Prevent Crop Loss Research Articles

Deep Metric Learning Based Citrus Disease Classification With Sparse Data

Early recognition of citrus diseases is important for preventing crop losses and employing timely disease control measures in farms. Employing machine learning-based approaches, such as deep learning for accurate detection of multiple citrus diseases is challenging due to the limited availability of labeled diseased samples. Further, a lightweight architecture with low computational complexity is required to perform citrus disease classification on resource-constrained devices, such as mobile phones. This enables practical utility of the architecture to perform effective monitoring of diseases by farmers using their own mobile devices in the farms. Hence, we propose a lightweight, fast, and accurate deep metric learning-based architecture for citrus disease detection from sparse data. In particular, we propose a patch-based classification network that comprises an embedding module, a cluster prototype module, and a simple neural network classifier, to detect the citrus diseases accurately. Evaluation of our proposed approach using publicly available citrus fruits and leaves dataset reveals its efficiency in accurately detecting the various diseases from leaf images. Further, the generalization capability of our approach is demonstrated using another dataset, namely the tea leaves dataset. Comparison analysis of our approach with existing state-of-the-art algorithms demonstrate its superiority in terms of detection accuracy (95.04%), the number of parameters required for tuning (less than 2.3 M), and the time efficiency in detecting the citrus diseases (less than 10 ms) using the trained model. Moreover, the ability to learn with fewer resources and without compromising accuracy empowers the practical utility of the proposed scheme on resource-constrained devices, such as mobile phones.

The impact of hemp (Cannabis sativa L.) plant density on critical period of weed control.

The impact of hemp (Cannabis sativa L.) plant density on critical period of weed control.

Infection with Spodoptera litura NPV Reduces Food Consumption and Weight Gain of Spodoptera litura Larvae

Insect-pathogenic baculoviruses have established potential as biological insect pest control agents. However, slow speed of kill relative to chemicals and continued feeding following application limit their effectiveness in preventing crop losses. Here we studied the food consumption and weight gain of the cotton leafworm Spodoptera litura following application of two viral doses of Spodoptera litura nucleopolyhedrovirus (Pakistan isolate SpltNPV-Pak-BNG). Infected larvae with final polyhedrosis (disease resulting in dissolution of larval tissues and accumulation of viral occlusion bodies) exhibited reduced food intake and weight gain relative to uninfected larvae. The unexposed larvae and the larvae that were exposed but survived exhibited the same food consumption and weight gain. This study did thus not reveal any sub-lethal effects of exposure to the virus on food consumption and weight gain. There was no viral dose dependency observed in food intake or weight gain by infected larvae, suggesting there is no increased crop damage upon virus treatment but rather a decrease to be expected.

Perspective of using fusariosis resistant varieties of lupines in organic farming

The expediency of fusarium resistant lupines usage in organic farming for improving soil fertility and producing high protein feed for livestock is justified in this article.
 Organic production excludes the use of mineral fertilizers and pesticides. In these circumstances, increases the value of cultures that positively affect the fertility of soils and their phytosanitary status. These crops include annual fodder lupine (yellow, white and angustifolia), especially varieties that are resistant to disease.
 Having the highest nitrogen-fixing ability among annual legume crops, lupins, depending on the type and conditions of cultivation, can accumulate from 80 to 300 kg/ha of environmentally pure symbiotic nitrogen in biomass. Plowing the green mass (30-45 t/ha) is equivalent to the corresponding amount of manure or introduction of 5-7 t/ha of ammonium nitrate. 30 kg/ha of phosphorus and 50 kg/ha of potassium are entering the soil with plant remains. Therefore, lupine provides itself with nutrients and still leaves up to 150 kg/ha of nitrogen in the soil after harvesting for subsequent crops in crop rotation.
 In organic production, fusariosis resistant varieties of lupines are also interesting as a source of high protein feeds for livestock. They are building up to 60 t/ha of biomass, which contains more than one ton of digestible protein. In grain of the fodder varieties contains 40-52% of crude protein, 5.5-6.0% of fat, 10-12% of sugar.
 The characteristic of fusarium resistant varieties of lupins (yellow, white and angustifolia), created in the NSC "Institute of Agriculture NAAS" and included in the Register of Plant Varieties of Ukraine is presented in this article. These varieties are practically not affected by fusariosis under the production conditions and do not require the use of fungicides during the growing season. They can be grown in crop rotation with a return period of 2-3 years, whereas for unstable it took 6-7 years. Because of the inability to use in organic farming fungicide to prevent crop losses from anthracnose, it is necessary to use predominantly angustifolia lupine varieties, which are now more tolerant to this disease, prevent sowing of infected seeds and adhere to crop rotation.
 Fusarium-resistant varieties of lupins are suitable for cultivation in poucous and sown crops, and in mixtures with other crops.

