scholarly journals Dificultades metodológicas en la selección de cultivos trampa para el manejo del complejo Bemisia tabaci-virus en tomate

2017 ◽  
Vol 51 (1) ◽  
pp. 76
Author(s):  
Luko Hilje ◽  
Philip A. Stansly

Se describe la evolución de una metodología para la evaluación de cultivos trampa para el manejo de Bemisia tabaci (biotipo A) como vector de virus en tomate, en Costa Rica. Se evaluaron la vainica (Phaseolus vulgaris, Fabaceae), tabaco (Nicotiana tabacum, Solanaceae) y berenjena (Solanum melongena, Solanaceae). Aunque los tres cultivos redujeron el impacto del Tomato yellow mottled virus (ToYMoV) sobre los rendimientos, el tabaco y la berenjena fueron superiores. No obstante, la extrapolación de estos resultados a condiciones comerciales es compleja, como también lo demuestran las experiencias mundiales, por varias razones que son discutidas.

2018 ◽  
Vol 29 (3) ◽  
pp. 585
Author(s):  
Luko Hilje ◽  
Philip A. Stansly

Despite being a polyphagous insect, Bemisia tabaci (Gennadius) shows a marked preference for certain hosts, which in turn may depend upon the particular whitefly biotype involved. The objective of this research was to compare preference towards a selected group of host crops, by two biotypes of Bemisia tabaci, New World in Costa Rica, and MEAM1 in Florida. Therefore, choice experiments were conducted in greenhouses both at Turrialba (Costa Rica) and Immokalee (Florida), in April and June-September, 1998, respectively. The same crops and varieties were exposed to the New World and MEAM1 biotypes, which predominate in each one of these locations, respectively. Host species included green beans (Phaseolus vulgaris), bell pepper (Capsicum annuum), eggplant (Solanum melongena), cucumber (Cucumis sativus), tobacco (Nicotiana tabacum) and tomato (Solanum lycopersicum). Seedlings were transplanted in large pots, which were distributed on the greenhouse floor. B. tabaci adults were released in the late afternoon, and the number of individuals on each plant was recorded the next morning. In Turrialba, tobacco was greatly preferred by New World biotype adults, followed by eggplant, whereas the MEAM1 biotype in Florida preferred green beans and eggplant. Thus, both biotypes showed a strong and significant preference for eggplant, which suggests its possible utility as a trap crop.


2017 ◽  
Vol 7 (1) ◽  
pp. 7
Author(s):  
P. K. Baidoo ◽  
M. B. Mochiah ◽  
D. Asare ◽  
A. A. Sefah

Loss of soil fertility as a result of continuous cropping on the same piece of land has necessitated the need to improve soil fertility for better crop yields. Inorganic and organic fertilizers have been used to improve soil fertility, however, excessive use of soil amendments improve vegetative growth of plants thereby attracting large numbers of insect pests. Cow dung and poultry droppings were used as soil amendments in a field experiment using eggplant Solanum melongena. The effects of these organic manures were compared with inorganic fertilizer (NPK) and a control where there was no application of soil amendment in a randomized complete block design with 3 replicates. Parameters studied were pests’ and their numbers, plant height, number of leaves per plant, leaf area, stem girth and yield. The major insect pests identified on the plant were Bemisia tabaci, Aphis gossypii, Leucinodes orbonalis and Eublemma olivacea. Bemisia tabaci and Aphis gossypii scores were significantly larger on cow dung and poultry manure plots. Leucinodes orbonalis and Eublemma olivacea numbers were not significantly different on the treated and control plots. Mean plant height, number of leaves and yield differed significantly among the soil amended plots. Even though soil amendments improve the nutrient content of the soil and the yield of crops it could lead to increase in pests numbers and damage caused to plants.


