scholarly journals Emerging Viral Diseases of Tomato Crops

2010 ◽  
Vol 23 (5) ◽  
pp. 539-548 ◽  
Author(s):  
Inge M. Hanssen ◽  
Moshe Lapidot ◽  
Bart P. H. J. Thomma

Viral diseases are an important limiting factor in many crop production systems. Because antiviral products are not available, control strategies rely on genetic resistance or hygienic measures to prevent viral diseases, or on eradication of diseased crops to control such diseases. Increasing international travel and trade of plant materials enhances the risk of introducing new viruses and their vectors into production systems. In addition, changing climate conditions can contribute to a successful spread of newly introduced viruses or their vectors and establishment of these organisms in areas that were previously unfavorable. Tomato is economically the most important vegetable crop worldwide and many viruses infecting tomato have been described, while new viral diseases keep emerging. Pepino mosaic virus is a rapidly emerging virus which has established itself as one of the most important viral diseases in tomato production worldwide over recent years. Begomovirus species and other whitefly-transmitted viruses are invading into new areas, and several recently described new viruses such as Tomato torrado virus and new Tospovirus species are rapidly spreading over large geographic areas. In this article, emerging viruses of tomato crops are discussed.

Agronomy ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1152
Author(s):  
Rebekah Waller ◽  
Murat Kacira ◽  
Esther Magadley ◽  
Meir Teitel ◽  
Ibrahim Yehia

Recognizing the growing interest in the application of organic photovoltaics (OPVs) with greenhouse crop production systems, in this study we used flexible, roll-to-roll printed, semi-transparent OPV arrays as a roof shade for a greenhouse hydroponic tomato production system during a spring and summer production season in the arid southwestern U.S. The wavelength-selective OPV arrays were installed in a contiguous area on a section of the greenhouse roof, decreasing the transmittance of all solar radiation wavelengths and photosynthetically active radiation (PAR) wavelengths (400–700 nm) to the OPV-shaded area by approximately 40% and 37%, respectively. Microclimate conditions and tomato crop growth and yield parameters were measured in both the OPV-shaded (‘OPV’) and non-OPV-shaded (‘Control’) sections of the greenhouse. The OPV shade stabilized the canopy temperature during midday periods with the highest solar radiation intensities, performing the function of a conventional shading method. Although delayed fruit development and ripening in the OPV section resulted in lower total yields compared to the Control section (24.6 kg m−2 and 27.7 kg m−2, respectively), after the fourth (of 10 total) harvests, the average weekly yield, fruit number, and fruit mass were not significantly different between the treatment (OPV-shaded) and control group. Light use efficiency (LUE), defined as the ratio of total fruit yield to accumulated PAR received by the plant canopy, was nearly twice as high as the Control section, with 21.4 g of fruit per mole of PAR for plants in the OPV-covered section compared to 10.1 g in the Control section. Overall, this study demonstrated that the use of semi-transparent OPVs as a seasonal shade element for greenhouse production in a high-light region is feasible. However, a higher transmission of PAR and greater OPV device efficiency and durability could make OPV shades more economically viable, providing a desirable solution for co-located greenhouse crop production and renewable energy generation in hot and high-light intensity regions.


Plant Disease ◽  
2021 ◽  
Author(s):  
Richard Smiley

Root-lesion nematodes (Pratylenchus spp.) are parasites that invade and deteriorate roots, thereby reducing the efficiency of water and nutrient uptake. Pratylenchus neglectus and P. thornei are the two species that are most prevalent and cause reduced yields of rainfed wheat and barley in semiarid regions of the Pacific Northwest. They are particularly damaging where wheat and barley are produced without irrigation in areas receiving less than 450 mm (18 inch) of precipitation annually. This review is focused on the biology and management of P. neglectus and P. thornei in semiarid rainfed agriculture. Characteristics of climates, soils and crop production systems are described as a preface to constraints placed upon management options. Discussions include the economic importance, host ranges, and protocols for sampling and species identification. Discussion of disease management options include crop rotation, genetic resistance and tolerance, planting date, trap and biofumigant crops, crop nutrition, chemical and biological nematicides, and tillage. Predictions for rainfed agriculture in a period of changing climate are presented, as are suggestions for important areas of research including crop genetics, nematode testing and communication of results, Pratylenchus biology, mechanisms of resistance, the phytobiome, and closing the ‘yield gap’ between actual and attainable yields.