An NMRA-Like Protein Regulates Gene Expression in Phytophthora capsici to Drive the Infection Cycle on Tomato.

Phytophthora spp. cause devastating disease epidemics on important crop plants and pose a grave threat to global crop production. Critically, Phytophthora pathogens represent a distinct evolutionary lineage in which pathogenicity has been acquired independently. Therefore, there is an urgent need to understand and disrupt the processes that drive infection if we aspire to defeat oomycete pathogens in the field. One area that has received little attention thus far in this respect is the regulation of Phytophthora gene expression during infection. Here, we characterize PcNMRAL1 (Phyca11_505845), a homolog of the Aspergillus nidulans nitrogen metabolite repression regulator NMRA and demonstrate a role for this protein in progression of the Phytophthora capsici infection cycle. PcNmrAL1 is coexpressed with the biotrophic marker gene PcHmp1 (haustorial membrane protein 1) and, when overexpressed, extends the biotrophic infection stage. Microarray analyses revealed that PcNmrAL1 overexpression in P. capsici leads to large-scale transcriptional changes during infection and in vitro. Importantly, detailed analysis reveals that PcNmrAL1 overexpression induces biotrophy-associated genes while repressing those associated with necrotrophy. In addition to factors controlling transcription, translation, and nitrogen metabolism, PcNMRAL1 helps regulate the expression of a considerable effector repertoire in P. capsici. Our data suggests that PcNMRAL1 is a transcriptional regulator that mediates the biotrophy to necrotrophy transition. PcNMRAL1 represents a novel factor that may drive the Phytophthora disease cycle on crops. This study provides the first insight into mechanisms that regulate infection-related processes in Phytophthora spp. and provides a platform for further studies aimed at disabling pathogenesis and preventing crop losses.

Increasing efficiency of crop production with LEDs

Light-emitting diode (LED) technology is paving the way to increase crop production efficiency with electric lamps. Users can select specific wavelengths to elicit targeted photomorphogenic, biochemical, or physiological plants responses. In addition, LEDs can help control the seasonality of flowering plants to accurately schedule uniform flowering based on predetermined market dates. Research has shown that the monochromatic nature of LEDs can help prevent physiological disorders that are common in indoor environments, and help reduce incidence of pest and disease pressure in agriculture, which could ultimately increase crop production efficiency by preventing crop losses. Furthermore, a significant attribute of LED technology is the opportunity to reduce energy costs associated with electric lighting. Studies have shown that by increasing canopy photon capture efficiency and/or precisely controlling light output in response to the environment or to certain physiological parameters, energy efficiency and plant productivity can be optimized with LEDs. Future opportunities with LED lighting include the expansion of the vertical farming industry, applications for space-based plant growth systems, and potential solutions to support off-grid agriculture.

