No abstract

Mung bean [Vigna radiata (L.) Wilczek] is an important cash pulse crop extensively cultivated in the arid region of Pakistan, which encounters intimidating charcoal rot disease caused by Macrophomina phaseolina (Tassi) Goid. The current research was conducted to check the potential of Zn (1.25, 2.44 and 5 mg kg −1) and FYM [farmyard manure (1% and 2%)] in mono-, bi-and trilateral interaction in managing disease and improving yield. Suppression of plant immunity by M. phaseolina was indicated by the change in activities of antioxidant enzymes (CAT and SOD) and cell wall strengthening enzymes (POX and PAL) that revealed inability of the protein receptor to identify the pathogen elicitor. FYM improved soil physicochemical properties and beneficial microbes activity, which released antimicrobial protein-and plant defense-stimulating protein and in response to ROS (reactive oxygen species) signaling molecules plant susceptibility was reduced. However, Zn as a co-factor chastened the ROS in stressed cells by upregulation of antioxidant enzymes in favor of the plant. The complex interaction of FYM and Zn potentially hijacked the further multiplication of pathogen. Finally, soil amendment improved biological attributes and grain yield to profitable farming in terms of harvest index percentage and benefit-cost ratio.

No abstract

No abstract

No abstract

No abstract

Early blight (EB) is one of the major fungal diseases caused by Alternaria solani that is responsible for destructive tomato production around the globe. Biocontrol agent/s can be adequately implemented in an integrated management framework by using it in combination with vital plant nutrients, e.g., nitrogen, phosphorus, and potassium (NPK) and zinc (Zn). The current study was aimed to assess the integrated effect of a biocontrol agent Bacillus subtilis (BS-01) and the selective plant nutrients (NPK and Zn) on EB disease management and tomato crop performance. A field experiment was conducted for the off-season tomato production (under walk-in tunnels) in Punjab, Pakistan. The trial was set in a randomized complete block design (RCBD) and comprised nine treatments of a biocontrol agent (BS-01) either alone or in combination with the plant nutrients, viz., NPK (64:46:50 kg acre–1) and Zn (10 kg acre–1) as sustainable disease managing approach against EB. In addition, the biocontrol efficacy of B. subtilis (BS-01) on a fungal load of A. solani was estimated by quantitative PCR assays, where the foliar application of BS-01 on tomato plants either alone or in combination with the plant nutrients was done as a preventive measure. Our results revealed that the interactive effect of BS-01 with plant nutrients conferred significantly a varying degree of resilience in the infected tomato plants against EB by effectively modifying the content of total chlorophyll, carotenoids, and total phenolics along with the activities of antioxidant enzymes (SOD, CAT, POX, PPO, and PAL). In addition, the integrative effect of BS-01 and plant nutrients proved significantly effective in reducing pathogen load on inoculated tomato foliage, displaying the desired level of protection against A. solani infection. Besides, the complementary interaction of BS-01 + Zn + NPK worked synergistically to improve crop productivity by providing the highest marketable yield (21.61 tons acre–1) and net profit (361,363 Pakistani rupees acre–1). This integrated approach is put forward as a way to reduce the fungicide doses to control EB that would act as a sustainable plant protection strategy to generate profitable tomato production.

Macrophomina phaseolina (Tassi) Goid is a destructive pathogen of cowpea that causes serious charcoal rot disease with significant yield losses. Antifungal activity of three indigenous Ascomycetes viz., Trichoderma harzianum, T. viride, and T. hamatum, and two Meliaceae members, i.e., Melia azedarach L. and Azadirachta indica L. were assessed against the pathogen. Laboratory screening trials with cell-free culture filtrate showed the maximum reduction in growth of M. phaseolina with T. harzianum, followed by T. viride. Various concentrations (1-5%) of methanolic leaf extract of A. indica showed more reduction in fungal biomass than M. azedarach. Pot experiment was performed by T. harzianum, T. viride, and dry leaf biomass of A. indica against M. phaseolina. Results revealed that potted soil amended with T. harzianum in combination with 1-3% dry leaf biomass of A. indica held a significant potential to decrease disease incidence to 20-25% and improve plant growth attributes up to fourfolds over positive control inoculated with M. phaseolina only. Physiology of the host plant was altered due to the incorporation of various soil amendments resulting in reduced activities of antioxidant enzymes (catalase, peroxidase, polyphenol oxidase, and phenylalanine ammonia lyase). It was concluded that fungal antagonists and allelopathic chemicals would be an effective and eco-friendly means of managing the charcoal rot disease.