{"id":3916,"date":"2024-11-22T11:11:48","date_gmt":"2024-11-22T05:26:48","guid":{"rendered":"https:\/\/blog.rajkrishna.info\/?p=3916"},"modified":"2024-11-22T11:11:48","modified_gmt":"2024-11-22T05:26:48","slug":"tomato-yellow-leaf-curl-virus-tylcv-physiology-management-practices-and-control-measures-in-the-context-of-nepal","status":"publish","type":"post","link":"https:\/\/blog.rajkrishna.info\/?p=3916","title":{"rendered":"Tomato Yellow Leaf Curl Virus (TYLCV): Physiology, Management Practices, and Control Measures in the Context of Nepal"},"content":{"rendered":"\n<p>Tomato Yellow Leaf Curl Virus (TYLCV) is a devastating plant pathogen causing significant economic losses in tomato production worldwide, including in Nepal. The virus belongs to the genus <em>Begomovirus<\/em> within the family <em>Geminiviridae<\/em>. It primarily affects solanaceous crops, with tomatoes (<em>Solanum lycopersicum<\/em>) being its most susceptible host.<\/p>\n\n\n\n<p>This post delves into the physiology of TYLCV, its impact on tomato crops, and sustainable management practices tailored to the agro-climatic conditions of Nepal.<\/p>\n\n\n\n<details class=\"wp-block-stackable-accordion stk-block-accordion stk-inner-blocks stk-block-content stk-block stk-8c3ab71 is-style-default\" data-block-id=\"8c3ab71\"><style>.stk-8c3ab71 {padding-top:0px !important;padding-right:0px !important;padding-bottom:0px !important;padding-left:0px !important;}<\/style>\n<summary class=\"wp-block-stackable-column stk-block-column stk-column stk-block stk-32e22a6 stk-block-background stk--container-small stk-block-accordion__heading\" data-v=\"4\" data-block-id=\"32e22a6\"><style>.stk-32e22a6 {background-color:var(--theme-palette-color-1, #335282) !important;border-top-left-radius:5px !important;border-top-right-radius:5px !important;border-bottom-right-radius:0px !important;border-bottom-left-radius:0px !important;overflow:hidden !important;}.stk-32e22a6:before{background-color:var(--theme-palette-color-1, #335282) !important;}<\/style><div class=\"stk-column-wrapper stk-block-column__content stk-container stk-32e22a6-container stk--no-background stk--no-padding\"><div class=\"stk-block-content stk-inner-blocks stk-32e22a6-inner-blocks\">\n<div class=\"wp-block-stackable-icon-label stk-block-icon-label stk-block stk-8f7ad8e\" data-block-id=\"8f7ad8e\"><div class=\"stk-row stk-inner-blocks stk-block-content\">\n<div class=\"wp-block-stackable-heading stk-block-heading stk-block-heading--v2 stk-block stk-df7c041\" id=\"strong-table-of-content-strong\" data-block-id=\"df7c041\"><style>.stk-df7c041 .stk-block-heading__text{font-size:20px !important;color:var(--theme-palette-color-8, #ffffff) !important;}@media screen and (max-width:999px){.stk-df7c041 .stk-block-heading__text{font-size:20px !important;}}<\/style><p class=\"stk-block-heading__text has-text-color\"><strong>Table of Content<\/strong><\/p><\/div>\n\n\n\n<div class=\"wp-block-stackable-icon stk-block-icon stk-block stk-16b0435\" data-block-id=\"16b0435\"><style>.stk-16b0435 .stk--svg-wrapper .stk--inner-svg svg:last-child, .stk-16b0435 .stk--svg-wrapper .stk--inner-svg svg:last-child :is(g, path, rect, polygon, ellipse){fill:var(--theme-palette-color-8, #ffffff) !important;}@media screen and (max-width:689px){.stk-16b0435 {margin-left:-43px !important;}}<\/style><span class=\"stk--svg-wrapper\"><div class=\"stk--inner-svg\"><svg style=\"height:0;width:0\"><defs><linearGradient id=\"linear-gradient-16b0435\" x1=\"0\" x2=\"100%\" y1=\"0\" y2=\"0\"><stop offset=\"0%\" style=\"stop-opacity:1;stop-color:var(--linear-gradient-16-b-0435-color-1)\"><\/stop><stop offset=\"100%\" style=\"stop-opacity:1;stop-color:var(--linear-gradient-16-b-0435-color-2)\"><\/stop><\/linearGradient><\/defs><\/svg><svg data-prefix=\"fas\" data-icon=\"chevron-down\" class=\"svg-inline--fa fa-chevron-down fa-w-14\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\" viewBox=\"0 0 448 512\" aria-hidden=\"true\" width=\"32\" height=\"32\"><path fill=\"currentColor\" d=\"M207.029 381.476L12.686 187.132c-9.373-9.373-9.373-24.569 0-33.941l22.667-22.667c9.357-9.357 24.522-9.375 33.901-.04L224 284.505l154.745-154.021c9.379-9.335 24.544-9.317 33.901.04l22.667 22.667c9.373 9.373 9.373 24.569 0 33.941L240.971 381.476c-9.373 9.372-24.569 9.372-33.942 0z\"><\/path><\/svg><\/div><\/span><\/div>\n<\/div><\/div>\n<\/div><\/div><\/summary>\n\n\n\n<div class=\"wp-block-stackable-column stk-block-column stk-column stk-block stk-75e3842 stk-block-background stk-block-accordion__content\" data-v=\"4\" data-block-id=\"75e3842\"><style>.stk-75e3842 {border-bottom-right-radius:5px !important;border-bottom-left-radius:5px !important;overflow:hidden !important;border-style:solid !important;}<\/style><div class=\"stk-column-wrapper stk-block-column__content stk-container stk-75e3842-container stk--no-background stk--no-padding\"><div class=\"stk-block-content stk-inner-blocks stk-75e3842-inner-blocks\">\n<div class=\"wp-block-rank-math-toc-block\" id=\"rank-math-toc\"><nav><ul><li class=\"\"><a href=\"#taxonomical-classification\">Taxonomical Classification<\/a><\/li><li class=\"\"><a href=\"#physiology-of-tomato-yellow-leaf-curl-virus-tylcv\">Physiology of Tomato Yellow Leaf Curl Virus (TYLCV)<\/a><\/li><li class=\"\"><a href=\"#symptoms-of-tylcv-in-tomatoes\">Symptoms of TYLCV in Tomatoes<\/a><\/li><li class=\"\"><a href=\"#disease-cycle\">Disease Cycle<\/a><\/li><li class=\"\"><a href=\"#impact-of-tylcv-on-tomato-production-in-nepal\">Impact of TYLCV on Tomato Production in Nepal<\/a><\/li><li class=\"\"><a href=\"#management-practices-and-control-measures\">Management Practices and Control Measures<\/a><\/li><li class=\"\"><a href=\"#future-prospects-for-tylcv-management-in-nepal\">Future Prospects for TYLCV Management in Nepal<\/a><\/li><li class=\"\"><a href=\"#conclusion\">Conclusion<\/a><\/li><li class=\"\"><a href=\"#notes\">Notes:<\/a><\/li><\/ul><\/nav><\/div>\n<\/div><\/div><\/div>\n<\/details>\n\n\n\n<h4 class=\"wp-block-heading\" id=\"taxonomical-classification\">Taxonomical Classification<\/h4>\n\n\n\n<figure class=\"wp-block-table is-style-stripes\"><table class=\"has-fixed-layout\"><thead><tr><th><strong>Taxonomic Rank<\/strong><\/th><th><strong>Classification<\/strong><\/th><\/tr><\/thead><tbody><tr><td><strong>Virus Group<\/strong><\/td><td>ssDNA (Single-stranded DNA virus)<\/td><\/tr><tr><td><strong>Family<\/strong><\/td><td>Geminiviridae<\/td><\/tr><tr><td><strong>Genus<\/strong><\/td><td>Begomovirus<\/td><\/tr><tr><td><strong>Species<\/strong><\/td><td><em>Tomato yellow leaf curl virus<\/em> (TYLCV)<\/td><\/tr><tr><td><strong>Strain<\/strong><\/td><td>TYLCV strains vary depending on geographic location, e.g., TYLCV-Israel, TYLCV-Egypt, etc.<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n<p>This classification highlights the primary taxonomic categories for TYLCV, which is a DNA virus transmitted by whiteflies<\/p>\n\n\n\n<h4 class=\"wp-block-heading\" id=\"physiology-of-tomato-yellow-leaf-curl-virus-tylcv\"><strong>Physiology of Tomato Yellow Leaf Curl Virus (TYLCV)<\/strong><\/h4>\n\n\n\n<p>TYLCV is a single-stranded DNA (ssDNA) virus that is transmitted by the whitefly (<em>Bemisia tabaci<\/em>). The virus infects phloem tissues, disrupting the plant&#8217;s vascular system and interfering with nutrient and water transport. Key aspects of TYLCV physiology include:<\/p>\n\n\n\n<ol class=\"wp-block-list\">\n<li><strong>Genome Organization<\/strong>\n<ul class=\"wp-block-list\">\n<li>The viral genome is monopartite, approximately 2.8 kb in size, and encodes both replication-associated proteins (Rep) and capsid proteins (CP).<\/li>\n\n\n\n<li>The Rep protein facilitates replication of the viral genome, while the CP protein ensures encapsidation and systemic movement within the host.<\/li>\n<\/ul>\n<\/li>\n\n\n\n<li><strong>Mechanism of Infection<\/strong>\n<ul class=\"wp-block-list\">\n<li>The virus enters plant cells via feeding wounds created by whiteflies.<\/li>\n\n\n\n<li>Inside the host cell nucleus, TYLCV uses the host\u2019s DNA polymerase machinery for replication.<\/li>\n\n\n\n<li>The virus induces the formation of replication complexes, hijacking host cell functions for its proliferation.<\/li>\n<\/ul>\n<\/li>\n\n\n\n<li><strong>Pathophysiological Effects on Tomatoes<\/strong>\n<ul class=\"wp-block-list\">\n<li>TYLCV infection suppresses photosynthesis by altering chlorophyll content and disrupting chloroplast structure.<\/li>\n\n\n\n<li>Hormonal imbalances, particularly reductions in cytokinin and auxin levels, lead to stunted growth and leaf curling.<\/li>\n<\/ul>\n<\/li>\n<\/ol>\n\n\n\n<h4 class=\"wp-block-heading\" id=\"symptoms-of-tylcv-in-tomatoes\"><strong>Symptoms of TYLCV in Tomatoes<\/strong><\/h4>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>Leaf Deformities<\/strong>: Upward curling and yellowing of leaves, often accompanied by reduced leaf size.<\/li>\n<\/ul>\n\n\n\n<div class=\"wp-block-stackable-image stk-block-image stk-block stk-db5be82\" data-block-id=\"db5be82\"><style>.stk-db5be82 .stk-img-figcaption{text-align:center !important;}.stk-db5be82 .stk-img-wrapper{width:50% !important;}<\/style><figure><span class=\"stk-img-wrapper stk-image--shape-stretch\"><img loading=\"lazy\" decoding=\"async\" class=\"stk-img wp-image-3920\" src=\"https:\/\/blog.rajkrishna.info\/wp-content\/uploads\/2024\/11\/image-3.png\" width=\"600\" height=\"450\" alt=\"Symptomatic tomato plant infected with TYLCV. Note the leaf curl.