Prediction of overlapping leaf area of ice plants using digital image processing technique

( Bolappa Gamage Kaushalya Madhavi ),( Anil Bhujel ),( Jihoon Park ),( Na Eun Kim ),( Hyeon Tae Kim ) 한국농업기계학회 2021 한국농업기계학회 학술발표논문집 Vol.26 No.2

Non-destructive, fast, and accurate leaf area estimation is critical in many plant physiological and ecological experiments. In modern agriculture, ubiquitous digital cameras and scanners are primarily replaced the traditional leaf area measurements. Thus, measuring the leaflet’s dimension is integral in analysing plant photosynthesis and growth. Moreover, leaf dimension assessment with image processing is widely used for presenting. This investigation proposed a new image segmentation algorithm to classify the ice plant (Mesembryanthemum crystallinum L.) canopy image with a threshold segmentation technique by grey colour model and calculating the degree of green colour in the HSV (hue saturation value) model. Notably, the segmentation technique is used to separate suitable surfaces from a defective noisy background. Eventually, the canopy area was measured by pixel number statistics. Furthermore, this paper proposed total leaf area estimation by a computer coordinating area curvimeter and lastly evaluated the overlapping percentage using the total leaf area and canopy area measurements. To verify the effectiveness of the proposed algorithm, a segmentation experiment was performed on 24 images of ice plants. The obtained results show the algorithm’s accuracy is above 90%, which is confirmed by comparing the results of the proposed algorithm with the curvimeter leaf area method. This system gives a vital contribution to crop evolution by computational tools, making easier the monitoring work.

STRAWBERRY LEAF COLOR ESTIMATION USING MACHINE LEARNING APPROACHES BASED ON SOIL PHYSICOCHEMICAL PARAMETERS

( Bolappa Gamage Kaushalya Madhavi ),( Gun Ho Lee ),( Hyeon Tae Kim ) 한국농업기계학회 2022 한국농업기계학회 학술발표논문집 Vol.27 No.2

Soil physicochemical parameters are crucial for strawberry growth and optimal production under greenhouse cultivation. The Strawberry leaf is a typical vegetative organ for determining the plant's growth status. Moreover, strawberry leaf colour analyses are the best approach to assess soil status and protect against over-fertilization. This study investigated to development of machine learning models such as multiple linear regression (MLR) and gradient boost regression (GBR), using RGB (red, green, and blue) mean values for simulating strawberry leaf colour variations based on soil physicochemical parameters and plant age. Simultaneously, the soil physicochemical parameters of different coloured strawberry leaves were precisely measured by a multifunctional soil sensor. Synchronously, 400 strawberry leaflets were detached in each vegetative and reproductive stage, and individual leaves were captured using a digital imaging system. The RGB mean values of coloured images were extracted using the image segmentation algorithms. Subsequently, MLR and GBR models were developed to predict the leaf RGB mean values related to soil physicochemical measurement and plant age. The GBR model vigorously fitted with RGB mean values throughout the growth stage, with R2 and RMSE values of (R = 0.77, 7.16, G = 0.72, 7.37, and B = 0.70, 5.68), respectively. Furthermore, the MLR model performed moderately with R2 and RMSE values of (R = 0.67, 8.59, G = 0.57, 9.12, and B = 0.56, 6.81) when consecutively predicting RGB mean values in strawberry leaves. Eventually, the GBR model performed more effectively than the MLR model with high-evaluation metrics. Additionally, the leaf colour model accurately predicts dynamic changes in strawberry leaf colour and uses visualization technology to track growth progress.

Properties of biodegradable seedling plug trays made up of recycled paper pulp mixed with different proportions of strength-enhancing additives.

( Bhola Paudel ),( Jayanta Kumar Basak ),( Bolappa Gamage Kaushalya Madhavi ),( Na-eun Kim ),( Gun-ho Lee ),( Gyeong-mun Choi ),( Young-woo Choi ),( Hyeon Tae Kim ) 한국농업기계학회 2022 한국농업기계학회 학술발표논문집 Vol.27 No.1

The harmful effects of plastic and their product increase the attention of researchers and farmers toward the development and use of biodegradable products. Biodegradable products have several advantages over the plastics, but one of the major concerns is strength. Several researchers found that the strength of the biodegradable product will reduce significantly with the addition of water. To overcome this problem, biodegradable products made from paper waste are mixed with different wet strength agents and surface sizing agents at various proportions to increase their strength against the effect of water. In this study, three types of biodegradable seedling pot, made from waste paper pulp, mixed with wet strength and surface sizing agent in aratio of 0%, 3% and 5%, namely B0, B3 and B5, were tested for their physical, mechanical, germination and degradation properties. In the moisture absorption test, pot with additives showed significantly different properties than pot without additives. The absorption was lower for B0 while the highest for B5. Mechanical properties of pots were tested in dry and wet conditions, where the strength in wet conditions was significantly lower compared to dry conditions. The strength in wet conditions was higher for the pot with additives than the pot without additives; however, no significant difference was found. When comparing the seedlings' total germination percentage and height, no difference was found during the germination and growing test of Broccoli seeds in each pot. In the biodegradation test, all the pots loosed around half of their weight when placed in the soil for a month; however, around 90% of the strength of all the pots was loosed during the same period. Overall, the additives do not show any effect on the germination and growth of broccoli seeds in the seedling tray. However, differences were found among the pots with and without additives for other properties.

Properties of paper-based biodegradable pots for growing seedlings

PAUDEL BHOLA,Basak Jayanta Kumar,Kaushalya Madhavi Bolappa Gamage,김나은,Lee Gun-Ho,최경문,Choi Young-Woo,김현태 한국원예학회 2022 Horticulture, Environment, and Biotechnology Vol.63 No.6

The disadvantageous properties of plastic and plastic wastes have resulted in biodegradable products and seedling pots gain- ing popularity. Agents of diff erent strengths and sizes agents are usually mixed in the paper pulp to enhance the strength of paper-based seedlings pots. In this study, three types of paper-based seedling pots, with 0%, 3% and 5% of additives, named N0, N3, and N5, respectively, were tested to determine their physical, mechanical and biodegradation properties. Water absorption test results showed that the absorption rate was higher in N0, followed by N3 and N5; a similar pattern was observed in the maximum water absorption, thickness and solubility tests. The tensile test showed the highest strength in N3 (3.9 MPa), followed by N0 (3.8 MPa) and N5 (3.1 MPa) at 0% moisture absorption. However, at 100% moisture absorption, tensile strength dropped the most for N0 (82%), followed by N3 (67%) and N5 (65%). Hybrid broccoli seeds germinated inside the plant factory showed that 95% germinated within 13 days. Temporal data showed that germination time was most delayed in N5. No signifi cant diff erence was found in seedling height; however, a signifi cant diff erence was found in the root to shoot height ratio. N0 showed maximum weight and tensile strength loss on the biodegradation test, followed by N3 and N5. At the end of the fourth week, the tensile strength of N0, N3 and N5 was found to be 0.25 MPa, 0.69 MPa and 0.79 MPa, respectively, which was reduced by 94%, 81%, and 79%, respectively, compared to their initial strength. In conclusion, pots containing water repellent additives showed diff erent properties than those without additives, except for germination and seedling growth. This experiment confi rms that using additives will increase the strength of paper-based seedling pots in wet conditions without aff ecting the germination and growth of seedlings.