Author(s):  
A.N. Ignatov ◽  
V.V. Gritsenko ◽  
F.S. Dzhalilov

Анализ наиболее вредоносных вирусных фитопатогенов на предприятиях защищенного грунта показывает, что проникновение новых видов с семенами и готовой продукцией из других регионов и стран подвергает производство томата большому риску. Главная проблема выявления заражения длительный инкубационный период для вирусных болезней и необходимость инструментальных методов идентификации патогена. Достижения в области иммунологического и молекулярного анализа вирусов растений позволяют технически обнаруживать большое число новых видов и биотипов, сводя проблему диагностики к вопросу экономической целесообразности такого анализа. Для того, чтобы определить минимальный набор диагностируемых видов, необходимо оценить разнообразие вирусов, поражающих томат, и риск их распространения в тепличных хозяйствах Российской Федерации. Авторы анализируют ранее опубликованные данные по зараженности томата в мире и РФ для определения наиболее опасных вирусов, которые могут нанести существенный ущерб производству томата. Если учитывать число видов и наносимый ущерб, то на первых местах находятся ДНК-вирусы семейств Geminiviridae (включая род Begomovirus) и РНК-вирусы родов Tobamovirus, Cucumovirus и некоторых других. Среди вирусов с максимальным потенциальным риском бегомовирус желтой курчавости листьев томата (TYLCV). Проблемы, вызываемые бегомовирусами, в том числе TYLCV и его многочисленными локальными вариантами, связаны в первую очередь с распространением биотипа B табачной белокрылки. Он способен размножаться на широком круге растений и служит своеобразным аккумулятором вирусов может переносить около 100 различных видов. Вирус коричневой (бронзовой) морщинистости плода (ToBRFV, род Tobamovirus) был обнаружен в 2015 году в Иордании, и представляет значительный риск для всего производства томатов РФ. Поскольку противовирусные препараты недоступны, стратегии борьбы с ними основываются на генетической устойчивости растений, уничтожении переносчиков и на карантинных мерах по предотвращению заболеваний, а также на дезинфекции теплиц. Расширение международной торговли растительными продуктами повысило риск ввоза новых вирусов в растительные экосистемы с идеальными условиями для заражения растений, развития вирусов и их сохранения в течение круглого года. Изменение климатических условий может способствовать успешному распространению привнесенных вирусов и их переносчиков в экосистемы открытого грунта.Analysis of the most harmful viruses pathogenic for tomato in greenhouses shows that the spreading of new species occurs with seeds and fruits from other regions and countries, and exposes tomato production to a great risk. Long latent period for virus diseases and the need for instrumental methods of pathogen identification are the main problem for identifying the pathogen and source of infection, and decision making for its control Advances in the field of immunological and molecular analysis of plant viruses allow technically a detection of a number of virus species and biotypes, reducing the problem of diagnosis to the question of economic feasibility of such work. In order to determine the minimum set of diagnosed virus species, the diversity of viruses that infect tomatoes and the risk of their spreading in greenhouses in the Russian Federation as assayed. We analyzed some previously published data on tomato viruses across the world and the Russian Federation to determine the most harmful viruses that can cause significant damage to tomato production. Taking in account the number of species and the damage caused, the first places are hold by DNA viruses Geminiviridae (including genus Begomovirus), and RNA-virus genera Tobamovirus, Cucumovirus and some others. Among the viruses with the highest potential risk is the tomato leaf yellow curl virus (TYLCV). Problems caused by begomoviruses, including TYLCV and related species are primarily associated with the spread of the tobacco whitefly biotype B. It is able to reproduce on wide range of host plants and serves as reservoir of viruses it can a vector for about 100 species. Tomato brown rugose fruit virus (ToBRFV, genus Tobamovirus) was discovered in 2015 in Jordan, and represents a significant risk for the entire production of tomatoes in the Russian Federation. Antiviral pesticides are not available, and control strategies rely on genetic resistance or phytosanitary measures to prevent diseases, or on eradication of diseased crops and vectors, and greenhouses sanitation. Increasing international travel and trade of plant materials enhances the risk of introducing new viruses and their vectors into production systems. In addition, changing climate conditions can contribute to a successful spread of newly introduced viruses or their vectors to agro-ecosystems in areas that were previously free of those viruses.


