Delta CWSI), and stomatal conductance index (Delta I-g). Canopy porosity was observed to be exponentially, inversely correlated with Delta CWSI and Delta I-g (R-2 > 90%). The nature of the relationship also points to the use of canopy porosity at early stages of canopy decline, where defoliation has only just commenced and detection is often beyond the capability of subjective human assessment.

Ensuring the sustainability of crop production, whilst simultaneously taking actions to mitigate the environmental impacts of agriculture, is a current global priority. Given around 75% of global food crop yields benefit from pollination services provided by diverse wild and managed insect taxa, management strategies that support diverse communities of pollinator taxa are valuable to ensure ongoing pollination service provisioning and agricultural production. In addition to pollination, realised crop yields are also influenced by other biotic and abiotic factors which vary across different spatial and temporal scales. This thesis addresses three important aspects of crop pollination, namely the need to merge disparate research fields, the degree to which pollinator taxa service multiple crops and regions and how pollination interacts with crop tree physiological factors such as tree vigour.
First, I reviewed the literature to evaluate the knowledge gaps concerning pollinator effectiveness and the utility of using remote sensing in crop pollination research. I conducted surveys and pollen deposition trials to identify pollinators in avocado, mango and macadamia crops in three geographically distinct growing regions in Australia across three years. Using single visit deposition rates, bipartite networks and spatial analyses I also investigated pollinator service provisioning and the land use types that influence pollinator communities in these crop and regions. Using hand pollination trials over two years I investigated the impact of supplemental cross pollination on the yield of avocado trees.
My first review identified important research directions to account for pollination processes occurring at a community level including: plant-pollinator interactions, heterospecific pollen transfer and variation in pollination outcomes. My second review identified the areas in which remote sensing technologies can facilitate our understanding of interactions between pollinators, pollination services, environmental and plant physiological factors which affect final harvest measures.
Using multi-crop, multi-year and multi-region crop-pollinator networks I demonstrated that shared wild pollinator taxa visit multiple crops across several regions. In particular, honey bees (A. mellifera) and two families of wild visitors, Syrphidae and Calliphoridae, are present across all regions and crops. Further, regional comparisons for both avocado and mango crops identified additional shared families that were locally abundant such as Coccinellidae and native Apidae.
I found that the effect of additional cross pollination on trees of different vigour varied between individual orchard blocks and across years. General patterns relating to the impact of interaction between tree vigour and pollination on yield were discernible in this study, with lower and medium vigour trees responding more positively to supplemental pollination than high vigour trees. High variability in results and differences in effect response across orchard blocks highlight the need to investigate further factors at a tree and block scale, in future analyses.
My research indicates that there is significant potential to identify shared pollinators that provide services across multiple crops. Pollination management strategies that are regionally specific and that include bee and non-bee taxa and co-flowering crop species are needed to ensure ongoing effective and resilient pollination services are delivered to crop systems. The merging of different research fields, such as remote sensing, pollinator ecology and precision agriculture offers exciting new approaches to facilitate our understanding of these complex crop-pollinator interactions.

Among the fundamental questions regarding cultivated plants is their geographic origin and region of domestication. The genus 'Cucumis', which includes cucumber ('Cucumis sativus') and melon ('Cucumis melo'), has numerous wild African species, and it has therefore been assumed that melon originated in Africa. For cucumber, this seemed less likely because wild cucumbers exist in India and a closely related species lives in the Eastern Himalayas. Using DNA sequences from plastid and nuclear markers for some 100 Cucumis accessions from Africa, Australia, and Asia, we show here that melon and cucumber are of Asian origin and have numerous previously overlooked species-level relatives in Australia and around the Indian Ocean. The wild progenitor of 'C. melo' occurs in India, and our data confirm that the Southeast Asian 'Cucumis hystrix' is the closest relative of cucumber. Most surprisingly, the closest relative of melon is 'Cucumis picrocarpus' from Australia. 'C. melo' diverged from this Australian sister species approximately 3 Ma, and both diverged from the remaining Asian/Australian species approximately 10 Ma. The Asian/Australian 'Cucumis' clade comprises at least 25 species, nine of them new to science, and diverged from its African relatives in the Miocene, approximately 12 Ma. Range reconstruction under maximum likelihood suggests Asia as the ancestral area for the most recent common ancestor of melon and cucumber, fitting with both having progenitor populations in the Himalayan region and high genetic diversity of 'C. melo' landraces in India and China. Future investigations of wild species related to melon and cucumber should concentrate on Asia and Australia.

Principal component analysis of ¹H NMR spectra of dichloromethane extracts taken from grapevine leaves reveals that phylloxera infestation of the root system causes metabolic changes in the leaves of infested grapevines, both in the field and in the glasshouse. A number of potential markers of phylloxera infestation were detected but their presence is transient and varies with the stage of the growing season. The changes in the metabolic profile caused by phylloxera infestation more closely resemble those caused by nitrogen deficiency than those induced by water stress. A reduction in the ratio of linoleic acid to linolenic acid in the triglyceride component of the leaf extract may provide an indicator of phylloxera infestation.

This paper uses cross-sectional data collected from 375 smallholder yam farmers in Ghana in 2010 to examine whether the adoption of yam minisett technology had an effect on the technical efficiency of production of the yam farmers. We correct for endogeneity in adoption and employ stochastic frontier analysis to investigate the effect of adoption of the technology on the technical efficiency of production. Our analysis suggests average technical efficiencies of 85.4% and 89.2% in the Ashanti and Brong Ahafo regions respectively. In addition, the effect of adoption of the technology on the technical efficiency of smallholder farmers was positive and significant in the Ashanti region, but negative in the Brong Ahafo region. Our results provide information to improve the uptake of production technologies and their effect on smallholder yam farmers in Ghana.

