Sugar Beet Crops Research Articles

Diagnostic Guide for Alternaria Leaf Spot on Sugar Beet, Red Beet, and Chard

Alternaria leaf spot, caused by Alternaria spp., is a common foliar disease of sugar beet and other Beta vulgaris crop types. Known to be present in the United States since at least the 1950s, this disease has been found in all major sugar beet growing regions of the United States as well being reported as present everywhere beets are grown. Alternaria leaf spot symptoms are similar to several other common foliar diseases of beets including Cercospora leaf spot and the early stages of Phoma leaf spot. Symptoms and signs of this disease in the field do not provide enough information to help distinguish between diseases unless the viewer is readily familiar with the pathogen, especially when viewed with the unaided eye. Alternaria cultures can be identified to species using colony and conidial morphology on select culture media or using molecular markers. While not as common as Cercospora leaf spot, Alternaria leaf spot can result in significant reductions in yield and quality when not managed.

СЕЛЕКЦІЙНА СПРАВА УКРАЇНИ: ОСНОВНІ НАПРЯМКИ, ЗАВДАННЯ ТА ЗДОБУТКИ (НА ПРИКЛАДІ ДЕЯКИХ ЗЕРНОВИХ ЗЛАКОВИХ І ТЕХНІЧНИХ КУЛЬТУР)

The agricultural sector constitutes gross share of Ukraine’s economy. Throughout the history of our country, the most common types of cereals have been wheat and rye. From the 19th century a significant percentage of crop acreage has carried a crop of sugar beet. In the 20th century domestic crop breeders have bred a number of high-yielding varieties of cereals and industrial crops having good indicators. However, at the end of the last century, the crop breeding business, as well as the agricultural complex in general, was in crisis, from which it began to emerge only in recent decades. Therefore, studying the history of this science and the achievements of scientists is an important factor in overcoming the crisis in this field. It will also allow us to better understand the importance of grain and industrial crops for Ukraine. The main purpose of this paper is to characterize the stages of cereals and industrial crops selection based on the analysis of sources and literature. The paper also aims at defining the basic trends of research and tasks in this field. In the process of writing the publication were used general methods (analysis, comparison, synthesis, generalization) and general history (historical-chronological, historical-genetic, historical-comparative, historical-systemic). The Article covers the history of selection work regarding the main cereal crops of Ukraine – wheat, rye, oats. It also covers one technical crop – sugar beet. The main emphasis is placed on the areas and key tasks that arose before scientists in the course of their work. The emphasis is made on the most common varieties of these crops. The publication describes the requirements for each of the presented crops, which are based on the cultivation of universal and high quality material. First of all, it is a selection to increase productivity, tolerance for winter conditions, drought hardness, grain quality, resistance to adverse pests and diseases, suitability for mechanized cultivation technology and other characteristics.

ЗАСОРЕННОСТЬ И УРОЖАЙНОСТЬ САХАРНОЙ СВЕКЛЫ ПРИ РАЗЛИЧНЫХ СПОСОБАХ УХОДА ЗА ПОСЕВАМИ

In field experiments carried out in the conditions of the forest-steppe of the Middle Volga region, the influence of various methods of caring for crops on the productivity of sugar beet was studied. For the period from 1998 to 2018.weed infestation of sugar beet crops increased from 52.5% to 55.3%, while the number of all root weeds increased from 1.1 to 6.1 pcs/m2, and sow thistles and plume thistles - from 3.20 to 7.05 pcs/m2. It was noted that at the beginning of the growing season, the number of weeds increased sharply (by 2.8 times) from the phase of mass shoots of the crop to the beginning of the closing of leaves in the inter-row spaces, then the rate of emergence of new weeds decreased, and starting from the phase of opening the rows of sugar beet it increased again (by 1, 3 times).Сounting the number of weeds made it possible to establish that the implementation of three chemical treatments leads to an increase in the number of weeds by the time sugar beets are harvested. If in the initial period of sugar beet growth the number of weeds in the variant with three inter-row treatments was more than 90 pcs/m2, in the case of chemical treatments it was more than 60 pcs/m2, then the opposite was observed during the harvesting period. As a result of the research, it was found that the highest yield of root crops was obtained during three herbicidal treatments.

