Inoculum reduction and vector control on the temporal progress of citrus variegated chlorosis incidence

2021 ◽  
Author(s):  
Renato B. Bassanezi ◽  
Isabela V. Primiano ◽  
Alécio S. Moreira
Keyword(s):  
Vector Control ◽  
Citrus Variegated Chlorosis ◽  
Temporal Progress

scholarly journals Efficacy of Area-Wide Inoculum Reduction and Vector Control on Temporal Progress of Huanglongbing in Young Sweet Orange Plantings

Plant Disease ◽  
2013 ◽  
Vol 97 (6) ◽  
pp. 789-796 ◽  
Author(s):  
Renato B. Bassanezi ◽  
Luiz H. Montesino ◽  
Nelson Gimenes-Fernandes ◽  
Pedro T. Yamamoto ◽  
Tim R. Gottwald ◽  
...  
Keyword(s):  
Vector Control ◽  
Field Experiments ◽  
Sweet Orange ◽  
Control Strategies ◽  
Disease Incidence ◽  
Critical Role ◽  
Control Program ◽  
Candidatus Liberibacter ◽  
Local Vector ◽  
Temporal Progress

Huanglongbing (HLB), caused by ‘Candidatus Liberibacter’ spp. and transmitted by the Asian citrus psyllid Diaphorina citri (ACP), is an important threat to citrus industries worldwide, causing significant yield loss. The current recommended strategies to manage HLB are to eliminate HLB-symptomatic trees to reduce sources of bacterial inoculum and to apply insecticides to reduce psyllid vector populations. The objective of this study was to assess the effectiveness and the importance of both strategies applied within young citrus plots (local management), in different frequencies and combinations, on HLB temporal progress. Two factorial field experiments, E1 and E2, were initiated in a new plantation of sweet orange in an HLB epidemic region of Sao Paulo, Brazil, in October 2005 and May 2006, respectively. Local inoculum reduction (tree removal) intervals for E1 were every 4, 8, and 16 weeks and, for E2, every 2, 4, 12, and 26 weeks. Local vector control strategies for E1 were no control, program A (PA), and program B (PB); and, for E2, no control and program C (PC), as follows. Psyllids were controlled with two 56-day-interval soil or drench applications of systemic insecticides concurrently with the rainy season each year and, during the rest of the year, with insecticide sprays every 28 days for PA and every 14 days for PB and PC. Regional HLB management was present for E1 and absent for E2. The beginning of the HLB epidemic was delayed for 10 months in E1 compared with appearance of the first diseased tree in E2 but wasn't affected by different local strategies in either experiment. After 60 (E1) and 53 (E2) months, the HLB incidence and progress rates were not affected by different frequencies of local inoculum reduction in either experiment, and were different only in plots with and without local vector control in E2. In E1, the disease incidence was reduced by 90% and the disease progress rate by 50% in plots both with and without vector control. These reductions were explained by smaller psyllid populations and lower frequency of bacterialiferous psyllids in E1 compared with E2. Annual productivity increased over time in E1, as expected for young plantings, but remained stable or decreased in E2. These results confirm that immigration of bacterialiferous ACP vectors plays a critical role in HLB epidemics and suggest that area-wide inoculum reduction and ACP management strongly affect HLB control.

Huanglongbing and citrus variegated chlorosis integrated management based on favorable periods for vector population increase and symptom expression

Plant Disease ◽  
2021 ◽  
Author(s):  
Renato Beozzo Bassanezi ◽  
Isabela V. Primiano
Keyword(s):  
Vector Control ◽  
Integrated Management ◽  
Area Under The Curve ◽  
Threshold Level ◽  
Population Increase ◽  
Citrus Variegated Chlorosis ◽  
Vector Population ◽  
Citrus Production ◽  
Candidatus Liberibacter ◽  
Autumn And Winter

Huanglongbing (HLB, associated with ‘Candidatus Liberibacter asiaticus’ and transmitted by the Asian citrus psyllid Diaphorina citri) and citrus variegated chlorosis (CVC, caused by Xylella fastidiosa subsp. pauca and transmitted by sharpshooter species) have been managed by vector control and removal of symptomatic trees. Although vectors and new symptomatic trees can be detected year-round, peaks of vector populations are higher in spring and summer and the most symptomatic trees are found in autumn and winter. This work aimed to compare the management of both diseases during these favorable periods. The experiment was conducted over five years in a commercial orchard and had a 3 by 2 factorial design. The factor “vector control” had 3 levels: monthly vector control year-round (VCYR); monthly vector control in spring and summer (VCSS); and vector control when a threshold level of 10% occupancy was detected (VCOT). The factor “inoculum removal” had 2 levels: monthly eradication year-round (TEYR); and monthly eradication in autumn and winter (TEAW). Host flush, both HLB and CVC vector populations, and the number of symptomatic citrus plants were visually assessed. The level of vectors over the seasons, as measured using the average area under the curve (AUC), was similar for all treatments with the exception of psyllid abundance, which was around 4.5 times higher for VCSS than other treatments. For both diseases, no difference in the average AUC of disease progress and disease final incidence was observed. VCOT or adjusted VCSS associated to TEAW could be integrated for sustainable citrus production.

