Soil Drench Research Articles

Pseudomonas fluorescens SP007S Formulations in Controlling Soft Rot Disease and Promoting Growth in Kale

Kale has gained popularity as a healthy food choice due to its rich nutrient profile. However, kale production systems are also affected by various pests and diseases, especially plant pathogenic bacteria, such as Pectobacterium carotovorum. The purpose of this research was to investigate the biocontrol activity of the Pseudomonas fluorescens strain SP007s and develop a formulation that provides stability, long shelf life, and disease control, as well as promoting growth in kale; we expect this formulation to have further commercial applications in the cultivation of kale. The results indicated that a unique mixture of paper sludge, sugar sludge, and glycerol at 40% relative humidity promoted SP007 survival for 6 months at room temperature (30 °C) with measures of 5.92 × 106 CFU/g. This treatment maintained the control efficacy of P. carotovorum in infected soil within 28 days of soil drenching. We evaluated the SP007s formula for controlling soft rot disease in greenhouse conditions, and our results revealed that it can reduce the disease in kale by 65.2% and promotes growth in terms of canopy width, shoot height, number of leaves per plant, fresh weight, and dry weight, which were superior to the control. In addition, the formula can induce the accumulation of endogenous salicylic acid and phenolic compounds, as well as a systemic acquired resistance pathway in the plant defense system. Therefore, the formula of SP007s can be a promising novel biocontrol formula for use in kale production, as it promotes plant growth and acts against P. carotovorum causal soft rot disease.

Effect of Biocapsule and Nano Micronutrients on Growth, Quality and Yield of Lettuce (Lactuca sativa)

The present experiment was carried out during 2021-22 in Central Horticulture Research Farm of Department of Horticulture, SHUATS, Prayagraj. The experiment was conducted in Randomized Block Design with 10 treatment replicated thrice with an objective to find out best treatment for growth, yield, quality and B:C ratio. The treatments were T0 (Control), T1 (NPK (RDF) 15:5:20),T2 (Biocapsule 500ppm (Soil drenching)),T3 (NPK (RDF) 15:5:20 + Biocapsule 500ppm (Soil drenching)),T4 (NPK (RDF) + Foliar application of Zno (12%) and Feo (12%) Nano particles (NPs)),T5 (Biocapsule 500ppm (Soil drenching) + Foliar application of Zno (12%) and Feo(12%) Nano particles (NPs)),T6 (NPK (RDF) 15:5:20 + Biocapsule 500ppm (Soil drenching) + Foliar application of Zno (12%) and Feo (12%) Nano particles (NPs)),T7 (NPK (RDF) 15:5:20 + Biocapsule 250ppm (Soil drenching)),T8 (Biocapsule 250ppm (Soil drenching) + Foliar application of Zno (12%) and Feo (12%) Nano particles (NPs)),T9 (NPK (RDF) 15:5:20 + Biocapsule 250ppm (Soil drenching) + Foliar application of Zno (12%) and Feo (12%) Nano particles (NPs)). From our experiment it was concluded that the treatment T5 (Biocapsule 500ppm (Soil drenching) + Foliar application of ZnO (12%) and FeO (12%) Nano particles (NPs)) was found to be best in the terms of germination percentage, vegetative growth, yield parameters, quality parameters and economics with Benefit Cost ratio 2.67.

Exogenous application of stevioside enhances root growth promotion in soybean (Glycine max (L.) Merrill)

