Blood disease in bananas caused by
subsp.
is a bacterial wilt causing significant crop losses in Indonesia and Malaysia. Disease symptoms include wilting of the plant and red-brown vascular staining, ...internal rot, and discoloration of green banana fruit. There is no known varietal resistance to this disease in the
genus, although variation in susceptibility has been observed, with the popular Indonesian cooking banana variety Kepok being highly susceptible. This study established the current geographic distribution of Blood disease in Indonesia and confirmed the pathogenicity of isolates by Koch's postulates. The long-distance distribution of the disease followed an arbitrary pattern indicative of human-assisted movement of infected banana materials. In contrast, local or short-distance spread radiated from a single infection source, indicative of dispersal by insects and possibly contaminated tools, water, or soil. The rapid expansion of its geographical range makes Blood disease an emerging threat to banana production in Southeast Asia and beyond.
The purposes of this study were (1) to assess the effectiveness of drought tolerance indices for selection of drought tolerance in upland rice, and (2) to identify the most suitable drought tolerance ...indices to select for drought tolerant, high yielding upland rice genotypes. This study employed a Split Plot design consisting of irrigation levels as the main plots, and rice genotype as the sub-plot treatments. There were three main plots: 100% field capacity (FC); 75% FC; and 50% FC level. The subplot treatments consisted of 40 upland rice genotypes. Grain yields under no-stress and stressed conditions were used to calculate drought tolerance indices. There were significant variations in grain yields and drought tolerance indices between different rice genotype treatments. The indices from the literature found to be most suitable for the selection of drought tolerant upland rice cultivars were STI, GMP, MRP, HARM, REI, ATI, YI, SNPI. Ten genotypes from among the 40 tested - namely HK-07, ADN-04, PMK-01, ADN-05, NGR-022, ALR-02, HK-06, and KMD-01 - were selected as combining drought tolerance with high yield potential.
Ecological intensification aims to reduce environmental costs of agricultural production by increasing biodiversity and using the associated ecosystem services instead of, or in combination with, ...external inputs, so that yields are maintained at high levels or increased. However, to date there are few measures available for which such benefits have already been demonstrated in the field.
In this study, the seeding pattern in winter wheat fields was manipulated to create a diversified crop architecture consisting of ‘unsown-rows’ and ‘densely-sown-rows’ in treatment fields in comparison to ‘conventionally-sown-rows’ in control fields to assess whether (i) in-field structural and microclimatic conditions are more heterogeneous in fields with manipulated crop architecture compared to conventionally managed fields, (ii) a change in crop architecture is related to higher species richness, activity density and altered body size distribution of carabid communities, (iii) this in turn increases natural pest and weed seed control, but (iv) does not lead to yield loss.
In-field structural and microclimatic conditions were more heterogeneous in treatment fields compared to control fields, which was associated with significantly increased body sizes of predatory carabids and a trend for increased predatory carabid species richness (in the ‘unsown-rows’ of treatment fields). These changes were related to significantly stronger pest suppression in the ‘densely-sown-rows’ of treatment fields compared to ‘conventionally-sown-rows’ in control fields, with 10 % higher experimental pest predation rates and 56 % reduced crop damage caused by cereal leaf beetles. Moreover, carabids known to consume weed seeds showed significantly higher activity densities in ‘unsown-rows’ compared to ‘conventionally-sown-rows’, which was related to significantly higher experimental weed seed predation in ‘densely-sown-rows’. Wheat yields were not significantly different in fields with or without manipulated crop architecture.
The results suggest that the simple measure of manipulating the seeding pattern in winter wheat fields creates a diversified crop architecture, thereby promoting carabid diversity and altering their community composition and activity density such that important ecosystem services are increased without yield losses. Thus, beyond fostering biodiversity, this measure has, although not directly tested here, the potential for being used for ecological replacement of pesticides through enhanced ecosystem services without entailing agronomic and economic disadvantages such as land opportunity costs or increased workload.
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•Manipulating crop architecture as new in-field measure for ecological intensification.•Easy applicability by simply closing some sowing coulters without reducing seed quantity.•Higher habitat heterogeneity in manipulated fields with different crop densities.•Changes in carabid communities were positively related to pest control services.•Potential to save pesticides without reducing wheat yield.
•Bird and hare densities increased over time in an ecologically improved landscape.•The major factor influencing species densities is the amount of high-quality habitat.•We conclude that 14% of ...arable farmland should be covered by high-quality habitat.
Causes for farmland bird declines are well studied, but on landscape level agri-environment schemes (AES) often show limited gains for biodiversity. We analysed population trends of nine farmland bird species and the brown hare in a Swiss arable landscape. Further, we focused on the impact of the quantity and quality of different ecological compensation area (ECA) options on densities of the study species, as well as on the extent of ECAs required on arable farmland to stop population declines of typical farmland species. Densities of bird species and hare counts were positively correlated with the quantity of ECAs and semi-natural habitat. However, effects of ECA options on birds and hares are species specific. The quantities of wildflower areas and semi-natural habitat strongly enhanced bird and hare numbers. The quality of the ECA options was also important, as densities were positively related to the amount of meadows of high ecological quality, but not to the amount of meadows of low ecological quality. To attain target densities, the required proportion of high-quality AES options and semi-natural habitat has to be at least 14%. This study provides evidence that intensively managed arable farmland can be improved for bird diversity and hare density by the Swiss AES. The amount of AES options of high ecological quality is of major relevance for nature conservation. We estimate that the amount of high-quality options and semi-natural habitats in the Swiss arable lowland must be four times higher than today's area to halt and reverse population declines of farmland species.