2020 ◽  
Vol 22 (1) ◽  
pp. 17-28
Author(s):  
Verónica Bonilla-Villalobos

Con la finalidad de describir la composición florística de la finca Los Llanos, (renombrada por la UNED, Estación Experimental Los Llanos, según acuerdo Rectoría CR 2019-914), se realizó una caracterización florística del bosque húmedo premontano transición a basal en un paisaje degradado ubicado en la comunidad de Los Llanos, Alajuela. El trabajo se realizó entre los años 2016 y 2017, por un periodo aproximado de siete meses. Se establecieron aleatoriamente 20 parcelas circulares donde se contabilizaron e identificaron todas las especies de plantas con un diámetro (DAP) mayor o igual a 10 cm. Se obtuvo información sobre: a) el estado actual del ecosistema, b) muestreo rápido de especies forestales, c) identidad taxonómica de las especies, d) gremios ecológicos de las especies, e) área basal, f) análisis de diversidad alfa y g) caracterización del suelo y h) recurso hídrico. Se encontró que el sitio es atravesado por la quebrada ojo de agua y cuenta con un bosque ribereño alterado, el cuál colinda con dos nacientes de agua registradas. Gran parte del territorio es dominado por plantas herbáceas, mayoritariamente de las familias Asteraceae, Poaceae, Verbenaceae, así como de cultivos mixtos como Phaseolus vulgaris y Zea mays. El sitio se caracteriza por tener suelos muy pedregosos y arcillosos (vertisoles), una cobertura forestal dispersa, con presencia de algunos árboles con alto valor comercial especialmente cedro (Cedrela), cenízaro (Samanea saman) y guanacaste (Enterolobium cyclocarpum) y el bosque ribereño está compuesto principalmente de especies como roble sabana (Tabebuia rosea), yos (Sapium glandulosum), cedro (Cedrela odorata) y guarumo (Cecropia). Además, la cobertura forestal riparia es discontinua y las áreas de cultivos dentro de la finca. Este estudio encontró una composición florística del bosque transicional muy alterada, pero con algunas especies representativas del Valle Central que pueden colaborar como remanentes para iniciar un proceso de restauración ecológica en la comunidad de Los Llanos.


Author(s):  
J. E. M. Mordue

Abstract A description is provided for Sclerotinia sclerotiorum. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOSTS: The fungus is plurivorous; hosts include Brassica oleracea var. capitata, B. chinensis, Helianthus annuus, Phaseolus vulgaris, Arachis hypogaea, Carthamus tinctorius, Citrus, Coriandrum sativum, Cucumis melo, Curcurbita pepo, Glycine max, Lycopersicon esculentum, Nicotiana tabacum, Lactuca saliva, Hibiscus sabdariffa, Cucumis sativus. DISEASE: The fungus causes dieases with several common names, e.g. cottony soft rot, white mould and watery soft rot. It is generally more important as a pathogen of vegetables in the field, during transit and in store. Woody plants, grasses and cereals are rarely attacked. Crops attacked include: cabbage (Brassica oleracea var. capitata and B. chinensis; 4, 713; 37, 611; 39, 515; 51, 2958); sunflower (Helianthus annuus; 3, 274; 4, 289; 8, 246; 38, 9; 43, 2012; 50, 3095; 51, 3486; 54, 4600; 55, 2832); common bean (Phaseolus vulgaris; 1, 116; 25, 592; 33, 401; 34, 425; 40, 446; 51, 870; 52, 531; 53, 731, 2373, 4183; 54, 4252, 4694; 55, 970); groundnut (Arachis hypogaea; 53, 3708); safflower (Carthamus tinctorius; 3, 650); citrus (Citrus spp. ; 24, 500; 43, 2910); coriander (Coriandrum sativum; 43, 2373); melon (Cucumis melo; 50, 1543; 53, 1109); squash (Curcurbitapepo; 50, 446); soyabean (Glycine max; 52, 3485; 53, 335, 336) tomato (Lycopersicon esculentum; 33, 56); tobacco (Nicotiana tabacum; 12, 729; 14, 126; 38, 279; 39, 46; 55, 2355); lettuce (Lactuca saliva; 16, 13); roselle (Hibiscus sabdariffa; 14, 106); cucumber (Cucumis sativus; 55, 2953). Most plant parts, above and at soil level, of herbaceous crops can be attacked at any age. The first symptoms are frequently the collapse of the plant due to stem infection near the soil. A soft rot develops, followed by the conspicuous, external white mycelium and the sclerotia which are often formed in the pith. Infections which arise at some height above soil level frequently begin from withering or fallen petals, infected by ascospores. GEOGRAPHICAL DISTRIBUTION: Very widespread but the disease is one of relatively cool moist conditions. In the Mediterranean area little or no disease occurs in the summer (31, 250; 43, 14). TRANSMISSION: Air-borne ascospores are the most important means of spread (12, 193; 33, 56, 401; 37, 611; 42, 527; 54, 4252, 4694; 55, 442, 970). The sclerotia (from which the apothecia arise) are the primary survival structures, in soil and host debris. Survival time is very variable but can be high after 3 years in soil (42, 244; 43, 2756; 45, 818; 50, 1621; 52, 3956; 54, 3712, 4252; Hoes, Phytopathology 65: 1431, 1975). Mycelium from sclerotia can also cause infection. Seed may be an infective source, either from contaminating sclerotia or internal mycelium (38, 169; 43, 1376; 47, 1998; 51, 3487; 52, 3485; 53, 335, 336).