The present study aims to investigate the impact of externally applied stevioside (a sugar-based glycoside) on soybean root growth by examining morpho-physiological characteristics, biochemical parameters, and gene expression. Soybean seedlings (10-day-old) were treated with stevioside (0, 8.0 μM, 24.5 μM, and 40.5 μM) for four times at six days’ intervals by soil drenching. Treatment with 24.5 μM stevioside significantly increased root length (29.18 cm plant−1), root numbers (38.5 plant−1), root biomass (0.95 g plant−1 FW; 0.18 g plant−1 DW), shoot length (30.96 cm plant−1), and shoot biomass (2.14 g plant−1 FW; 0.36 g plant−1 DW) compared to the control. Moreover, 24.5 μM of stevioside was effective in enhancing photosynthetic pigments, leaf relative water content, and antioxidant enzymes compared to control. Conversely, plants exposed to a higher concentration of stevioside (40.5 μM), elevated total polyphenolic content, total flavonoid content, DPPH activity, total soluble sugars, reducing sugars, and proline content. Furthermore, gene expression of root growth development-related genes such as GmYUC2a, GmAUX2, GmPIN1A, GmABI5, GmPIF, GmSLR1, and GmLBD14 in stevioside-treated soybean plants were evaluated. Stevioside (8.0 μM) showed significant expression of GmPIN1A, whereas, 40.5 μM of stevioside enhanced GmABI5 expression. In contrast, most of the root growth development genes such as GmYUC2a, GmAUX2, GmPIF, GmSLR1, and GmLBD14, were highly expressed at 24.5 μM of stevioside treatment. Taken together, our results demonstrate the potential of stevioside in improving morpho-physiological traits, biochemical status, and the expression of root development genes in soybean. Hence, stevioside could be used as a supplement to enhance plant performance.

Effects of Foliar and Soil Applications of Silicic Acid (Silicon 0.8%) on the Growth and Yield of Tomato under Greenhouse Conditions

Tomato (Solanum Lycopersicum L.) is an important vegetable crop in Iraq. Experiments have been conducted to compare the effects of foliar and soil surface (drench) applications of silicic acid on tomato under greenhouse conditions. The experiment consisted of treatments with or without silicic acid (AB Yellow) treatments with different concentrations to evaluate the efficacy on growth, yield, and quality parameters of tomato. The results showed that foliar applied and soil drenching of silicic acid in different concentrations (0.5, 1 and 2 ml/L) significantly increased yield and quality attributes compared to control. Silicic acid, applied as foliar spray or as soil drench, as 2 ml/L increased growth and yield significantly.

Effect of Biosynthesized Nanoselenium on Controlling Tomato Root-Knot Nematode Meloidogyne incognita

Tomato is a globally important fruit crop, which is easily susceptible to infection by plant-parasitic nematodes during growth. In this study, selenium nanoparticles were biosynthesized through the selenite reduction pathway in a wild-type Pseudomonas stutzeri BB19 and were characterized by uniform nanostructured needle-like forms with an average size of 95.2 nm. The nematicidal effect of biosynthesized selenium nanoparticles (BioSeNPs) at different concentrations (2, 6, and 10 ppm) during the pre- or post-infection of tomato root-knot nematode (RKN), Meloidogyne incognita, was assessed under greenhouse conditions. The BioSeNPs were applied as a foliar spray or a soil drench, compared to ethoprophos nematicide (100 mL/pot). The results showed that the ethoprophos nematicide significantly reduced the number of galls, egg mass, and eggs/egg mass of M. incognita by 94.2, 92.8, and 49.8%, respectively. BioSeNPs, as foliar sprays, significantly reduced the number of galls in post-treated infected tomato plants at 10 ppm and in pre-treated infected tomato plants at 2 ppm by 91.9 and 91.4%, respectively. Concerning the egg mass, BioSeNPs significantly reduced it in pre-treated infected tomato plants at 2 ppm as a foliar spray by 90.9%. Moreover, BioSeNPs significantly reduced the eggs/egg mass in pre-treated infected tomato plants at 2 ppm as a soil drench by 43.3%. On the other hand, the BioSeNPs considerably improved tomato growth, chlorophyll a and b, carotenoid content, and enzymes (i.e., catalase and peroxidase) activity compared to untreated infected tomato plants (negative control). Hence, the BioSeNPs show a significant application potential as a cost-effective and environmentally friendly biocontrol agent for RKN management in tomato plants.

