Jabuticaba (Plinia cauliflora (Mart.) Kausel) was originated from Brazil (Lorenzi 2000). The production of jabuticaba is growing globally as its value in the food and pharmaceutical industries (Benvenutti 2021). In August 2019, jabuticaba plants with symptoms of leaf blight were observed in the field at the Meinong of Kaohsiung City, Taiwan. Disease incidence was 40%. Symptoms first presented as small, water-soaked lesions on young leaves, and then dark brown lesions of 1-3 cm in diameter on mature leaves. Six symptomatic leaves were collected from 6 jabuticaba plants for verifying the causal agents. Tissues (5 × 5 mm2) were cut from the margin of symptomatic leaf. Samples were sterilized in 1% sodium hypochlorite for 60 s, rinsed with sterile distilled water three times and then placed in 1% water agar in the dark for 5 days at room temperature. Resultant fungal colonies were purified by subculturing fungal hyphal tips on potato dextrose agar in a growth chamber (28°C, 12 h photoperiod) until fungal conidia appeared. The fungi initially produced white, cottony, aerial mycelium, after which concentric black conidiomata appeared on the plates after 7 days of incubation. The 5-celled conidia were fusiform to ellipsoid, straight to slightly curved, with sizes of 24.00-44.00 µm × 6.00-13.00 µm (avg. size, 32.00 × 9.37 µm, n = 120). The apical and basal cells were hyaline, and 3 median cells were pale brown and versicolorous. Conidia had 2-3 apical appendages and a conical basal cell with a truncate base. Based on the characteristics, which were common among isolates from diseased samples, the causal pathogen was identified as Neopestalotiopsis sp. (Solarte et al. 2018). Internal transcribed spacer (ITS), translation elongation factor 1α (TEF), β-tubulin, and large ribosomal subunit (LSU) DNA sequences were obtained from these isolates and deposited in GenBank (MN723897, ITS; MN813055, TEF; MN813054, β-tubulin; MN860104, LSU). Sequences demonstrated high sequence identity with those of Neopestalotiopsis formicarum ex-type cultures CBS 362.72 (Maharachchikumbura et al. 2014): 99.44% for ITS (KM199358), 99.38% for TEF (KM199517), 98.86% for β-tubulin (KM199455), and 100.00% for LSU (KM116248). The phylogenetic relationship in Neopestalotiopsis species supported the identification of our isolates as N. formicarum. Three independent 3-isolate inoculation experiments were performed to fit Koch's postulates. Surface-sterilized leaves on live plants were punctured with a needle and inoculated with 5 µL of conidial suspension (1 × 105 conidia/mL). Inoculated plants were kept in a growth chamber (25°C, 70% relative humidity) for 7 days. Control plants were inoculated with sterile distilled water and kept under the same conditions. Inoculated leaves developed brown lesions around wounds after seven days. The pathogen was re-isolated from diseased plants, following the steps used for the original procedure, with identical characteristics as the initial isolates. This is the first report of leaf brown blight caused by N. formicarum on jabuticaba in Taiwan. N. formicarum was recently considered as a new threat to jabuticaba (Gualberto et al. 2021). In addition, it has a broad host range on many tropical crops, such as guarana and banana (Gualberto et al. 2021). Neopestalotiopsis spp. have been reported to cause important economic fruit diseases (Gualberto et al. 2021). Therefore, N. formicarum may become the potential risk for fruit production of tropical crops.

We developed an insulated isothermal PCR (iiPCR) method for the efficient and rapid detection of Fusarium oxysporum (Fo), which is a fungus that infects various hosts and causes severe crop losses. The Fo iiPCR method was sensitive enough to detect up to 100 copies of standard DNA template and 10 fg of Fo genomic DNA. In addition, it could directly detect 1 pg of mycelium and 10 spores of Fo without DNA extraction. Our study compared the performance of Fo iiPCR to that of three published in planta molecular detection methods—conventional PCR, SYBR green-based real-time PCR, and hydrolysis probe-based real-time PCR—in field detection of Fo. All diseased field samples yielded positive detection results with high reproducibility when subjected to an Fo iiPCR test combined with a rapid DNA extraction protocol compared to Fo iiPCR with an automated magnetic bead-based DNA extraction protocol. Intraday and interday assays were performed to ensure the stability of this new rapid detection method. The results of detection of Fo in diseased banana pseudostem samples demonstrated that this new rapid detection method was suitable for field diagnosis of Fusarium wilt and had high F1 scores for detection (the harmonic mean of precision and recall of detection) for all asymptomatic and symptomatic Fo-infected banana samples. In addition, banana samples at four growth stages (seedling, vegetative, flowering and fruiting, and harvesting) with mild symptoms also showed positive detection results. These results indicate that this new rapid detection method is a potentially efficient procedure for on-site detection of Fo.

Melon (Cucumis melo L.) is a global commercial crop that is sensitive to seed-borne wilt infections caused by Fusarium oxysporum f. sp. melonis (Fom). To address the challenge of detecting Fom contamination, we designed a probe-based real-time PCR method, TDCP2, in combination with rapid or column-based DNA extraction protocols to develop reliable molecular detection methods. Utilizing TDCP2, the detection rate reached 100% for both artificially Fom-inoculated (0.25–25%) and pod-inoculated melon seeds in conjunction with DNA samples from either the rapid or column-based extraction protocol. We performed analyses of precision, recall, and F1 scores, achieving a maximum F1 score of 1 with TDCP2, which highlights the robustness of the method. Additionally, intraday and interday assays were performed, which revealed the high reproducibility and stability of column-based DNA extraction protocols combined with TDCP2. These metrics confirm the reliability of our developed protocols, setting a foundation for future enhancements in seed pathology diagnostics and potentially broadening their applicability across various Fom infection levels. In the future, we hope that these methods will reduce food loss by improving the control and management of melon diseases.

When the soil at the plant roots is poorly ventilated due to few pores, the root system will grow short and shallow, leading to poor growth. In this paper, we developed a shockwave soil-loosening device. It can first drill a hollow drill bit containing multi-directional holes into the soil near the roots of the crops and then generate high-pressure gas to impact the soil outside the drill bit to increase the soil pores. Therefore, this can quickly improve soil aeration. We conducted numerical simulations of shockwave loosening to explore how 3.4 atm shockwaves are emitted from the drill bit’s porous nozzles and analyze the behavior and efficiency of shockwave loosening. We also performed visual observation experiments of shockwave multi-directional impact in a transparent acrylic water tank. Furthermore, we used eight pressure sensors to automatically measure the range of shockwave impact and found that when the storage tank volume was 5000 cm³, we could achieve a soil loosening range of 30 cm. Finally, this shockwave-loosening mechanism ensures that the soil surface will not be damaged during the loosening process, thus avoiding large-scale tillage disturbance of the soil. This will reduce carbon emissions stored in soil and released into the atmosphere.