Vietnam is well-known as the second largest global coffee producer and the largest worldwide exporter of Robusta coffee. However, the Robusta coffee sector in Vietnam is facing many problems, including low quality, high external inputs and water shortages as a result of shade tree eradication. A six-month research project was conducted that focused on effects of shaded tree types on variation of light intensity and aspects of Robusta production. Three shade tree species at different planting densities and shade provision were investigated, including 46 trees of Durian ha⁻¹ (14% shade), 35 trees of Sennaha⁻¹ (17% shade), and 60 trees of Leucaena ha⁻¹ (34% shade), and unshaded site (Open) was used as a control. The study found that light intensity declined 50% with Durian, 58% with Senna and 60% with Leucaena compared with the Open site (2096 μmol.m⁻².s⁻¹). Within the coffee canopy, a significant decline in light intensity was observed from the top of the canopy to the bottom. The percentage of light at the middle (90 cm above ground) and bottom (30cm) levels of the coffee canopy was declined by 81% and 88% respectively for the Open site, and 86% and 92% for the Leucaena site. There were no differences in the number of flowers branch⁻¹ tree⁻¹ and fruit set between shaded and unshaded coffee sites. However, a significant difference in first fruit drop was observed.

Background and Aims: Current methods of frost protection in vineyards involve fans, air heaters or sprinklers; each is limited by environmental constraints or available water. An alternative, all-electrical technique offers growers wider choice to match options with their vineyard operations. This study evaluates the ability of electrical heating cables, wrapped around the vine cordons, to protect inflorescences from frost damage. Methods and Results: Five heating cable treatments in six replicates were applied to a 2-ha block of Sauvignon Blanc in the southern New England Region of Australia. Vines were subjected to a single −3°C frost event in November 2006 when at approximately 30% capfall. Non-heated vines suffered 41% (Control) and 46% (No heat) inflorescence loss. Those subjected to Low heat suffered a 28% loss, Medium-heated vines suffered a 16% loss and High-heated vines suffered a 13% loss. Qualitative scoring of the vines indicated that more than half of the Medium-/High-heated vines suffered no appreciate damage, whereas all non-heated vines suffered some form of potential crop loss or damage. Conclusion: Electrical heating cables of minimum 10 W/m power rating were found to significantly reduce frost damage to inflorescences at 30% capfall. Significance of the Study: At approximately 43 kW/ha, electrical heating cable offers an alternative frost protection method for small vineyards.

Phytophthora root rot disease (PRR) is a major threat in avocado orchards. To identify a potential alternative to the current methods of assessing PRR in avocado for example visual assessment of canopy decline by human eyes, data has been collected from number of novel remote sensing technologies for measuring PRR induced canopy decline in avocado. Included Red Green and Blue (RGB) imagery acquired from a smartphone; thermal imagery from a hand-held camera and hyperspectral data acquired with a hand-held FieldSpec® 3 spectroradiometer

Many pollinator species visit multiple crops in multiple regions, yet we know little about their pollination service provisioning at local and regional scales. We investigated the floral visitors (n = 13,200), their effectiveness (n = 1718 single visits) and response to landscape composition across three crops avocado, mango and macadamia within a single growing region (1 year), a single crop (3 years) and across different growing regions in multiple years. In total, eight wild visitor groups were shared across all three crops. The network was dominated by three pollinators, two bees (Apis mellifera and Tetragonula spp.) and a fly, Stomorhina discolor. The visitation network for the three crops was relatively generalised but with the addition of pollen deposition data, specialisation increased. Sixteen managed and wild taxa were consistently present across three years in avocado, yet their contribution to annual network structure varied. Node specialisation (d’) analyses indicated many individual orchard sites across each of the networks were significantly more specialised compared to that predicted by null models, suggesting the presence of site-specific factors driving these patterns. Identifying the taxa shared across multiple crops, regions and years will facilitate the development of specific pollinator management strategies to optimize crop pollination services in horticultural systems.

Frost damage in broadacre cropping and horticulture (including viticulture) results in substantial economic losses to producers and may also disrupt associated product value chains. Frost risk windows are changing in timing, frequency, and duration. Faced with the increasing cost of mitigation infrastructure and competition for resources (e.g., water and energy), multiperil insurance, and the need for supply chain certainty, producers are under pressure to innovate in order to manage and mitigate risk. Frost protection systems are cyber-physical systems (CPSs) consisting of sensors (event detection), intelligence (prediction), and actuators (active protection methods). The Internet-of-Things communication protocols joining the CPS components are also evaluated. In this context, this article introduces and reviews existing methods of frost management. This article focuses on active protection methods because of their potential for real-time deployment during frost events. For integrated frost prediction and active protection systems, prediction method, sensor types, and integration architecture are assessed, research gaps are identified and future research directions proposed.

The efficacy of biological control of Greenhouse whitefly ( Trialeurodes vaporariorum Westwood (1856) (Hemiptera: Aleyrodidae) by three natural enemies, Encarsia formosa Gahan (1924), Eretmocerus warrae Naumann & Schmidt (2000) (Hymenoptera: Aphelinidae) and Nesidiocoris tenuis Reuter (1895) (Hemiptera: Miridae), may be reduced by interactions between the species. I quantified host discrimination between the parasitoids through examination of multiparasitism (interspecific), superparasitism (intraspecific), and selfsuperparasitism (on own parasitism). The choice to host feed increases adult resources, whilst reducing oviposition resources. Host feeding contributes to whitefly control, but may destructively interfere with parasitoid population sizes. I report the level of host feeding and feeding preferences on parasitized and nonparasitized nymphs by the parasitoids. Comparative control by the two parasitoids, separately and together, is presented to determine if multiple or single introductions are more effective to achieve control. Feeding preferences by the omnivorous predator, N. tenuis, were analysed for potential interference on the establishment of En. formosa.