Profitability of Sugar Beet Crop in Campaign 2019/2020

The work presents a complex analysis and cost accounting of beet sugar cultivation in the 2019/2020 campaign for individual farms of the Lublin region. About 119 farms were analyzed. On the basis of this analysis, the criteria for the model farm were defined, which were adapted for the calculation of sugar beet production costs. The economic results obtained by the producers are mainly affected by indirect costs accounting for 60.48% of the revenue from the total production. Within this group of costs, the major components are sowing service, harvest and soil liming operations reaching 39.26%. Sugar beet production in the analyzed campaign was profitable, with the profitability index 1.21 and unit production cost of 15.07 PLN/dt. Sugar beet growing is considered to be one out of profit-making activities, in agricultural production, yet it is characterized by the high production cost that gobbled up 82.48% of total revenue in the analyzed campaign of 2019/20.

Productivity of sugar beets and winter wheat depending on tillage systems and crop rotation protection

Purpose. Establish the impact of basic tillage and weed protection measures on soil density in winter wheat and sugar beet crops. Investigate the criteria for the formation of winter wheat and sugar beet productivity depending on weather conditions, measures of basic tillage and protection against weeds.
 Methods. Field, laboratory.
 Results. Soil density for the period of winter wheat harvesting for plowing to a depth of 20–22 cm and direct sowing was in the same range at the level of 1.22 and 1.23 g/cm3, which can be explained by the peculiarity of the soil and the root system of the plants themselves. In sugar beet crops, the combination of plowing to a depth of 25–27 cm with subsequent shelfless loosening at 34–36 cm makes it possible to maintain the density of the arable soil at the level of equilibrium for this type of soil. In other treatments, the soil density increases to 1.27 and 1.28 g/cm3, with compaction of the upper 0–10 cm layer of soil to 1.25 g/cm3 for plowing by 30–32 cm and 1.29 g/cm3 – for shelf-free loosening by 34–36 cm, which has a negative impact on the productivity of sugar beets.
 Conclusions. With the optimal sowing period for the conditions of Kyiv region on September 12–15, the most optimal sowing rate remains 4.5 million units. nas./ha, for increase in density of standing of plants we note lodging of plants and damp years and essential shortage of grain in arid. According to our research, the main tillage for winter wheat plowing by 20–22 cm remains the most rational for obtaining stable yields of winter wheat (yield was 5.03 t/ha). At the same time, good predecessors of peas for grain, rape, buckwheat can be used direct sowing with the introduction of herbicide continuous action Roundup, 48% v.r. 3.0 l/ha. The highest productivity of sugar beets was obtained by using the main tillage plowing by 25–27 cm + shelfless loosening by 34–36 cm yield of root crops at the level of 52.13–51.73 t/ha, sugar content – 14.80–14.83%, sugar harvest – 7.73–7.81 t/ha. On deep medium loam chernozems, this tillage allows to ensure optimal agrophysical indicators of the soil, remove the plow sole, earn crop residues and ensure yields in arid conditions. Application of sugar-free loosening to sugar beets to a depth of 34–36 cm reduces the yield of root crops by 5.32 and 7.20 t/ha compared to plowing to a depth of 30–32 cm, which is associated with an increase in weediness of crops and soil density.

Differences in biological efficiency of one- and two-component graminicide on sugar beet crops in Tula region

One of the most urgent tasks in sugar beet production for Russia today is irregularities in cultivation technology and a low-efficiency crop protection. It leads to a high level of weed infestation of agricultural fields. Developing and identifying the most efficient, selective and accessible herbicides, which have low phytotoxicity, do not have a negative effect on soil chemical characteristics and can be used in sugar beet cultivation is relevant today. The aim of this study was to examine and compare biological efficiency of various doses and concentrations of one- and two-component graminicides on sugar beet crops against the following weeds: Cockspur grass Echinochloa crusgalli (L.) Beauv., Wild millet Setaria glauca (L.) Beauv. and Couch Grass Elytrigia repens (L.) Nevski. The experiment was conducted on the territory of the Tula region in 2020. The total field experiment area was 480 m2. Application of clethodim + quizalofop-P-ethyl (0.5 l/ha) resulted in reducing the number and weight of annual weeds by 6471 %, reducing the number and weight of perennial weeds by 5458 %, which had the same efficiency as clethodim (0.6 l/ha). The efficiency of clethodim + quizalofop-P-ethyl (1.0 l/ha) was higher than Clethodim (0.6 l/ha) and amounted to 7387 % of reduction in the number of weeds compared to the control, but was lower than Clethodim (1.8 l/ha), which resulted in 8995 % reduction in the number of weeds compared to the control. The highest sugar beet yields were obtained in the variants with clethodim (1.8 l/ha) and two-component herbicide (1 l/ha), which amounted to 28 and 25 % yield increase, in comparison with the control.

