Projects / Programmes source: ARIS


Research activity

Code Science Field Subfield
4.03.01  Biotechnical sciences  Plant production  Agricultural plants 

Code Science Field
B006  Biomedical sciences  Agronomics 

Code Science Field
4.01  Agricultural and Veterinary Sciences  Agriculture, Forestry and Fisheries 
apple, competitive production, fruit quality, mechanical pruning, floor management, nutrition, mechanical thinning, biennial bearing
Evaluation (rules)
source: COBISS
Researchers (17)
no. Code Name and surname Research area Role Period No. of publicationsNo. of publications
1.  34840  Matjaž Beber  Plant production  Researcher  2016  25 
2.  37631  Biserka Donik Purgaj  Plant production  Technical associate  2016 - 2019  142 
3.  17045  Boštjan Godec  Plant production  Researcher  2016 - 2019  652 
4.  26536  PhD Jože Hladnik  Plant production  Researcher  2018 - 2019  62 
5.  00927  PhD Janez Hribar  Plant production  Retired researcher  2016 - 2019  860 
6.  34206  Matjaž Lerš    Researcher  2016 - 2019 
7.  13492  PhD Mario Lešnik  Plant production  Researcher  2016 - 2019  601 
8.  17305  Roman Mavec    Technical associate  2017 - 2019  272 
9.  19348  PhD Črtomir Rozman  Plant production  Researcher  2016 - 2019  634 
10.  14861  Andrej Soršak  Plant production  Technical associate  2017  47 
11.  08746  PhD Matej Stopar  Plant production  Head  2016 - 2019  440 
12.  13520  PhD Stanislav Tojnko  Plant production  Researcher  2016 - 2019  497 
13.  51375  Tadej Toplak  Plant production  Technical associate  2018 - 2019 
14.  19081  PhD Tatjana Unuk  Plant production  Researcher  2016 - 2019  289 
15.  05733  PhD Rajko Vidrih  Plant production  Researcher  2016 - 2019  749 
16.  39613  Igor Zidarič  Chemistry  Technical associate  2017  148 
17.  19640  PhD Emil Zlatić  Plant production  Researcher  2016 - 2019  156 
Organisations (4)
no. Code Research organisation City Registration number No. of publicationsNo. of publications
1.  0148  Institute of Agriculture  Maribor  5129877000  780 
2.  0401  Agricultural institute of Slovenia  Ljubljana  5055431  20,185 
3.  0481  University of Ljubljana, Biotechnical Faculty  Ljubljana  1626914  67,218 
4.  0482  University of Maribor, Faculty of Agriculture and Life Sciences  Hoče  5089638004  9,966 
Slovenia is a traditionally fruit growing region. Apple is the main fruit species. In the last ten years the acreage of intensive apple production decreased from 3,000 hectares to less than 2,500 hectares. The reason could be found in low-income attraction of apple production. Average yield on Slovenian apple orchard in recent years is less than 30 t/ha, while on the comparable fruit-growing regions in Europe the average yield exceed 35 t/ha. At the same time, several years of low prices of apples in the European market, push Slovenian producers to abandon production, mainly due to the weak competitiveness. In order to improve the competitive position of Slovenian apple producer is necessary to increase the yield per hectare in intensive apple plantations and to improve the quality of harvested fruit. The reasons for the small average apple yield per hectare are different. The first to be mention is small and incomplete bearing volume of trees in the area of ​​intensive orchard. The second reasons hold mostly physiological aspect; the non-homogeneous fruit set and variable crop load in the crowns of individual trees between the years. Irregular bearing of individual trees (canopies) refers to physiological causes of too heavy flower/fruit set in the previous year (alternative bearing phenomenon), or is the consequence of improper fertilization or orchard floor management (complex of soil conditions in the orchard, water-air conditions, accessibility of nutrients,...). The aim of the project after the completion of three years research is to advise the growers and to offer solutions in the technological level, how to increase the yield of apple per hectare. Solutions will primarily relate to technological measures for building bearing volume, to maximize it in relation to the area of ​​the orchard, to maintain regular bearing in this volume (adapted crowns), and to reduce costs and increase the environmental acceptability of apple production. Among the latter the introduction of modern technologies, mechanical pruning of crowns and the mechanical flower thinning will be investigated. Both measures are relevant to the original goal of the project to build a bearing volume, which will be adjusted to machine handling and adapted in the direction of homogeneous fruit wall. The project will be divided into four work packages. The first will be the analysis of the state of competitiveness of apple production in Slovenia. With the help of ten representative orchards we will try to identify those technological parameters that are systemically responsible for low average yield per hectare. In the second the most comprehensive set, the technological trials will be performed. Every year seven types of experiments will be done: new approaches to orchard floor management and methods of rehabilitation of cart track; new tree training methods; fertilization trials; mechanical pruning and mechanical flower thinning experiments; and a series of trials to prevent biennial bearing of apple trees. In the third section we will focus on the development of new apple quality standards. In addition to revision of old standards for apple picking in the technological maturity state we will also introduce standards for so-called crop "Higher quality apples". Further, we will introduce the criteria for the quality of apples at the end of storage, which will contribute to a better quality of fruit shelf life in supermarkets. In the fourth part the economy of new technologies and the recommendations for the apple growers will be set as follows: the use of modern technologies of orchard floor management, mineral nutrition of apple and use of organic fertilizers, mechanical pruning and mechanical flower thinning, and technologies to prevent alternate bearing. We will also offer parameters for quality of apples before and after the end of storage. Seven major apple fruit variety will be used on the project so the research results will be applicable to a
Significance for science
