The true bottleneck of artificial intelligence (AI) is not access to the data, but rather labeling this data. We have tons of raw agriculture image data coming from various sources and manual labelling remains to be a crucial step to keep the data well organized which requires considerable amount of time, money, and labor. This process can be made more efficient if we can automatically label the raw data. We propose contrastive learning representations for agriculture images (AgCLR) model that uses self-supervised representation learning approach on unlabeled real-world agriculture field data, to learn the useful image feature representations from the images. Contrastive learning is a self-supervised approach that enables model to learn attributes by contrasting samples against each other without the use of labels. AgCLR leverages the state-of-the-art SimCLRv2 framework to learn representations by maximizing the agreement between differently augmented views of same sample. We have incorporated critical enablers like mixed precision, multi-GPU distributed parallel computing, and use of Google Cloud's Tensor Processing Units (TPU) for optimizing the training process. We achieved 80.2% accuracy while classifying the test data. We further applied AgCLR to unrelated task to determine the alleys and rows in corn field videos for corn phenotyping and we observed two cluster formations for alleys and rows when plotted embeddings in a 3-dimensional space. We also developed a content-based image retrieval tool (pixel affinity) to identify similar images in our database and results were visually very promising.

Stomata are the microscopic pores on plant leaves that open or close to regulate the flux of water from leaves. Guard cells of stomata are known to react to environmental conditions such as light and CO2 in order to optimize CO2 uptake and water loss. Stomatal anatomy (aperture, length, width, etc.) influences leaf-level physiology traits including conductance to water. Stomatal anatomy can be visualized in situ by microscopy, but the difficulty of regulating the atmospheric environment of a microscope stage means that the conditions under which imaging is done are rarely physiologically relevant. Alternatively, portable photosynthesis measuring instruments offer a non-destructive estimate of leaf gas exchange, including stomatal conductance, while the leaf experiences tightly controlled steady-state or dynamic environmental conditions. However, these measurements reflect stomatal characteristics in aggregate on a leaf area basis, which are heavily influenced by the mesophyll as well as epidermal structure and function. Observing the behavior of stomata by microscopy simultaneous to controlling the leaf environment and measuring gas exchange fluxes would allow advances in the understanding of leaf structure-function relationships. To reconcile the microscopic stomatal characteristics with leaf-level gas exchange we have combined laser scanning confocal microscopy and gas exchange instruments to simultaneously observe stomatal characteristics (e.g. stomatal aperture, pore depth, closing speed) and leaf-level traits like photosynthesis, transpiration, and stomatal conductance. Results are presented for the use of this approach on diverse plant species.

High-oil tobacco varieties have been recently engineered to produce increased leaf oil content for future food and fuel needs. An engineered variety of Nicotiana tabacum produces ~30 percent of leaf dry weight in lipids in the form of triacylglycerol (TAG), a significant increase relative to the less than 1 percent storage oil normally found in wild-type leaves. This high-oil tobacco also accumulates oil bodies in stomatal guard cells. In order to understand the impact of oil on guard cell shape, aperture, and dynamics, we have co-opted computer vision tools in PlantCV to create an accurate, flexible, and high-throughput method for microscopy image analysis of stomata. To this end, leaf impressions are made with silicone putty; clear nail polish peels of the putty impressions are imaged using light microscopy. Binary thresholding followed by point-and-click regions of interest and morphology calculations provide stomatal counts, aperture, and other shape characteristics. Applying this method to high-oil tobacco demonstrated reduced stomatal aperture but the same number of stomata per unit leaf area, providing a mechanistic explanation of high-oil tobacco responses to high temperature and water deficit stresses.

From preventing scurvy to being part of religious rituals, citrus are intrinsically connected to human health and perception. From tiny mandarins to head-sized pummelos, citrus capability of hybridization provides a vastly diverse array of fruit sizes and shapes, which in turn corresponds to a diversity of flavors and aromas. These sensory qualities are tightly linked to oil glands in the citrus skin. The oil glands are also key to understanding fruit development, and the essential oils contained by them are fundamental in the food and perfume industries. We study the shape of citrus based on 3D X-ray CT scan reconstruction of 163 different citrus samples comprising 58 different species and cultivars, including samples of all fundamental citrus species. First, using the power of X-rays and image processing, we are able to compare and contrast size ratios between different tissues, such as the size of the skin compared to the rind or the flesh. Second, we model the fruit shape as an ellipsoidal surface, and later we study and infer possible oil gland distributions on this surface using principles of directional statistics. We finally compare and contrast these overall fruit shape models along their gland distributions across different citrus species. This morphological modeling will allow us later to link genotype with phenotype, furthering our insight on how the physical shape is genetically specified in DNA.