Agroecological Bases of Sustainable Development Strategy for the Rural United Territorial Communities of the Western Polissya Region

The article considers the influence of agroecological indicators on the sustainable development of the rural united territorial communities of the Western Polissya region (Ukraine) based on the current state analysis of crop production. To study the state of crop production and determine its role in the development of rural areas of the Western Polissya region, the authors used their field research, as well as data from the Main Departments of Statistics in Rivne and Volyn regions, the State Statistics Service of Ukraine, statistical collection “Crop Production of Ukraine” (2018). The following methods were applied throughout the research process: system analysis, comparison, graphical and statistical methods. The development of crop production was assessed taking into account the dynamics of the following indicators: sown areas of crops (thousand hectares), production volume (gross harvest) of crops (thousand centners), crop yields (thousand hectares-1), sown areas of crops in enterprises and households on the territory of the Western Polissya region in terms of Rivne and Volyn regions for the period from 1995 to 2019. During the study period, changes in the ratio of areas between different crops were discovered: a decrease in the sown area of sugar beet, fruit and berry crops, cereals and legumes, and an increase in sunflower, vegetable crops, etc. An increase in crop yields and a slight decrease in gross harvest were established only for sugar beet in the two regions and fruit and berry crops in the Volyn region. In the region, 51.6% of the sown area of crops is accounted for by households that supply the market with products included in the consumer basket of ordinary citizens: roots and tubers, vegetables, and melons. Enterprises are focused on growing profitable crops (technical, grain, and legumes) for export

DEVELOPMENT OF A DEVICE FOR INTRODUCING HERBICIDES INTO THE PROTECTIVE ZONE ROWING INTO THE EFFICIENCY OF THEIR APPLICATION FOR SUGAR BEET

This article examines the effectiveness of the use of post-emergence herbicides on sugar beet crops. The technology of cultivation with three-fold application of herbicides is presented. A comparison of the recommended technology of chemical weeding with the investigated scheme is given and a technical means for its implementation is presented.

Cys-SH based quantitative redox proteomics of salt induced response in sugar beet monosomic addition line M14

BackgroundSalt stress is a major abiotic stress that limits plant growth, development and productivity. Studying the molecular mechanisms of salt stress tolerance may help to enhance crop productivity. Sugar beet monosomic addition line M14 exhibits tolerance to salt stress.ResultsIn this work, the changes in the BvM14 proteome and redox proteome induced by salt stress were analyzed using a multiplex iodoTMTRAQ double labeling quantitative proteomics approach. A total of 80 proteins were differentially expressed under salt stress. Interestingly, A total of 48 redoxed peptides were identified for 42 potential redox-regulated proteins showed differential redox change under salt stress. A large proportion of the redox proteins were involved in photosynthesis, ROS homeostasis and other pathways. For example, ribulose bisphosphate carboxylase/oxygenase activase changed in its redox state after salt treatments. In addition, three redox proteins involved in regulation of ROS homeostasis were also changed in redox states. Transcription levels of eighteen differential proteins and redox proteins were profiled. (The proteomics data generated in this study have been submitted to the ProteomeXchange and can be accessed via username: reviewer_pxd027550@ebi.ac.uk, password: q9YNM1Pe and proteomeXchange# PXD027550.)ConclusionsThe results showed involvement of protein redox modifications in BvM14 salt stress response and revealed the short-term salt responsive mechanisms. The knowledge may inform marker-based breeding effort of sugar beet and other crops for stress resilience and high yield.

