BananaLSD: A banana leaf images dataset for classification of banana leaf diseases using machine learning.

Bananas, one of the most widely consumed fruits globally, are highly susceptible to various leaf spot diseases, leading to significant economic losses in banana production. In this article, we present the Banana Leaf Spot Diseases (BananaLSD) dataset, an extensive collection of images showcasing three prevalent diseases affecting banana leaves: Sigatoka, Cordana, and Pestalotiopsis. The dataset was used to develop the BananaSqueezeNet model [1]. The BananaLSD dataset contains 937 images of banana leaves collected from banana fields, which were then further augmented to generate another 1600 images. The images were acquired using three smartphone cameras in diverse real-world conditions. The dataset has potential for reuse in the development of machine learning models that can help farmers identify symptoms early. It can be useful for researchers working on leaf spot diseases and serve as motivation for further researches.

Effect of Metarhizium anisopliae (MetA1) on growth enhancement and antioxidative defense mechanism against Rhizoctonia root rot in okra.

Rhizoctonia solani is an important necrotrophic pathogenic fungus that causes okra root disease and results in severe yield reduction. Many biocontrol agents are being studied with the intent of improving plant growth and defense systems and reducing crop loss by preventing fungal infections. Recently, a member of the Hypocrealean family, Metarhizium anisopliae, has been reported for insect pathogenicity, endophytism, plant growth promotion, and antifungal potentialities. This research investigated the role of M. anisopliae (MetA1) in growth promotion and root disease suppression in okra. The antagonism against R. solani and the plant growth promotion traits of MetA1 were tested in vitro. The effects of endophytic MetA1 on promoting plant growth and disease suppression were assessed in planta. Dual culture and cell-free culture filtrate assays showed antagonistic activity against R. solani by MetA1. Some plant growth promotion traits, such as phosphate solubilization and catalase activity were also exhibited by MetA1. Seed primed with MetA1 increased the shoot, root, leaves, chlorophyll content, and biomass content compared to control okra plants. The plants challenged with R. solani showed the highest hydrogen peroxide (H2O2) and lipid peroxidation (MDA) contents in the leaves of okra. Whereas MetA1 applied plants showed a reduction of H2O2 and MDA by 5.21 and 14.96%, respectively, under pathogen-inoculated conditions by increasing antioxidant enzyme activities, including catalase (CAT), peroxidase (POD), glutathione S-transferase (GST), and ascorbate peroxidase (APX), by 30.11, 10.19, 5.62, and 5.06%, respectively. Moreover, MetA1 increased soluble sugars, carbohydrates, proline, and secondary metabolites, viz., phenol and flavonoid contents in okra resulting in a better osmotic adjustment of diseases infecting plants. MetA1 reduced disease incidence by 58.33% at 15 DAI compared to the R. solani inoculated plant. The results revealed that MetA1 improved plant growth, elevated the plant defense system, and suppressed root diseases caused by R. solani. Thus, MetA1 was found to be an effective candidate for the biological control program.

Understanding Phakopsora pachyrhizi in soybean: comprehensive insights, threats, and interventions from the Asian perspective.

Soybean (Glycine max L.) is an important crop in Asia, accounting for 17% of global soybean cultivation. However, this crop faces formidable challenges from the devastating foliar disease, Asian Soybean Rust (ASR), caused by Phakopsora pachyrhizi, a biotrophic fungus with a broad host range, causing substantial yield losses (10-100%) in Asia. This comprehensive review consolidates knowledge on ASR, encompassing its impact, historical perspectives, genetic diversity, epidemic drivers, early detection, risk assessment, and sustainable management strategies of ASR in the region. ASR has expanded globally from Asia, reaching Africa and Americas, driven by wind-dispersed urediniospores. Genetic diversity studies reveal the complexity of P. pachyrhizi, with distinct populations exhibiting varying virulence patterns. Factors affecting ASR epidemics in Asia include host susceptibility, landscape connectivity, climate, and environmental conditions. Understanding the interplay of these factors is essential for early intervention and control of ASR in soybean fields. Effectively managing ASR can exploit the utilization of diverse intervention strategies, encompassing disease forecasting, automated early detection, disease resistance, fungicide application, and biological control. A pivotal aspect of successful, sustainable disease management lies in reducing the ASR pathogen virulence and preventing it from developing fungicide resistance, while the highpoint of effectiveness in disease control is attained through a synergistic approach, integrating various strategies. In summary, this comprehensive review provides insights into multifaceted approaches that contribute to the development of sustainable and economically impactful soybean production in the face of the persistent threat of ASR in Asia.

Characterization of Pestalotiopsis sp. causing gray leaf spot in coconut (Cocos nucifera L.) in Bangladesh.

Coconut (Cocos nucifera L.) is one of the most important fruit trees in Bangladesh. This tree is susceptible to various pathogens. Among them, a fungus was consistently isolated from gray leaf spot symptom in coconut. This study aimed to isolate, characterize, and find the management strategies of the causal fungus of gray leaf spot disease in coconut. Both morphological and molecular characters identified the pathogen as Pestalotiopsis sp. for the first time in Bangladesh. Artificial inoculation of this fungus showed symptoms similar to those previously observed in the field. Cross-inoculation test suggests that Pestalotiopsis sp. has a wide host range. The infection process of Pestalotiopsis sp. started at 2 h after inoculation (hai) with the formation of germ tube followed by the formation of infection hyphae, which penetrated directly into the host at 6 hai. Gray leaf spot symptom was developed at 120 hai. Numerous conidia developed from the acervuli at 168 hai. These conidia acted as the source of inocula for secondary infection. The optimum temperature for the growth of Pestalotiopsis sp. was 25°C, however, the growth of Pestalotiopsis sp. ceased at 15°C and 35°C. This pathogen was completely inhibited by Autostin 50 WDG (carbendazim) at 100 ppm. Trichoderma viride (Pb-7) was found as the potential biocontrol agent against Pestalotiopsis sp. These findings could contribute to describing the disease cycle and epidemiology of Pestalotiopsis sp. that would ultimately require to undertake effective control measures against this pathogen.

The emergence of novel coronavirus disease (COVID-19) in Bangladesh: Present status, challenges, and future management.

Immediate after the official declaration of COVID-19 in Bangladesh on 8 March 2020, it has created public panic which results in price plummeting of the capital market and price hike of many essential commodities. Worldwide, the outbreak of COVID-19 has declared a pandemic. In response, the Government of Bangladesh has initiated some strict measures such as stopping the entry of passengers from Europe, stopping on-arrival visas and self-quarantine for 2 weeks for all passengers return from abroad. Still, many loopholes exist at the entry points of Bangladesh. Most of the people of Bangladesh are yet to aware of the consequences of COVID-19. In this backdrop, this article has attempted to create public awareness about COVID-19, providing some guidelines to restrict this deadly disease, enlisting current challenges of this disease in Bangladesh. This review would be helpful to undertake future management practices against the fearsome COVID-19 in Bangladesh.