\" srcset=\"https:\/\/blog.rajkrishna.info\/wp-content\/uploads\/2024\/11\/image-3.png 600w, https:\/\/blog.rajkrishna.info\/wp-content\/uploads\/2024\/11\/image-3-300x225.png 300w\" sizes=\"auto, (max-width: 600px) 100vw, 600px\" \/><\/span><figcaption class=\"stk-img-figcaption\">Fig: Symptomatic tomato plant infected with TYLCV. Note the leaf curl.<br>Source: <a href=\"https:\/\/content.ces.ncsu.edu\/tomato-yellow-leaf-curl-virus\" target=\"_blank\" rel=\"noopener\">NC State Extension<\/a><\/figcaption><\/figure><\/div>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>Chlorosis<\/strong>: TYLCV symptoms can resemble nutrient deficiencies like potassium, magnesium, and micronutrients, or environmental stress like high temperatures or drought. However, TYLCV typically causes chlorosis and curling on young leaves, whereas nutrient deficiencies often affect older leaves uniformly across the crop. Environmental stress or aphid feeding may cause leaf curl without chlorosis. Diagnosis should be confirmed by a plant clinic or specialist due to similar-looking disorders.<\/li>\n<\/ul>\n\n\n\n<div class=\"wp-block-stackable-image stk-block-image stk-block stk-c5cb6a3\" data-block-id=\"c5cb6a3\"><style>.stk-c5cb6a3 .stk-img-figcaption{text-align:center !important;}.stk-c5cb6a3 .stk-img-wrapper{width:50% !important;}<\/style><figure><span class=\"stk-img-wrapper stk-image--shape-stretch\"><img loading=\"lazy\" decoding=\"async\" class=\"stk-img\" src=\"https:\/\/content.ces.ncsu.edu\/media\/images\/IMG_4525.jpeg\" width=\"50\" height=\"300\" alt=\"Interveinal and marginal chlorosis on young tomato leaves infected with TYLCV\"\/><\/span><figcaption class=\"stk-img-figcaption\">Fig: Interveinal and marginal chlorosis on young tomato leaves infected with TYLCV<br>Source: <a href=\"https:\/\/content.ces.ncsu.edu\/tomato-yellow-leaf-curl-virus\" target=\"_blank\" rel=\"noopener\">NC State Extension<\/a><\/figcaption><\/figure><\/div>\n\n\n\n<p><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>Stunted Growth<\/strong>: Infected plants exhibit slow or arrested development, with shortened internodes.<\/li>\n<\/ul>\n\n\n\n<div class=\"wp-block-stackable-image stk-block-image stk-block stk-c30c652\" data-block-id=\"c30c652\"><style>.stk-c30c652 .stk-img-figcaption{text-align:center !important;}.stk-c30c652 .stk-img-wrapper{width:50% !important;}<\/style><figure><span class=\"stk-img-wrapper stk-image--shape-stretch stk--has-lightbox\"><img loading=\"lazy\" decoding=\"async\" class=\"stk-img\" src=\"https:\/\/content.ces.ncsu.edu\/media\/images\/IMG_4522_GvdJ98j.jpeg\" width=\"50\" height=\"300\" alt=\"Stunted and bushy tomato infected with tomato yellow leaf curl virus\"\/><\/span><figcaption class=\"stk-img-figcaption\">Fig: Stunted and bushy tomato infected with tomato yellow leaf curl virus<br>Source: <a href=\"https:\/\/content.ces.ncsu.edu\/tomato-yellow-leaf-curl-virus\" target=\"_blank\" rel=\"noopener\">NC State Extension<\/a><\/figcaption><\/figure><\/div>\n\n\n\n<p><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>Flower and Fruit Drop<\/strong>: Premature abscission of flowers and fruits, severely impacting yields.<\/li>\n\n\n\n<li><strong>Poor Fruit Quality<\/strong>: If fruits are produced, they are often small, malformed, and less marketable.<\/li>\n<\/ul>\n\n\n\n<div class=\"wp-block-stackable-image stk-block-image stk-block stk-6e9b780\" data-block-id=\"6e9b780\"><style>.stk-6e9b780 .stk-img-figcaption{text-align:center !important;}.stk-6e9b780 .stk-img-wrapper{width:50% !important;}<\/style><figure><span class=\"stk-img-wrapper stk-image--shape-stretch stk--has-lightbox\"><img loading=\"lazy\" decoding=\"async\" class=\"stk-img\" src=\"https:\/\/www.researchgate.net\/publication\/346801604\/figure\/fig1\/AS:11431281246265565@1716323018578\/A-Photograph-representing-differences-in-TYLCV-infection-symptoms-on-a-TYLCV-resistant_W640.jpg\" width=\"50\" height=\"300\" alt=\"Photograph representing differences in TYLCV infection symptoms on a TYLCV-resistant and -susceptible tomato genotype under intense TYLCV pressure.\"\/><\/span><figcaption class=\"stk-img-figcaption\">Fig: &nbsp;Photograph representing differences in TYLCV infection symptoms on a TYLCV-resistant and -susceptible tomato genotype under intense TYLCV pressure.