Recent advancements in proximal remote sensing have increased the spatial and temporal resolution of data collection, as well as the availability of these technologies for applications to precision agriculture. These sensors have allowed the collection of new and large quantities of data, which have been used to successfully determine phenotypes and parametrize crop growth models. So far, these data streams have been mostly used separately, though they contain unique structural, spatial, and spectral information. Thus, this research aims to integrate these disparate data sources to improve estimations of agronomically important crop traits. In this study, we examine two high-throughput and relatively inexpensive remote platforms: unoccupied ground vehicles (UGV) and unoccupied aerial vehicles (UAV). Data were collected on maize hybrids from the Genomes to Fields initiative over 5 years, from 2018 to 2022, in Aurora, NY. We used ground rovers to collect lidar scans, which were converted to point clouds, to construct the three-dimensional sub-canopy architecture of maize plants. Multispectral sensors, covering red, green, blue, red-edge, and near infrared (NIR) were deployed on a UAV platform to characterize maize canopies. Machine learning methods, including autoencoders, will be used to extract latent phenotypes from the lidar point clouds and multispectral images. Ultimately, these will be used to predict manually measured traits, such as yield, in order to compare the prediction accuracies of models using these measurements separately and jointly.  

Root exudation refers to the processes by which plants release compounds called root exudates into the soil. These exudates are primarily carbon-containing compounds that interact with microbial communities in the rhizosphere. Microbial consumption of exudates reduces the concentration of the exudated compounds in the soil, causing the plant to exude more of those compounds. Currently, there is limited understanding of the interaction between plant-root exudation mechanisms and the surrounding microbial communities. Among the Sorghum Association Panel (SAP), an established and genetically characterized sorghum diversity panel, we observed a spectrum of root colors (tan, yellow, red, purple-brown, black) identical to the range of observed sorghum seed colors. Previous studies examining differentially expressed metabolites between colorful seeds showed that flavonoids and anthocyanins were higher in dark seeds than white seeds. Root color is genotype-dependent and consistent over time. We hypothesized that the observed color diversity of sorghum roots was due to differential metabolite profiles in the root exudates across genotypes. We designed an experiment to collect exudates from 15 genotypes (n=60). After three weeks of growth, sorghum roots were washed and submerged in ultrapure water for 24 hours. The hydroponic solution was filtered and incubated with methanol. The whole root system was also ground after exudation. The root exudate solutions and the ground-up roots underwent either HILIC and RPLC analysis to separate and detect polar and hydrophobic metabolites. Through metabolite profiling of root exudates, we aim to identify sorghum genotypes that more efficiently allocate carbon below ground via their root systems.

Unmanned aerial vehicles (UAVs) provide growers and researchers with an efficient way to evaluate fields at high resolution. Flying UAVs and collecting imagery are made easily approachable through high-performance sensors that measure a wide spectrum of light and free flight software available on smartphones and tablets. In contrast to the efficiency of collecting imagery, extracting data from this imagery presents a major hurdle for researchers and growers. Current data analysis options require either an expensive subscription service or complex coding packages, effectively preventing many from utilizing remote sensing data. These solutions also are designed as a "black-box", where imagery goes in and data comes out, making customization and adaptability to the user's needs a challenge. To address these shortcomings, I developed an open-source analysis pipeline that is both approachable and robust. Starting with an orthomosaic and combining stock tools in the QGIS graphical user interface, this pipeline follows a simple step-by-step process to mask out soil and apply any user-defined index. From there the user can segment plots using a fast yet highly customizable gridding system, allowing for plot segmentation in unusual field layouts or planting regimes. This feature has been previously unsupported in many subscription and open-source programs alike. Plot-level data can then be exported for statistical analyses. Ultimately, this pipeline is aimed to attract more researchers and growers towards using remote sensing data in their research.