Laboratory choice experiments were conducted, using all parasitoid combinations (pairs of interspecifics, conspecifics, or the same parasitoid), where females had to choose between nonparasitized or parasitized whitefly nymphs, with treatments of a delay between the first and second parasitoids of 0 or 1 hr, or 1 day. All combinations showed the ability to host discriminate, and a preference for feeding and ovipositing on nonparasitized whitefly nymphs. Multiparasitism occurred in 19%, superparasitism in 7% and self-superparasitism in 4% of ovipositions by the parasitoids. Laboratory choice tests were conducted using N. tenuis, with a choice between parasitized or nonparasitized whitefly nymphs or pupae. These tests showed no preference between feeding on parasitized or nonparasitized whitefly nymphs, indicating N. tenuis may impact on En. formosa establishment. Caged tomato plants, in a greenhouse, were inoculated with whitefly; parasitoids were then released into the cages using a full factorial design, with four replicates of all treatments. All combinations of parasitoids decreased whitefly numbers relative to control, with no significant difference between the treatments. This demonstrates that En. formosa and Er. warrae are compatible as biological control agents in multiple introductions.

Land cover mapping of intensive cropping areas facilitates an enhanced regional response to biosecurity threats and to natural disasters such as drought and flooding. Such maps also provide information for natural resource planning and analysis of the temporal and spatial trends in crop distribution and gross production. In this work, 10 meter resolution land cover maps were generated over a 6200 km² area of the Riverina region in New South Wales (NSW), Australia, with a focus on locating the most important perennial crops in the region. The maps discriminated between 12 classes, including nine perennial crop classes. A satellite image time series (SITS) of freely available Sentinel-1 synthetic aperture radar (SAR) and Sentinel-2 multispectral imagery was used. A segmentation technique grouped spectrally similar adjacent pixels together, to enable object-based image analysis (OBIA). K-means unsupervised clustering was used to filter training points and classify some map areas, which improved supervised classification of the remaining areas. The support vector machine (SVM) supervised classifier with radial basis function (RBF) kernel gave the best results among several algorithms trialled. The accuracies of maps generated using several combinations of the multispectral and radar bands were compared to assess the relative value of each combination. An object-based post classification refinement step was developed, enabling optimization of the tradeoff between producers’ accuracy and users’ accuracy. Accuracy was assessed against randomly sampled segments, and the final map achieved an overall count-based accuracy of 84.8% and area-weighted accuracy of 90.9%. Producers’ accuracies for the perennial crop classes ranged from 78 to 100%, and users’ accuracies ranged from 63 to 100%. This work develops methods to generate detailed and large-scale maps that accurately discriminate between many perennial crops and can be updated frequently.

Australia's Aboriginal and Torres Strait Islander peoples are an eclectic society with diverse needs and aspirations in relation to the commercialisation of their traditional plant foods (bush foods). Their interests reflect different worldviews, social structures, personal circumstances and development goals. There is very little legal support for the interests of Aboriginal and Torres Strait Islander peoples in bush food commercialisation. This thesis uses a combination of methods to develop an integrated framework of legal and institutional strategies to better support the diverse interests of Aboriginal and Torres Strait Islander peoples in this commercial context. The research draws upon legal and systems-based analysis to identify pivotal transactions that occur along bush food commercialisation pathways and interventions that might better enable Aboriginal and Torres Strait Islander peoples to realise their goals. While a central focus of the research is legal arrangements, of necessity the proposals suggested in this thesis go beyond the conventional bounds of legal research. This is because useful applications or reforms of the law depend upon there being potential strategies that the law might enable. A large part of this research has been to identify potential strategies and then place possible legal arrangements within this context.

Ensuring the sustainability of crop production, whilst simultaneously taking actions to mitigate the environmental impacts of agriculture, is a current global priority. Given around 75% of global food crop yields benefit from pollination services provided by diverse wild and managed insect taxa, management strategies that support diverse communities of pollinator taxa are valuable to ensure ongoing pollination service provisioning and agricultural production. In addition to pollination, realised crop yields are also influenced by other biotic and abiotic factors which vary across different spatial and temporal scales. This thesis addresses three important aspects of crop pollination, namely the need to merge disparate research fields, the degree to which pollinator taxa service multiple crops and regions and how pollination interacts with crop tree physiological factors such as tree vigour.
First, I reviewed the literature to evaluate the knowledge gaps concerning pollinator effectiveness and the utility of using remote sensing in crop pollination research. I conducted surveys and pollen deposition trials to identify pollinators in avocado, mango and macadamia crops in three geographically distinct growing regions in Australia across three years. Using single visit deposition rates, bipartite networks and spatial analyses I also investigated pollinator service provisioning and the land use types that influence pollinator communities in these crop and regions. Using hand pollination trials over two years I investigated the impact of supplemental cross pollination on the yield of avocado trees.
My first review identified important research directions to account for pollination processes occurring at a community level including: plant-pollinator interactions, heterospecific pollen transfer and variation in pollination outcomes. My second review identified the areas in which remote sensing technologies can facilitate our understanding of interactions between pollinators, pollination services, environmental and plant physiological factors which affect final harvest measures.
Using multi-crop, multi-year and multi-region crop-pollinator networks I demonstrated that shared wild pollinator taxa visit multiple crops across several regions. In particular, honey bees (A. mellifera) and two families of wild visitors, Syrphidae and Calliphoridae, are present across all regions and crops. Further, regional comparisons for both avocado and mango crops identified additional shared families that were locally abundant such as Coccinellidae and native Apidae.
I found that the effect of additional cross pollination on trees of different vigour varied between individual orchard blocks and across years. General patterns relating to the impact of interaction between tree vigour and pollination on yield were discernible in this study, with lower and medium vigour trees responding more positively to supplemental pollination than high vigour trees. High variability in results and differences in effect response across orchard blocks highlight the need to investigate further factors at a tree and block scale, in future analyses.
My research indicates that there is significant potential to identify shared pollinators that provide services across multiple crops. Pollination management strategies that are regionally specific and that include bee and non-bee taxa and co-flowering crop species are needed to ensure ongoing effective and resilient pollination services are delivered to crop systems. The merging of different research fields, such as remote sensing, pollinator ecology and precision agriculture offers exciting new approaches to facilitate our understanding of these complex crop-pollinator interactions.

