scholarly journals Effect of Bacillus and Trichoderma species in the management of the bacterial wilt of tomato (Lycopersicum esculentum) in the field

Author(s):  
Caroline K. Kariuki ◽  
Eunice W. Mutitu ◽  
William M. Muiru

Abstract Background Bacterial wilt caused by Ralstonia solanacearum is one of the most devastating diseases in tomato cultivation. This study aimed to evaluate the effect of Bacillus and Trichoderma isolates to manage the bacterial wilt disease. Main body of the abstract Field experiments were conducted in a randomized complete block design at Mwea and Kabete sites in Kenya. The treatments included 3 Trichoderma; 2 Bacillus isolates; a mixture of T1, T2, and T4; chemical standard; and distilled water as control. Trichoderma and Bacillus isolates were grown on sterilized sorghum grain and cow manure carriers respectively. Antagonist’s inoculation was carried out by dipping tomato plants for 30 min in each treatment suspension. Each treatment was then applied at a rate of 150 ml/plant hole and this was repeated after 35 days. All the treatments significantly reduced bacterial wilt incidence and severity at P ≤ 0.05 than the control at both sites. Trichoderma isolate T1, followed by Bacillus isolate CB64, was the best in reducing the disease incidence by more than 61.66 and 53%, respectively at both sites. Treatment CB64 and T1 had the highest reduction of R. solanacearum population in the soil by 93.17 and 92.07%, respectively. However, control had a pathogen increase of 20.40%. CB64 and T1 performed significantly better compared to the standard, while the mixture of isolates T1, T2, and T4 performed the poorest in all parameters. The treatments also increased the yield of tomato. Short conclusion Results from this study showed that Trichoderma and Bacillus isolates are effective biological control agents for use in management of bacterial wilt.

2014 ◽  
Vol 8 ◽  
pp. 50-55 ◽  
Author(s):  
Ram D. Timila ◽  
Sharada Joshi

Bacterial wilt caused by Ralstonia solanacearum E.F. Smith is one of the destructive diseases of tomato. Experiments were conducted to confirm the resistance and to evaluate varieties received from Asian Vegetable Research and Development Center against bacterial wilt disease in the farmers’ bacterial wilt sick fields at Thaiba and at Panchkhal during 1999 and 2000-2001 respectively. A total of five varieties such as CLN 2026 C, CLN 2026 D, CLN 1466 J, CLN 1466 P and susceptible check Lapsigede or L 390 were included in the experiments. Randomized complete block design with 4 replications was commenced at both the locations. In terms of disease incidence and yield parameters as well as consumers’ preference on the fruit size, CLN 2026 C was found the best variety followed by CLN 2026 D. Wilt incidence was significantly lower in those varieties showing resistant reaction than in susceptible check. However, the marketable fruit yields were significantly higher with low wilt incidences in CLN 1466 P and CLN 1466 J also compared to susceptible check. But the large fruit size of those varieties was not acceptable to the consumers and the  growers. Thus, CLN 2026 C and CLN 2026 D could be used as resistant variety to minimize crop losses from bacterial wilt disease.Nepal Agric. Res. J. Vol. 8, 2007, pp. 50-55DOI: http://dx.doi.org/10.3126/narj.v8i0.11580


2018 ◽  
Vol 46 (2) ◽  
pp. 189
Author(s):  
Muhammad Roiyan Romadhon ◽  
Surjono Hadi Sutjahjo ◽  
Dan Siti Marwiyah

<p><em></em><em>ABSTRACT<br /><br />Bacterial wilt and fruit cracking are serious problems in tomatoes cultivation in the lowland area. This research aimed to evaluate the yield of M4 generation of tomatoes in the field and the incidence of bacterial wilt disease and fruit cracking in low altitude. The research was conducted at the IPB Experimental Field in Leuwikopo, Dramaga, Bogor, from December 2015 to April 2016. The experiment used a randomized complete block design with three replications. The material consisted of 15 M4 genotypes and two controls (Berlian and Kefaminano 6). The results showed that genotype of M4/495 Lombok 1-9-2 (U2) has high  productivity. Genotype M4/990 Lombok 1-5-1 (U1) has  high weight  per fruit and resistant to fruit cracking. Genotype M4/495 GL2-8-10 (U2), M4/495 Kemir 1- 4-7 (U3), M4/495 STBGL 1-2-3 (U1) M4/990 Lombok 1-5-1 (U1), and  M4/495 STBGL 1-2-9 (U1) have the lowest incidence of bacterial wilt (0.00%). Two genotypes which have high productivity and resistant to fruit cracking are M4/495 Lombok 1-9-2 (U2) and M4/990 Lombok 1-5-1 (U1), and to be evaluated in a preliminary yield trial.<br /><br />Keywords: bacterial wilt, fruit cracking, genotype, yield<br /><br /></em></p>


