Mustard Flea Beetle Damage Dataset

Description

Flea beetles (Phyllotreta spp.) are a major early-season pest of mustard (Brassica juncea) in Bangladesh, capable of causing economically significant defoliation within one to two days of onset. Images were captured across three mustard fields in two districts (Gazipur and Tangail), at varying times of day and planting densities ranging from sparse stands to frames containing over 200 overlapping seedlings, using four smartphone models (iPhone 16 Pro Max; Samsung Galaxy A34, M11, M32) to introduce natural variation in resolution, colour balance, and sharpness. The dataset has two parts: Detection has 1,603 field photographs, each manually annotated in Roboflow with a bounding box around every visible mustard seedling under a single class ("mustard plant"). Annotations follow the YOLO format: one .txt per image, each line giving class_index x_center y_center width height, normalised to [0, 1]. Only one class is present (index 0). Images are split 80:10:10 at the image level, so no plant appears in more than one split. Classification has 35,948 plant-level crops, extracted by applying the trained detector to all field images, padding each bounding box by 30 pixels, and resizing to a fixed square canvas with letterbox padding. Crops were manually sorted into four severity classes by the proportion of leaf area showing feeding damage: healthy (0–10%), mild (10–50%), moderate (50–70%), severe (70–100%). Contents: mustard_flea_beetle_dataset/ |── detection/ | |── images/ | | ├── train/ (1,282) | | ├── val/ (160) | | └── test/ (161) | |── labels/ | ├── train/ | ├── val/ | └── test/ |── classification/ ├── healthy/ (32,432) ├── mild/ (1,219) ├── moderate/ (927) └── severe/ (1,370) The class distribution reflects natural incidence in the sampled fields and is heavily skewed. The four-class severity scale contains an unlearnable boundary. Merging the moderate and severe classes substantially improved classification performance. How to interpret and use the data: The four original labels are preserved so users can apply their own severity scheme. Anyone reproducing the three-class formulation should merge moderate into severe. Several characteristics affect interpretation. Severity boundaries were assigned by visual estimation rather than measured leaf area. Annotation was performed by a single annotator, so inter-annotator agreement was not assessed. Classification crops carry black letterbox borders from aspect-ratio-preserving resizing. Generalisation to other regions, seasons, and mustard varieties is untested. All images are unmodified field photographs or crops derived from them. No synthetic or augmented images are included.

Institutions

• Daffodil International University

  Dhaka Division, Dhaka

Categories

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