<br>Source: Paper from <a href=\"https:\/\/www.researchgate.net\/publication\/346801604_Tomato_Yellow_Leaf_Curl_Virus-Resistant_and_-Susceptible_Tomato_Genotypes_Similarly_Impact_the_Virus_Population_Genetics\" target=\"_blank\" rel=\"noopener\">ResearchGate<\/a><\/figcaption><\/figure><\/div>\n\n\n\n<h4 class=\"wp-block-heading\" id=\"disease-cycle\"><strong>Disease Cycle<\/strong><\/h4>\n\n\n\n<p>The disease cycle of TYLCV revolves around its vector, the whitefly:<\/p>\n\n\n\n<ol class=\"wp-block-list\">\n<li><strong>Virus Acquisition<\/strong>\n<ul class=\"wp-block-list\">\n<li>Whiteflies acquire the virus while feeding on infected plants. The virus becomes persistent in the insect&#8217;s salivary glands.<\/li>\n<\/ul>\n<\/li>\n\n\n\n<li><strong>Transmission<\/strong>\n<ul class=\"wp-block-list\">\n<li>The virus is transmitted to healthy plants when the infected whitefly feeds again.<\/li>\n\n\n\n<li>This transmission is circulative <sup data-fn=\"df089492-8b4a-40ad-b632-7454f01fddb3\" class=\"fn\"><a id=\"df089492-8b4a-40ad-b632-7454f01fddb3-link\" href=\"#df089492-8b4a-40ad-b632-7454f01fddb3\">1<\/a><\/sup>and non-propagative<sup data-fn=\"b629faec-ae7f-455f-8698-672dd9523598\" class=\"fn\"><a id=\"b629faec-ae7f-455f-8698-672dd9523598-link\" href=\"#b629faec-ae7f-455f-8698-672dd9523598\">2<\/a><\/sup>; the virus does not replicate within the insect vector.<\/li>\n<\/ul>\n<\/li>\n\n\n\n<li><strong>Spread in the Field<\/strong>\n<ul class=\"wp-block-list\">\n<li>Whitefly populations can spread TYLCV across fields, especially under favorable conditions such as warm temperatures and high humidity.<\/li>\n<\/ul>\n<\/li>\n<\/ol>\n\n\n\n<div class=\"wp-block-stackable-image stk-block-image stk-block stk-03f0acc\" data-block-id=\"03f0acc\"><style>.stk-03f0acc .stk-img-figcaption{text-align:center !important;}.stk-03f0acc .stk-img-wrapper{width:50% !important;}<\/style><figure><span class=\"stk-img-wrapper stk-image--shape-stretch stk--has-lightbox\"><img loading=\"lazy\" decoding=\"async\" class=\"stk-img wp-image-3932\" src=\"https:\/\/blog.rajkrishna.info\/wp-content\/uploads\/2024\/11\/image-4.png\" width=\"573\" height=\"423\" alt=\"Whitefly feeding on the tomato leaf.\" srcset=\"https:\/\/blog.rajkrishna.info\/wp-content\/uploads\/2024\/11\/image-4.png 573w, https:\/\/blog.rajkrishna.info\/wp-content\/uploads\/2024\/11\/image-4-300x221.png 300w\" sizes=\"auto, (max-width: 573px) 100vw, 573px\" \/><\/span><figcaption class=\"stk-img-figcaption\">Fig: &nbsp;Whitefly feeding on the tomato leaf.<br>Source: <a href=\"https:\/\/en.wikipedia.org\/wiki\/Silverleaf_whitefly\" target=\"_blank\" rel=\"noopener\">Wikipedia<\/a><\/figcaption><\/figure><\/div>\n\n\n\n<div class=\"wp-block-stackable-image stk-block-image stk-block stk-a922a4b\" data-block-id=\"a922a4b\"><style>.stk-a922a4b .stk-img-figcaption{text-align:center !important;}.stk-a922a4b .stk-img-wrapper{width:50% !important;}<\/style><figure><span class=\"stk-img-wrapper stk-image--shape-stretch stk--has-lightbox\"><img loading=\"lazy\" decoding=\"async\" class=\"stk-img\" src=\"https:\/\/upload.wikimedia.org\/wikipedia\/commons\/a\/a5\/Bemisia_argentifolii_5194038.jpg\" width=\"50\" height=\"300\" alt=\"Bemisia tabaci\u00a0adult whiteflies on green leaf\n\"\/><\/span><figcaption class=\"stk-img-figcaption\">Fig: &nbsp;<em>Bemisia tabaci<\/em>&nbsp;adult whiteflies on green leaf<br>Source: <a href=\"https:\/\/en.wikipedia.org\/wiki\/Silverleaf_whitefly\" target=\"_blank\" rel=\"noopener\">Wikipedia<\/a><\/figcaption><\/figure><\/div>\n\n\n\n<div class=\"wp-block-stackable-columns stk-block-columns stk-block stk-341454e stk-block-background\" data-block-id=\"341454e\"><style>.stk-341454e {background-color:var(--theme-palette-color-5, #E6F0EE) !important;border-style:solid !important;border-top-width:0px !important;border-right-width:0px !important;border-bottom-width:0px !important;border-left-width:5px !important;margin-bottom:0px !important;}.stk-341454e:before{background-color:var(--theme-palette-color-5, #E6F0EE) !important;}<\/style><div class=\"stk-row stk-inner-blocks stk-block-content stk-content-align stk-341454e-column\">\n<div class=\"wp-block-stackable-column stk-block-column stk-column stk-block stk-1f1bcda\" data-v=\"4\" data-block-id=\"1f1bcda\"><div class=\"stk-column-wrapper stk-block-column__content stk-container stk-1f1bcda-container stk--no-background stk--no-padding\"><div class=\"stk-block-content stk-inner-blocks stk-1f1bcda-inner-blocks\">\n<div class=\"wp-block-stackable-icon-box stk-block-icon-box stk-block stk-9dfdd9e\" data-v=\"2\" data-block-id=\"9dfdd9e\"><div class=\"stk-block-content stk-inner-blocks stk-block-icon-box__content stk-container stk-9dfdd9e-container stk--no-background stk--no-padding\">\n<div class=\"wp-block-stackable-icon-label