Effect of Ta41 on Growth, Yield and Quality of Cucumber (Cucumis Sativus L.) Laxmi F1 Hybrid

The present experiment was carried out during 2021-22 in Central Horticulture Research Farm of Department of Horticulture, SHUATS, Prayagraj. The experiment was conducted in Randomized Block Design with 10 treatments replicated thrice. The treatments were T0 (Without TA41),T1 (soil drenching of TA41 @10ml/L),T2 (soil drenching of TA41 @ 10ml/L+ Foliar spray 20ml/spray tank),T3 (Soil drenching of TA41 @ 15ml/L),T4 (Soil drenching of TA41@ 15ml/+Foliar spray 30ml/Spray tank),T5 (Soil drenching of TA41@ 20ml/L),T6 (Soil drenching of TA41 @ 20ml /L + foliar spray 40ml / spray tank),T7 (Soil drenching of TA41 @ 25ml /L),T8 (Soil drenching of TA41 @ 25ml/l + foliar spray 50ml/spray tank) and T9 (Foliar spray of TA41 @ 30 ml/spray tank). On the basis of our findings it was concluded that the treatment T4 (Soil drenching of TA41@ 15ml/+Foliar spray 30ml/Spray tank) was found to be best in the terms of vegetative growth, yield and yield parameters, quality parameters, shelf life and benefit cost ratio.

Identification of Resistant Genotypes and Integrated Management of Dry Root Rot of Chickpea

Background: Dry root rot is an economically important soil borne disease of chickpea in India. The pathogen, Rhizoctonia bataticola, is a soil borne fungus resulting in significant losses in yield. Therefore, the present investigation was aimed to identify the management strategy of disease through identification new sources of resistance and integrated management of disease. Methods: R. bataticola was isolated and purified by using hyphal tip technique and molecular detection was done by using ITS primers. One hundred chickpea germplasm entries were screened under in both field and advanced phenotyping in glass house. The field trials on integrated management of the disease were conducted with different treatments using randomized block design. Result: Fourteen resistant and five moderately resistant genotypes were identified under artificial epiphytotic conditions. Advanced screening of these 19 genotypes under phenotyping technique yielded four resistant and five moderately resistant genotypes. Among nine treatments, seed treatment with mancozeb 50% + carbendazim 25% WP @ 3.5 g/kg followed by soil drenching of mancozeb 50% + carbendazim 25% WP @ 3 g/l water to infected and surrounding plants was found highly effective by recording least disease incidence with highest seed yield, test weight and benefit cost ratio.

Effect of Cyanobacterial Combinations on Peanut Yield

The characteristics of two cyanobacterial strains, Anabaena oryzae and Nostoc muscorum, were studied in order to use them as biofertilizers in a field experiment conducted in the two winter seasons of 2021 and 2022 at the Ismailia Agricultural Research Center Station to study the effect of both strains on peanut plant in sandy soil. Cyanobacterial strains were used individually by coating seed, soil drench, and foliar applications, as well as mixed applications of two strains in various ways. Both cyanobacterial strains morphological examination revealed that they both have heterocysts, nitrogen, phosphorus, and potassium in their culture filtrate, and they were able to produce chlorophyll a and phosphatase enzymes. The results of an agricultural experiment showed that using Nostoc muscorum and Anabaena oryzae separately had a positive effect on peanut plants in a variety of applications, but combining both of these applications with 75% nitrogen increased the growth traits, nutrient contents, and soil biological activities in both peanut plants and their rhizosphere soil. The soil drench treatment with A. oryzae and Nostoc muscorum plus 75% nitrogen produced the highest growth results and peanut yields in a single application. The A. oryzae Soil Drench Application (S) + N. muscorum Foliar Application (F) with 75% N reported the best outcomes in mixed treatments. However, compared to single applications, all blended applications displayed better growth and yield characteristics. The results of the study suggest that employing cyanobacteria in a mixed application will enhance its advantages over a single use.