Weeds: reserves of parasitic phytonematode species populations

Purpose. Analysis of domestic and foreign literature on the role of alternative weed hosts of phytonematode families Heteroderidae and Meloidogynidae. Results. The nematodes of the Heteroderidae family can be hosted by 350 species of weeds from 40 families and 155 genera. Most of these weeds belong to five families: Chenopodiaceae (37 species from three genera), Solanaceae (44 species from 6 genera), Poaceae (47 species from 24 genera), Brassicaceae (67 species from 29 genera) and Fabaceae (85 species out of 25 genera) and have a total of 280 species of 87 genera. Weeds belonging to the families Lathurus (13 species), Vicia (15 species), Chenopodium (14 species) and Solanum (30 species) generally comprise 72 nematode host species. All other genera have fewer than 10 species of weed hosts. Nematodes of the Meloidogynidae family can be hosted by 994 weed species from 118 families and 487 genera. The greatest number of weeds that host parasitic nematodes belong to five families: Fabaceae (308 species), Asteraceae (267 species), Poaceae (8 species), Solanaceae (155 species) and Amaranthaceae (89) and among the families Solanum (61 species), Amaranthus (40 species), Trifolium (36 species), Nicotiana (30 species), Chenopodium and Euphorbia (each 28 species). Conclusions . In order to develop a joint strategy of effective protection of crops from weeds and parasitic nematode species, the biological and ecological characteristics of these harmful organisms should be thoroughly studied and the factors that would reduce their negative impact on plants and prevent crop losses to establish should be found.

Gradation of yellow mosaic virus disease of okra and bitter gourd based on entropy based binning and Naive Bayes classifier after identification of leaves

Crop diseases in India are a major concern in the field of agriculture today. Efforts are being made to tackle this problem as agriculture is an important aspect of our economy. Due to diseases, a major part of crops produced is lost every year. This is due to lack of expertise among the farmers, failing to detect and diagnose the disease correctly in time or due to commencement of control measure in late. To prevent crop loss, image processing for diagnosis of disease symptom using soft computing techniques is a need of modern day agriculture. In this study, initial focus was paid towards automatic identification of leaves between okra and bitter gourd from the images. To diagnose disease symptom from leaf images, forty-three morphological features of leaves of both the crops were chosen. The Pearson Correlation Coefficient technique was exercised to set key identifying features depending on a particular type of leaf image. Ten key morphological features of okra leaf and nine key morphological features of bitter gourd leaf were selected for the purpose. The proposed technique was experimented on 79 and 75 okra and bitter gourd leaf images, respectively. Finally Yellow Vein Mosaic Virus (YVMV) disease gradation was done based on entropy based binning and Naive Bayes classifier. The success rate of leaf identification was 96.78%.YVMV disease affected leaves were graded with a success rate of 95% for okra and 82.67% for bitter gourd.

SWAPDT: A method for Short-time Withering Assessment of Probability for Drought Tolerance in Camellia sinensis validated by targeted metabolomics

Climate change is causing droughts affecting crop production on a global scale. Classical breeding and selection strategies for drought-tolerant cultivars will help prevent crop losses. Plant breeders, for all crops, need a simple and reliable method to identify drought-tolerant cultivars, but such a method is missing. Plant metabolism is often disrupted by abiotic stress conditions. To survive drought, plants reconfigure their metabolic pathways. Studies have documented the importance of metabolic regulation, i.e. osmolyte accumulation such as polyols and sugars (mannitol, sorbitol); amino acids (proline) during drought. This study identified and quantified metabolites in drought tolerant and drought susceptible Camellia sinensis cultivars under wet and drought stress conditions. For analyses, GC–MS and LC–MS were employed for metabolomics analysis.%RWC results show how the two drought tolerant and two drought susceptible cultivars differed significantly (p≤0.05) from one another; the drought susceptible exhibited rapid water loss compared to the drought tolerant. There was a significant variation (p<0.05) in metabolite content (amino acid, sugars) between drought tolerant and drought susceptible tea cultivars after short-time withering conditions. These metabolite changes were similar to those seen in other plant species under drought conditions, thus validating this method. The Short-time Withering Assessment of Probability for Drought Tolerance (SWAPDT) method presented here provides an easy method to identify drought tolerant tea cultivars that will mitigate the effects of drought due to climate change on crop losses.

Going beyond sprays and killing agents: Exclusion, sterilization and disruption for insect pest control in pome and stone fruit orchards

Because of their perennial nature, orchards harbor one of the most complex ecosystems in agriculture. Nevertheless, crop protection programs still mainly focus on pesticides (synthetic or organic-approved) to prevent or limit the action of so-called noxious species in these systems. Killing agents represent the dominant paradigm and have been used in agriculture for decades. This paper synthesizes the available literature about the other approaches, more suited to organic farming, which recognize that the radicalness of killing is not necessary to prevent crop losses. Exclusion barriers represent one of the most readily available means of protecting the crop that way, but other behavior-based techniques have been developed, such as sterile insect technique and mating disruption. While there are many other possibilities, these are the three approaches that are currently getting the most interest in tree fruit production, due to ecological and agronomical characteristics, some of which will be detailed in this review.