Elucidation of genetic diversity among some accessions of sugar beet (Beta vulgaris L.) using inter-simple sequence repeats (ISSR) markers

BackgroundSugar beet is considered a very important strategic economic crop, as it comes at the second place for white sugar production in Egypt after sugar cane and the sugar percentage in its roots is 20%. This work was conducted in Egypt as a direct response to bridge the gap which began to expand significantly between the production and consumption of white sugar and the desire for the genetic improvement process to increase the productivity of this crop. Further, as serious attempt to understand the nature of the genetic diversity among a group of sugar beet accessions with different origins, it constitutes an important source for establishing a program of breeding and improving sugar beet crop under Egyptian conditions.ResultsThe process of verifying the existence of significant genetic variation between the eight sugar beet varieties with various origins was carried out through a set of genetic parameters through two growing seasons besides, the data of ISSR markers profile. Further, all the sugar beet varieties were superior in all the studied traits during their evaluation over two agricultural years, where the two sugar beet accessions Oscar Poly and Rass Poly are superior in TSS % and sucrose % traits, Mont Bianco and Sultan in apparent purity % trait, Blino and Sultan in root yield and top yield traits and Rass Poly and Blino in sugar yield trait, respectively. In addition, the values of heritability in broad sense were high in all studied traits except the two traits; sucrose % and sugar yield where their results were appeared medium during both growing seasons. In the same regard, expected genetic advance values showed significant genetic progress in all studied traits during the two growing seasons. As well, highly genetic diversity was obtained between the eight sugar beet accessions through generated 169 amplified fragments from the twelve ISSR primers, 122 of them were polymorphic with 72.18% polymorphism.ConclusionsThe eight sugar beet varieties achieved remarkable and distinctive results for all traits under study during two agricultural years. However, they were differentiated and various from each other. As they differed in their superiority in all estimated traits and they proved to be fertile material for studying in this investigation and very suitable for enriching the breeding and genetic improvement program to promote the sugar beet yield in order to increase the productivity of white sugar in Egypt.

Some ecological studies on sugar beet crop insects in Kafr El-Sheikh and Nubaria regions

The present studies were conducted at the experimental farms in Agricultural Research Stations of Kafr El-Sheikh and Nubaria regions during two seasons (2019/2020 and 2020/2021) to survey the insect pests and predators that inhibiting sugar beet crop, and to study the seasonal abundance of main insect pests in such crop, and to evaluate the impact of some climatic factors in both regions on the seasonal abundance of some serious insects. Survey studies revealed that sugar beet plants attacked by 45 insect species: 15 of them were accidently visitors. In addition, ten predator species were recorded during the period extended from October until April in both regions during the two seasons. Spodoptera littoralis larvae gave the highest monthly average in December, while Pegomyia mixta larvae recorded the highest monthly average numbers in February and March in Kafr El-Sheikh and Nubaria regions in both seasons. On the other hand, the highest monthly average numbers of Cassida vittata adults were recorded in April in Kafr El-Sheikh region but in February-March in Nubaria region, during both seasons. Scrobipalpa ocellatella appeared with the highest monthly average only in April of both seasons in Kafr El-Sheikh. Whereas, itdoesn’t exist in Nubaria region. Results revealed that effects of the three weather factors (temperature, relative humidity and wind speed) were non-significant during the two seasons in both regions. I could be concluded that sugar beet plants that cultivated Nubaria region received less numbers of insect species than that cultivated in Kafr El-Sheikh region, and given that the sugar beet crop is considered a reclamation crop for new lands, so it must be reassurance in its cultivation due to the lack of insect infestation as well.

Response of Productivity and Quality of Sugar Beet Crop to Different Nitrogen and Potassium Fertilizer Levels in Sandy Soils

Response of Productivity and Quality of Sugar Beet Crop to Different Nitrogen and Potassium Fertilizer Levels in Sandy Soils

Sugar beet root rot loss: ANN and Regression models

Root rot diseases of sugar beet resulted by Rhizoctonia solani, Pythium aphanidermatum can arouse significant losses in sugar beet crops. Simple and accurate statistical techniques are essential to predict sugar beet yield loss as an industrial crop for agricultural management specialists. The objectives of the present study were to compare: (1) the prediction capabilities of different statistical models at several regions and cultivars, (2) the effectiveness of artificial neural network (ANN) models to predict root rot yield loss, and (3) the effectiveness of simple and multiple linear regression models compare to ANN models. In order to measure crop loss, during two consecutive growing seasons, eleven different sugar beet cultivars were planted in the infected fields in Qazvin, Torbate Jam, Urmia and Kermanshah regions in Iran. To calculate the crop loss, the correlation between Disease incidence (DI) and the important components was considered. The highest correlation (P ≤ 0.01) was observed between DI and Root yield (RY), so we developed different yield loss models. Consequently, the best-fitted simple regression model obtained for RC01 and Urmia with 94.51 % and 90.44 % R-squared, respectively. Then the proper parameters specified in the regression models considered to develop an ANN model using Matlab software to predict the yield loss. Interestingly, obtained ANN models resulted in R2, RMSE of 87.07 %, 5.01 and the lowest AIC vs. 86.78 % and 6.033 for final linear regression, respectively. Our results suggest that, based on the simplicity of the model, simple linear regression is the best model although the artificial neural network models are more accurate for prediction.