Effects of tomato inoculation with the entomopathogenic fungus Metarhizium brunneum on spider mite resistance and the rhizosphere microbial community.

Entomopathogenic fungi have been well exploited as biocontrol agents that can kill insects through direct contact. However, recent research has shown that they can also play an important role as plant endophytes, stimulating plant growth, and indirectly suppressing pest populations. In this study, we examined the indirect, plant-mediated, effects of a strain of entomopathogenic fungus, Metarhizium brunneum on plant growth and population growth of two-spotted spider mites (Tetranychus urticae) in tomato, using different inoculation methods (seed treatment, soil drenching and a combination of both). Furthermore, we investigated changes in tomato leaf metabolites (sugars and phenolics), and rhizosphere microbial communities in response to M. brunneum inoculation and spider mite feeding. A significant reduction in spider mite population growth was observed in response to M. brunneum inoculation. The reduction was strongest when the inoculum was supplied both as seed treatment and soil drench. This combination treatment also yielded the highest shoot and root biomass in both spider mite-infested and non-infested plants, while spider mite infestation increased shoot but reduced root biomass. Fungal treatments did not consistently affect leaf chlorogenic acid and rutin concentrations, but M. brunneum inoculation via a combination of seed treatment and soil drenching reinforced chlorogenic acid (CGA) induction in response to spider mites and under these conditions the strongest spider mite resistance was observed. However, it is unclear whether the M. brunneum-induced increase in CGA contributed to the observed spider mite resistance, as no general association between CGA levels and spider mite resistance was observed. Spider mite infestation resulted in up to two-fold increase in leaf sucrose concentrations and a three to five-fold increase in glucose and fructose concentrations, but these concentrations were not affected by fungal inoculation. Metarhizium, especially when applied as soil drench, impacted the fungal community composition but not the bacterial community composition which was only affected by the presence of spider mites. Our results suggest that in addition to directly killing spider mites, M. brunneum can indirectly suppress spider mite populations on tomato, although the underlying mechanism has not yet been resolved, and can also affect the composition of the soil microbial community.

Colonization and endophytic effect of Beauveria bassiana (Bals.-Criv.) Vuill. UHSB-END1 against Myzus persicae (Sulzer) and Plutella xylostella (L.) in cabbage

BackgroundFungal microbial biocontrol agent playing an important role in sustainable pest management with low cost. Conidial contact with cuticle is sufficient to cause disease in insects by entomopathogenic fungi (EPF) compared to bacteria and viruses which required ingestion of contaminated food. The field level application of fungi resulted inconsistent in their efficacy against insects as they withstand in the agroecosystem with adverse environmental conditions. To overcome this bottleneck, endophytic EPF, Beauveria bassiana (Bals.-Criv.) Vuill. (Cordycipitaceae: Hypocreales), is well-studied for the management of insects of cultivated crops and got promising results. The colonization of endophytic isolates varied from one host plant to another and virulence against insects too. Hence, the study was undertaken to know the colonization of indigenous B. bassiana UHSB-END1 isolate in cabbage plant and its efficacy against major insects of cabbage.ResultsThe indigenous isolate of B. bassiana UHSB-END1 was able to colonize cabbage in all the methods of inoculations (seed treatment, seedling root dip, soil drenching, foliar spray and combination treatment) at 30, 45 and 60 days of post-inoculation (dpi). However, the colonization of the fungus inside the cabbage was restricted to tissues of inoculation, and movement from the site of inoculation to other parts of the plant was poor. In the present study, colonization was the highest at 30 dpi in all methods of colonization with restricted colonization to the site of exposure of fungus. Further, in vivo and in planta assay confirmed the effectiveness of B. bassiana UHSB-END1 colonized cabbage against Myzus persicae (Sulzer) and Plutella xylostella (Linnaeus). Under in vivo conditions the maximum mortality of M. persicae and P. xylostella was recorded at 30 dpi. It was decreased slightly at 45 dpi, and the lowest morality was recorded at 60 dpi. In planta experiment also proved better efficacy against both the test insects. Wherein mortality of M. persicae ranged from 22 to 36% five days after release (DAR), it was increased to 48–68% at 10 DAR and reached highest mortality rate at 15DAR (72–96%). Similarly, mortality of P. xylostella ranged from 14 to 24% after five DAR, and it was 27–44% at 10 DAR, and maximum mortality rate of larvae were recorded at 15 DAR (64–96%).ConclusionThe present study reported 100% colonization of cabbage plant by indigenous B. bassiana UHSB-END1 at 30 dpi in combination of treatment and showed a maximum efficacy in managing the population of major insects of cabbage. Introducing this indigenous isolate will pave a ray of hope in managing the both key insects (P. xylostella and M. persicae) in cabbage agroecosystem without disturbing the environment and further helps in production of cabbage with minimum pesticide residue for consumers.