2016 ◽  
Vol 15 (1) ◽  
pp. 20
Author(s):  
Yadi Suryadi ◽  
Sri A. Rais

<p>The objective of the study was to evaluate resistance response of groundnut genotypes against bacterial wilt (Ralstonia solanacearum) in the green house of Biochemistry Department, ICABIOGRAD, Bogor. Ralstonia solanacearum isolate was obtained from groundnut plant showing wilt symptom, collected from Karadenan village (Cibinong). Preparation of bacterial RS inoculum was done using SP (sucrose peptone) medium. Groundnut plants were inoculated by RS isolate using inoculum capacity of 107 cfu/ml. The experiment was arranged in randomized complete block design (RCBD) consisted of seven treatments with four replications, whilst Tupai and Kelinci genotypes were used as resistant and susceptible control check, respectively. The result indicated that groundnut genotypes i.e. ICGV 88262, Local Sindangbarang, PI 203395, ICG 10067, and ICG 3400, showed resistant response against bacterial wilt causing wilt damage of &lt;20%. Bacterial wilt disease could affect reductions of some groundnut phenotypic character. The plant height of resistant groundnut showed relatively tall than that of Kelinci. In addition, it showed the lowest healthy pod yield among the genotypes tested.</p><p> </p><p><strong>Abstrak</strong></p><p>Penelitian bertujuan untuk mempelajari tingkat ketahanan genotipe kacang tanah terhadap penyakit layu bakteri (Ralstonia solanacearum) di rumah kaca Kelompok Peneliti Biokimia BB-Biogen. Isolat R. solanacearum diperoleh dari tanaman kacang tanah yang menunjukkan gejala layu dari Desa Karadenan (Cibinong). Penyiapan dan penyediaan inokulum bakteri R. solanacearum menggunakan media SP (sukrose pepton). Tanaman kacang tanah diinokulasi dengan isolat R. solanacearum dengan kerapatan koloni 107 cfu/ml. Penelitian disusun menggunakan rancangan acak kelompok dengan tujuh perlakuan dan empat ulangan. Untuk pembanding tahan dan rentan masing-masing digunakan genotipe Tupai dan Kelinci. Hasil penelitian menunjukkan bahwa genotipe ICGV 88262, lokal Sindangbarang, PI 203395, ICG 10067, dan ICG 3400 tahan terhadap penyakit layu bakteri dengan nilai kerusakan &lt;20%. Penyakit layu bakteri berpengaruh terhadap penurunan beberapa karakter fenotipik kacang tanah, di mana tanaman genotipe kacang tanah tahan PLB relatif lebih tinggi dibandingkan dengan genotipe Kelinci. Polong bernas Kelinci paling sedikit di antara semua genotipe uji.</p>


Plant Disease ◽  
2019 ◽  
Vol 103 (4) ◽  
pp. 668-676
Author(s):  
Krishna D. Puri ◽  
Gary E. Vallad ◽  
Qing-Ming Qin ◽  
Ryan J. Hayes ◽  
Krishna V. Subbarao

Verticillium wilt of lettuce, caused by the soilborne pathogen Verticillium dahliae, poses a serious threat to the California lettuce industry. Knowledge of disease development and its impact on postharvest marketability would facilitate better management of the affected fields. This study investigated postharvest marketability of 22 lettuce varieties harvested from two Verticillium-infested commercial lettuce fields in Salinas and Watsonville, CA, in 2005 using a randomized complete block design. Periodic sampling to monitor disease in several crisphead varieties in the field demonstrated that root symptoms developed quickly at later stages of heading, followed by the onset of foliar symptoms as the crop reached harvest maturity. Harvested marketable heads were vacuum cooled soon after harvest to about 4°C and maintained at this temperature in commercial coolers. The impact of V. dahliae on postharvest marketability was assessed based on the percentage of heads per case deemed marketable following 1, 2, and 3 weeks of refrigerated storage. Across both field experiments, the average disease incidence and postharvest marketability ranged from 4.2 to 87.5% and from 69.4 to 100.0%, respectively, among lettuce types and varieties. The Pearson correlation analysis detected no significant relationship between disease incidence and postharvest marketability across all varieties tested (r = 0.041, P = 0.727), or within lettuce types, even though V. dahliae was recovered from 34% of the plants harvested, and recovery ranged from 0 to 73.3% for V. dahliae and from 10 to 91.7% for non-V. dahliae (V. isaacii or V. klebahnii) species. These findings demonstrate that growers can harvest lettuce from an infested field before foliar symptoms develop with negligible impact by Verticillium spp. on postharvest marketability or quality.