Application of a Growth Regulator Based on 24-Epibrassinolide in Sugar Beet Cultivation Technology

To suppress weeds in the crops of sugar beets, 2 to 5 treatments with herbicides are carried out, which worsens the quality of the resulting plant products and increases the risk of the formation of populations of weeds resistant to herbicides. To reduce the application rate of the herbicide in sugar beet crops, growth regulators based on the active ingredient–24–epibrassinolide were used, which increases the culture’s resistance to unfavorable environmental factors. It has been experimentally shown that the use of a growth regulator in a tank mixture with a 23% lower rate of herbicide applicaition in the growth phase of a BBCH 12–14 crop increased the herbicidal effect and promoted active growth of the crop. This technique had a positive effect on the quantity and quality of the sugar beet root crop. A statistically significant effect is shown from the use of 24-epibrassinolide in a tank mixture with a fungicide, as a result of which an increase in the adaptive potential of a cultivated plant against fungal diseases (the causative agent of micromycetes Cercospora beticola, Phoma betae) was observed.

New ways to control the development of sugar beet leaf pathogens

Increasing the yield of sugar beet is a strategic goal of modern agricultural production. The area under crops in the south of Russia makes it possible to fully provide sugar production with raw materials. However, changes in climatic conditions in recent years have a negative impact on plants development. Extreme conditions of 2020, when dust storms gave way to torrential rains, contributed to the repeated reseeding of the culture. Sugar beet is a demanding crop. Production efficiency is possible with the right combination of breeding, seed and plant protection. Sugar beet leaf diseases negatively affect the formation of quality indicators. The article presents research results of effectiveness of using new fungicides on sugar beet crops based on active substances from chemical classes: triazoles, strobilurins and carboxamides, under irrigation conditions.

Addition biochar to enhanced soil quality and sugar beet crop grown under water stress treatments in salt-affected soils

Addition biochar to enhanced soil quality and sugar beet crop grown under water stress treatments in salt-affected soils

Effect of Nitrogen Fertilizer and Plant Spacing on Vegetative Growth of Sugar Beet (Beta vulgaris)

Despite the existing several Sugar manufacturing companies in Sudan, there is an acute shortage in sugar supply, therefore the government imports Sugar to bridge the gap. One of the strategies to be followed is the introduction of Sugar beet (Beta vulgaris) crop, mainly for sugar production. This crop has several advantages over Sugarcane such as short duration, less water requirement, in addition to other uses like animal feed. Therefore it became necessary to have good understanding of agricultural operations, cultural practices and adaptation. However, the main objective of this study was to assess the effect of Nitrogen fertilizer and plant spacing on vegetative growth of Sugar beet. This study was conducted at the farm of the College of Agriculture, University of Bahri, Alkadro, Khartoum State-Sudan; during the season 2016/2017. The experiment was arranged in Split plot in Randomized Complete Block Design with six treatments and four replications. Two plant spacing (15 and 20 cm.) were used as main plot, referred as (S1, S2) along with three levels of Nitrogen fertilizer (40, 80 and 120 kg/ha.), as subplot; referred as (N1, N2 and N3) and the control (0). Data regarding leaf number, leaf area index (LAI), leaf dry weight (g) (LDW), root diameter (mm.) and root fresh weight were recorded and statistically analyzed. The results showed S2 (20 cm) increased all the studied plant characters, namely the leaf number (29.139), leaf area index by (7.54), leaf dry weight (g) to (89.870), root diameter (mm) (94,992), root fresh weight (g) (695.80) compared to S1(1015 cm). On the other hand; the application of N3 (120 kg/ha.) increased the lead number (30.956), leaf Area Index (8.841), Leaf dry weight (102.47), root diameter (97.955) and root fresh weight (851.77) compared to S2 and S1 as presented in (table 4, table 5 and table 6).