The research results will enhance knowledge for technological processes in fruit production. Some basic measures of apple production will be concerned: construction and manipulation of volume of the crowns in apple orchards, fruit set regulation measures especially regulation of flowering and measures for regulation of alternate bearing. We will introduce new modern ways of floor management in orchards, i. e. measures which in some trials in Europe have shown extremely positive effects on the sustainable apple production because of the positive impact on humus and microbiological composition of the soil and also affect nature friendly way for pest and disease protection of orchards. In recent years, in modern horticulture measures of reducing the production costs was performed. In this context, we will follow developments and also contributed to the latest techniques of mechanical pruning in apple orchards. Machine pruning has been the subject of research in fruit production for more than 30 years ago, but this time the renew of machine pruning technology came out. The key of a renewed interest of machine-cut technology is introduction of weak rootstocks, bases on M.9, which has tendency to weak growth and easier control of the volume of the crown in orchards. We already have two-year initial experience in the field of machine pruning and with the new experiments we will follow the development of these techniques in Europe and the world, and could do the knowledge transfer into the Slovenian production area. In technologies of apple fruit set regulation we have many years of experience. In the experiments for apple flowering enhancement we will spray NAA and ethephon in small doses, doses which do not cause thinning of apple fruitlets but only promote better formation of flower buds and thus have an impact on the prevention of alternate bearing. Technology of NAA small doses application in Europe for the previously described purpose is not yet used, even less is known in Slovenia. The technology of ethephon small doses application is better known. For this technology the potential of undesirable side effects on the size of the fruit can be expected. In connection with the orchards productivity we will introduce new technologies of apple blossoms thinning. It is an environmentally acceptable method of mechanical removal of flowers on too heavy flower setting apple crowns. The experiments on mechanical flower thinning have carried out in Slovenia for many years, similarly as in other well-known fruit growing countries of Europe. Experience shows up the many shortcomings of this type of flower thinning in comparison with the chemical thinning, therefore it is necessary to upgrade existing knowledge and to overcome the shortcomings. As a contribution to this field, we will expand the knowledge of the impact of crown mechanical damage to growth/fruiting balance in the crown after the application of this measure, and especially knowledge on the effects of mechanical thinning on fruit quality and to return bloom of apple trees. In the world these studies are still in its infancy. Work on apple fruit quality parameters will contribute to the expansion of the new standards for determining the quality of apples. As a new knowledge for the field of fruit quality we will introduce new non-destructive methods of determining the quality of the fruit. We will also introduce new standards for the quality of the fruit at the end of cold storage, which has a direct impact on the quality of the apples selling on the supermarket. Given the fact that the apple production is the most important fruit species produced in Slovenia, we can expect expansion of knowledge about the use of new apple training systems or the use of mechanical procedures for pruning and thinning, to other areas of fruit growing (pear and peach growing ...). By mastering modern methods of cultivation, we will place Slovenian apple production alongside high-tech developed orc
Significance for the country
In recent years apple production in Slovenia has become a poor competitive. Average yields do not achieve results comparable to the developed fruit-growing areas of Europe, neither in quantity (yield / hectare) nor to the fruit quality. Enhancing the technology level of apple production will have wider benefits. Multiannual trend of decreasing apple production will be stopped or turned up if the introduction of new technological processes will be set. Reasons of reducing apple production are mainly in the low-income. Using the latest technology has the potential to increase yield per hectare while reducing the cost of production. In particular, this refers to the introduction of new tree training methods in the direction of the homogeneous fruit wall concept with a maximum volume of crowns per hectare. The so-called fruit wall will offer a simplification of the production while reducing costs, especially for pruning fruit trees, as well as the costs of manual thinning (introduction of mechanical pruning and mechanical flower thinning). Some companies in Slovenia, which is engaged in the production of agricultural machinery, will get the opportunity for the development and manufacture of machines for crown pruning and flower thinning. Finally, all new measures for the production of apples are also environmentally acceptable and will contribute to the sustainable production of fruit and to more environmentally friendly solutions. The introduction of new standards of apple quality at the end of storage will result in raising the level of the fruit quality at retail. As a result, the expected greater consumption of apples will stimulate the interest for higher apple production and stop the trend of fruit growing reduction. Introducing the standards of "higher quality apples” will stimulate consumer awareness of the value of home grown fruit and encourage the consumption of home-produced apples. The new standard "higher quality apples" can serve as a basis for the creation of a new marketing brand. We will offer some solutions for economically viable production based on an innovative approach, as well as environmentally and consumer friendly technological solutions for apple production. Some companies have already felt this marketing opportunity and they offer some facilities to carry out experiments. Finally, at the end of the project the commercial apple growers will be familiar with the guidelines for: - floor management in apple orchards - new tree training methods - mineral nutrition and the application of organic fertilizers in apple orchards - mechanical pruning - mechanical apple flower thinning - alternate bearing avoidance - quality parameters of apples - standard quality - quality parameters of apples - higher quality - quality parameters of apples at the end of storage
Most important scientific results Annual report 2016, 2018, final report
Most important socioeconomically and culturally relevant results Annual report 2016, 2018, final report
Views history