Cover crops, plants grown during fallow periods between cash crops, are a promising solution to mitigating soil degradation induced by conventional agricultural practices and improving soil health. Cover crops can provide several beneficial ecosystem functions, such as soil structure remediation, soil microbial diversification, and nutrient recycling, depending on the plant species. Interactions between plant roots and the surrounding soil are key to the plant's ability to perform their ecosystem functions. The lack of data on cover crop roots inhibits our understanding of cover crop phenotype-ecosystem function relationships. We combine aboveground and belowground phenotyping measurements with physicochemical soil measurements to evaluate the field performance of 19 different plant species in monocultures and polycultures as winter cover crops in Missouri. Canopy cover imaging reveals significant differences in winter hardiness and weed suppression among cover crop varieties. Root biomass and root length density measured at depths up to 1 meter indicate differences in rooting behavior between cultivars suggesting the ability to breed cover crop varieties with improved root system architecture. I will also highlight our collaborative efforts utilizing remote sensing technologies (aerial RGB and hyperspectral imaging) to model carbon and nitrogen cycling in cover crop systems at a field scale. Finally, we have begun to characterize 3D root system architecture traits at the seedling stage using a gel-imaging system. Better understanding of cover crop rooting behavior will allow us to breed varieties with enhanced performance of beneficial ecosystem functions for sustainable agricultural systems.

A high-throughput image analysis pipeline was developed to facilitate root phenotyping by reducing time-consuming labeling while maintaining phenotyping accuracy. This pipeline leverages a deep learning-based tool named SLEAP (SLEAP Estimates Animal Poses) which is designed to automate the detection of distinct morphological landmarks. By training SLEAP to detect the root branch points, tips, and midline of each root imaged in a gel cylinder, we were able to robustly and efficiently recover the root system geometry. We trained models to identify these landmarks on primary, lateral, and seminal roots across a range of crop plants, including soybean, rice, canola, and pennycress. We find that our SLEAP models are robust across genotypes and experiments, enabling automated root system quantification at the rate of hundreds of plants per hour. Using predictions of root landmark locations, we developed Python-based pipelines to extract phenotypic traits, including tip depths, root lengths, convex hulls, root angles, measures of curviness, and lateral root distribution (available at https://github.com/talmolab/sleap-roots). In order to extract meaningful patterns from this high-dimensional description of plant phenotypes, we use machine learning-based methods for dimensionality reduction and manifold embedding, allowing us to capture the statistical structure of root phenotypes present in our screens. In future work, we will use these quantitative phenotypic traits as a predictor for root system traits that enhance carbon sequestration capabilities in genome-wide association studies.

Hemp (Cannabis sativa L. <0.3% THC) is a versatile crop cultivated for grain, fiber, and cannabinoids used for health and wellness purposes. Following the passage of the 2018 Farm Bill, which removed hemp from the controlled substances list, there is potential for expanded hemp acreage and a concomitant need to breed cultivars with suitable agronomic performance in US growing regions. Understanding the relationships between morphological, biochemical, and spectral traits with respect to yield will allow for high-throughput phenotyping and advanced breeding efforts. For five years, the Cornell Hemp research team has evaluated high-cannabinoid hemp cultivars in replicated field trials, with populations originating from both commercial sources and the Cornell Hemp Breeding Program. These field trials evaluated plants for phenotypic traits, including plant height, morphology, flowering time, cannabinoid concentration, and total biomass yield. We have also determined key morphometric measurements that are correlated with end-of-season biomass yield. Also, both floral and foliar cannabinoid samples were correlated with end-of-season whole plant biomass cannabinoid concentration. To improve phenotyping efficiency, an unmanned aerial vehicle (UAV)-based multispectral system was deployed to characterize morphological and biochemical traits over time. These datasets are being used to develop high-throughput phenotyping methods to predict biomass yield, and in the future cannabinoid concentration and flowering time.

ORCiD: https://orcid.org/0000-0003-4699-3733 Rootstocks are gaining importance in viticulture as a strategy to combat abiotic challenges, as well as enhancing scion physiology and attributes. Therefore, understanding how the rootstock affects photosynthesis is insightful for genetic improvement of either genotype in the grafted grapevines. Photosynthetic parameters such as maximum rate of carboxylation of RuBP (Vcmax) and the maximum rate of electron transport driving RuBP regeneration (Jmax) has been identified as ideal targets for breeding and genetic studies. However, techniques used to measure these photosynthetic parameters are time consuming and subjective to leaf level which is complex to implement at field scale. Hyperspectral remote sensing uses the optical properties of the entire vine to predict photosynthetic capacity at canopy level. In this study, estimates of Vcmax and Jmax were assessed using different machine learning models: PLS (Partial least Squares), LR (Least Angle Regression), LASSO (Least Absolute Shrinkage and Selection Operator), PCR (Principle Component Regression) based on leaf reflectance metrics obtained with hyperspectral wavelength ranging from 400 to 1000nm. Prediction models were developed for six different rootstock genotypes with common scion Marquette considering three different sampling dates carried out in Brookings, South Dakota in 2021. Preliminary results indicate that each rootstock has distinctly different Vcmax and Jmax profiles across the season. From the model assessment, PLS was found to have robust prediction of Vcmax with R2 of 0.53 and for Jmax with R2 of 0.63. Multiple year trials will be used to validate precise and rapid quantification of photosynthesis using hyperspectral remote sensing.

