Pieter Blok

• Doctor of Philosophy
• Assistant Professor at Jheronimus Academy of Data Science

Downy mildew ( Plasmopara ), apple scab ( Venturia inaequalis ), and Alternaria leaf blight are endemic diseases that affect crops worldwide. The diseases can cause severe losses in grapes, apples and carrots when not detected and treated in an early stage. The European Union Horizon 2020 OPTIMA project aimed to improve disease detection in the ope...

Species-level crop and weed semantic segmentation in agricultural field images enables plant identification and enhanced precision weed management. However, the scarcity of labeled data poses significant challenges for model development. Here, we report a patch-level synthetic data generation pipeline that improves semantic segmentation performance...

The increase in the global population is leading to a doubling of the demand for protein. Soybean (Glycine max), a key contributor to global plant-based protein supplies, requires ongoing yield enhancements to keep pace with increasing demand. Precise, on-plant seed counting and localization may catalyze breeding selection of shoot architectures an...

In recent years, powerful data-driven deep-learning techniques have been developed and applied for automated catch registration. However, these methods are dependent on the labelled data, which is time-consuming, labour-intensive, expensive to collect and need expert knowledge. In this study, we present an active learning technique, named BoxAL, wh...

Potato yield is an important metric for farmers to further optimize their cultivation practices. Potato yield can be estimated on a harvester using an RGB-D camera that can estimate the three-dimensional (3D) volume of individual potato tubers. A challenge, however, is that the 3D shape derived from RGB-D images is only partially completed, underes...

The detection and sizing of fruits with computer vision methods is of interest because it provides relevant information to improve the management of orchard farming. However, the presence of partially occluded fruits limits the performance of existing methods, making reliable fruit sizing a challenging task. While previous fruit segmentation works...

Apple scab is a fungal disease caused by Venturia inaequalis. Disease is of particular concern for growers, as it causes significant damage to fruit and leaves, leading to loss of fruit and yield. This article examines the ability of deep learning and hyperspectral imaging to accurately identify an apple symptom infection in apple trees. In total,...

This paper characterizes, with static and roving GNSS receivers in the context of precision agriculture research, the hybrid ionospheric-geodetic GNSS model Wide-Area Real-Time Kinematics (WARTK), which computes and broadcasts real-time corrections for high-precision GNSS positioning and navigation within sparse GNSS receiver networks. This researc...

The generalisation performance of a convolutional neural network (CNN) is influenced by the quantity, quality, and variety of the training images. Training images must be annotated, and this is time consuming and expensive. The goal of our work was to reduce the number of annotated images needed to train a CNN while maintaining its performance. We...

The generalisation performance of a convolutional neural network (CNN) is influenced by the quantity, quality, and variety of the training images. Training images must be annotated, and this is time consuming and expensive. The goal of our work was to reduce the number of annotated images needed to train a CNN while maintaining its performance. We...

The growth and the harvestability of a broccoli crop is monitored by the size of the broccoli head. This size estimation is currently done by humans, and this is inconsistent and expensive. The goal of our work was to develop a software algorithm that can estimate the size of field-grown broccoli heads based on RGB-Depth (RGB-D) images. For the alg...

Purpose of Review The world-wide demand for agricultural products is rapidly growing. However, despite the growing population, labor shortage becomes a limiting factor for agricultural production. Further automation of agriculture is an important solution to tackle these challenges. Recent Findings Selective harvesting of high-value crops, such as...

In current practice, broccoli heads are selectively harvested by hand. The goal of our work is to develop a robot that can selectively harvest broccoli heads, thereby reducing labor costs. An essential element of such a robot is an image‐processing algorithm that can detect broccoli heads. In this study, we developed a deep learning algorithm for t...

Virus diseases are of high concern in the cultivation of seed potatoes. Once found in the field, virus diseased plants lead to declassification or even rejection of the seed lots resulting in a financial loss. Farmers put in a lot of effort to detect diseased plants and remove virus-diseased plants from the field. Nevertheless, dependent on the cul...

