Development of a canopy constructing and analyzing system for long-term estimation of crown information of fruit trees (CACOAS)

Summary In order to collect information of fruit tree crowns concerning improvement of light environment, lowering of tree height and mechanization of orchard work, a system by personal computer (CACOAS) was developed to construct and analyze a tree crown throughout long term. Processing and calculation in CACOAS consisted of 11 steps. Namely, input of parameters, selection of configuration of frame branches, selection of pruning methods, estimation of shoot variables and calculation of shoot coordinates, drawing of tree and crown forms, analysis of tree crown, processing of thickening of all branches, processing of pruning, drawing of tree forms after pruning, output of information concerning pruning and age renewal of all branches. This cycle was repeated by last age of tree. Using data from CACOAS, the other system to analyze orchard light environment (OLEAS) enabled analysis of the light environment. Many array variables were prepared whose element was branch number, i.e., the producing order from the beginning. Various calculation techniques were devised by referring to branch age and branch number of the parent branch, and used in the program. Multiple regression estimation method was mainly used in the estimation of shoot variables. If necessary, the Monte Carlo simulation method was combined with it. These parameters were measured mainly by a stereophotogrammetry. Space geometry was used in the calculation of spatial coordinate of shoot. Performance tests of CACOAS on typical five types of tree shape of apple 'Fuji' were carried out for 20 years. Another performance tests were done on the two types of tree shape by changing configuration of their frame branches or their pruning factors for 20 years. As the result, the program worked as was expected, and brought good results for us. CACOAS outputted much crown information, much pruning information, many tree form images and crown form ones. Remarkable effects of the difference in the configurations or the conditions on their tree forms, crown information and light environments were found by CACOAS. This program was written in a visual BASIC, and the all line number was about 4600. The estimation time spent for 20 years of the one tree shape was slightly about 45 minutes by a usual personal computer.