2001 ◽  
Vol 183 (12) ◽  
pp. 3597-3605 ◽  
Author(s):  
Julie Tans-Kersten ◽  
Huayu Huang ◽  
Caitilyn Allen

ABSTRACT Ralstonia solanacearum, a widely distributed and economically important plant pathogen, invades the roots of diverse plant hosts from the soil and aggressively colonizes the xylem vessels, causing a lethal wilting known as bacterial wilt disease. By examining bacteria from the xylem vessels of infected plants, we found thatR. solanacearum is essentially nonmotile in planta, although it can be highly motile in culture. To determine the role of pathogen motility in this disease, we cloned, characterized, and mutated two genes in the R. solanacearum flagellar biosynthetic pathway. The genes for flagellin, the subunit of the flagellar filament (fliC), and for the flagellar motor switch protein (fliM) were isolated based on their resemblance to these proteins in other bacteria. As is typical for flagellins, the predicted FliC protein had well-conserved N- and C-terminal regions, separated by a divergent central domain. The predicted R. solanacearum FliM closely resembled motor switch proteins from other proteobacteria. Chromosomal mutants lackingfliC or fliM were created by replacing the genes with marked interrupted constructs. Since fliM is embedded in the fliLMNOPQR operon, the aphAcassette was used to make a nonpolar fliM mutation. Both mutants were completely nonmotile on soft agar plates, in minimal broth, and in tomato plants. The fliC mutant lacked flagella altogether; moreover, sheared-cell protein preparations from the fliC mutant lacked a 30-kDa band corresponding to flagellin. The fliM mutant was usually aflagellate, but about 10% of cells had abnormal truncated flagella. In a biologically representative soil-soak inoculation virulence assay, both nonmotile mutants were significantly reduced in the ability to cause disease on tomato plants. However, the fliC mutant had wild-type virulence when it was inoculated directly onto cut tomato petioles, an inoculation method that did not require bacteria to enter the intact host from the soil. These results suggest that swimming motility makes its most important contribution to bacterial wilt virulence in the early stages of host plant invasion and colonization.


2016 ◽  
Vol 41 (4) ◽  
pp. 713-723
Author(s):  
S Akther ◽  
F Ahmed ◽  
MR Islam ◽  
MA Hossen ◽  
AHMM Rahman Talukder

Field experiments were carried out in the Agronomy field of BARI, Joydebpur, RARS, Jamalpur and RARS, Ishurdi during two consecutive kharif seasons of 2012 and 2013 to determine the suitable plant spacing and optimum fertilizer dose for higher yield of mukhikachu. Three levels of spacing viz., 60 cm x 60 cm, 60 cm x 45 cm and 60 cm x 30 cm and three levels of fertilizer dose viz., recommended dose (3000-96-27-81-18 kg ha-1 of CD-N-P-K-S), 25% less than the recommended dose and 25% higher than the recommended dose were used as treatment variables. The experiments were laid out in factorial randomized complete block design with three replications. Results revealed that the closer spacing (60 cm x 30 cm) in combination with 25% higher than the recommended fertilizer dose gave the maximum edible yield of mukhikachu (two years average) at all locations (20.04 t ha-1, 20.75 t ha-1 and 16.63 t ha-1 at Joydebpur, Jamalpur and Ishurdi, respectively). The wider spacing (60 cm x 60 cm) coupled with 25% less than the recommended fertilizer dose produced the lowest yield (two years average). The maximum benefit- cost ratio (two years average) was obtained from the combination of the recommended fertilizer dose and 60 cm x 30 cm spacing, that were 2.93 at Joydebpur and 3.42 at Ishurdi, while at Jamalpur the maximum benefit-cost ratio (two years average) was found maximum from 60 cm x 30 cm spacing with 25% higher than the recommended fertilizer dose (3.12).Bangladesh J. Agril. Res. 41(4): 713-723, December 2016


2021 ◽  
Author(s):  
April M MacIntyre ◽  
Valerian Meline ◽  
Zachary Gorman ◽  
Steven P Augustine ◽  
Carolyn J Dye ◽  
...  

Ralstonia solanacearum causes plant bacterial wilt disease, leading to severe crop losses. Xylem sap from R. solanacearum-infected tomato is enriched in host produced trehalose. Water stressed plants accumulate the disaccharide trehalose, which increases drought tolerance via abscisic acid (ABA) signaling networks. Because infected plants have reduced water flow, we hypothesized that bacterial wilt physiologically mimics drought stress, which trehalose could mitigate. Transcriptomic responses of susceptible vs. resistant tomato plants to R. solanacearum infection revealed differential expression of drought-associated genes, including those involved in ABA and trehalose metabolism. ABA was enriched in xylem sap from R. solanacearum-infected plants. Treating roots with ABA lowered stomatal conductance and reduced R. solanacearum stem colonization. Treating roots with trehalose increased ABA in xylem sap and reduced plant water use by reducing stomatal conductance and temporarily improving water use efficiency. Further, trehalose-treated plants were more resistant to bacterial wilt disease. Trehalose treatment also upregulated expression of salicylic acid (SA)-dependent defense genes, increased xylem sap levels of SA and other antimicrobial compounds, and increased wilt resistance of SA-insensitive NahG tomato plants. Additionally, trehalose treatment increased xylem concentrations of jasmonic acid and related oxylipins. Together, these data show that exogenous trehalose reduced both water stress and bacterial wilt disease and triggered systemic resistance. This suite of responses revealed unexpected linkages between plant responses to biotic and abiotic stress and suggests that that R. solanacearum-infected tomato plants produce more trehalose to improve water use efficiency and increase wilt disease resistance. In turn, R. solanacearum degrades trehalose as a counter-defense.