2016 ◽  
Vol 25 (3) ◽  
pp. 246
Author(s):  
Redy Gaswanto ◽  
Muhammad Syukur ◽  
B S Purwoko ◽  
S H Hidayat

<p>Hasil iradiasi sinar gamma pada benih lima genotipe cabai telah menghasilkan populasi mutan M2 yang harus diuji ketahanannya terhadap infeksi Begomovirus menggunakan serangga vektor Bemisia tabaci. Keefektifan metode penularan secara individu lebih tinggi dibandingkan metode penularan massal, namun jika uji penapisan diaplikasikan untuk suatu populasi yang besar maka metode yang cocok adalah penularan massal. Penelitian bertujuan (1) mendapatkan metode penularan massal yang keefektifannya sama dengan metode penularan individu, (2) mengetahui tanaman inang yang cocok untuk perbanyakan serangga vektor B. tabaci, (3) mengetahui tingkat ketahanan cabai genotipe M<br />hasil iradiasi sinar gamma terhadap infeksi Begomovirus, dan (4) mengetahui perbedaan pertumbuhan dan hasil tanaman dari genotipe M2 dan genotipe tetua M2 saat terinfeksi Begomovirus. Penelitian dilaksanakan di Rumah Kasa dan Kebun Percobaan Balai Penelitian Tanaman Sayuran sejak bulan Mei sampai dengan Agustus 2013. Kajian penularan massal menggunakan rancangan acak kelompok (RAK) dengan lima perlakuan dan tiap perlakuan diulang lima kali, sedangkan kajian jenis tanaman inang untuk perbanyakan imago B. tabaci menggunakan rancangan yang sama diulang empat kali. Hasil penelitian menunjukkan bahwa tanaman terung ungu (Solanum melongena) dan kapas (Gossypium hirsutum) cocok dijadikan sebagai tanaman inang dalam usaha perbanyakan serangga vektor B. tabaci. Penggunaan vektor B. tabaci dalam kondisi viruliferous (masa akuisisi 48 jam) dengan jumlah sekitar 20–30 ekor dalam satu kotak sungkup kain kasa dapat digunakan sebagai metode penularan massal untuk populasi 50 bibit tanaman cabai (kondisi 2–4 daun sejati) dengan keefektifan setara dengan metode penularan secara individu. Rerata dari 195 individu cabai genotipe Kencana M2 dan SSP M2 masuk dalam kategori tahan dan agak tahan terhadap infeksi Begomovirus, sedangkan rerata dari 195 individu cabai genotipe Seloka M2, Lembang-1 M2, dan Tanjung-2 M2 masuk dalam kategori rentan-agak rentan. Perubahan karakter kuantitatif dari pertumbuhan dan hasil tanaman pada lima genotipe M2 jauh lebih kecil jika dibandingkan dengan genotipe tetua M2 saat terinfeksi Begomovirus.</p><p><br /><br /></p>