Tree condition, pruning and orchard management practices within intensive horticultural tree crop systems can be determined via measurements of tree structure. Multi-spectral imagery acquired from an unmanned aerial system (UAS) has been demonstrated as an accurate and efficient platform for measuring various tree structural attributes, but research in complex horticultural environments has been limited. This research established a methodology for accurately estimating tree crown height, extent, plant projective cover (PPC) and condition of avocado tree crops, from a UAS platform. Individual tree crowns were delineated using object-based image analysis. In comparison to field measured canopy heights, an image-derived canopy height model provided a coefficient of determination (R²) of 0.65 and relative root mean squared error of 6%. Tree crown length perpendicular to the hedgerow was accurately mapped. PPC was measured using spectral and textural image information and produced an R² value of 0.62 against field data. A random forest classifier was applied to assign tree condition into four categories in accordance with industry standards, producing out-of-bag accuracies >96%. Our results demonstrate the potential of UAS-based mapping for the provision of information to support the horticulture industry and facilitate orchard-based assessment and management.

Ensuring the sustainability of crop production, whilst simultaneously taking actions to mitigate the environmental impacts of agriculture, is a current global priority. Given around 75% of global food crop yields benefit from pollination services provided by diverse wild and managed insect taxa, management strategies that support diverse communities of pollinator taxa are valuable to ensure ongoing pollination service provisioning and agricultural production. In addition to pollination, realised crop yields are also influenced by other biotic and abiotic factors which vary across different spatial and temporal scales. This thesis addresses three important aspects of crop pollination, namely the need to merge disparate research fields, the degree to which pollinator taxa service multiple crops and regions and how pollination interacts with crop tree physiological factors such as tree vigour.

First, I reviewed the literature to evaluate the knowledge gaps concerning pollinator effectiveness and the utility of using remote sensing in crop pollination research. I conducted surveys and pollen deposition trials to identify pollinators in avocado, mango and macadamia crops in three geographically distinct growing regions in Australia across three years. Using single visit deposition rates, bipartite networks and spatial analyses I also investigated pollinator service provisioning and the land use types that influence pollinator communities in these crop and regions. Using hand pollination trials over two years I investigated the impact of supplemental cross pollination on the yield of avocado trees.

My first review identified important research directions to account for pollination processes occurring at a community level including: plant-pollinator interactions, heterospecific pollen transfer and variation in pollination outcomes. My second review identified the areas in which remote sensing technologies can facilitate our understanding of interactions between pollinators, pollination services, environmental and plant physiological factors which affect final harvest measures.

Using multi-crop, multi-year and multi-region crop-pollinator networks I demonstrated that shared wild pollinator taxa visit multiple crops across several regions. In particular, honey bees (A. mellifera) and two families of wild visitors, Syrphidae and Calliphoridae, are present across all regions and crops. Further, regional comparisons for both avocado and mango crops identified additional shared families that were locally abundant such as Coccinellidae and native Apidae.

I found that the effect of additional cross pollination on trees of different vigour varied between individual orchard blocks and across years. General patterns relating to the impact of interaction between tree vigour and pollination on yield were discernible in this study, with lower and medium vigour trees responding more positively to supplemental pollination than high vigour trees. High variability in results and differences in effect response across orchard blocks highlight the need to investigate further factors at a tree and block scale, in future analyses.

My research indicates that there is significant potential to identify shared pollinators that provide services across multiple crops. Pollination management strategies that are regionally specific and that include bee and non-bee taxa and co-flowering crop species are needed to ensure ongoing effective and resilient pollination services are delivered to crop systems. The merging of different research fields, such as remote sensing, pollinator ecology and precision agriculture offers exciting new approaches to facilitate our understanding of these complex crop-pollinator interactions.