Control efficacy of azadirachtin on the fall armyworm, Spodoptera frugiperda (J. E. Smith) by soil drenching.

The fall armyworm (FAW), Spodoptera frugiperda, is an important agricultural pest species native to the Western Hemisphere and has recently invaded to Africa and Asia. Owing to the development of pesticide resistance and environmental contamination, ecofriendly pesticides are desirable for FAW control. Azadirachtin is a plant-derived natural pesticide with low toxicity to humans and the natural environment. Azadirachtin is primarily applied by foliar spraying; however, this approach lowers the efficacy of controlling target insects owing to photodegradation and might give a harmful effect on nontarget beneficial insects. Thus, we investigated whether applying azadirachtin to soil improves FAW control and its toxicity to corn plants. Soil drainage of azadirachtin exhibited no phytotoxic effects on corn plants but significantly reduced the larval body weight and delayed the developmental period of each larval instar of FAW. Applying 10, 15, and 20 ppm azadirachtin to soil inhibited larval growth by 68%, 76%, and 91%, respectively. Furthermore, the survival rate of FAW gradually decreased when larvae were fed azadirachtin-treated corn leaves. Collectively, this is the first study suggesting the systemic efficacy of azadirachtin by soil drenching against FAW.

Response of Phaseolus vulgaris plants to foliar spray and soil drenching by silver nanoparticles (Ag+NPS).

Response of Phaseolus vulgaris plants to foliar spray and soil drenching by silver nanoparticles (Ag+NPS).

Side-Effect of Soil Fumigation and Soil Drench by some Methyl Bromide Alternatives on three Soil Enzyme Activities

Side-Effect of Soil Fumigation and Soil Drench by some Methyl Bromide Alternatives on three Soil Enzyme Activities

<i>In Vitro </i>and<i> in Vivo </i>Management of <i>Sclerotium rolfsii</i> the Cause of Sugar Beet Root Rot Disease

Management of sugar beet damping off and root rot diseases caused by <i>Sclerotium rolfsii</i> is urgently needed. Therefore, antifungal activities of 13 materials including 2 bio agents, 2 seaweeds, 3 chemical inducers and 6 fungicides were evaluated. Required inoculum potential of either fungal mass or sclerotia to reach more than 50% of disease incidence was firstly investigated. Fungal mass inoculation (40-500g/10kg of soil) provided 70-100% damping off and 100% root rot. Meanwhile, 6.7-36.7% of damping off and no or negligible root rot were obtained using 300-500 sclerotia /10kg of soil. On the other hand, <i>S. rolfsii</i> mycelial growth was completely suppressed <i>in vitro</i> by all tested materials. However, various antifungal activities of these materials were shown <i>in vivo</i> after seed soaking in the 1^st (2020/2021) trail or seed soaking followed by soil drenching in the 2^nd (2021/2022) trail. Tipo top (Tebuoconazole 25.9%: 1cm/L) fungicide was the most effective material in the 1^st trail since the seedling survival was up to 80%, followed by potassium silicate (1cm/L) and Score (Difenoconazole 25%: 1cm/L) fungicide. Seed soaking followed by soil drenching with Tipo top in the 2^nd trail were protected sugar beet from sowing to harvest and enhanced the root weight. Additionally, this study illustrated that both of sugar beet root weight and sucrose content were decreased as root rot severity increased. In conclusion, chemical fungicides are unfortunately still the fast and potent way for <i>S. rolfsii</i> management, especially with the limitation of resistant sugar beet cultivars.