stk-block-icon-label stk-block stk-8d299ea\" data-block-id=\"8d299ea\"><style>.stk-8d299ea .stk-inner-blocks{gap:39px !important;}.stk-8d299ea {margin-bottom:0px !important;}@media screen and (max-width:999px){.stk-8d299ea .stk-inner-blocks{gap:39px !important;}}@media screen and (max-width:689px){.stk-8d299ea .stk-inner-blocks{gap:39px !important;}}<\/style><div class=\"stk-row stk-inner-blocks stk-block-content\">\n<div class=\"wp-block-stackable-icon stk-block-icon has-text-align-left stk-block stk-983e9b1\" data-block-id=\"983e9b1\"><style>.stk-983e9b1 .stk--svg-wrapper .stk--inner-svg svg:last-child{height:25px !important;width:25px !important;}.stk-983e9b1 .stk--svg-wrapper .stk--inner-svg svg:last-child, .stk-983e9b1 .stk--svg-wrapper .stk--inner-svg svg:last-child :is(g, path, rect, polygon, ellipse){fill:var(--theme-palette-color-1, #335282) !important;}<\/style><span class=\"stk--svg-wrapper\"><div class=\"stk--inner-svg\"><svg style=\"height:0;width:0\"><defs><linearGradient id=\"linear-gradient-983e9b1\" x1=\"0\" x2=\"100%\" y1=\"0\" y2=\"0\"><stop offset=\"0%\" style=\"stop-opacity:1;stop-color:var(--linear-gradient-983-e-9-b-1-color-1)\"><\/stop><stop offset=\"100%\" style=\"stop-opacity:1;stop-color:var(--linear-gradient-983-e-9-b-1-color-2)\"><\/stop><\/linearGradient><\/defs><\/svg><svg xmlns=\"http:\/\/www.w3.org\/2000\/svg\" viewBox=\"0 0 384 512\" aria-hidden=\"true\" width=\"32\" height=\"32\"><path d=\"M272 384c9.6-31.9 29.5-59.1 49.2-86.2l0 0c5.2-7.1 10.4-14.2 15.4-21.4c19.8-28.5 31.4-63 31.4-100.3C368 78.8 289.2 0 192 0S16 78.8 16 176c0 37.3 11.6 71.9 31.4 100.3c5 7.2 10.2 14.3 15.4 21.4l0 0c19.8 27.1 39.7 54.4 49.2 86.2H272zM192 512c44.2 0 80-35.8 80-80V416H112v16c0 44.2 35.8 80 80 80zM112 176c0 8.8-7.2 16-16 16s-16-7.2-16-16c0-61.9 50.1-112 112-112c8.8 0 16 7.2 16 16s-7.2 16-16 16c-44.2 0-80 35.8-80 80z\"><\/path><\/svg><\/div><\/span><\/div>\n\n\n\n<div class=\"wp-block-stackable-heading stk-block-heading stk-block-heading--v2 stk-block stk-e6a4fc5\" id=\"strong-always-remember-strong\" data-block-id=\"e6a4fc5\"><style>.stk-e6a4fc5 .stk-block-heading__text{font-size:25px !important;}@media screen and (max-width:999px){.stk-e6a4fc5 .stk-block-heading__text{font-size:25px !important;}}<\/style><p class=\"stk-block-heading__text\"><strong>Always Remember!<\/strong><\/p><\/div>\n<\/div><\/div>\n\n\n\n<div class=\"wp-block-stackable-text stk-block-text stk-block stk-42a0383\" data-block-id=\"42a0383\"><p class=\"stk-block-text__text\">There are various plant viruses that transmit via. seed, however, Tomato Yellow Leaf Curl Virus <strong>doesn&#8217;t transmits via. seed<\/strong>. While TYLCV can spread through vegetative propagation (such as cuttings) if the mother plant is infected. Therefore, using disease-free seeds from healthy plants is an important practice to prevent the introduction of the virus.<\/p><\/div>\n<\/div><\/div>\n<\/div><\/div><\/div>\n<\/div><\/div>\n\n\n\n<h4 class=\"wp-block-heading\" id=\"impact-of-tylcv-on-tomato-production-in-nepal\"><strong>Impact of TYLCV on Tomato Production in Nepal<\/strong><\/h4>\n\n\n\n<p>In Nepal, tomatoes are cultivated in diverse agro-climatic regions, ranging from the Terai plains to mid-hill areas. TYLCV outbreaks are prevalent in lowland regions with warm climates, where whitefly populations thrive. Losses due to TYLCV can reach up to 80% in severely affected fields, exacerbated by limited access to resistant varieties and inadequate vector management practices.<\/p>\n\n\n\n<h4 class=\"wp-block-heading\" id=\"management-practices-and-control-measures\"><strong>Management Practices and Control Measures<\/strong><\/h4>\n\n\n\n<p>Managing TYLCV requires an integrated approach that addresses both the virus and its vector. Here are effective strategies tailored to Nepal&#8217;s context:<\/p>\n\n\n\n<ol class=\"wp-block-list\">\n<li><strong>Use of Resistant Varieties<\/strong>\n<ul class=\"wp-block-list\">\n<li>Cultivate TYLCV-resistant or tolerant tomato cultivars such as &#8216;Roma VF&#8217; and hybrids like &#8216;Tyking&#8217; or &#8216;Himal&#8217;.<\/li>\n\n\n\n<li>Promote local breeding programs to develop varieties adapted to Nepal&#8217;s agro-climatic conditions.<\/li>\n<\/ul>\n<\/li>\n\n\n\n<li><strong>Cultural Practices<\/strong>\n<ul class=\"wp-block-list\">\n<li><strong>Crop Rotation<\/strong>: Rotate tomatoes with non-host crops like cereals or legumes to break the virus&#8217;s life cycle.<\/li>\n\n\n\n<li><strong>Sanitation<\/strong>: Remove and destroy infected plants and weeds that serve as virus reservoirs.