2 results
Search Results
Now showing 1 - 2 of 2
- ItemCarbon consumption of developing fruit and the fruit bearing capacity of individual RoHo 3615 and Pinova apple trees(Lublin : IA PAS, 2020) Penzel, Martin; Lakso, Alan Neil; Tsoulias, Nikos; Zude-Sasse, ManuelaThis paper describes an approach to estimate the photosynthetic capacity and derive the optimum fruit number for each individual tree, in order to achieve a defined fruit size, which is named as the fruit bearing capacity of the tree. The estimation of fruit bearing capacity was carried out considering the total leaf area per tree as measured with a 2-D LiDAR laser scanner, LALiDAR, and key carbon-related variables of the trees including leaf gas exchange, fruit growth and respiration, in two commercial apple orchards. The range between minLALiDAR and maxLALiDAR was found to be 2.4 m on Pinova and 4.3 m on RoHo 3615 at fully developed canopy. The daily C requirement of the growing fruit and the associated leaf area demand, necessary to meet the average daily fruit C requirements showed seasonal variation, with maximum values in the middle of the growing period. The estimated fruit bearing capacity ranged from 33-95 fruit tree-1 and 45-121 fruit tree-1 on the trees of Pinova and RoHo 3615, respectively. This finding demonstrates sub-optimal crop load at harvest time in both orchards, above or below the fruit bearing capacity for individual trees. In conclusion, the LiDAR measurements of the leaf area combined with a carbon balance model allows for the estimation of fruit bearing capacity for individual trees for precise crop load management. © 2020 Polish Academy of Sciences. All rights reserved.
- ItemFruit removal forces of early stage pickling cucumbers for harvest automation(Lublin : IA PAS, 2021) Jakob, Martina Carola; Geyer, MartinEuropean growers are demanding selective mechanical harvesting solutions, such as robotic solutions, because hand harvesting is extremely labour intensive. Mechanical harvesting depends on low fruit retention forces between fruit and plant. Over two consecutive growing seasons, including a winter greenhouse trial, more than 1 600 samples were taken to determine the fruit removal force of early stage cucumbers for pickling and canning. Compared to studies with other fruit the fruit removal force of cucumbers was fairly high and also showed a large degree of variation. A significant percentage of the harvest had stalk residues, which cause the expenditure of extra man-hours on the processing lines. It was therefore concluded, that mere pulling is not sufficient to disconnect the fruit. Harvesting robots require an extra device for ease of separation.