Crop Protection最新文献

Traditional weed detection technology has several limitations, including low detection accuracy, substantial computational demands, and large-scale detection models. To meet the requirements of weed multi-target identification and portability, this study proposes the YOLO–WEED model for weed recognition. The proposed model has the following innovations: (1) The backbone standard convolution module in YOLOv5 was replaced by the lightweight MobileNetv3 network to simplify the network structure and reduce parameter complexity; (2) The addition of convolutional block attention module (CBAM) to the neck network enabled the model to focus on the most important features while filtering out noise and irrelevant information; (3) To further improve classification accuracy and reduce loss, the C2f module was employed to improve the C3 module in the neck network; and (4) During the model plot process, a coordinate variable was added in the box label to help the model accurately locate the weeds. In the study, six species of weeds and one crop were used as test subjects. After image enhancement techniques were used, ablation experiments were deployed. The experimental results indicated that the YOLO–WEED model achieved an average accuracy of 92.5% in identifying six types of weeds and one type of crop. The accuracies for each type of plant were 82.7%, 97.3%, 98.8%, 86%, 93.5%, 99.3% and 89.6%, respectively. The number of model parameters was reduced by 39.4% compared with YOLOv5s. Furthermore, the localisation, classification and object losses were reduced by 0.025, 0.005 and 0.014, respectively. The model optimisation and deployment of the Jetson mobile terminal for multi-target detection were realised, and the performance was better than six network models such as YOLOv5s.

Red Guava is widely grown in numerous parts of southern China and is a favorite fruit among Chinese consumers due to its imperative nutritional value, high medicine value and excellent economic value. Black spot is one of the serious diseases that causes fruits rot. In July 2023, 25–30% of postharvest red guava fruits rot exhibiting disease symptoms were observed in surrounding markets of Haikou city, Hainan province, China. The purpose of this study was to isolate and identify the pathogenic fungi of red guava black spot. A total of 26 pathogenic fungal strains were isolated from the rotten red guava fruits with typical characteristics. One representative isolate, FSL2, was selected for subsequent experiments. Combining morphological analysis with phylogenetic analysis (internal transcribed spacer regions 4 and 5, translation elongation factor1, and β-tubulin genes), the pathogens should be identified as Neopestalotiopsis saprophytica. Pathogenic tests indicated that the symptoms of red guava fruit decay caused by N. saprophytica isolated from the sample were almost the same. The fungal species has been previously reported in China on Persimmon related with fruits rot. Thus, this study concluded that the pathogen of red guava black spot may be N. saprophytica. To best of our knowledge, this is the first report of red guava black spot caused by N. saprophytica.

Intercropping with greater pulse seeding rates for weed mitigation could increase growers yield returns and potentially reduce weed resistance, caused by frequent herbicide applications. In 2021, a split-split plot experiment in North Star, Alberta was sown to wheat (Triticum aestivum L.) in two fields; half the plots were sprayed with Thifensulfuron-methyl + tribenuron-methyl at 29.65 g.a.i.ha⁻¹ (9.89 + 4.94 respectively) at flag leaf with other half left untreated. In the following spring (2022), field pea (Pisum sativum L.) was sown at 0.5X, 1X and 1.5X seeding rate (101, 202 and 303 kgha⁻¹, respectively) with either ryegrass (Lolium multiflorum L.) or rye (Secale cereale L.) at 5.6 and 19.1 kgha⁻¹, barley (Hordeum vulgare L.) or oat (Avena fatua L.) at 33.7 kgha⁻¹, plus monocrop control. Objectives were to a) identify most weed suppressive intercrop, and b) how companion crops affected pea seeding rates. Herbicide sprayed plots had less weeds compared to unsprayed despite cropping system adopted and rye was best companion crop to reduce weeds. Rye-pea (1.11) or ryegrass-pea (0.98) land equivalent ratio (LER) were greater than oat-pea (0.75). Cereal Agressivity (A) (2.64X10⁻³ and 2.18X10⁻² in oat and barley) and actual yield loss (AYL) (3.06 in oat, 0,39 in barley) was greater than pea (−2.67X10⁻³, −2.29X10⁻² for A and 2.95, 0.73 for AYL in oat and barley respectively), inversely to competitive ratio (CR) (0.07, 2.60 in oat and pea; 0.25, 0.63 in barley and pea). More pea stands decreased cereal CR (0.36,0.11 and 0.05 at 0.5X, 1X and 1.5X pea seeding rates) and AYL (1.56, 1.41 and 0.59 for same pea seeding rates). Overall, a) increasing pea seeding rates reduce weeds and increase competitivity towards cereals, and b) despite rye being more suppressing, barley and oat promote pea yields with less area likewise. This study demonstrated the variety of IWM strategies possible in Northern Alberta.