<\/li>\n\n\n\n<li><strong>Barrier Crops<\/strong>: Plant barrier crops such as maize or sorghum around tomato fields to reduce whitefly migration. Sowing sunflower seeds at a density of 10-12 plants per Kattha in border rows, approximately 7 days before transplanting tomato seedlings into the main field, has proven effective.<\/li>\n\n\n\n<li><strong>Cow\/Bufflao Milk<\/strong>: Spraying fresh cow or buffalo milk at a ratio of 1:10 (1 part milk to 10 parts water) three times after the onset of the disease to minimize infestation or spraying after 7-10 days after transplanting tomato seedlings at the regular interval 7-10 days has been found effective in managing Tomato Yellow Leaf Curl Virus (TYLCV)<\/li>\n<\/ul>\n<\/li>\n\n\n\n<li><strong>Vector Management<\/strong>\n<ul class=\"wp-block-list\">\n<li><strong>Monitoring and Surveillance<\/strong>: Regularly monitor whitefly populations using yellow sticky traps.<\/li>\n\n\n\n<li><strong>Biological Control<\/strong>: Introduce natural enemies of whiteflies, such as parasitoid wasps (<em>Encarsia formosa<\/em>) and predatory beetles (<em>Delphastus catalinae<\/em>).<\/li>\n\n\n\n<li><strong>Chemical Control<\/strong>: Use insecticides judiciously to manage whitefly populations. Rotational use of neonicotinoids, pyrethroids, and insect growth regulators (IGRs) can prevent resistance development.<\/li>\n<\/ul>\n<\/li>\n\n\n\n<li><strong>Integrated Pest Management (IPM)<\/strong>\n<ul class=\"wp-block-list\">\n<li>Combine biological, cultural, and chemical methods for sustainable TYLCV control.<\/li>\n\n\n\n<li>Train farmers in IPM techniques through agricultural extension programs.<\/li>\n<\/ul>\n<\/li>\n\n\n\n<li><strong>Environmental Modifications<\/strong>\n<ul class=\"wp-block-list\">\n<li>Use reflective mulches to repel whiteflies and reduce their population.<\/li>\n\n\n\n<li>Employ net houses or poly-tunnels to physically exclude whiteflies from crops.<\/li>\n<\/ul>\n<\/li>\n\n\n\n<li><strong>Chemical Contro<\/strong>l\n<ul class=\"wp-block-list\">\n<li>Use insecticides judiciously, focusing on the early stages of the crops<\/li>\n\n\n\n<li>Applying systemic insecticides like imidacloprid or acetamiprid and rotating chemical groups to prevent resistance development.<\/li>\n<\/ul>\n<\/li>\n<\/ol>\n\n\n\n<h4 class=\"wp-block-heading\" id=\"future-prospects-for-tylcv-management-in-nepal\"><strong>Future Prospects for TYLCV Management in Nepal<\/strong><\/h4>\n\n\n\n<ol class=\"wp-block-list\">\n<li><strong>Biotechnological Interventions<\/strong>\n<ul class=\"wp-block-list\">\n<li>Develop genetically engineered tomato varieties using RNA interference (RNAi) to target viral replication genes.<\/li>\n<\/ul>\n<\/li>\n\n\n\n<li><strong>Advanced Diagnostics<\/strong>\n<ul class=\"wp-block-list\">\n<li>Implement rapid and cost-effective diagnostic tools, such as loop-mediated isothermal amplification (LAMP), for early detection of TYLCV in Nepalese fields.<\/li>\n<\/ul>\n<\/li>\n\n\n\n<li><strong>Awareness and Policy Support<\/strong>\n<ul class=\"wp-block-list\">\n<li>Conduct awareness campaigns to educate farmers about TYLCV management.<\/li>\n\n\n\n<li>Encourage government subsidies for resistant seeds and vector control measures.<\/li>\n<\/ul>\n<\/li>\n\n\n\n<li><strong>Research and Development<\/strong>\n<ul class=\"wp-block-list\">\n<li>Support research on TYLCV epidemiology and its interactions with local whitefly biotypes.<\/li>\n<\/ul>\n<\/li>\n<\/ol>\n\n\n\n<h4 class=\"wp-block-heading\" id=\"conclusion\"><strong>Conclusion<\/strong><\/h4>\n\n\n\n<p>Tomato Yellow Leaf Curl Virus poses a severe threat to tomato production in Nepal, especially in regions with conducive climates for whitefly proliferation. Implementing an integrated disease management approach, supported by modern technology and farmer education, can significantly mitigate the impact of TYLCV. Collaborative efforts among farmers, researchers, and policymakers are essential to safeguard Nepal&#8217;s tomato industry and ensure food security.