Crop Protection最新文献

Crop diseases significantly impact yield and quality, posing a direct threat to food security. The application of Convolutional Neural Networks (CNN) in crop disease recognition has notably improved diagnosis accuracy and efficiency. This study presents an innovative crop disease classification model based on the VGG-16 network. Enhancements include the incorporation of Batch Normalization (BN) and a novel activation function synergizing with Exponential Linear Units (ELU), improving model convergence speed and accuracy. Additionally, Global Average Pooling (GAP) is integrated to streamline the network architecture, and the InceptionV2 module is introduced to extract leaf disease features from different dimensions, enhancing model robustness. Validation on the PlantVillage dataset shows an accuracy rate of 98.89%, demonstrating the model's competitiveness and its potential to support sustainable agricultural production.

New strategies for protecting crops from aphid attacks must be developed. The present study aimed to examine the effect of cis-Jasmone (CJ), an activator of plant defense, on potato plants. Plants were sprayed with an exogenous application of CJ at 12, 24, and 48 h; and the green peach aphid, Myzus persicae Sulzer, and its parasitoid, Aphidius gifuensis, were used to evaluate the tri-trophic interactions of the aphids, parasitoids, and plants. In this work, we examined that the adult M. persicae produced fewer nymphs on CJ-treated plants at 12, 24, and 48 h than on control plants. Furthermore, M. persicae nymphs that fed on CJ-treated plants at 48 h had a lower mean relative growth rate (MRGR). Moreover, the intrinsic rate of population increase (r) was significantly lowered in CJ-treated plants at 12, 24, and 48 h. CJ-treated plants at all time durations showed considerably less settlement of aphid than control plants. In the olfactometer bioassay, the parasitoid exhibited a prolonged duration in the arm treated with volatiles from CJ-treated plants at 12, 24, and 48 h in comparison to the control. Moreover, the salicylic acid and jasmonic acid marker gene expression levels were significantly upregulated by CJ-treatment. Surprisingly, aphids raised on CJ-treated potato plants showed higher transcriptional levels of detoxifying enzymes. The findings of this research will provide new insights into the possible applications of important volatile components like cis-jasmone in integrated pest management systems, in addition to enhancing our comprehension of the ways in which plant volatiles affect the crop community.

The fungal disease of Cordyceps militaris has become the primary disease during the cultivation of C. militaris. However, some of the causal organism remains unclear. During our investigation in 2020–2022, three fungal strains were isolated from both the mycelium and fruiting bodies of C. militaris in mushroom farms located in Changchun. The observed disease incidence was approximately 20%. White villous mycelium on the surface of hyphae or fruiting bodies of C. militaris, is one of the main features of the disease, which can cause slow growth of mycelium, delayed primordia differentiation, and growth failure. Finally, the white cotton flocculent mycelium covered the surface of the medium, and the C. militaris stopped differentiating and failed to produce the primordium, ultimately leading to the stunted growth and lodging of the fruiting body. The objective of this study was to identify the pathogen based on Koch's Postulates, thereby confirming its pathogenicity and characterizing it through morphological and molecular features. The phylogenetic analyses showed that they belong to the Trichoderma gamsii. This study presented the first evidence of T. gamsii caused fungal disease in C. militaris, providing a theoretical basis for the prevention and control measures.

Considering that the use of essential oils is a promising technique and a valuable alternative in the control of unwanted organisms, this study aimed to chemically characterize the essential oil of Acanthospermum australe (Loefl.) O. Kunze (Asteraceae) through gas chromatography, as well as to evaluate the repellent and acaricidal effect of the essential oils from A. australe and Baccharis psiadioides (Less.) Joch.Müll (Asteraceae) against Tetranychus urticae Koch (Tetranychidae). For the repellency test, concentrations of 0.25, 0.5 and 1% were used for both oils, and concentrations of 10 μL/L(air) and 20 μL/L(air) to evaluate acaricidal effects. Eight compounds were identified in the essential oil of A. australe, with thymyl isobutyrate (63.4%) being the major compound, followed by thymol (13.4%) and thymyl 2-methylbutyrate (4.96%). The results demonstrated higher repellency to the essential oil of A. australe at a concentration of 0.5%, followed by B. psiadioides at a concentration of 1%. The mortality rate of TSSM exceeds 90% when exposed to both tested concentrations of the essential oil of A. australe proving effective in both cases.