Soilless cultivation is increasingly common, but the nutrient-rich drainage from substrate cultivation is often discarded. However, drainage can be safely reused if previously disinfected. Slow sand filtration (SSF) is a low-cost, ecological, and effective method for water disinfection, primarily through biological control. Enhancing SSF with antagonistic microorganisms is not well-studied. Additionally, SSF has not been tested to control Rhizoctonia solani, a phytopathogen that can be spread by irrigation water. Therefore, the objective of his work was to test the efficacy of a slow sand filter improved through the inoculation of the antagonistic fungus Trichoderma atroviride, evaluating its suppression capacity against Rhizoctonia solani spread by the irrigation water in a closed substrate cultivation of cucumber (Cucumis sativus). Five experiments were conducted, testing the presence and absence of a sand filter, T. atroviride, and R. solani in each trial. Median disease severity was expressed on a scale of 1–5. The improved SSF increased disease control percentage by 49% compared to SSF alone and by 86% compared to no disease control method. In some experiments, SSF with T. atroviride totally controlled R. solani. The results confirm that biologically enhanced SSF with T. atroviride can effectively disinfect drainage in closed soilless cultivation systems infected with R. solani.

The pigeonpea cyst nematode (PCN) Heterodera cajani Koshy infects black gram (Vigna mungo L.), causing significant yield losses. However, there is a lack of systematic information on PCN pathogenicity, as well as quantitative and qualitative yield losses in black gram under various inoculum levels and soil conditions. Therefore, we have assessed the threshold inoculum level(s), estimated the yield and protein losses caused by PCN, and evaluated eco-friendly management option(s) with botanicals (neem cake, neem seed powder) and a microbial agent (Trichoderma harzianum). The results revealed a gradual and significant decline in crop growth parameters as the inoculum levels increased from 0 to 3000 juveniles (J2s)(2 kg soils). The severity of PCN infestation was notably higher in alluvial soils compared to lighter soils, exhibiting higher cyst counts (+63%) in plant roots. The threshold inoculum level(s) causing a 25% reduction in various agronomic parameters was significantly lower in alluvial soil(176–1262 J2s; mean = 921) compared to light soil (720–1444 J2s, mean = 1308), indicating that alluvial soil conditions favored increased PCN infestation over light soils, leading to more substantial growth inhibition. Strong positive correlations were found between initial inoculum levels and final populations of PCN. Inoculum levels ranging from 90 to 120 thousand J2s (representing 45–60 J2s per 100 cc soils) resulted in yield losses of 26–78% (p < 0.001). Additionally, there was a corresponding decrease in grain protein content by 9–22% (p < 0.01), subsequently reducing protein productivity by 11–83% (p < 0.001). In the PCN management experiment, among the different bio-organic components, neem cake at 1.0 t ha⁻¹ exhibited the highest efficacy against PCN at crop harvest stage, leading to significant improvements in both dry shoot weight (4.3 g) and dry root weight (1.0 g)/plant compared to the inoculated check. Also, neem seed powder (at 0.1 t ha⁻¹) and T. harzianum + farmyard manure (1 kg in 100 kg farmyard manure ha⁻¹) showed increased effectiveness against the nematode. This study emphasizes the substantial influence of nematode infection on crop performance, particularly in alluvial soils, resulting in significant losses in both yield and protein content. Neem cake emerges as a promising eco-friendly management for managing the PCN in black gram.