<\/p>\n\n\n\n<details class=\"wp-block-stackable-accordion stk-block-accordion stk-inner-blocks stk-block-content stk-block stk-f053b27 is-style-default\" data-block-id=\"f053b27\"><style>.stk-f053b27 {padding-top:0px !important;padding-right:0px !important;padding-bottom:0px !important;padding-left:0px !important;}<\/style>\n<summary class=\"wp-block-stackable-column stk-block-column stk-column stk-block stk-40e2445 stk-block-background stk--container-small stk-block-accordion__heading\" data-v=\"4\" data-block-id=\"40e2445\"><style>.stk-40e2445 {background-color:var(--theme-palette-color-1, #335282) !important;border-top-left-radius:5px !important;border-top-right-radius:5px !important;border-bottom-right-radius:0px !important;border-bottom-left-radius:0px !important;overflow:hidden !important;}.stk-40e2445:before{background-color:var(--theme-palette-color-1, #335282) !important;}<\/style><div class=\"stk-column-wrapper stk-block-column__content stk-container stk-40e2445-container stk--no-background stk--no-padding\"><div class=\"stk-block-content stk-inner-blocks stk-40e2445-inner-blocks\">\n<div class=\"wp-block-stackable-icon-label stk-block-icon-label stk-block stk-ce4ba0f\" data-block-id=\"ce4ba0f\"><div class=\"stk-row stk-inner-blocks stk-block-content\">\n<div class=\"wp-block-stackable-heading stk-block-heading stk-block-heading--v2 stk-block stk-ababd20\" id=\"strong-best-recommendations-for-furthur-study-strong\" data-block-id=\"ababd20\"><style>.stk-ababd20 .stk-block-heading__text{font-size:20px !important;color:var(--theme-palette-color-8, #ffffff) !important;}@media screen and (max-width:999px){.stk-ababd20 .stk-block-heading__text{font-size:20px !important;}}<\/style><h4 class=\"stk-block-heading__text has-text-color\"><strong>Best Recommendations for Furthur Study<\/strong><\/h4><\/div>\n\n\n\n<div class=\"wp-block-stackable-icon stk-block-icon stk-block stk-9ac184e\" data-block-id=\"9ac184e\"><style>.stk-9ac184e .stk--svg-wrapper .stk--inner-svg svg:last-child, .stk-9ac184e .stk--svg-wrapper .stk--inner-svg svg:last-child :is(g, path, rect, polygon, ellipse){fill:var(--theme-palette-color-8, #ffffff) !important;}@media screen and (max-width:689px){.stk-9ac184e {margin-left:-43px !important;}}<\/style><span class=\"stk--svg-wrapper\"><div class=\"stk--inner-svg\"><svg style=\"height:0;width:0\"><defs><linearGradient id=\"linear-gradient-9ac184e\" x1=\"0\" x2=\"100%\" y1=\"0\" y2=\"0\"><stop offset=\"0%\" style=\"stop-opacity:1;stop-color:var(--linear-gradient-9-ac-184-e-color-1)\"><\/stop><stop offset=\"100%\" style=\"stop-opacity:1;stop-color:var(--linear-gradient-9-ac-184-e-color-2)\"><\/stop><\/linearGradient><\/defs><\/svg><svg data-prefix=\"fas\" data-icon=\"chevron-down\" class=\"svg-inline--fa fa-chevron-down fa-w-14\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\" viewBox=\"0 0 448 512\" aria-hidden=\"true\" width=\"32\" height=\"32\"><path fill=\"currentColor\" d=\"M207.029 381.476L12.686 187.132c-9.373-9.373-9.373-24.569 0-33.941l22.667-22.667c9.357-9.357 24.522-9.375 33.901-.04L224 284.505l154.745-154.021c9.379-9.335 24.544-9.317 33.901.04l22.667 22.667c9.373 9.373 9.373 24.569 0 33.941L240.971 381.476c-9.373 9.372-24.569 9.372-33.942 0z\"><\/path><\/svg><\/div><\/span><\/div>\n<\/div><\/div>\n<\/div><\/div><\/summary>\n\n\n\n<div class=\"wp-block-stackable-column stk-block-column stk-column stk-block stk-a1a32e4 stk-block-background stk-block-accordion__content\" data-v=\"4\" data-block-id=\"a1a32e4\"><style>.stk-a1a32e4 {border-bottom-right-radius:5px !important;border-bottom-left-radius:5px !important;overflow:hidden !important;border-style:solid !important;}<\/style><div class=\"stk-column-wrapper stk-block-column__content stk-container stk-a1a32e4-container stk--no-background stk--no-padding\"><div class=\"stk-block-content stk-inner-blocks stk-a1a32e4-inner-blocks\">\n<figure class=\"wp-block-embed is-type-video is-provider-youtube wp-block-embed-youtube wp-embed-aspect-16-9 wp-has-aspect-ratio\"><div class=\"wp-block-embed__wrapper\">\n<iframe loading=\"lazy\" title=\"7 CAUSES - Tomato Leaf Curl Disease! (Solve This way)\" width=\"1778\" height=\"1000\" src=\"https:\/\/www.youtube.com\/embed\/FMA50rV9MB8?feature=oembed\" frameborder=\"0\" allow=\"accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture; web-share\" referrerpolicy=\"strict-origin-when-cross-origin\" allowfullscreen><\/iframe>\n<\/div><figcaption class=\"wp-element-caption\">Video suggestion for possible causes of leaf curling in tomato.<\/figcaption><\/figure>\n\n\n\n<figure class=\"wp-block-embed is-type-video is-provider-youtube wp-block-embed-youtube wp-embed-aspect-16-9 wp-has-aspect-ratio\"><div class=\"wp-block-embed__wrapper\">\n<iframe loading=\"lazy\" title=\"The Truth About TOMATO LEAF CURL Will Blow Your Mind\" width=\"1778\" height=\"1000\" src=\"https:\/\/www.youtube.com\/embed\/FV3uzTX79pw?feature=oembed\" frameborder=\"0\" allow=\"accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture; web-share\" referrerpolicy=\"strict-origin-when-cross-origin\" allowfullscreen><\/iframe>\n<\/div><figcaption class=\"wp-element-caption\">Video suggestion on why tomato rolls up and curls?