Author(s):  
Daniel P. Roberts ◽  
Nicholas M. Short ◽  
James Sill ◽  
Dilip K. Lakshman ◽  
Xiaojia Hu ◽  
...  

AbstractThe agricultural community is confronted with dual challenges; increasing production of nutritionally dense food and decreasing the impacts of these crop production systems on the land, water, and climate. Control of plant pathogens will figure prominently in meeting these challenges as plant diseases cause significant yield and economic losses to crops responsible for feeding a large portion of the world population. New approaches and technologies to enhance sustainability of crop production systems and, importantly, plant disease control need to be developed and adopted. By leveraging advanced geoinformatic techniques, advances in computing and sensing infrastructure (e.g., cloud-based, big data-driven applications) will aid in the monitoring and management of pesticides and biologicals, such as cover crops and beneficial microbes, to reduce the impact of plant disease control and cropping systems on the environment. This includes geospatial tools being developed to aid the farmer in managing cropping system and disease management strategies that are more sustainable but increasingly complex. Geoinformatics and cloud-based, big data-driven applications are also being enlisted to speed up crop germplasm improvement; crop germplasm that has enhanced tolerance to pathogens and abiotic stress and is in tune with different cropping systems and environmental conditions is needed. Finally, advanced geoinformatic techniques and advances in computing infrastructure allow a more collaborative framework amongst scientists, policymakers, and the agricultural community to speed the development, transfer, and adoption of these sustainable technologies.


2021 ◽  
pp. 1-25
Author(s):  
Mandy Bish ◽  
Brian Dintelmann ◽  
Eric Oseland ◽  
Jacob Vaughn ◽  
Kevin Bradley

Abstract The evolution of herbicide-resistant weeds has resulted in the necessity to integrate non-chemical control methods with chemicals for effective management in crop production systems. In soybean, control of the pigweed species, particularly herbicide-resistant waterhemp and Palmer amaranth, have become predominant concerns. Cereal rye planted as a winter cover crop can effectively suppress early-season weed emergence in soybean, including waterhemp, when planted at a rate of 123 kg ha−1. The objectives of this study were to determine the effects of different cereal rye seeding rates (0, 34, 56, 79, 110, and 123 kg ha−1) on early-season waterhemp suppression and soybean growth and yield. Soybean was planted into fall-seeded cereal rye, which was terminated within four days of soybean planting. The experiment was conducted over the 2018, 2019, and 2020 growing seasons in Columbia, Missouri. Effects of cereal rye on early-season waterhemp suppression varied by year and were most consistent at 56 kg ha−1 or higher seeding rates. Linear regression analysis of cereal rye biomass, height, or stand at soybean planting showed inverse relationships with waterhemp emergence. No adverse effects to soybean growth or yield were observed at any of the cereal rye seeding rates relative to plots that lacked cereal rye cover. Result differences among the years suggest that the successfulness of cereal rye on suppression of early-season waterhemp emergence is likely influenced by the amount of waterhemp seed present in the soil seed bank.


Author(s):  
Gert Kootstra ◽  
Xin Wang ◽  
Pieter M. Blok ◽  
Jochen Hemming ◽  
Eldert van Henten

Abstract Purpose of Review The world-wide demand for agricultural products is rapidly growing. However, despite the growing population, labor shortage becomes a limiting factor for agricultural production. Further automation of agriculture is an important solution to tackle these challenges. Recent Findings Selective harvesting of high-value crops, such as apples, tomatoes, and broccoli, is currently mainly performed by humans, rendering it one of the most labor-intensive and expensive agricultural tasks. This explains the large interest in the development of selective harvesting robots. Selective harvesting, however, is a challenging task for a robot, due to the high levels of variation and incomplete information, as well as safety. Summary This review paper provides an overview of the state of the art in selective harvesting robotics in three different production systems; greenhouse, orchard, and open field. The limitations of current systems are discussed, and future research directions are proposed.