•Reintroduced grey partridges chose heterogeneous biodiversity promoting areas for breeding.•Heterogeneous land cover enhances habitat leading to greater hatching success.•Protecting nests with ...electric wire fences enhanced hatching success.•High proportions of heterogeneous land cover around the nest can compensate for nest fencing.
Throughout Europe ground-nesting farmland bird species are rapidly declining and have become a conservation concern. Intensive agriculture and high nest predation rates are major factors causing the decline. Species conservation efforts often focus on habitat enhancement to increase the quantity and quality of available habitat structures (habitat enhancement hypothesis) or active nest protection by fencing and predator control (predation mitigation hypothesis). Within the context of a reintroduction project of grey partridges (Perdix perdix) into two regions of Switzerland, we investigated breeding habitat preferences and hatching success in relation to properties of the habitat surrounding the nest. Then we tested whether predator exclusion by fencing can increase hatching success. The location and hatching success of 121 nests were observed by radio-tracking and available habitats in both regions were mapped. Grey partridges preferred nesting habitats in highly heterogeneous wildflower areas, which had been implemented as biodiversity promoting areas (BPA) and nest fencing significantly increased hatching success. Likewise, increased proportions of wildflower BPAs tended to enhance hatching success, which is probably related to higher availability of cover in these structures. Increasing proportions of cover vegetation around the nest had a positive effect on hatching success. Increasing the quality of rural habitats by providing heterogeneous habitat structures as well as reducing predator access to nests by fencing can increase hatching success in grey partridges and is likely to benefit other ground-nesting birds as well. In fact, high amounts of cover vegetation around the nest can compensate for nest fencing by hampering nest depredation.
•Farmers can enhance biodiversity with ecological compensation and in-field options.•Ecological compensation is associated with plant richness and butterfly abundance.•Farm settings (e.g. altitude) ...explain variation in grasshopper and bird diversity.•The effect of the biodiversity measures differed between species groups.•The result differs between biodiversity measures and species groups.
Despite the introduction of agri-environmental schemes, no general increase of farmland biodiversity in Europe has been observed. Farmers take decisions about the implementation of agri-environmental schemes at the farm scale, and it is thus highly relevant to assess the relationship between farm management and biodiversity at this scale to increase the effectiveness of agri-environmental schemes. The present study quantifies to what extent and with which practices farmers can influence biodiversity on their farm and to what extent conditions outside farmers’ control may mediate biodiversity.
We grouped 27 variables into four variable sets: (1) ecological compensation (mainly semi-natural habitats), (2) in-field options (e.g. no growth regulator, insecticide and herbicide treatment), and (3) farm characteristics, which can be influenced by farmers (e.g. land-use types) as well as (4) farm settings, which cannot be influenced by farmers (e.g. altitude). As biodiversity metrics, plant, grasshopper, butterfly and bird richness and abundance of farmland target species were assessed on 133 farms of the Swiss Central Plateau from 2009 to 2011. Variance partitioning and generalised linear mixed models were used to analyse the impact of each variable set on farmland species diversity.
Our results provide evidence that farmers can indeed positively influence biodiversity by ecological compensation and in-field options. The variables of the ecological compensation set explained the highest proportion in the variation of plant richness and butterfly abundance. We found a significant positive relationship between in-field options and plant abundance. Our study illustrated that the effects of biodiversity-related farming practices differ between species and biodiversity metrics. Conditions outside farmers’ control explained a high variation in grasshopper and bird diversity. One variable within the set of farm settings, the degree of consolidation, had a significant negative impact on five out of eight biodiversity metrics (plant, butterfly and bird richness; plant and bird abundance). We demonstrate that farmers can substantially enhance biodiversity on their farms and provide knowledge on how such biodiversity improvements can be achieved by farmers. Further, we highlight the value of new biodiversity-related management practices such as in-field options.
•Large loss of low-nutrient grassland over 22 years in an extant hotspot for agro-biodiversity.•Strong negative effects on biodiversity of “amelioration” projects indicated.•Preservation of fertile ...meadows used at low intensity (valuable for biodiversity; some extensification); large interchange with fertile meadows of high intensity.•Relevant data from a comparably large area for the further development of agro-policies.•Overall moderate abandonment, but affecting mainly parcels of high value for biodiversity.
Agricultural intensification has reached mountain areas with retardation. This development is worrying as it targets some of the last remaining strongholds of traditionally farmed land in central Europe which are important hotspots of biodiversity. However, large-scale documentations of changes in agricultural habitats are rare, but are needed to guide agricultural policy for the conservation of biodiversity.