For the first time, we isolated and identified Alternaria argyroxiphii on Upland cotton (Gossypium hirsutum) in Australia and elsewhere. A single-spored A. argyroxiphii isolate was obtained from diseased cotton leaves that exhibited small circular to enlarged and coalesced irregular necroses in the 2021–2022 cropping season in northwest New South Wales, Australia. We identified A. argyroxiphii based on its large conidia with filiform beaks and sequences of the internal transcribed spacer (ITS), glyceraldehyde-3-phosphate dehydrogenase (GAPDH) and calmodulin (CAL). These multigene sequences of the cotton-A. argyroxiphii were 100% identical to those of the type A. argyroxiphii isolate CBS 117222; thus, confirming the identity. On two-true-leaf cotton seedlings, A. argyroxiphii was able to incite necrotic symptoms resembling those observed in the field, and was reisolated and re-identified, thus, fulfilling Koch's postulates. This is the first record of A. argyroxiphii on Upland cotton.

Successful maize (Zea mays L.) cultivation is largely reliable by weed interference. Among weeds, annual species are usually dominant, whereas less prevalent perennials can be challenging to control, too. Driven by profitability, maize is often cultivated continuously using the same management practices over time, resulting in increased weed infestations, particularly perennials. However, crop rotation might reduce the abundance of weed species, lower herbicide impact on the environment, delaying herbicide resistance occurrence in weeds and thus contribute to sustainable maize production,. The aim of this study was to explore the impact of continuous maize cropping (Maize-CC) and a three-crop rotation, maize–winter wheat–soybean (Maize-WW-S), in combination with three weed management treatments: 1) application of a pre-emergence herbicide mixture of acetochlor/S-metolachlor + isoxaflutole at the full label rate, 2) at ½ of full label rate, and 3) an the untreated control, over a 12-year period. The trial was initiated in 2009, and maize was grown in both cropping systems, Maize-CC and Maize-WW-S, in 2012, 2015, 2018, and in 2021. Total weed density, fresh biomass of all annual and perennial weed species and total dry biomass of all weed species was measured four weeks after herbicide application. Maize leaf area index (LAI) was measured at the anthesis, whereas grain yield was measured at the end of the growing cycle. Weed species diversity, number of individuals, weed fresh and dry biomass, were significantly lower with the combination of Maize-WW-S and the herbicide treatments. Grain yield was significantly and negatively correlated with the fresh weight of annual weeds in Maize-CC and was higher in both herbicide treatments, especially in Maize-WW-S. There was no significant difference between pre-emergence herbicide full labelled rate and ½ of the labelled rate in reducing the total fresh weed biomass in Maize-CC (66.3% and 65.9%, respectively) and Maize-WW-S (92.1% and 85.8%, respectively). Thus, the importance of the combined employment of rotation and chemical measures in maize production was confirmed and could be adopted for long-term weed management without compromising yields.