Agriculture ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 626
Author(s):  
Tinashe Zenda ◽  
Songtao Liu ◽  
Anyi Dong ◽  
Huijun Duan

Sulphur plays crucial roles in plant growth and development, with its functions ranging from being a structural constituent of macro-biomolecules to modulating several physiological processes and tolerance to abiotic stresses. In spite of these numerous sulphur roles being well acknowledged, agriculture has paid scant regard for sulphur nutrition, until only recently. Serious problems related to soil sulphur deficiencies have emerged and the intensification of food, fiber, and animal production is escalating to feed the ever-increasing human population. In the wake of huge demand for high quality cereal and vegetable diets, sulphur can play a key role in augmenting the production, productivity, and quality of crops. Additionally, in light of the emerging problems of soil fertility exhaustion and climate change-exacerbated environmental stresses, sulphur assumes special importance in crop production, particularly under intensively cropped areas. Here, citing several relevant examples, we highlight, in addition to its plant biological and metabolism functions, how sulphur can significantly enhance crop productivity and quality, as well as acclimation to abiotic stresses. By this appraisal, we also aim to stimulate readers interests in crop sulphur research by providing priorities for future pursuance, including bettering our understanding of the molecular processes and dynamics of sulphur availability and utilization in plants, dissecting the role of soil rhizospherical microbes in plant sulphur transformations, enhancing plant phenotyping and diagnosis for nutrient deficiencies, and matching site-specific crop sulphur demands with fertilizer amendments in order to reduce nutrient use inefficiencies in both crop and livestock production systems. This will facilitate the proper utilization of sulphur in crop production and eventually enhance sustainable and environmentally friend food production.


2020 ◽  
Vol 98 (Supplement_4) ◽  
pp. 184-185
Author(s):  
Caleb M Shull

Abstract Swine producers in the U.S. face a significant challenge. On top of the ever-changing market dynamics that lead to wide swings in profitability or loss, is an underlying issue of pig mortality that the industry must address. While significant improvements in total piglets born per litter have been achieved over the last 10 years, pig mortality has seen no improvement or has worsened (Figure 1). When expressed as a percentage of piglets born (excluding mummies), a total of 7.9% were recorded as stillborn and 13.4% died prior to weaning in 2019. Assuming a typical mortality range of 7–10% from weaning to harvest, a typical U.S. producer could expect to lose around 27–30% of all piglets born. In addition, the average producer had around 12% annual sow mortality (Figure 1). Litter size and post-weaning growth rate and feed efficiency will always factor heavily into research priorities due to the economic impact associated with those traits; however, the opportunity to drive value through reduction in pig losses across the production cycle is staggering. In defense of the industry, improving pig survival is not an easy task for a number of reasons. The sample size (i.e., number of pigs) required to do mortality research correctly is often a limiting factor for many production systems. Furthermore, a cross-functional approach is likely required to make significant improvements in mortality. Specifically, the relationship between genetics, health, and management practices warrant consideration. Recent collaboration across the industry to improve mortality is a positive step forward and this collaboration should continue moving forward.


2006 ◽  
Vol 7 (1) ◽  
pp. 29
Author(s):  
S. N. Rampersad

Tomato production in Trinidad has suffered considerable losses in yield and fruit quality due to infections of hitherto surmised etiology. In order to develop strategies for controlling viral diseases in tomato, the relative distribution and incidence of seven viruses that commonly infect tomato were determined. Of the 362 samples tested, Potato yellow mosaic Trinidad virus (PYMTV) was found in every farm except two and was present at relatively high incidence throughout the country. Tobacco mosaic virus (TMV) and Tobacco etch virus (TEV) were found in fewer farms and at lower incidences while the other viruses were absent. Single infections of either virus were more common than double infections and multiple infections were rare but present. The results indicated that PYMTV is the predominant and most important viral pathogen in tomato production systems in Trinidad; however, begomovirus disease management strategies will also have to accommodate controls Accepted for publication 10 January 2006. Published 9 March 2006.


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