Management of Fusarium wilt of tomato (Pusa Ruby) by plant extracts and fungicides

Fusarium wilt disease of tomato caused by Fusarium oxysporum f. sp. lycopersici is one of the most important and widespread disease of the cultivated tomato.The yield loss in tomato in temperate region of India due to this disease is 10 to 90 percent. Investigation was undertaken to screen out the fungicides viz., Azoxystrobin(T1), Propineb(T2), Thiophanate Methyl (T3), Difenoconazole(T4), Mancozeb(T5), Mancozeb + Thiophanate Methyl(T6), Boscolid+Pyraclostrobin(T7) and control (T8) and plant extracts viz, onion bulb(T9), ,ginger rhizome(T10), garlic clove(T11), neem leaf (T12), ashwagandha leaf(T13), sarpgandha leaf(T14), ashok leaf(T15) and control (T16) , against wilt of tomato under in vivo and in vivo conditions. Ginger rhizome extract (T10) was found very promising as it produced 82.2 % growth inhibition of F. oxysporumf.sp. lycopersiciat @t 15 % concentration followed by garlic clove(T11) (76.1%). Two soil drenching withgarlic clove(T11), @ 15 percent showed minimum disease incidence of (16.6%) with maximum yield (435.3 q/ha) followed by ginger rhizome(T10) extract (18.4% and 428.2 q/ha). Mancozeb + Thiophanate Methyl(T6), Difenoconazole(T4) and Thiophanate Methyl(T6) completely inhibited the radial growth and sporulation of Fusarium oxysporumf.sp. lycopersici after 144 hrs of incubation. Two soil drenching of Mancozeb +Thiophanate Methyl(T6), @ 15 per cent was also found the best for managing the disease as minimum disease incidence (5.3%) and highest yield (470.9 q/ha) was recorded.

Biological management of coffee wilt disease (Fusarium xylarioides) using antagonistic Trichoderma isolates.

Coffee wilt disease (CWD) is a serious threat to the food security of small-scale farmers in Ethiopia, causing significant reductions in coffee yield. Currently, there are no effective control measures available against the causative agent of CWD, Fusarium xylarioides. The main objective of this study was therefore to develop, formulate, and evaluate a range of biofungicides against F. xylarioides, derived from Trichoderma species and tested under in vitro, greenhouse, and field conditions. In total, 175 Trichoderma isolates were screened as microbial biocontrol agents against F. xylarioides. The efficacy of two biofungicide formulations, wettable powder and water dispensable granules, were tested on the susceptible Geisha coffee variety in three different agro-ecological zones in southwestern Ethiopia over three years. The greenhouse experiments were set up using a complete block design, while in the field a randomized complete block design was used, with twice yearly applications of biofungicide. The test pathogen spore suspension was applied to the coffee seedlings by soil drenching, and the subsequent incidence and severity of CWD evaluated annually. The mycelial growth inhibition profiles of the Trichoderma isolates against F. xylarioides ranged from 44.5% to 84.8%. In vitro experiments revealed that T. asperelloides AU71, T. asperellum AU131 and T. longibrachiatum AU158 reduced the mycelial growth of F. xylarioides by over 80%. The greenhouse study indicated that wettable powder (WP) of T. asperellum AU131 had the highest biocontrol efficacy (84.3%), followed by T. longibrachiatum AU158 (77.9%) and T. asperelloides AU71 (71.2%); they also had a significant positive impact on plant growth. The pathogen-treated control plants had a disease severity index of 100% across all the field experiments, and of 76.7% in the greenhouse experiments. In comparison to untreated controls, the annual and cumulative disease incidence over the three years of the study period varied from 46.2 to 90%, 51.6 to 84.5%, and 58.2 to 91%, at the Teppi, Gera and Jimma field experimental locations. Overall, the greenhouse and field experiments and in vitro assays support the biocontrol potential of Trichoderma isolates, and T. asperellum AU131 and T. longibrachiatum AU158 in particular are recommended for the management of CWD under field conditions.