The aim of this paper is to demonstrate how Geographical Information System (GIS) can be used effectively to study infestations of Dubas bug (DB), 'Ommatissus lybicus' Bergevin, in date palm ('Phoenix dactylifera L.') that occurred in northern Oman during 2006-2015. The ability to produce geographical and spatiotemporal layers using GIS is expected to serve an important role in both monitoring and surveillance of DB infestation and its impact in the study area. By using of spatial analytic and geostatistical functions in ArcGIS 10.3™, data that quantified the infestation levels of DB over a 10-year period from 2006 to 2015 were used to map and model the risk of infestation spatiotemporally. We modelled the spatiotemporal risk of DB infestation by performing hotspot analysis using the Getis-Ord statistic, Gi*. Our results show that annual hotspots over the study period were mainly concentrated in the mountain plains, particularly where farms are located between gradient elevations. Furthermore, the distribution pattern varied considerably with time and space. These results demonstrated the usefulness in following annual DB infestation patterns by studying the average seasonal infestation levels and distribution of hotspots as they can facilitate the allocation of resources for the treatment of infestations and allow for more effective monitoring of its influence on date palm trees.

BACKGROUND: Ommatissus lybicus de Bergevin (Hemiptera: Tropiduchidae) (Dubas Bug, DB) is an insect pest attacking date palms. It occurs in Arab countries including Oman. In this paper, the logistic, ordinary least square, and geographical weighted regressions were applied to model the absence/presence and density of DB against climate factors. A method is proposed for modelling spatially correlated prorations annually over the study period, based on annual and seasonal outbreaks. The historical 2006–2015 climate data were obtained from weather stations located in nine governorates in northern Oman, while dataloggers collected the 2017 microclimate data in eight of these nine governorates. RESULTS: Logistic regression model showed the percentages of correctly predicted values using a cut‐off point of 0.5 were 90%, 88% and 84%, indicating good classification accuracy. OLS and GWR models showed an overall trend of strong linear correlation between DB infestation levels and short‐ and long‐term climate factors. The three models suggested that precipitation, elevation, temperature, humidity, wind direction and wind speed are important in influencing the spatial distribution and the presence/absence of dense DB populations. CONCLUSION: The results provide an improved understanding of climate factors that impact DB's spread and is considered useful for managing DB infestations in date palm plantations.

The New England Australia wine region was formally defined on the basis of geographical indicators (GIs) in January 2008. To date, the region has pursued a marketing approach built principally on its GI-defined regional status, emphasising cool climate diurnal variation, as well as some markers of cultural and political identity, such as 'family' and 'artisan' production. This general marketing profile fits hand in glove with that of a region 'presenting an image of quality and tradition' (Chang et al, 2006: 6). Yet, as Garcia-Parpet (2007) has reminded us, marketing is not merely about product promotion. It is also about the strategies that businesses adopt to achieve market entry, both legal and cultural, and the mechanisms for circumventing possible barriers. With this in mind, we contrast the marketing strategies of the New England wine-producing region in Australia with that of the Languedoc-Roussillon region in France. While the two occupy similar market positions, they nonetheless reveal diametrically opposed marketing strategies. Against the background of this comparative discussion, we seek to propose methods to enhance the development of the New England wine region so that it becomes a more complete example of successful rural restructuring.

Obtaining average canopy temperature (T_c) by thresholding canopy pixels from on-ground thermal imagery has historically been undertaken using ‘wet’ and ‘dry’ reference surfaces in the field (reference temperature thresholding). However, this method is extremely time inefficient and can suffer inaccuracies if the surfaces are non-standardised or unable to stabilise with the environment. The research presented in this paper evaluates non-reference techniques to obtain average canopy temperature (T_c) from thermal imagery of avocado trees, both for the shaded side and sunlit side, without the need of reference temperature values. A sample of 510 thermal images (from 130 avocado trees) were acquired with a FLIR B250 handheld thermal imaging camera. Two methods based on temperature histograms were evaluated for removing non-canopy-related pixel information from the analysis, enabling T_c to be determined. These approaches included: 1) Histogram gradient thresholding based on temperature intensity changes (HG); and 2) histogram thresholding at one or more standard deviation (SD) above and below the mean. The HG method was found to be more accurate (R2 > 0.95) than the SD method in defining canopy pixels and calculating T_c from each thermal image (shaded and sunlit) when compared to the standard reference temperature thresholding method. The results from this study present an alternative non-reference method for determining T_c from ground-based thermal imagery without the need of calibration surfaces. As such, it offers a more efficient and computationally autonomous method that will ultimately support the greater adoption of non-invasive thermal technologies within a precision agricultural system.

Ensuring the sustainability of crop production, whilst simultaneously taking actions to mitigate the environmental impacts of agriculture, is a current global priority. Given around 75% of global food crop yields benefit from pollination services provided by diverse wild and managed insect taxa, management strategies that support diverse communities of pollinator taxa are valuable to ensure ongoing pollination service provisioning and agricultural production. In addition to pollination, realised crop yields are also influenced by other biotic and abiotic factors which vary across different spatial and temporal scales. This thesis addresses three important aspects of crop pollination, namely the need to merge disparate research fields, the degree to which pollinator taxa service multiple crops and regions and how pollination interacts with crop tree physiological factors such as tree vigour.
First, I reviewed the literature to evaluate the knowledge gaps concerning pollinator effectiveness and the utility of using remote sensing in crop pollination research. I conducted surveys and pollen deposition trials to identify pollinators in avocado, mango and macadamia crops in three geographically distinct growing regions in Australia across three years. Using single visit deposition rates, bipartite networks and spatial analyses I also investigated pollinator service provisioning and the land use types that influence pollinator communities in these crop and regions. Using hand pollination trials over two years I investigated the impact of supplemental cross pollination on the yield of avocado trees.
My first review identified important research directions to account for pollination processes occurring at a community level including: plant-pollinator interactions, heterospecific pollen transfer and variation in pollination outcomes. My second review identified the areas in which remote sensing technologies can facilitate our understanding of interactions between pollinators, pollination services, environmental and plant physiological factors which affect final harvest measures.
Using multi-crop, multi-year and multi-region crop-pollinator networks I demonstrated that shared wild pollinator taxa visit multiple crops across several regions. In particular, honey bees (A. mellifera) and two families of wild visitors, Syrphidae and Calliphoridae, are present across all regions and crops. Further, regional comparisons for both avocado and mango crops identified additional shared families that were locally abundant such as Coccinellidae and native Apidae.
I found that the effect of additional cross pollination on trees of different vigour varied between individual orchard blocks and across years. General patterns relating to the impact of interaction between tree vigour and pollination on yield were discernible in this study, with lower and medium vigour trees responding more positively to supplemental pollination than high vigour trees. High variability in results and differences in effect response across orchard blocks highlight the need to investigate further factors at a tree and block scale, in future analyses.
My research indicates that there is significant potential to identify shared pollinators that provide services across multiple crops. Pollination management strategies that are regionally specific and that include bee and non-bee taxa and co-flowering crop species are needed to ensure ongoing effective and resilient pollination services are delivered to crop systems. The merging of different research fields, such as remote sensing, pollinator ecology and precision agriculture offers exciting new approaches to facilitate our understanding of these complex crop-pollinator interactions.