Monitoring the coffee leaf miner and natural parasitism is an important part of integrated pest management, and knowing the spatial distribution patterns of this pest can help improve sampling plans. This study aimed to determine spatial and temporal distributions of the coffee leaf miner infestation and natural parasitism in coffee plantations of different insecticide use and landscape configurations in the Planalto region, Bahia, Brazil. We monitored five coffee farms with different insecticide management practices in insecticide use and landscape features during two seasons, from December 2020 to November 2021. In each coffee farm, four regular grid plots of 30 points were established, for a total of 120 sample points per farm, that were georeferenced. Each point was a group of five coffee plants within 5 m of each other, 30 m in distance. Monthly collections of mined leaves were carried out at each sampling point to determine the L. coffeella infestation and natural parasitism rates. Geostatistical analysis was used to determine the spatial distribution of infestations and natural parasitism using semivariograms. Landscape metrics of each coffee plantation were surveyed in buffers ranging from 500 to 3000 m to assess their effects on population aggregation. Infestations of L. coffeella and natural parasitism of the pest occurred throughout the year and at varying intensities among farms. Leucoptera coffeella infestation and natural parasitism exhibited moderate aggregation patterns in most sampling months. The aggregation of L. coffeella infestations and natural parasitism were influenced by landscape and insecticide use. Forest cover, land cover use diversity, and insecticide use increased aggregation of L. coffeella infestations and natural parasitism, whereas edge density decreased aggregation of both. The study suggests that it may be beneficial to review the current sampling plans for the coffee leaf miner and the natural parasitism in coffee farms. This information can improve the integrated management of the pest in coffee farms and assist in decision-making regarding L. coffeella control strategies.

This study aimed to investigate the management of Alternaria rot in citrus by evaluating the efficacy of late-season fungicide programs in reducing latent infections and fruit drop. Furthermore, the occurrence of mutations conferring resistance to QoI and SDHI fungicides within an Alternaria population isolated from citrus was investigated. In field trials, high frequencies of Alternaria infections were observed on the stem end and stylar end of Satsuma and Shiranui mandarins, with a higher prevalence of stem-end infections. Fungicide treatments applied towards the end of the season effectively reduced the frequency of latent infections on the stem end, indicating that such infections occur during this period under specific conditions. While some fungicide treatments demonstrated efficacy in reducing fruit drop caused by Alternaria rot, the results varied across different orchards and years. Latent infections on fruits persisted at high frequencies in the majority of trials, highlighting the complex nature of disease management. Mutations associated with resistance against QoI and SDHI fungicides were identified within the Alternaria population affecting California citrus. Our study suggests the potential need for fungicide sprays at the onset of the season to reduce the frequency of Alternaria infections on the stem end and stylar end of fruits. However, the observed non-correlation or low correlation between latent infections and fruit drop indicates that latent infections alone cannot reliably predict fruit drop. Our findings indicate that pre-harvest fungicide treatments have inconsistent efficacy and are cost-effective only during unpredictable disease outbreaks.

Field studies were conducted over two successive seasons to test the effects of maize-legume intercropping system on fall armyworm (FAW) (Spodoptera frugiperda (J.E. Smith)) and if insecticide use was necessary in intercropping systems. Three insecticide treatments [no spray, Emastar 112 EC (a.i. emamectin benzoate 48 g/L + acetamiprid 64 g/L), Neem seed oil (NSO) (a.i. 3% azadirachtin)] and three intercropping systems [sole maize (Zea mays L.), maize + soybean (Glycine max (L.) Merr.) and maize + groundnut (Arachis hypogaea L.)] were arranged as a 3 × 3 factorial experiment in a randomized complete block design. Data were collected on FAW larval infestations, parasitism rates, damage, grain yield and gross financial returns. Results from combined-years analyses showed that larval infestation was significantly affected by intercropping (p = 0.034) only, with maize + soybean recording the lowest infestation while sole maize was highest. Damage to crop and cobs were significantly affected by years and insecticide treatments. Cob damage was also significantly affected by intercropping system with maize + soybean being lowest and sole maize recording the highest damage. Parasitoids recorded were Coccygidium luteum, Chelonus bifoveolatus, and Charops sp. Grain yield was significantly affected by the intercropping systems only (p = 0.004), with no significant year (p = 0.152), insecticide (p = 0.726) and insecticide × intercropping system (p = 0.660) effects. Sole maize (1.6 t/ha) had the lowest yield while maize + groundnut (2.2 t/ha) was highest. In terms of income, an economic analysis showed that spraying intercropped maize with NSO resulted in the highest marginal rate of return. Thus, the use of NSO and intercropping is an effective FAW management strategy.