Modeling Fruit Morphological Formation on Muskmelon

Abstract

Modeling fruit morphological formation on muskmelon is of significant importance for realizing virtual and digital plant growth. Two experiments were carried out for data acquisition, involving different organic fertilizer rates and cultivars. Time-course observations were made on fruit morphological properties (fruit size, color and netted) on muskmelon plant under different experiment conditions. The results showed that the fruit swelling process (vertical diameter and horizontal diameter) of muskmelon exhibited a slow-rapid-slow pattern, which could be well described with a logistic curve against growing degree-days (GDD); Fruit color changes based on the RGB values could be represented quadratic relationship to cumulative GDD; The fruit netted changes over growth progress could be partitioned into 3 phases according to before and after pollination 30 and 40 days. The first phase was the process from pollination 1 day to after pollination 30 days, in which the vertical stripe becomes at fruit middle part and the horizontal stripe at fruit handles and hilum part. The second phase was the process from pollination 30 to 40 days, in which the horizontal stripe becomes at fruit middle part and the netted formed. The third phase was the process of after 40 days, in which the netted breadth and thick are gradually increased. The model was validated with the independent experiment data involving different muskmelon cultivars, and the mean RMSEs of fruit were 0.28 cm and 0.19 cm, respectively, for vertical diameter and horizontal diameter, 12.6 for fruit color, 0.13 cm for stripe length and diameter at varied GDD. Thus the present model had a good performance in predicting morphological growth of muskmelon fruit, which should be useful for further realizing virtual expression of fruit growth dynamics in muskmelon plant.