We investigated vegetation changes of the agricultural landscape in a valley of the Alps (Engadin, a rather dry valley in Switzerland) between 1987/1988 and 2009/2010. In 58 plots (total area 1253ha) we recorded changes in vegetation types and the intensity of usage and we investigated correlations between these changes and site factors.
By 2009/2010, all unimproved vegetation types have lost 20% of the area they covered in 1987/1988. The loss was greatest in areas where new agricultural infrastructure/reallocation projects (“ameliorations”) had been realized. This observation illustrates the potentially devastating effect of such projects for farmland biodiversity.
Overall, intensively used fertile meadows (which are of limited nature value) have increased. The afflux came from the above mentioned unimproved grassland types, and not, as might be expected, from low-intensity fertile meadows (traditional hay meadows with a high nature value). In fact, the latter meadow type has seen a net gain from the intensively used fertile meadows (i.e. extensification). Both of these opposing processes (intensification and extensification) were subsidized by the government: money for infrastructure projects on the one hand and money for ecological compensation areas on the other hand.
Abandonment of farmland, unlike in some other regions in the Alps, is not a general problem in the Engadin, but it did reduce the area of xerotherm grassland by 19% and of nutrient-poor meadows by 8%. Grazing, which could prevent abandonment, increased during our study period, but was mostly of high intensity, thus was not optimal from a conservation point of view. Recent contracts for nature conservation are likely to help maintain mowing and extensive grazing management on marginal land.
The Engadin remains a biological hotspot and a beautiful landscape of high value for tourism. But these values are not secured as illustrated by the loss during the last 20 years. Thus, planers of irrigation and other infrastructure projects and decision-makers in general need to better incorporate both the extant nature values and their fragility into their planning.
•The CPS was developed as a new tool for assessing biodiversity.•The approach was tested on 133 typical lowland farms in Switzerland.•The CPS was correlated with farm-scale biodiversity.•The CPS ...score was found to be more suitable than other biodiversity predictors.
Farmland biodiversity has often been assessed, but seldom at the farm scale, although it is ultimately the farm level at which decisions are taken. Therefore, a credit point system (CPS) was developed based on 32 options known to enhance farmland biodiversity. It was verified whether the resulting CPS score and farm-scale biodiversity are correlated considering four indicator groups (plants, grasshoppers, butterflies and birds) on 133 farms in the Swiss lowland. We further compared the suitability of the CPS score in reflecting farm-scale biodiversity to three alternative habitat measures, i.e. the amount of ecological compensation areas (ECAs, i.e. agri-environment scheme options), ECAs with a high ecological quality and valuable semi-natural elements (SNEs).
Species richness and density of plants, grasshoppers, butterflies and birds were analysed, for ‘all species’, stenotopic farmland species and ‘red-listed’ species within each group, resulting in 19 biodiversity measures (dependent variables). Basic models were built, first without, then by including a range of environmental variables and compared to models expanded by the CPS score or one of the three habitat measures (ECAs, high-quality ECAs or SNEs). For each of the 19 biodiversity measures, the CPS score and the three habitat measures were ranked by how much their inclusion improved the basic model, to determine which measure best captured biodiversity at the farm scale.
We demonstrate that the CPS score reflects farm-scale biodiversity. For 13 out of 19 biodiversity measures, models including the CPS score performed better than those without. The CPS score was found to be the most suitable predictor for a fast and efficient assessment of farm-scale biodiversity, which makes it suitable for use in large scale agri-environment schemes.
Markus JER, Ndiwa ASS, Oematan SS, Mau YS. 2021. Variations of grain physical properties, amylose and anthocyanin of upland red rice cultivars from East Nusa Tenggara, Indonesia. Biodiversitas 22: ...1345-1354. Red rice is becoming more popular nowadays due to the increasing awareness of rice consumers on its health benefits. The demands for red rice are increasing but the supply is limited, thus, local red rice cultivars can be used to fill this gap. Optimal use of local rice germplasm requires a comprehensive evaluation of their traits, and the genotypes having the most desirable traits can be selected for direct use. Several upland red rice cultivars from East Nusa Tenggara Province have been evaluated for various traits while their grain properties are still unrevealed. Information on grain properties is important, both for consumer preference and rice breeders. This study aimed to elucidate the grain physical properties, amylose, and anthocyanin of upland red rice germplasm from ENT Province, and to identify genotypes with the most desirable characters for further employment. Eighteen rice genotypes were used in this study. They were cultivated in the field, and the harvested grains were analyzed in the laboratory. Both ANOVA and descriptive statistics were used for data analysis. Substantial variations were observed on all variables, except the chalky grain percentage. The kernel length of tested genotypes was classified as long, medium, and short while the kernel shapes were slender, medium, and bold. Most tested genotypes had high head rice percentage and low to medium percentages of large and small broken kernels. Chalky grain was almost absent. Amylose content ranged from 1.0% to 28% while anthocyanin was about 1.0 - 20 mg/100 g. The evaluated genotypes were clustered into three main groups. Percentages of large and small broken kernels, and amylose content were mostly responsible for the observed variations among the rice genotypes. The red rice genotypes were diverse in the studied characters, thus, those with desirable grain characters are useful for further development and utilization.
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