Baseline sensitivity of Brazilian Mycosphaerella fijiensis isolates to protectant and systemic fungicides

Black Sigatoka caused by Mycosphaerella fijiensis is a foliar disease that affects banana plants and large amounts of fungicides are required to prevent crop losses. Intensive applications of single-site fungicides can select for fungicide-resistant isolates. The objective of this study was to assess the sensitivity of 60 isolates of M. fijiensis to commonly used fungicides. Using two different protocols, microtiter and Petri plate tests, the effective concentration at which mycelium growth is reduced by 50% (EC50) was determined for thiophanatemethyl, tebuconazole, chlorothalonil and mancozeb. Additionally, partial sequences of the cytochrome b gene were obtained for 46 isolates to detect the G143A mutation, commonly associated with strobilurin resistance. The EC50 values for tebuconazole and thiophanate-methyl ranged from 0.02 to 1.39 and from 0.008 to 8.22 µg mL-1, respectively. For chlorothalonil, the lowest and highest EC50 values were 0.39 µg mL-1 and 53.7 µg mL-1, respectively. For mancozeb, approximately 50% of the isolates had EC50 values greater than 1000 µg mL-1. No mutation was found in the isolates assayed for strobilurin resistance. There was no correlation between sensitivity levels to any fungicide and geographic region. Low EC50 values were estimated for most fungicides but, some isolates had high EC50 values for mancozeb.

The impact, uses, and ecological role of agrestals in two selected agroecosystems of Eastern India

Agricultural fields contain some small plants (weeds) which are known as agrestals. Generally, weeds are perceived as unwanted intruders in agro-ecosystems that compete for resources, reduce yields, and force the use of human labor and technology to prevent crop losses; but not all weeds are undesirable. Some weeds act as valuable agro-ecosystem components. They serve as nutritious foods, and important sources of fodder and medicine. Certain weeds may limit insect damage to crops. These beneficial effects indicate that weeds are not just agricultural pests, but can also play beneficial roles in the human society. So, the main objective of the study is to know about the beneficial agrestals of the district and their roles. Detailed field surveys were made in different blocks of the district to collect data about agrestals and their usefulness. These fields contain various medicinal plants such as Solanum nigrum L., Eclipta prostrata L. Oxalis corniculata L., Rungia pectinata L. etc., edible plant Amaranthus viridis L., ornamental plant Grangea maderaspatana (L.) Poir, and aromatic plant Trachyspermum copticum L. It is clear from the study that these two fields of the district contain some valuable agrestals which are used by the locals. Key words: Agrestals, agro-ecosystems, weeds, food, fodder, medicine, insects, society.

Wildlife or crop production: the dilemma of conservation and human livelihoods in Serengeti, Tanzania

Crop-raiding by wildlife is a common concern in areas where agriculture plays an important role for sustaining rural livelihoods. Different techniques have been used to prevent crop loss by wildlife. This study examined wildlife crop damage as reported and experienced by people in villages surrounding Serengeti National Park (SNP). The results showed that generally crop production was not the only important economic activity people relied on. We conclude that hunting could be an alternative to crop production. Furthermore, education, employment status, wealth, immigration status and location influenced crop production significantly. Perceptions towards problematic wildlife varied between districts, but small- to medium-sized wildlife were perceived most problematic to crop production. Furthermore, respondents identified climate change factors and inadequate agriculture extension services to affect crop production. The study proposes further development of income-generating activities such as beekeeping and ecotourism as alternatives to crop production. These natural resources-based activities address food insecurity and increase livelihood options. Compensation for extreme cases of crop destruction and improved capacity and delivery of extension services could make agriculture around Serengeti more sustainable.

The cucurbit downy mildew pathogen Pseudoperonospora cubensis.

