An Automated and Continuous Plant Weight Measurement System for Plant Factory

Abstract

In plant factories, plants are usually cultivated in nutrient solution under a controllable environment. Plant quality and growth are closely monitored and precisely controlled. For plant growth evaluation, plant weight is an important and commonly used indicator. Traditional plant weight measurements are destructive and laborious. In order to measure and record the plant weight during plant growth, an automated measurement system was designed and developed herein. The weight measurement system comprises a weight measurement device and an imaging system. The weight measurement device consists of a top disk, a bottom disk, a plant holder and a load cell. The load cell with a resolution of 0.1 g converts the plant weight on the plant holder disk to an analog electrical signal for a precise measurement. The top disk and bottom disk are designed to be durable for different plant sizes, so plant weight can be measured continuously throughout the whole growth period, without hindering plant growth. The results show that plant weights measured by the weight measurement device are highly correlated with the weights estimated by the stereo-vision imaging system; hence, plant weight can be measured by either method. The weight growth of selected vegetables growing in the National Taiwan University plant factory were monitored and measured using our automated plant growth weight measurement system. The experimental results demonstrate the functionality, stability and durability of this system. The information gathered by this weight system can be valuable and beneficial for hydroponic plants monitoring research and agricultural research applications.

Nondestructive and Continuous Fresh Weight Measurements of Bell Peppers Grown in Soilless Culture Systems

“…Several studies on the development of continuous fresh weight measurement systems have been conducted. Chen [11] and Kim [12] installed a compressive force load cell to measure the fresh weight of leafy vegetables in deep-flow or nutrient-film techniques. This technique is not applicable for soilless cultures of bell peppers using solid growing media, where the moisture content of growing media changes continuously from irrigation, drainage, and crop water uptake.…”

Evaluation of Fertilizer Electrical Conductivity (EC) and Temperature Distribution via Vertical Farming System under Plant Factory

“…It can be noted that high temperature resulted in a decrease in photosynthesis rates as well as reduced wateruse efficiency for the crop growth (Sakamoto & Suzuki, 2015). Chen et al (2016) studied the growth of Boston lettuce and coral lettuce for 14 days for germination with the nutrient solution circulating between the planting beds and storage tank with a pump in order to maintain the uniformity of the nutrient intake. An efficient plant factory governed by factors that affected the crop growth which was light intensity, EC, pH, temperature, humidity, CO2, etc.…”

Modeling the Dynamic Response of Plant Growth to Root Zone Temperature in Hydroponic Chili Pepper Plant Using Neural Networks

“…Dynamic changes in plant development were monitored through changes in the fresh weight of the plants during observation. In a controlled environment, the fresh weight of a plant provides useful information on the status of the plant and is also an indicator of plant growth [34][35][36]. In this study, an automated non-destructive plant weight measurement system for pepper plants was developed.…”