Bananas and plantains provide food and income for more than 50 million smallholder farmers in East and Central African (ECA) countries. However, banana productivity generally achieves less than optimal yield potential (<30%) in most regions, including Uganda. Numerous studies have been undertaken to identify the key challenges that smallholder banana growers face at different stages of the banana value chain, with one of the main constraints being a lack of policy-relevant agricultural data. The World Bank (WB) initiated a methodological survey design aimed at identifying the distribution of banana varieties across a number of key Ugandan growing regions, at the individual household scale. To achieve this outcome a number of approaches including ground-based surveys, DNA tissue collection of selected banana plants and remote sensing were evaluated. For the remote sensing component, the set objectives were to develop statistical models from the hyperspectral reflectance properties of individual leaves that could differentiate typical ECA banana varieties, as well as their parentage (usage). The study also explored the potential of extrapolating the ground-based hyperspectral measures to high-resolution WorldView-3 (WV3) satellite imagery, therefore creating the potential of mapping the distribution of banana varieties at a regional scale. The DNA testing of 43 banana varieties propagated at the National Banana Research Program site at National Agricultural Research Organization (NARO) research station in Kampala, Uganda, identified 12 genetically different varieties. A canonical powered partial least square (CPPLS) model developed from hyperspectral reflectance properties of the sampled banana leaves successfully differentiated BLU, BOG, GON, GRO and KAY genotypes. The Random Forest (RF) algorithm was also evaluated to determine if spectral bands coinciding with those provided by WV3 data could segregate banana varieties. The results suggested that this was achievable and as such presents an opportunity to extrapolate the hyperspectral classifications to broader areas of land. The ability to spectrally differentiate these five genotypes has merit as they are not typical east African varieties. As such, identifying the distribution and density of these varieties across Uganda provides vital information to the banana breeders of NARO of where their new varieties are being disseminated too, data that has been previously difficult to obtain. Although the results from this pilot study indicated that not all banana varieties could be spectrally differentiated, the methodology developed and the positive results that were achieved do present remote sensing as a complimentary technology to the ongoing surveying of banana and other crop types grown within Ugandan household farming systems.

The accessibility and low cost of global positioning systems (GPS) means that grape-growers can accurately locate themselves within their vineyard when sampling for vine growth, development and productivity. These data, when incorporated into maps, give new interpretative power to measurements that may otherwise have been used to generate simple vineyard or regional averages. Maps of yield and various quality parameters identify potential zones for segmenting harvest, areas requiring fertilization or differential irrigation management. Soil maps can be used to locate different varieties when planning a new vineyard site or aid in irrigation design. Measurement and mapping of these parameters is not confined to traditional on-ground sampling methodologies either. Emerging technologies involving on-ground, airborne or spaceborne remote sensing are attracting interest because of their potential for rapidly generating data of appropriate spatial resolution. For example, on-ground electromagnetic survey techniques may provide an insight into soil texture variations and is a valuable tool in vineyard planning. Airborne or spaceborne digital imaging systems can delineate different levels of vine canopy vigor in an entire vineyard, providing up-to-date information on canopy development, and may aid in identifying the incidence of pests or diseases and in forecasting yield or fruit quality. This paper will describe the current status of precision viticulture research in Australia. Examples of emerging technologies will be used to illustrate current benefits, as well as future opportunities for improved management at not only the vineyard but at an industry-wide scale.

The Dubas bug (Ommatissus lybicus de Bergevin) is a pest species whose entire life cycle occurs on date palms, Phoenix dactylifera L, causing serious damage and reducing date palm growth and yield. Pseudoligosita babylonica Viggiani, Aprostocetus nr. Beatus, and Bocchus hyalinus Olmi are very important parasitic natural enemies of Ommatissus lybicus in northern Oman. In this study, random farms were selected to (a) model the link between occurrences of the Pseudoligosita babylonica, Aprostocetus nr beatus, and Bocchus hyalinus (dependent variables) with environmental, climatological, and Dubas bug infestation levels (the independent variables), and (b) produce distribution and predictive maps of these natural enemies in northern Oman. The multiple R2 values showed the model explained 63%, 89%, and 94% of the presence of P. babylonica, A. nr beatus, and Bocchus hyalinus, respectively. However, the distribution of each species appears to be influenced by distinct and geographically associated climatological and environmental factors, as well as habitat characteristics. This study reveals that spatial analysis and modeling can be highly useful for studying the distribution, the presence or absence of Dubas bugs, and their natural enemies. It is anticipated to help contribute to the reduction in the extent and costs of aerial and ground insecticidal spraying needed in date palm plantations.