Kingdom Straminipila; Phylum Oomycota; Class Oomycetes; Order Peronosporales; Family Peronosporaceae; Genus Pseudoperonospora; Species Pseudoperonospora cubensis. Angular chlorotic lesions bound by leaf veins on the foliage of cucumber. Symptoms vary on different cucurbit species and varieties, specifically in terms of lesion development, shape and size. Infection of cucurbits by Ps. cubensis impacts fruit yield and overall plant health. Sporulation on the underside of leaves results in the production of sporangia that are dispersed by wind. On arrival on a susceptible host, sporangia germinate in free water on the leaf surface, producing biflagellate zoospores that swim to and encyst on stomata, where they form germ tubes. An appressorium is produced and forms a penetration hypha, which enters the leaf tissue through the stomata. Hyphae grow through the mesophyll and establish haustoria, specialized structures for the transfer of nutrients and signals between host and pathogen. Management of downy mildew in Europe requires the use of tolerant cucurbit cultivars in conjunction with fungicide applications. In the USA, an aggressive fungicide programme, with sprays every 5-7 days for cucumber and every 7-10 days for other cucurbits, has been necessary to control outbreaks and to prevent crop loss. http://www.daylab.plp.msu.edu/pseudoperonospora-cubensis/ (Day Laboratory website with research advances in downy mildew); http://veggies.msu.edu/ (Hausbeck Laboratory website with downy mildew news for growers); http://cdm.ipmpipe.org/ (Cucurbit downy mildew forecasting homepage); http://ipm.msu.edu/downymildew.htm (Downy mildew information for Michigan's vegetable growers).

Phototransformation of imidacloprid on isolated tomato fruit cuticles and on tomato fruits

Imidacloprid, a neonicotinoid insecticide, is widely used in plant protection to prevent crop losses. The objective of this study was to show the photochemical fate of imidacloprid on plant surfaces by irradiation experiments on isolated tomato fruit cuticles and tomato fruits ( Lycopersicon esculentum Mill.). Imidacloprid spiked samples were irradiated both under sunlight simulator and natural sunlight conditions for 24 h, which resulted in recoveries of 23% and 24%, respectively, if isolated cuticles were studied. On whole tomato fruits, recoveries were 33% and 71%, respectively. Similar results were obtained on cuticles spiked with the formulation Confidor and irradiated under natural sunlight. However, on tomato fruits the application of Confidor resulted in a higher loss (56%) of imidacloprid. During all irradiation experiments both on cuticles and whole fruits, 1-[(6-chloropyridin-3-yl)methyl]imidazolidin-2-imine was generally formed at 10–14 mol%, but different other photoproducts were also detected in low amounts, whereas N-nitrosoimidacloprid was only detected under natural sunlight conditions. Rapid photodegradation of imidacloprid could be demonstrated in all experiments. The identified photoproducts, 1-[(6-chloropyridin-3-yl)methyl]imidazolidin-2-imine and N-nitrosoimidacloprid, are possible reaction partners for plant cuticle constituents to form cuticle bound residues.

Modeling Salt Accumulation with Subsurface Drip Irrigation Using HYDRUS‐2D

Salts that accumulate near the soil surface with subsurface drip irrigation (SDI) can hinder the establishment of succeeding direct‐seeded crops. To prevent crop loss or yield reduction, producers rely on sprinklers for germination, which is often expensive and requires added capital inputs. Predicting salt movement and accumulation with SDI will allow producers to anticipate the need for sprinkler irrigation for salt control. The HYDRUS‐2D model was used to model salt accumulation from an SDI system on successive crops of cantaloupe (Cucumis melo L. ssp. melo var. cantalupensis Naudin) and broccoli (Brassica oleracea L. var. italica Plenck) with two tape depths (18 and 25 cm), different germination practices (germination with SDI and with sprinklers), and water salinity (1.5 and 2.6 dS m−1). Predicted saturated‐paste electrical conductivity (ECe) values from HYDRUS‐2D were significantly correlated with actual ECe data obtained from field experiments (r2 = 0.08–0.93). After Season 1, the correlation coefficients were highly variable, with the majority of model ECe values being higher than field data. Season 2 results indicated a much stronger relationship, with R2 values as high as 0.93. Model predictions for Season 2 showed underprediction of ECe when compared with actual ECe. Relationships between model‐predicted ECe and actual ECe resulted in a slope of nearly 1.0 for all treatments and a y intercept close to −1 dS m−1 A better understanding of the processes that occur at the field scale, such as root growth, root distribution, and plant water uptake, is essential for modeling water and solute transport with SDI. A better characterization of evapotranspiration from SDI is required to accurately model salt accumulation.