1960 ◽  
Vol 40 (1) ◽  
pp. 104-109 ◽  
Author(s):  
D. S. MacLachlan

Two viruses were isolated from Ruby Red rhubarb growing in the Ottawa district. Isolate I produced a severe rugosity and mottle on rhubarb, a systemic mottle in Nicotiana tabacum, N. glutinosa and Datura stramonium, and local lesions on Phaseolus vulgaris, Vigna sinensis and Beta vulgaris. The virus was inactivated after being heated for 10 minutes at 65 °C., and became non-infective after the sap was diluted to 1:2000. Isolate II incited the formation of chlorotic and necrotic spots on rhubarb, and produced a systemic mottle in N. tabacum, N. glutinosa, and D. stramonium. The virus was inactivated by being heated at 75 °C. for ten minutes, and became non-infective after the sap was diluted 1:8000. Both isolates were mechanically transmitted by diluting crude sap 1;100 in 0.1 M. phosphate buffer (pH 8–9) and rubbing on leaves dusted with carborundum. The success in isolating these viruses or virus strains was dependent on the season in which isolations were attempted. The size of the virus particles of both isolates was 478 × 15μm.


2011 ◽  
Vol 68 (1) ◽  
pp. 120-123 ◽  
Author(s):  
Kelly Cristina Gonçales Rocha ◽  
Julio Massaharu Marubayashi ◽  
Jesús Navas-Castillo ◽  
Valdir Atsushi Yuki ◽  
Carlos Frederico Wilcken ◽  
...  

Bemisia tabaci (Genn.) is one of the most important pests in cultivated areas of vegetables and ornamental crops around the world. Based on the mitochondrial cytochrome oxidize I (mtCOI) sequence, there is evidence that B. tabaci should be considered a cryptic species complex of 11 groups containing 24 species. Two of the groups, Middle East-Asia Minor 1 and Mediterranean include biotypes B and Q, respectively. In this study we evaluated the mtCOI sequence of B. tabaci populations collected in sites of the state of São Paulo, Brazil. Using PCR-RFLP with Taq I, a typical biotype B profile was obtained for all specimens. Based on the comparison with mtCOI reference sequences we found four haplotypes all belonging to the Middle East-Asia Minor 1. They occurred in the hosts pepper (Capsicum annuum L.), tomato (Solanum lycopersicum L.), eggplant (Solanum melongena L.) and cucurbitaceae plants.


Insects ◽  
2020 ◽  
Vol 11 (2) ◽  
pp. 78
Author(s):  
Tingfei Sun ◽  
Zhang Shen ◽  
Mobeen Shaukat ◽  
Cailian Du ◽  
Shaukat Ali

This study reports the effects of seed treatment with Cordyceps fumosorosea on seed germination, growth, colonization of eggplant (Solanum melongena), and growth of Bemisia tabaci (feeding on fungal colonized eggplant leaves). Germination rates of eggplant seeds were similar among different treatments. The growth parameters such as root length, shoot length, and number of leaves) differed significantly after 15, 30, and 60 days of seed treatment. The total dry weight of eggplant in response to treatment with C. fumosorosea isolates increased significantly when compared with the control. Both isolates of C. fumosorosea colonized different plant tissues, although the extent of colonization decreased during the experimental period. The colonization of eggplants by both C. fumosorosea isolates resulted in a significant reduction of B. tabaci incidence. This study possibly provides the first report of increased plant growth and increased insect mortality in eggplants inoculated with C. fumosorosea isolates.


2021 ◽  
Vol 5 (2) ◽  
pp. 62-66
Author(s):  
Md. Touhidul Islam

The aim of this study was to investigate the behavioral response of Bemisia tabaci towards Metarhizium anisopliae (isolates PR1 and GT3) volatiles. Behavioral response of B. tabaci was investigated based on adult feeding and oviposition preference in eggplant Solanum melongena L. The highest mean number of adult (87) and egg (418) of B. tabaci were observed in the control plant, while the lowest mean number of adult (26) and egg (107) of B. tabaci were deposited in the PR1-treated plant. There were 8 and 5 compounds identified from the isolates PR1 and GT3, respectively. The highest amount of compounds of 1-Hydroxy-2-aminopropane (61.96%) and 1, 4-Dioxane-2-ol (54.18%) were released by PR1 and GT3 respectively. The results obtained so far revealed that whitefly avoided the eggplants provided with cultures of the M. anisopliae isolates emanating the volatile organic compounds and suitability largely depended upon the volatile profile.


Sign in / Sign up

Export Citation Format

Share Document