This paper reports on an analysis of production and technical inefficiency in pistachio farming systems in Iran. A random sample of 233 farmers was selected from the province of Kerman during 2003 and 2004, which is a larger data set with a wider spatial coverage compared with the previous studies on pistachio production. Technical inefficiency indices are computed using a stochastic frontier production function assuming a translog form. The study also reports on productivity and efficiency differences between varieties of pistachio trees and provides estimates of age-yield and density-yield functions. Estimates of mean technical efficiency in 2003 and 2004 are 65.2 and 63.7%, which are not significantly different. The mean technical efficiency scores across both years for plantations of the Kalleh-Ghuchi, Akbari, Fandoghi varieties and for plantations containing a mixture of all three varieties are 65.8, 59.4, 62.4 and 78.7%, respectively. Farmers cultivating the more traditional mixed-variety plantation are more technically efficient than those specializing in one of the three tree varieties. We found a positive relation between technical efficiency and experience, and suggest that extension programmes should be aimed at the less experienced farmers.

Context: Birds active in vineyards in south-eastern Australia can reduce or enhance crop yields via their foraging activities (e.g. by consuming grapes or by preying on grape-eating species). Aims: We examined the effectiveness of artificial perches in encouraging predatory birds into vineyards to scare frugivorous birds and consequently reduce the damage they cause to grapes. Methods: We monitored 12 artificial perches for 4 months during the growing season, spread over six vineyards in north-eastern Victoria, and compared bird damage to grapes at these sites with control sites without perches. Key results: We found that raptors did not use the artificial perches. However, the large and aggressive Australian magpie (Cracticus tibicen) commonly used perches and we recorded 38 513 perch visits by this species. Grapevines around perch sites suffered >50% less grape damage (4.13% damage per bunch) than control sites (8.57% damage per bunch). Conclusions: Our results suggest that providing artificial perches in vineyards can play a role in reducing frugivore damage to grapes. However, the effectiveness of perches can vary under different environmental conditions and certain perch types are not suitable for all predatory or aggressive birds. Implications: Future research should focus on the potential role of large-bodied and competitively aggressive species such as the Australian magpie in altering the activity of smaller frugivorous birds in vineyards, and also on the optimum height and location of artificial perches within vineyards to increase visitation by other predatory or aggressive bird species.

This volume of some ten essays by seven scholars draws on a wide range of sources, both documentary and archaeological, to explore the physical landscape, the patterns of rural life, and the natural environment, of people in medieval England. Thus animals, both kept and hunted, and vegetation, as well as agriculture and contemporary 'technology' are carefully appraised. The result is an amazingly comprehensive guide to the landscape of the past and its exploitation, particularly in the twelfth and thirteenth centuries. Much of the documentation is presented in excellent diagrams and tables.

Grapevine phylloxera ('Daktulosphaira vitifoliae' Fitch) is a significant threat to the Australian viticulture industry, with over 80% of grapevines planted on highly susceptible, ungrafted 'Vitis Vinifera' L. Early detection of phylloxera is critical as it can spread unnoticed in the early years of infestation when vine foliar symptoms may not reflect subterranean root damage. Management strategies such as phylloxera exclusion zones (PEZ) and a number of quarantine protocols relating to movement of machinery and grape materials are already established within Australia in an attempt to contain proliferation throughout viticultural regions. Such measures are particularly important for regions like the Hunter Valley in New South Wales, Australia and the Barossa Valley in South Australia, which are phylloxera-free and sustain a high volume of viticultural production. Currently, early detection protocols include labour-intensive, systematic sampling of vine roots to inspect for the presence of phylloxera and multispectral aerial imagery to identify potentially stressed vines. Airborne remote sensing identifies weak spots in the vineyard that are not necessarily due to phylloxera infestation, rather the expression of non-specific water or nutrient related symptoms. Healthy, vigorously growing canopies may also disguise the early expression of above-ground signs of phylloxera-induced root degradation. The delayed appearance of visible symptoms, coupled with the dynamics of phylloxera infestation means current detection methods could be significantly improved through development of a risk-based monitoring strategy to indicate the potential susceptibility of vineyards to phylloxera infestation. This paper presents the targeted use of several primary and secondary detection techniques already being utilised across the viticulture industry, including EM38, Greenseeker™ and a soil-based DNA assay specific for phylloxera.

The return on public investment in agricultural research depends, in part, on the extent to which primary producers adopt the products of that research. Consequently, a pre-condition for maximising the return on investment in the development of agricultural innovations is to identify how many primary producers will adopt different innovations and determining what processes are required to ensure innovations diffuse among producers as rapidly as possible. In other words, maximising the return on investment in agricultural research requires identifying the relevant market for innovations and determining what processes will accelerate diffusion through that market. A method for identifying the market for an agricultural innovation is presented in this paper. The method is, in essence, a process for discovering how agricultural innovations contribute to satisfying the needs of primary producers as managers of agricultural enterprises. The method draws on consumer behaviour theory and farming systems theory. It is based on the assumption that the adoption of agricultural innovations is a highly involving decision for producers. It has been used to identify the markets for innovations in irrigation systems in the horticultural, viticultural, vegetable and dairy industries, breeding practices and animal health practices in sheep and cattle, pest and disease management practises in horticulture and viticulture. While the decision to adopt most innovations is highly involving, we have discovered this is not necessarily so for all innovations. We further describe, in this paper, a fertiliser innovation where involvement appears low. We consider and contrast the different decision styles associated with high and low involvement. We then discuss the implications for identifying the market for low involvement agricultural innovations and for promoting the adoption of low and high involvement innovations in agriculture.