Breeding Temperate Fruit Crops for Improved Freezing Tolerance

Low temperature is one of the most important environmental factors limiting crop plant growth, distribution, and productivity. New cultivars with improved freezing tolerance are a common breeding objective of many temperate fruit breeding programs. Improved freezing tolerance would prevent crop loss due to low temperature and reduce yearly fluctuations in crop quantity and quality. Breeding temperate fruit cultivars for improved freezing tolerance is made difficult by several factors, including complexity of the phenotype, difficulty in accurate measurement of the phenotype, and lack of fundamental knowledge concerning the inheritance and genetic control of this trait. Results from inheritance studies of freezing tolerance in temperate fruit crops as well as recent research in forestry genetics highlight some of the challenges and opportunities for further elucidating the inheritance of freezing tolerance in temperate fruit crops. A tremendous amount of research has been conducted describing the molecular biology and signal transduction of the cold acclimation response in the model plant, Arabidopsis thaliana. These findings have begun the transfer to research in agriculturally important crops and hold great promise for elucidating novel methods for generating new fruit cultivars with improved freezing tolerance.

Drawing lines and borders: how the dehiscent fruit ofArabidopsis is patterned

The advent of fruits marked a key innovation in the evolution of flowering plants and helped generate a diverse array of mechanisms for seed dispersal. In the model plant, Arabidopsis thaliana, seed dispersal occurs through a process known as "pod-shatter" in which the fruit structure falls to pieces upon light mechanical pressures. This dispersal mechanism is dependent on the careful patterning of tissues in the fruit, which perform diverse functions that enable the fruit to open at maturation. Using the genetic power of Arabidopsis, many of the molecular components that help specify these tissues have been identified. Studies of the interactions among these genes have revealed a regulatory network that limits processes such as cell-cell separation and lignification to discreet regions of the fruit. Knowledge of these processes in a model fruit creates a foundation on which to build an understanding of the evolution of fruit form in other species and provides tools to engineer shatter-resistant seed pods to prevent crop loss in plants of agronomic importance such as canola.

Effect of a Formulation ofBacillus thuringiensisBerliner var.kurstakionPodisus nigrispinusDallas (Heteroptera: Pentatomidae: Asopinae)

Pest control in agricultural crops is generally achieved by chemical pesticides which are effective and have a ‘knock-down’ effect on life stages of insects and mites. Recently, plant products have been experimented on in indoor cultivation and in fields. Water extracts (5–10%) of leaf or seed/kernel, crude oil (0.5–3%), and soil application of seed cake (2 t/ha) are used as traditional measures while essential oils, extracts in organic solvents, and formulations based on pure allelochemicals are marketed products. Neem (Azadirachta indica A. Juss.) derived products are applied extensively in agricultural crops, and other plants that are readily available locally are being exploited for their actions. The potential benefits are that they are economical, environmentally friendly, effective and of low toxicity to non-target organisms including humans. In the future, integration of plant products in pest management strategies would enhance sustainable organic agriculture and prevent crop loss in terms of both quality and production.

The operational planting stock quality testing program at Weyerhaeuser

The value of the Seedling Testing System (STS) is five-fold. First, it minimizes the utilization of poor quality stock that might result in regeneration failure. Second, it assists nursery managers in estimating cold hardiness of seedlings in support of the nursery frost control program. Third, it helps prevent crop losses due to pathological problems in the greenhouse and nursery. Fourth, it helps the nursery staff develop good working relationships with outside customers who benefit from the testing service. Fifth, it is a valuable tool for the nursery and tree improvement research program.