Bactericidal and plant defense elicitation activities of Eucalyptus oil decrease the severity of infections by Xylella fastidiosa on almond plants.

The activity of Eucalyptus essential oil against eleven strains pertaining to six species of plant pathogenic bacteria was studied using growth inhibition and contact assays. All strains were susceptible to the formulation EGL2, and Xylella fastidiosa subspecies and Xanthomonas fragariae were the most sensitive. The bactericidal effect was strong causing 4.5 to 6.0 log reductions in survival in 30min at concentrations in the range of 0.75 to 15.0 μl/ml depending on the bacteria tested. Transmission electron microscopy of the formulation EGL2 against the three X. fastidiosa subspecies studied allowed the observation of a strong lytic effect on bacterial cells. In addition, the preventive spray application of EGL2 to potted pear plants subsequently inoculated with Erwinia amylovora significantly decreased the severity of infections. Almond plants treated by endotherapy or soil drenching, and then inoculated with X. fastidiosa showed a significant decrease in disease severity as well as in the levels of the pathogen, depending on the strategy used (endotherapy/soil drenching, preventive/curative). The treatment by endotherapy in almond plants induced the expression of several genes involved in plant defense. It was concluded that the reduction of infections by the Eucalyptus oil treatments was due to the combination of its bactericidal and plant defense induction activities.

Efficacy of different combinations of microbial biocontrol agents against sheath blight of rice caused by Rhizoctonia solani

BackgroundSheath blight of rice caused by Rhizoctonia solani is one of the most important diseases worldwide, causing considerable yield losses. The estimation of losses due to sheath blight of rice in India has been reported to be up to 54.30%. As a consequence of this fact, eco-friendly approaches were explored in this investigation.ResultsThe pathogen R. solani was isolated from the infected sheath of rice plant, which was identified and characterized on the basis of morphology and through molecular Sequencing. The sequences of ITS were submitted to NCBI GenBank and the accession number allotted is SUB11543577. In dual culture best two potential isolates of biocontrol agents were selected Pseudomonas fluorescens (Pf27) and Trichoderma harzianum (Th47). Their different combinations with Herbal Kunapajala (HKJ) were tested in glasshouse, experimental field and farmers’ fields against sheath blight pathogen R. solani. The maximum plant vigor index was found in treatment combination P. fluorescens (27) + T. harzanium (47) + Herbal Kunapajala, seed treatment, soil drenching and three foliar applications. Minimum disease severity and incidence at 30 days after sowing (DAS) and 60DAS, maximum Phenylalanine Ammonia Lyase Activity (PAL), Polyphenol Oxidase Activity (PPO) and Peroxidase Activity (PO) were also recorded in the same treatment. In field experiment the maximum population of biocontrol agents after 60 days of transplanting cfu/g soil for Trichoderma spp. (32.33 × 104) and Pseudomonas spp. (36.33 × 104) in rhizosphere and in rhizoplane. Maximum cfu/g soil for Trichoderma spp. (24.67 × 104) and Pseudomonas spp. (24.0 × 104) was observed in treatment Th + Pf + HKJ [seed treatment + soil drenching + foliar spray]. At experimental and farmers field minimum disease severity, disease incidence at 60 DAT was recorded in treatment Th + Pf + HKJ [seed treatment + soil drenching + foliar spray] and was at par with the chemical treatment Carbendazim, but the maximum yield was obtained in the treatment Th + PF + HKJ [seed treatment + soil drenching + foliar spray] due to the maximum growth promotion activity.ConclusionsAmong various treatment seed treatment, soil drenching and three foliar sprays with combination T. harzianum (47), P. fluorescens (27) and Herbal Kunapajala was found very effective in reducing the disease incidence, disease severity and increasing growth promotion activity at all conditions. Therefore, the recommendation of this investigation could be exploited under bio-intensive disease management program for sustainable cultivation of rice.