Mixed models incorporating the inverse of a numerator relationship matrix (NRM) are widely used to estimate genetic parameters and to predict breeding values in animal breeding. A simple and quick method to directly calculate the inverse of the NRM has been historically developed for diploid animal species. Mixed models are less used in plant breeding partly because the existing method for diploids is not applicable to autopolyploid species. This is because of the phenomenon of double reduction and the possibility that gametes carry alleles which are identical by descent. This paper generalises the NRM and its inverse for autopolyploid species, so it can be easily incorporated into their genetic analysis. The technique proposed is to first calculate the kinship coefficient matrix and its inverse as a precursor to calculating the NRM and its inverse. This allows the NRM to be calculated for populations containing individuals of mixed ploidy levels. This generalization can also accommodate uncertain parentage by generating the "average" relationship matrix. The possibility that non-inbred parents can produce inbred progeny (double reduction) is also discussed. Rules are outlined that are applicable for any level of ploidy.

Accurate pre-harvest estimation of avocado (Persea americana cv. Haas) yield offers a range of benefits to industry and growers. Currently there is no commercial yield monitor available for avocado tree crops and the manual count method used for yield forecasting can be highly inaccurate. Remote sensing using satellite imagery offers a potential means to achieve accurate pre-harvest yield forecasting. This study evaluated the accuracies of high resolution WorldView (WV) 2 and 3 satellite imagery and targeted field sampling for the pre-harvest prediction of total fruit weight (kg·tree⁻¹) and average fruit size (g) and for mapping the spatial distribution of these yield parameters across the orchard block. WV 2 satellite imagery was acquired over two avocado orchards during 2014, and WV3 imagery was acquired in 2016 and 2017 over these same two orchards plus an additional three orchards. Sample trees representing high, medium and low vigour zones were selected from normalised difference vegetation index (NDVI) derived from the WV images and sampled for total fruit weight (kg·tree⁻¹) and average fruit size (g) per tree. For each sample tree, spectral reflectance data was extracted from the eight band multispectral WV imagery and 18 vegetation indices (VIs) derived. Principal component analysis (PCA) and non-linear regression analysis was applied to each of the derived VIs to determine the index with the strongest relationship to the measured total fruit weight and average fruit size. For all trees measured over the three year period (2014, 2016, and 2017) a consistent positive relationship was identified between the VI using near infrared band one and the red edge band (RENDVI1) to both total fruit weight (kg·tree⁻¹) (R² = 0.45, 0.28, and 0.29 respectively) and average fruit size (g) (R² = 0.56, 0.37, and 0.29 respectively) across all orchard blocks. Separate analysis of each orchard block produced higher R² values as well as identifying different optimal VIs for each orchard block and year. This suggests orchard location and growing season are influencing the relationship of spectral reflectance to total fruit weight and average fruit size. Classified maps of avocado yield (kg·tree⁻¹) and average fruit size per tree (g) were produced using the relationships developed for each orchard block. Using the relationships derived between the measured yield parameters and the optimal VIs, total fruit yield (kg) was calculated for each of the five sampled blocks for the 2016 and 2017 seasons and compared to actual yield at time of harvest and pre-season grower estimates. Prediction accuracies achieved for each block far exceeded those provided by the grower estimates.

Estimates of technical inefficiency in agricultural production are suspect so long as variations exist in production technology among the sampled farmers. Traditional methods of dealing with these technological differences risk attributing "technology gaps" to technical inefficiency between farms, pointing to the need to undertake a metafrontier analysis that allows technology gaps to be distinguished from technical inefficiency. Using farm-level data on the production of three different varieties of pistachio trees in Iran, we outline two criteria to justify its use: an inability in farmers to switch between production technologies except in the long term, and satisfaction of statistical tests on metafrontier coefficients. The application of metafrontier analysis enabled technical efficiency scores to be corrected for differences in production capacity imposed by tree variety. Results reveal that there is very little difference in technical efficiency between farms growing the different tree varieties. But they show that ignoring the production constraints imposed by variety choice could overstate the scope for farmers to improve their technical performance by adopting better farming practices. The results also indicate that it is misleading to compare the performance of different tree varieties on the basis of yield per hectare alone.

Remote optical imaging can rapidly acquire information describing spatial variability in vineyard block performance. Canopy characteristics were derived from very high spatial resolution (0.25 m) optical imagery of a Cabernet Sauvignon vineyard acquired at various canopy growth stages. Within-season changes to correlation coefficients between vineyard canopy and ultimate composition and yield of harvested fruit were then investigated. Canopy area and density were observed to have significant relationships with yield and fruit quality indicators including berry size, anthocyanins and total phenolic content, but less significant relationships with total soluble solids. The strength and type of correlation varied with canopy growth stage. For anthocyanins and total phenolic content, correlations varied from non-significant before flowering to negative after flowering. For berry weight and yield, correlations varied from negative before flowering to positive after flowering. For total soluble solids, there were some significant relationships but no clear temporal pattern. The results confirm that remote sensing is a useful tool to determine spatial variability in fruit composition and yield. However, both the timing of image acquisition and the way in which canopy is quantified are important determinants of the direction and strength of correlations with fruit composition and yield.