<\/figcaption><\/figure>\n\n\n\n<figure class=\"wp-block-embed is-type-video is-provider-youtube wp-block-embed-youtube wp-embed-aspect-16-9 wp-has-aspect-ratio\"><div class=\"wp-block-embed__wrapper\">\n<iframe loading=\"lazy\" title=\"Tomato leaf curl Disease: Tomato leaf curl virus (TLCV) by Dr  Jayarama Reddy\" width=\"1778\" height=\"1000\" src=\"https:\/\/www.youtube.com\/embed\/l3axIc3F_54?feature=oembed\" frameborder=\"0\" allow=\"accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture; web-share\" referrerpolicy=\"strict-origin-when-cross-origin\" allowfullscreen><\/iframe>\n<\/div><figcaption class=\"wp-element-caption\">Tomato Yello Leaf Curl Disease<\/figcaption><\/figure>\n\n\n\n<figure class=\"wp-block-embed is-type-video is-provider-youtube wp-block-embed-youtube wp-embed-aspect-16-9 wp-has-aspect-ratio\"><div class=\"wp-block-embed__wrapper\">\n<iframe loading=\"lazy\" title=\"TOMATO LEAF CURL - 3 Causes and What to Do When Your Tomato Leaves are Curling Up.\" width=\"1778\" height=\"1000\" src=\"https:\/\/www.youtube.com\/embed\/KZeEHYn5I0g?start=565&#038;feature=oembed\" frameborder=\"0\" allow=\"accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture; web-share\" referrerpolicy=\"strict-origin-when-cross-origin\" allowfullscreen><\/iframe>\n<\/div><figcaption class=\"wp-element-caption\">Tomato Yello Leaf Curl Virus<\/figcaption><\/figure>\n<\/div><\/div><\/div>\n<\/details>\n\n\n\n<h4 class=\"wp-block-heading\" id=\"notes\">Notes:<\/h4>\n\n\n<ol class=\"wp-block-footnotes\"><li id=\"df089492-8b4a-40ad-b632-7454f01fddb3\"><strong>Circulative Virus<\/strong>: \u00a0virus that enters the body of an insect and spreads to different tissues before being transmitted to a plant host<strong> <\/strong> <a href=\"#df089492-8b4a-40ad-b632-7454f01fddb3-link\" aria-label=\"Jump to footnote reference 1\">\u21a9\ufe0e<\/a><\/li><li id=\"b629faec-ae7f-455f-8698-672dd9523598\"><strong>Non-Propagative<\/strong>: a plant virus that is transmitted by an insect vector without replicating or expressing any of its genes <a href=\"#b629faec-ae7f-455f-8698-672dd9523598-link\" aria-label=\"Jump to footnote reference 2\">\u21a9\ufe0e<\/a><\/li><\/ol>","protected":false},"excerpt":{"rendered":"<p>Tomato Yellow Leaf Curl Virus (TYLCV) is a devastating plant pathogen causing significant economic losses in tomato production worldwide, including in Nepal. The virus belongs to the genus Begomovirus within the family Geminiviridae. It primarily affects solanaceous crops, with tomatoes (Solanum lycopersicum) being its most susceptible host. This post delves into the physiology of TYLCV, [&hellip;]<\/p>\n","protected":false},"author":2,"featured_media":3920,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":"[{\"content\":\"<strong>Circulative Virus<\/strong>: \u00a0virus that enters the body of an insect and spreads to different tissues before being transmitted to a plant host<strong> <\/strong>\",\"id\":\"df089492-8b4a-40ad-b632-7454f01fddb3\"},{\"content\":\"<strong>Non-Propagative<\/strong>: a plant virus that is transmitted by an insect vector without replicating or expressing any of its genes\",\"id\":\"b629faec-ae7f-455f-8698-672dd9523598\"}]"},"categories":[30,33],"tags":[56,34,15,58],"class_list":["post-3916","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-plant-protection","category-plant-diseases","tag-diseases-of-vegetables","tag-plant-disease","tag-plant-protection","tag-viral-diseases"],"blocksy_meta":[],"_links":{"self":[{"href":"https:\/\/blog.rajkrishna.info\/index.php?rest_route=\/wp\/v2\/posts\/3916","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/blog.rajkrishna.info\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/blog.rajkrishna.info\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/blog.rajkrishna.info\/index.php?rest_route=\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/blog.rajkrishna.info\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=3916"}],"version-history":[{"count":28,"href":"https:\/\/blog.rajkrishna.info\/index.php?rest_route=\/wp\/v2\/posts\/3916\/revisions"}],"predecessor-version":[{"id":3964,"href":"https:\/\/blog.rajkrishna.info\/index.php?rest_route=\/wp\/v2\/posts\/3916\/revisions\/3964"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/blog.rajkrishna.info\/index.php?rest_route=\/wp\/v2\/media\/3920"}],"wp:attachment":[{"href":"https:\/\/blog.rajkrishna.info\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=3916"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/blog.rajkrishna.info\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=3916"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/blog.rajkrishna.info\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=3916"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}