Using Unoccupied Aerial Systems (UASs) to collect image data for field phenotyping enables the coverage of large spatial scales, but the extraction of phenotypes at the level of an individual plant remains a challenge. Phenotypes are generally extracted at the plot level after manual delineation of the plots in an orthomosaic image. However, this approach is impractical when individual plant phenotypes are of interest, such as in mutant screenings, heterozygous population trials, and other cases where individual plants in a plot or a landscape may be very diverse. For mutant studies in particular, UASs have had limited utility since one typically wants to identify individual plants with outlier phenotypes. Current mutant population screenings require scientists to walk through the field on a regular basis to manually identify and record plants of interest. If UAS software could be designed to identify these plants, much larger studies could be conducted with lower labor costs. Here, we use deep Convolutional Neural Network (CNN) models to detect individual maize plants in raw UAS images followed by the extraction of individual phenotypes. The predictions from the CNN models are used to identify plants in the orthomosaic image to derive information on plot location. For the extraction of phenotypes, plant pixels are segmented from the background and traits including color-based indices and canopy coverage are calculated. Individual plant height is derived from the corresponding Digital Surface Model (DSM). This project will contribute to a more efficient approach for the phenotyping of individual plants using UAS images.

Root studies in controlled environments are typically conducted either in rhizotrons, pots, or small scale mesocosm systems, like PVC tubes or root boxes. These systems have two limitations for translating results to crop roots grown in fields. First, the size and shape of containers change the root phenotype when plants are in the mature stage. Second, often only one plant is planted per container without interaction among neighboring plants. Therefore, the root architecture observed in these isolated environments has low predictability for the root architecture in a community setting in fields. To better translate the root traits observed in a controlled environment to field observations, we developed a macro-mesocosm system (5.5 m (W) x 6.7 m (L) x 0.7 m (H)) to mimic the real field soil conditions in a greenhouse. We also installed 64 capacitance soil moisture sensors to monitor the whole macro-mesocosm system at 15.24 cm and 38.10 cm soil depths in real-time. We evaluated the phenotypic spectrum in one common bean (Phaseolus vulgaris. L) genotype, SEQ7, in a time series experiment. We grew SEQ7 for two, six, nine, and twelve weeks under sensor-controlled water-stressed and well-watered irrigation regimes. SEQ7 showed four different root architecture types across developmental stages. These four root architecture types are consistent with previous field observation. This novel macro-mesocosm system will be a great setup to study the field dynamics of the root phenotypic spectrum in a controlled environment.

The application of herbicides in agriculture has significantly increased in recent decades. While many herbicides improve the efficiency and efficacy of weed control, their excessive use at the wrong growth stage can cause crop foliar damage, higher input cost and negative environmental footprints. There are limited techniques to accurately monitor herbicide effects. Visual ratings are highly subjective and require extensive training or experience. High-throughput digital imaging is a promising tool to measure plant herbicide interaction in field crops. In this study, proximal and aerial based advanced sensors have been utilized to evaluate different herbicide modes-of-action in two model species, tame oat [Avena sativa; model for wild oat (Avena fatua)] and oriental mustard [Brassica juncea; model for wild mustard (Sinapis arvensis)]. The experimental trials were performed at three agro-climatic locations in Canada (Lethbridge (AB), Saskatoon (SK), and Lacombe (AB)). The proximal and UAV multispectral imagery data were collected for baseline (before treatment) and 1, 3, 7, 10, 14 and 21 days after treatments (DAT), alongside visual ratings. The Normalized Difference Vegetation Index (NDVI), Photochemical Reflectance Index, Chlorophyll Vegetation Index, and Optimized Soil Adjusted Vegetation Index were used to assess variation of different DAT pigment content (photosynthetic rate) and chlorosis (damage %) in plot vegetation. The variation in obtained temporal indices (NDVI) suggest that the developed technology has potential to replace visual ratings (R2 ≈0.65-0.94) and can be used as a rapid screening tool for herbicide activity. Therefore, remote sensing tools could improve the precision and consistency of future herbicide assessments.