Conventional farming prioritizes monocultures and synthetic chemicals to secure high yields. However, there are a growing number of initiatives worldwide to reduce or eliminate the use of pesticides. One option for pesticide-free weed management is the adjustment of sowing pattern (row distance, plant arrangement, sowing density). This study investigated the effects of an equal distance sowing versus a normal distance sowing (EDS and NDS¹) at constant sowing density on plant morphology, growth and yield of silage maize (Zea mays L.) and soybean (Glycine max (L.) Merr.) as well as the weed occurrence. Therefore, a 3-year (2020–2022) pesticide-free, field experiment was conducted at the Heidfeldhof Research Station, University of Hohenheim, Germany. In silage maize, neither plant architecture nor biomass yield showed significant differences between EDS with 0.375 m and NDS with 0.75 m row distance. In contrast, soybean developed a bushier plant architecture with more branches and shorter petioles in EDS with 0.15 m compared to plants in NDS with 0.50 m row distance, demonstrating phenotypic plasticity. A higher number of pods per plant (EDS: 28.05; NDS: 22.73) and seed yield (EDS: 406.58 g m⁻²; NDS: 389.34 g m⁻²) indicated the potential for increased yields applying EDS. Crop competitiveness against weeds was higher in EDS than in NDS, especially early in the growing season. The results highlight the importance of EDS as a valuable tool for pesticide-free, non-organic cropping systems through positive effects on crop yield and efficient weed control.

Spider mites cause substantial economic losses and are difficult to control in agricultural systems. Ginkgo biloba L. extract has potential as an acaricide, although its specific acaricidal components have yet to be identified. We used bioassay-guided isolation to isolate and purify three main ginkgolic acid (GA) compounds (C13:0, C15:1, and C17:1). Their chemical structures were identified as ¹H, ¹³C, and IR, respectively. The LC₅₀ values of GA C13:0, GA C15:1, and GA C17:1 against Tetranychus cinnabarinus were 777.75, 481.07, and 180.25 μg mL⁻¹, respectively, demonstrating high toxicity. The efficacies of 23% GA soluble liquid (SL) with a dosage of 1500 a.i. g·hm⁻² after 14 days were 82.45% and 85.41%, respectively, in Dali County and Chengcheng County, Weinan, China. The GA extraction process was optimized using methanol as the extraction solvent, heating and refluxing at 60 °C for 4 h at a solid-liquid ratio of 1:4, and repeating the process twice. The GA extraction rate of G. biloba exocarp was 43.2%, and the total extraction content of the three main GA compounds was 68.73%. Our optimization of the GA extraction process from G. biloba exocarp has the potential to be applied on an industrial scale, and GAs could be used as a commercial acaricide for controlling mites in the future.

Weeds are the primary pest that reduces crop yield. Herbicide-based weed control is an efficient strategy for farmers, offering economically feasible weed management for agricultural crop production. The effectiveness of agrochemicals relies on the correct calibration and exact calculations of the rates needed per unit area, uniform distribution over treated surface and spraying conditions. The current investigation aims to investigate the efficacy of selected herbicides for weed control using drones. A field experiment was carried out in a commercial plot in Sungai Besar, Sabak Bernam Selangor, from September to December 2022 and April to July 2023 to assess the effectiveness of using drones to apply herbicides in direct-seeded rice. The main goal was to assess the effectiveness of Rinskor (Loyant), Rinskor + Cyhalofop (Novlect), Cyhalofop (Clincher), Bispyribac (Nominee), and Propanil (Stam 80WG) herbicides in suppressing weeds in direct-seeded rice using drone and mist blower sprayers, as well as their operational efficiency. The experimental plot was arranged using a randomized complete block design with three replications. The results of the experiments recorded the toxicity of the herbicides on rice at early stage but rice plant was recovered at 21 days after spray. High grain yield components were recorded for the Novlect and Loyant treated plots. The density and dry weight of grasses, sedges, and broad-leaved weeds were considerably reduced when the herbicides were applied using mist blowers and drones. Nominee showed the lowest weed control efficiency compared to other applied herbicides in both seasons. Results showed that compared to the mist blower application, applying Novlect via drone is more successful for timely weed control in direct-seeded rice, which in turn reduces labor intensity and hardship.