Plant Disease ◽  
2016 ◽  
Vol 100 (7) ◽  
pp. 1364-1370 ◽  
Author(s):  
Carl A. Strausbaugh ◽  
Erik J. Wenninger ◽  
Imad A. Eujayl

Curly top in sugar beet caused by Beet curly top virus (BCTV) is an important yield-limiting disease that can be reduced via neonicotinoid and pyrethroid insecticides. The length of efficacy of these insecticides is poorly understood; therefore, field experiments were conducted with the seed treatment Poncho Beta (clothianidin at 60 g a.i. + beta-cyfluthrin at 8 g a.i. per 100,000 seed) and foliar treatment Asana (esfenvalerate at 55.48 g a.i./ha). A series of four experiments at different locations in the same field were conducted in 2014 and repeated in a neighboring field in 2015, with four treatments (untreated check, Poncho Beta, Asana, and Poncho Beta + Asana) which were arranged in a randomized complete block design with eight replications. To evaluate efficacy, viruliferous (contain BCTV strains) beet leafhoppers were released 8, 9, 10, or 11weeks after planting for each experiment, which corresponded to 1, 2, 3, and 4 weeks after Asana application. Over both years, in 30 of 32 observation dates for treatments with Poncho Beta and 14 of 16 observation dates for Asana, visual curly top ratings decreased an average of 41 and 24%, respectively, with insecticide treatments compared with the untreated check. Over both years, in eight of eight experiments for treatments with Poncho Beta and six of eight experiments for Asana, root yields increased an average of 39 and 32%, respectively, with treatment compared with the untreated check. Over both years, the Poncho Beta treatments increased estimated recoverable sucrose (ERS) yield by 75% compared with the untreated check for weeks 8 and 9. By week 10, only the Poncho Beta + Asana treatment led to increases in ERS in both years, while the influence of increasing host resistance may have made other treatments more difficult to separate. When considering curly top symptoms, root yield, and ERS among all weeks and years, there was a tendency for the insecticides in the Poncho Beta + Asana treatment to complement each other to improve efficacy.


Author(s):  
Edward F. Durner

Abstract This chapter focuses on randomized complete block design (RCBD). The RCBD can be simple, holding several levels of a single treatment, or complex, holding a complicated factorial. Field experiments may be blocked due to an observed or potential gradient in the field where the experiment will be performed. The yield of four lettuce cultivars was used as an example.


2016 ◽  
Vol 49 (1) ◽  
pp. 91-98 ◽  
Author(s):  
H. Barari

AbstractTrichodermaspp. have long been used as biological control agents against plant fungal diseases, but the mechanisms by which the fungi confer protection are not well understood. Our goal in this study was to isolate species ofTrichoderma, that exhibit high levels of biocontrol efficacy from natural environments and to investigate the mechanisms by which these strains confer plant protection. In this study, efficacy of the native isolates ofTrichodermaspecies to promote the growth and yield parameters of tomato and to manageFusariumwilt disease underin vitroandin vivoconditions were investigated. The dominant pathogen, which causesFusariumwilt of tomato, was isolated and identified asFusarium oxysporumf. sp.lycopersici(FOL). Twenty eight nativeTrichodermaantagonists were isolated from healthy tomato rhizosphere soil in different geographical regions of Mazandaran province, Iran. Underin vitroconditions, the results revealed thatTrichoderma harzianum, isolate N-8, was found to inhibit effectively the radial mycelial growth of the pathogen (by 68.22%). Under greenhouse conditions, the application ofT. harzianum(N-8) exhibited the least disease incidence (by 14.75%). Also, tomato plants treated withT. harzianum(N-8) isolate showed a significant stimulatory effect on plant height (by 70.13 cm) and the dry weight (by 265.42 g) of tomato plants, in comparison to untreated control (54.6 cm and 195.5 g). Therefore, the antagonistT. harzianum(N-8) is chosen to be the most promising bio-control agent forF. oxysporumf. sp.lycopersici. On the base of present study, the biocontrol agents of plant diseases might be exploited for sustainable disease management programs to save environmental risk.


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