ORCiD: https://orcid.org/0000-0002-6391-1907. High-throughput phenotyping (HTP) are cost effective platforms that provide efficient evaluation of genetic resources, promote germplasm utilization, and inform breeding efforts for development of climate-resilient crops. MultispeQ device, a rapid, cost effective, and reliable HTP tool was employed to screen 112 cowpea genotypes for photosynthetic performance under drought stress conditions in a 8× 14 alpha-lattice design during the 2020/2021 and 2021/2022 dry seasons in three agro-ecological zones in Nigeria. Drought stress was imposed at 35 DAP and relative chlorophyll content (RCC), leaf temperature differential (LTD), leaf angle, linear electron flow (LEF), Phi2 (Quantum yield of Photosystem II) before and during drought stress imposition, were measured. Data was subjected to ANOVA using a mixed model for individual and combined environment analysis. Each stress condition by year was considered as an environment, giving a total of twelve environments. Best Linear Unbiased Predictions and broad-sense heritability (H 2) were computed. Significant genotypic effects for RCC, LEF, LTD, Phi2 before and during stress conditions were recorded while genotype × environment effects were observed for all measured traits. LEF had lowest H 2 (27%) while LTD had highest H 2 (63%). High RCC and lower LTD under drought stress suggested drought tolerance and stomatal closure, reported to be associated with plant biomass under limited water conditions. Genetic variation in photosynthetic performance exists among the cowpea genotypes under drought stress. RCC, LTD and Phi2 were identified as useful traits in selection for drought resistant lines aimed at boosting crop production in a changing climate and extreme weather conditions.

A document by Annarita Marrano. Click on the document to view its contents.

The majority of domesticated plant species are herbaceous annuals and woody perennials, yet many herbaceous perennial species hold potential for future agricultural systems. In addition to multiyear harvests, herbaceous perennials provide many ecosystem services, including erosion control as a result of their large and persistent root systems. However, the multiyear lifespan of perennial species has been a barrier to rapid domestication as breeding cycles require phenotyping over multiple growing seasons. Using phenomic selection, high-dimensional secondary traits measured on seedlings could be used to develop relationship matrices among individuals which are then used to predict field traits. Additionally, these models can serve as the selection criteria to identify individuals to advance to the next (pre)breeding generation, thus shortening the breeding cycle. This project substitutes costly genomics data with high-dimensional phenomics data asking: Can elite individuals of perennial species be predicted by phenomic relatedness models based on high-dimensional traits recorded on seedlings? To date, we have imaged 2280 seedlings from each of the following three perennial crop candidate species: intermediate wheatgrass (Thinopyrum intermedium), sainfoin (Onobrychis viciifolia), and silphium (Silphium integrifolium) on the Bellwether Foundation Phenotyping Facility housed at the Danforth Center. The images were processed using PlantCV to generate high-dimensional color and near-infrared profiles for each plant on each image day. Additionally, profiles were generated with handheld spectrometers. This work re-imagines innovations in plant traits, kinship matrices, genomic selection, phenotyping centers, and ultimately domestication, in order to expedite the development of an emerging generation of climate resilient, ecologically sustainable crops.

Texas A&M University recently completed a set of Automated Precision Phenotyping (APP) Greenhouses that incorporate robotic systems for automated collection of advanced sensor-based plant phenotypes. Transiting the length of a greenhouse is a gantry beam, on which a rolling truck provides a second axis of motion along the gantry. Attached to the truck is a 3.0-m long robotic arm that is controlled to position a sensor head at virtually any position relative to any plant in a greenhouse. The robotic arm can be programmed to operate quickly and safely in complicated scanning patterns to enable data collection on all plants in the greenhouse within a time window of a few hours, ensuring consistent conditions during data collection. The sensor head includes a high-speed multispectral camera and eventually a Raman spectrometer. Relative to phenotyping greenhouses at other institutions, the APP Greenhouses have the advantage of maximum flexibility in configuration of plants in the greenhouses, in positioning of sensors relative to the plants, and in the types of sensors used, making research capabilities in the APP Greenhouses truly unique. Preliminary data have been collected on sorghum and maize plants. Four-band multispectral images have been collected daily, scanning the side of each plant from top to bottom. Preliminary software development is directed at automated image stitching to create a full side-view image of each plant, from which consistent metrics can be automatically calculated, such as plant height, stalk diameter, leaf angle, etc.