PENGARUH PELATIHAN PENGENDALIAN VEKTOR DEMAM BERDARAH TERHADAP MAYA INDEX PADA SISWA SEKOLAH DASAR DI MAJALENGKA

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Wawan Kurniawan
Keyword(s):  
Vector Control ◽  
Dengue Fever ◽  
Dengue Hemorrhagic Fever ◽  
Intervention Group ◽  
Hemorrhagic Fever ◽  
Control Group ◽  
Control Group Design ◽  
Group Design ◽  
Quasi Experimental ◽  
Dengue Vector Control

ABSTRAK  Latar belakang: Demam Berdarah Dengue (DBD) disebabkan oleh virus Dengue dapat menyebabkan kematian. Pencegahan DBD yang dianggap paling tepat adalah Pemberantasan Sarang Nyamuk (PSN). Penelitian ini bertujuan untuk mengetahui pengaruh pelatihan pengendalian vektor Demam Berdarah pada siswa sekolah dasar terhadap Maya Index di Majalengka. Metode: Penelitian ini menggunakan desain quasi experiment (pretest-posttest control group design). Sebanyak 4 sekolah terpilih sebagai kelompok intervensi dan 4 sekolah lainnya sebagai kontrol. Subyek penelitian adalah siswa kelas IV-VI yang terdiri dari 171 siswa pada kelompok intervensi dan 163 pada kelompok kontrol. Instrumen yang digunakan adalah formulir pemantauan jentik berkala. Hasil: Jumlah rumah dengan kategori Maya Index tinggi berkurang dari 27,5% menjadi 9,4%. Terjadi penurunan angka BRI kategori tinggi pada kelompok intervensi dari 20,5% menjadi 1,8%. Pada kelompok kontrol tidak terjadi penurunan angka BRI kategori tinggi (22,1%), sebaliknya terjadi penurunan kategori rendah dari 34,4% menjadi 3,7%. Tidak terjadi penurunan angka HRI pada kelompok intervensi maupun kontrol. Kesimpulan: Pelatihan pengendalian vektor Demam Berdarah dapat menurunkan nilai BRI dan Maya Index, tetapi tidak berpengaruh terhadap nilai HRI. Tidak adanya perubahan nilai HRI menunjukkan bahwa kebersihan dan sanitasi lingkungan merupakan faktor yang berpengaruh terhadap probabilitas kejadian demam berdarah. Kata Kunci : Demam Berdarah, Maya Index, pelatihan, pengendalian vektor   ABSTRACT Background: Dengue Hemorrhagic Fever (DHF) caused by Dengue virus could cause death. The most appropriate prevention of Dengue is eradication of mosquito nests (PSN). This study aims to determine the effect of Dengue vector control training on elementary students towards Maya Index in Majalengka. Method: This study used quasi-experimental design (pretest-posttest control group design). A total of 4 schools were selected as intervention groups and 4 other schools as controls. The subjects were students in grades IV-VI consisting of 171 students in the intervention group and 163 in the control group. The instrument used was periodic larva monitoring form. Results: The number of houses with a high Maya Index category in the intervention group decreased from 27.5% to 9.4%. There was a decrease in the high BRI category in the intervention group from 20.5% to 1.8%. In the control group, there was no decrease in the high BRI category (22.1%), on the contrary, there was a decrease in the low category from 34.4% to 3.7%. There was no decrease in HRI rates both of intervention or control groups. Conclusion: Dengue Fever vector control training could decrease the value of BRI and Maya Index, but does not affect the value of HRI. The absence of changes in HRI  indicate that environmental hygiene and sanitation are factors that influence the probability of dengue fever occurrence. Keywords: Dengue Hemorrhagic Fever, Maya Index, training, vector control

PG-less Vector Control with Estimating Functions of Motor Parameter.

1991 ◽  
Vol 111 (5) ◽  
pp. 373-378 ◽  
Author(s):  
Naoki Yamamura ◽  
Masahiko Iwasaki ◽  
Hirotaka Sakurai ◽  
Yuzuru Tunehiro
Keyword(s):  
Vector Control ◽  
Estimating Functions ◽  
Motor Parameter

Sensorless Vector Control Using Simplified DC-Link Current Sampling

2013 ◽  
Vol 133 (7) ◽  
pp. 668-675
Author(s):  
Satoshi Sumita ◽  
Yasuo Notohara ◽  
Daisuke Maeda ◽  
Yoshiki Ito
Keyword(s):  
Vector Control ◽  
Sensorless Vector Control ◽  
Current Sampling
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