Fruit production in orchards currently relies on high labor inputs. Concerns arising from the increasing labor cost and shortage of labor can be mitigated by the availability of an autonomous orchard robot. A core feature for every mobile orchard robot is autonomous navigation, which depends on sensor-based robot localization in the orchard environ...

Potato blackleg is a tuber-borne bacterial disease caused by species within the genera Dickeya and Pectobacterium that can cause decay of plant tissue and wilting through the action of cell wall degrading enzymes released by the pathogen. In case of serious infections, tubers may rot before emergence. Management is largely based on the use of patho...

In mountainous orchards, agricultural tasks, such as crop protection and harvesting, are characterized as being labor intensive and dangerous. An autonomous orchard robot that can execute these unattended seems a promising alternative to increase task operability. An essential function in the development of an autonomous orchard robot is navigation...

In mountainous orchards, agricultural tasks, such as crop protection and harvesting, are characterized as being labor intensive and dangerous. An autonomous orchard robot that can execute these tasks unattended seems a promising alternative to increase task operability. An essential function in the development of an autonomous orchard robot is navi...

The selective hand-harvest of fresh market broccoli is labor-intensive and comprises about 35% of the total production costs. This research was conducted to determine whether machine vision can be used to detect broccoli heads, as a first step in the development of a fully autonomous selective harvester. A texture and color based image segmentation...

Virus- en bacterieziekten vormen één van de grootste problemen in de pootaardappelteelt. Eenmaal aangetroffen in het veld kunnen viruszieke (Y-virus) en Erwinia zieke aardappelen leiden tot afkeuringen van partijen pootgoed met een financiële schade tot gevolg. De directe schade door Erwinia aandoeningen bedraagt voor de pootgoedtelers jaarlijks ca...

The reduction of the emission of plant protection products (PPP) to the environment is an important issue when applying agrochemicals in the Netherlands. Much attention always has been paid to reduce spray drift, however an application having an use reduction in combination with the same level of spray drift reduction implicitly means higher levels...

The quality assessment of seeds and particularly the crop emergence rate is an important parameter in plant breeding, especially in open field crops which should withstand fluctuating and unfavorable conditions. To evaluate different plant varieties and to assess the effect of different cultivation methods on plant growth, breeders and researchers...

Een vroege detectie van zieke planten met moderne vision technieken kan de kosten voor selectie in de pootaardappelteelt flink drukken. De nadruk ligt hierbij op de detectie van Erwinia, gezien de grote financiële schade. In 2010 zijn een eerste serie metingen in pootaardappelen uitgevoerd met een bestaande opstelling voor detectie van viruszieke t...

Dit onderzoek was gericht op het vinden van de meest geschikte opnametechniek voor het ziekzoeken, waarmee een eenduidig onderscheid te maken is tussen zieke en niet-zieke planten. Een belangrijk accent lag op het vroegtijdig herkennen van zieke planten. De nieuwe technologieën hebben vooral meerwaarde als het herkennen mogelijk wordt voordat de sy...

In 2010 en 2011 is de stikstofbijbemesting volgens verschillende strategieën op drie aparte stroken uitgevoerd op een praktijkperceel met aardappelpootgoed (ras Mustang) in Vierhuizen (Groningen). Op elke strook werden tevens twee stikstofvensters aan gelegd. Op één venster werd geen basisbemesting toegepast en het andere kreeg de dubbele hoeveelhe...

Studenten die nu worden opgeleid voor een functie in de agrarische sector of agrarisch ondernemer krijgen met precisielandbouw te maken. Het is de taak van het agrarisch onderwijs hen hierop voor te bereiden. Een groep medewerkers van het praktijkonderzoek van Wageningen UR-PPO-agv heeft samen met vier leerkrachten techniek van agrarische HBO, MBO...