Improving weed segmentation in sugar beet fields using potentials of multispectral unmanned aerial vehicle images and lightweight deep learning

In our study, a real-world application using the latest unmanned aerial vehicle (UAV) functionality is presented. Sugar beet is an important industrial crop in many countries. According to estimates, weeds in sugar beet fields dramatically reduce both the quantity and quality of sugar beet crops. Due to the spectral similarities between weeds and sugar beet seedlings, visual identification of weeds is extremely difficult in the sugar beet fields. In the present study, a lightweight, end-to-end trainable guided feature-based deep learning method, called DeepMultiFuse, has been developed to improve the weed segmentation performance using multispectral UAV images that aim to fulfill these requirements (to identify weed in sugar beet fields). The proposed architecture is composed of five basic concepts, including guided features, fusion module, dilation convolution operation, modified inception module, and gated encoder–decoder network extracting the object-level image representation for different scenes. The proposed network was trained on the generated dataset, including four multispectral orthomosaic reflectance maps using the RedEdge-M sensor in Rheinbach and three multispectral orthomosaic reflectance maps applying Sequoia sensor in Eschikon for mapping weed segmentation on the field. Experimental results demonstrated that the proposed network taking advantage of the feature fusion module-rich features outperforms state-of-the-art networks.

The First Record of Tortoise Beetle Damage to Sugar Beet in the UK: Is Global Warming Responsible?

The authors thought they had experienced everything that the sugar beet crop could throw at them from a pest point of view after almost 40 years of working with the sugar beet industry. It was therefore very exciting to be confronted with a highly unusual pest this summer, so unusual that its presence in high numbers causing significant damage to a sugar beet crop in Norfolk in August 2021, is the first record of such damage in the UK. The pest was the exotic tortoise beetle, Cassida nebulosa, which the sugar beet bible, Pests, Diseases and Disorders of Sugar Beet, published by the International Institute de la Recherches Betteraves (IIRB), describes as rare, and never important in northern Europe. Indeed, this species has never, in our memory, been recorded before as a pest in sugar beet in the UK, only a very rare presence. Dewar and Cooke (2006) stated in their review of pest problems in sugar beet the UK, that crop damage by tortoise beetles never occurs in western Europe, but can be severe in warmer Mediterranean regions and in Russia.

Broken, silent, and in hiding: tamed endogenous pararetroviruses escape elimination from the genome of sugar beet (Beta vulgaris).

Endogenous pararetroviruses (EPRVs) are widespread components of plant genomes that originated from episomal DNA viruses of the Caulimoviridae family. Due to fragmentation and rearrangements, most EPRVs have lost their ability to replicate through reverse transcription and to initiate viral infection. Similar to the closely related retrotransposons, extant EPRVs were retained and often amplified in plant genomes for several million years. Here, we characterize the complete genomic EPRV fraction of the crop sugar beet (Beta vulgaris, Amaranthaceae) to understand how they shaped the beet genome and to suggest explanations for their absent virulence. Using next- and third-generation sequencing data and genome assembly, we reconstructed full-length in silico representatives for the three host-specific EPRVs (beetEPRVs) in the B. vulgaris genome. Focusing on the endogenous caulimovirid beetEPRV3, we investigated its chromosomal localization, abundance and distribution by fluorescent in situ and Southern hybridization. Full-length beetEPRVs range between 7.5 and 10.7 kb in size, are heterogeneous in structure and sequence, and occupy about 0.3 % of the beet genome. Although all three beetEPRVs were assigned to the florendoviruses, they showed variably arranged protein-coding domains, different fragmentation, and preferences for diverse sequence contexts. We observed small RNAs that specifically target the individual beetEPRVs, indicating stringent epigenetic suppression. BeetEPRV3 sequences occur along all sugar beet chromosomes, preferentially in the vicinity of each other and are associated with heterochromatic, centromeric and intercalary satellite DNAs. BeetEPRV3 members also exist in genomes of related wild species, indicating an initial beetEPRV3 integration 13.4-7.2 million years ago. Our study in beet illustrates the variability of EPRV structure and sequence in a single host genome. Evidence of sequence fragmentation and epigenetic silencing implies possible plant strategies to cope with long-term persistence of EPRVs, including amplification, fixation in the heterochromatin, and containment of EPRV virulence.