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Crop production might suffer severe economic losses due to insufficient fertiliser availability. Specific signs of nutrient shortage influence plant morphology and physiology. This study pioneers the non-destructive tracking and characterization of nutrient deficiency symptoms in common beans using multispectral and chlorophyll fluorescence imaging, offering novel insights into the dynamic responses of plant morphology and physiology to specific nutrient shortages. Plants were cultivated in nutrient solutions with and without nitrogen (N), phosphorus (P), potassium (K), magnesium (Mg), iron (Fe) and control solution. Measurements were taken every three days for 12 days (MT1-MT4) of growth. K and N deficit plants had the earliest symptoms and most noticeable changes, whereas Fe deficiency plants had the slowest and least noticeable symptoms. Except for Fe, the most responsive chlorophyll fluorescence parameter was electron transport rate, which was reduced in plants from all nutrient deprivation treatments compared to control. All nutrient deficit treatments reduced leaf area at MT2, which was the most affected morphological parameter. The green leaf index, reflection in blue, and specific green were the most affected multispectral traits by nutritional deprivation. These findings demonstrate that plant nutrient deficit can be recognized and tracked non-destructively utilizing multispectral and chlorophyll fluorescence analysis. Overall, our work not only sheds light on the dynamics of nutrient deficiency in common bean plants but also offers practical implications for improving crop management strategies using non-destructive digital technology.

The lack of plant nutrients is a major problem for agriculture. Because of their essential role in the most important metabolic processes of plants, their deficiency depresses photosynthesis and disrupts the efficient operation of the photosynthetic apparatus. In this study, we investigated the gas exchange of common beans bean under the N, P, K, Mg, and Fe deficiency. The experiment was set up as a hydroponic, fully aerated, floating system in 6 hydroponic tubs. Each hydroponic tub contained 10 plants and was filled with a modified Hoagland nutrient solution. One group of plants was grown in a complete nutrient solution (control), while the other treatments lacked one of the following nutrients: N, P, K, Mg and Fe. During the experiment, gas exchange parameters: net photosynthetic rate (A), transpiration rate (E), stomatal conductance (gs) and intercellular CO2 concentration (Ci) were measured. At the end of the experiment, the nutrient content of the plant tissue was determined. Nutrient deficiency significantly affected all measured photosynthetic parameters and visual symptoms indicated that a lack of different nutrients affected the photosynthetic machinery at different points. Potassium deficiency lower stomatal conductance and increased mesophyll resistance to CO2 diffusion and/or RubisCO activity. Nitrogen and Mg deficiency affected chlorophyll synthesis and accelerated leaf senescence. Phosphorus deficiency caused less damage to gas exchange parameters probably due to protective mechanisms of reduced leaf area. Seed Fe content was surplus to sustain photosynthetic machinery during the early developmental phase.

Common bean (Phaseolus vulgaris L.) exhibits a wide range of seed coat colors and this morphological trait is widely used in cultivar identification and assessment of diversity within this species. With an advancement in technology and informatics, new methods of assessing seed color are emerging in addition to traditionally used visual observation. Due to a great variety of color measuring techniques, the evaluation of the agreement between methods is needed prior to using the methods interchangeably. Seed coat color in terms of CIE L*a*b* color coordinates of 100 common bean accessions belonging to five mono-colored landraces was assessed using two methods, colorimeter and Computer vision. The percentage difference between the two methods across all samples for L* color coordinate was 5.81%, for a* color coordinate 23.32% and for b* color coordinate 44.44%. According to Bland-Altman difference plot there is a considerable lack of agreement between the two methods. However, using stepwise discriminant analysis revealed that colorimeter method correctly classified 97% of accessions into their respective landrace, while the classification success of the Computer vision was 99%.

Common bean (Phaseolus vulgaris L.) is an important legume crop. In Croatia, many different common bean landraces are grown mostly on small farms and in kitchen gardens. The aim of this research was to determine and compare nutrient content of Croatian common bean landraces and to test the existence of the relationship between common bean nutrient content with origin of accessions. A total of 226 common bean accessions from all over Croatia were collected, grown in unreplicated field trial at the experimental field in Zagreb, harvested and analyzed for nutrient content. Results showed high nutrient content, but clear difference between Mesoamerican and Andean gene pool regards the nutrient profile of Croatian common bean landraces was not determined. Regardless of gene pool, the average nutrient content in dry weight of Croatian common bean landraces was in range: 3.13–3.92% N, 0.49–0.57% P, 1.38–1.66% K, 0.34–0.42% Ca, 0.17–0.20% Mg, 63.75–75.77 mg Fe∙kg-1, 13.55–19.94 mg Mn∙kg-1 and 24.98–29.32 mg Zn∙kg-1. Present research provides a solid basis for future breeding programs and improvement of common bean traits.

Soil is a non-renewable resource, so it should be taken care of it. High quality food with sufficient yield for a growing human population can be produced only if plant nutrients are added to the soil by fertilizers to increase soil fertility, but the fertilizers have to be used economically, with the aim of raising the nutrient content available in the soil in order to meet plants' needs. The goal of the present investigation was to determine the effect of application of organic and mineral fertilizers as well as the effect of research environment on micronutrient content in red beet root. A field trial (2003-2005) was set up in a hilly part of Croatia according to the Latin square method, with four types of fertilization (control, 50 t stable manure*ha-1, 500 and 1,000 kg NPK 5-20-30*ha-1). After digestion of plant material with concentrated HNO3, iron, manganese, and zinc were determined by an atomic absorption spectrophotometer (AAS). The highest average red beet root micronutrient contents (270 mg Fe*kg-1 in dry matter, 96 mg Zn*kg-1 in dry matter, and 53 mg Mn*kg-1 in dry matter) were determined in the first research environment (Brašljevica in 2003) with low potassium soil content. There was a general decreasing trend in contents of the studied micronutrients (Fe, Mn and Zn) with NPK 5-20-30 fertilization (and by application of high doses of potassium), certainly due to antagonistic activity with potassium. It is suggested to fertilize with both 500 kg NPK 5-20-30*ha-1 and microelement fertilizers.