Potato (Solanum tuberosum L.) is a co-staple food and a source of cash income for the smallholder farmers' in eastern Ethiopia; however, the productivity of the crop is constrained by biotic and abiotic factors. Of which viruses are considered to be major yield limiting factor, but information is lacking on the prevalence and distribution of potato viruses in major growing districts of eastern Ethiopia. This research is therefore initiated to assess and determine the status of six major and multiple potato viruses' infection at farmers' fields during the main rainy and irrigation seasons in four major potato-growing districts of eastern Ethiopia. The dot-blot assays performed for 1000 leaf samples collected from 20 farmers' fields during the two seasons indicated an overall high incidence (71.9% samples detected positive for at least one virus) of potato virus in the surveyed districts of the regions. The most prevalent (19.4%) type of infection was the mixture of all six potato viruses. Among the major viruses, the results also confirmed PVM as the most prevalent (57.3%) virus followed by PVY (48.1%), whereas PVA (45.1%), which was not commonly detected in the other regions of the country, was detected as third most prevalent virus in the current study. The comparison of the results of virus detection in the samples from two seasons indicated remarkable differences in the incidence and prevalence of viruses, where an increasing trend of virus incidence and mixed virus infections from 59 to 84.8% and 41.2 to 72%, respectively, were recorded from rainy to irrigation season. The two viruses; PVX and PVS, which were identified as least prevalent during rainy season, were ranked the 3rd and 4th most prevalent viruses after PVM and PVY during irrigation season. The detected high incidence of virus in potato plants during this first systemic research conducted suggested the importance of continuing the intensive survey and detecting the status of viruses' infection in potato growing districts of eastern Ethiopia. It is also suggested to create awareness among smallholder farmers about the management practices to reduce the effects of viruses’ infection on the productivity of potato in eastern Ethiopia.

Rhododendron agastum, a well-known flower with significant aesthetic and medicinal value, belongs to the Rhododendron genus in the Ericaceae family. In April 2023, a leaf spot disease on R. agastum plants was found in the Baili Azalea Forest Area in Guizhou province, China. Approximately 400 plants were surveyed, and the incidence of leaf spot on R. agastum leaves was 20%. The damaged leaves had gray-white irregular diseased spots with black-brown margins and black conidiomata on the surface of the spots. When the disease is severe, the leaves fall. Leaf spot disease is a serious problem for rhododendrons, reducing their ornamental value and causing significant economic losses. To identify the pathogen, we conducted pathogen isolation and pathogenicity study. The pathogen was identified as Pestalotiopsis kenyana by morphological features and combined analysis of multiple genes (ITS, tef1-α, and Tub2). Koch's postulates was tested by isolating and reidentifying the pathogen from inoculated plants, showing that P. kenyana was the causative agent of the disease. To our knowledge, this is the first report of P. kenyana causing leaf spot in R. agastum. This study gives important information for the identification and control of the leaf spot disease caused by P. kenyana.

The black cutworm (BCW), Agrotis ipsilon (Hufnagel) (Lepidoptera: Noctuidae), is an economically significant pest affecting numerous crops and turf grasses. Despite employing various methods, such as chemical and biological control, to mitigate this pest, the efficacy of these methods often fails to reach the desired level. Hence, the integration of diverse strategies is a key to sustainable management. In this study, we assessed the toxicity of four insecticides (indoxacarb, pyridalyl, lufenuron, and methoxyfenozide) and three local EPN isolates (two isolates of Heterorhabditis indica and one of Heterorhabditis bacteriophora) in targeting the fifth instar larval (L5) and pupal stages of BCW. After demonstrating their potential use in BCW control, we explored the combined use of sublethal concentrations of insecticides (LC₁₅ or LC₃₀) alongside the LC₂₀ values of EPNs. The findings revealed that lufenuron and methoxyfenozide, when combined with EPNs, exhibited a synergistic effect on the L5 stage of BCW, whereas the same combination displayed antagonism on pupae. On the other hand, the combination of indoxacarb and pyridalyl with EPNs demonstrated a synergistic effect on the pupal stage of BCW. These results highlight the potential of employing a combination of insecticides and EPNs at sublethal concentrations to control BCW effectively. This approach shows promise for designing sustainable pest management strategies within the framework of integrated pest management (IPM).