Biostimulation Effects of Seaweed Extract (Ascophyllum nodosum) on Phytomorpho-Physiological, Yield, and Quality Traits of Tomato (Solanum lycopersicum L.)

Biostimulants are innovative organic tools, which promote the growth, plant development, production, and quality of various crops without harming the environment; however, the effects of biostimulants on the production of tomato needed to be explored further under open field conditions. Based on this view, this study’s objective was to assess the impact of Kendal Root, a biostimulant-containing seaweed, Ascophyllum nodosum, and plant extracts on the phytomorpho-physiological, yield, and quality of tomato. Three doses of Kendal Root (2.5, 5.0, and 10 L ha−1) were given as soil drenching, and the results were compared with control. Generally, the Kendal Root treatments positively improved the growth, physiological, yield, and quality attributes of tomato. However, among the three different concentrations, Kendal Root 5.0 L ha−1 significantly improved the plant growth and physiological aspects of tomato, such as plant height, leaf area, shoot and root dry weight, SPAD value, and gas exchange parameters. Considering the yield traits, the Kendal Root 5.0 L ha−1 application significantly improved the tomato fruit number, yield per plant, and yield per hectare. Conversely, flower number per plant and average fruit weight was not remarkably improved by Kendal Root 5.0 L ha−1. Moreover, Kendal Root 5.0 L ha−1 positively improved the quality traits of tomato, including total soluble solids, ascorbic acid content, lycopene, and total sugars than the titratable acidity content of tomato fruits. Hence, the integration of Kendal Root biostimulant in tomato production could be an effective way to boost plant growth, production, and quality of tomato.

Root-knot nematode pathogen suppression in eggplant using antagonistic fungi

BackgroundMeloidogyne incognita (Kofoid and White) Chitwood is a major pest of eggplant in Pakistan. The second-stage juveniles (J2s) feed on the roots of eggplant. Damaged roots swell and the plant exhibits stunted growth. Mostly farmers rely on the use of broad-spectrum nematicides. However, due to hazardous effects on the environment and non-target species, its application is greatly criticized. Fungal biocontrol agents have been long used for curtailing root-knot nematode infections. The present study was conducted to determine the virulence of four fungal biocontrol agents against M. incognita under laboratory and greenhouse conditions.ResultsThe in vitro results revealed that Trichoderma harzianum significantly caused 77.60% egg inhibition, followed by Pochonia chlamydosporium (53.0%) at 1:1 concentration after 72 h. The maximum J2s mortality was achieved by T. harzianum (82.0%), followed by P. chlamydosporium (70.20%) at 1:1 concentration after 72 h. The in-planta examination carried out at a greenhouse demonstrated that the soil drench treatment of fungal biocontrol agents significantly suppressed M. incognita parameters and upraised the eggplant growth. The mean least number of galls (22.25) was in T. harzianum treated plants, while the control had (206.8) galls. Likewise, T. harzianum curtailed the least egg masses to 35.75 and swollen females to 21.12 than control negative (224.13 egg masses and 182.75 swollen females).ConclusionT. harzianum was the best agent to control M. incognita (J2s) effectively, followed by P. chlamydosporum. T. harzianum may be a contribution to the biological control of M. incognita in Pakistan.