Journal of Berry Research - Volume 6, issue 4

Authors: Mauri, Sofia | Cellini, Antonio | Buriani, Giampaolo | Donati, Irene | Costa, Guglielmo | Spinelli, Francesco

Article Type: Research Article

Abstract: BACKGROUND: The bacterial canker of kiwifruit, caused by Pseudomonas syringae pv. actinidiae (Psa), affects several cultivated Actinidia species, including A. chinensis and A. deliciosa . Its development is related to permissive environmental conditions, such as temperature, humidity, presence of entry points, genetic and physiological features of the host plant. Moreover, also cultural practices influence, directly or indirectly, the disease development. OBJECTIVE: The role of agricultural practices on disease development and spread was studied. METHODS: Irrigation, pruning and training systems were tested in the field according to conventional orchard management. Experiments on …mineral nutrition, use of bio-regulators and rootstock susceptibility were performed in controlled conditions. Bacterial growth, symptom development and disease incidence were assessed in relation to the different practices. RESULTS: High nitrogen fertilization, iron deficiency and water stress were related to more severe symptoms. Open canopies allow a better irradiation, aeration, and penetration of phytosanitary treatments. Synthetic gibberellins reduced disease incidence and severity in controlled conditions. Fruits from diseased plants showed a lower quality and storability. CONCLUSIONS: Dense canopies are harder to manage and more exposed to bacterial canker. Pruning tools and irrigation water are relevant for the bacterial spread. Show more

Keywords: Pseudomonas syringae pv. actinidiae, fertilization, irrigation, pruning, training system

DOI: 10.3233/JBR-160115

Citation: Journal of Berry Research, vol. 6, no. 4, pp. 355-371, 2016

Authors: Rocchi, Lorenzo | Vidoni, Serena | Ceccarelli, Alessandro | Fiori, Giovanni | Costa, Guglielmo

Article Type: Research Article

Abstract: BACKGROUND: The assessment of the fruit maturity stage is essential to establish the optimal harvest time and it is considered to be crucial to determine the overall quality and the length of fruit storage-life. In fact the maturity stage reached at harvest is strictly related to the fruit characteristics such as flesh color, taste and aroma resulting in high consumer acceptability. Fruits from the Actinidia chinensis cultivar are traditionally harvested when the flesh color reaches a value of 103° Hue equivalent to a bright yellow color (“gold”), recognized as optimal to fulfill the supply chain requirements. This parameter …is measured on a fruit sample in the last phase of maturity with a colorimeter, after removing of a thin layer of epicarp. However, since this method implicates the fruit sample destruction, the batch of the considered fruits could be poorly representative. OBJECTIVES: A non-destructive alternative for the assessment of fruit ripening/harvesting was investigated. METHODS: The recently developed Kiwi-meter, a device based on the vis/Near Infrared Spectroscopy (NIRs) allows to monitor fruit flesh color evolution non-destructively by means of the DAindexTM . RESULTS: This work reports the results obtained in different trials in the past years on two A. chinensis cultivars and confirms the importance of the Kiwi-meter device to establish the proper fruit harvest time, fundamental to optimize quality and post-harvest management of kiwifruit, by grouping fruits in homogeneous ripening classes. CONCLUSIONS: The results showed that the Kiwi-Meter could be used “in planta ” to monitor the ripening evolution and to assess the harvest time. Show more

Keywords: NIRs, non-destructive technique, fruit ripening homogeneity, standard quality traits, “Jintao”, “Dorì”

DOI: 10.3233/JBR-160116

Citation: Journal of Berry Research, vol. 6, no. 4, pp. 373-379, 2016

Authors: Zoffoli, Juan Pablo | Flores, Katherinne | D’Hainaut, Dominique

Article Type: Research Article

Abstract: BACKGROUND: Kiwifruit (Actinidia deliciosa (A. Chev.) C.F. Liang et A.R. Ferguson cv. ‘Hayward’) is usually harvested firm, unripe, and with a high starch content, and thus fruit do not always achieve a suitable soluble solid concentration (SSC), and soft texture when ripe. A high dry matter concentration at harvest can be used to predict fruit sweetness at ripening. However, fruit softening capacity is difficult to predict because of the interaction between postharvest practices and biochemical processes that occur at 0°C. OBJECTIVE: To understand the effect of ethylene on restoring the lost softening capacity of kiwifruit treated …with1-methylcyclopropene (1-MCP) alone or in combination with modified atmosphere packaging (MAP) or controlled atmosphere storage (CA). METHODS: The effect of ethylene (100 μl l–1 for 12 h at 20°C) on kiwifruit harvested at commercial maturity (6.2% SSC) and treated with 1-MCP (1 μl l–1 , 24 h) and packed in perforated bags (PB) or MAP for 60, 90 or 120 days at 0°C and ripened at 20°C for 17 days was determined. The effect of ethylene applied at 100 μl l–1 for 24, 48 or 72 h was also evaluated on fruit treated with 1-MCP (1 μl l–1 , 24 h) subjected to 108 days of CA (2% O2 and 5% CO2 ) and a further 30 days in PB at 0°C. RESULTS: Both 1-MCP and MAP reduced fruit softening after 60 and 90 days at 0°C, and delayed fruit ripening at 20°C. A synergistic effect of 1-MCP and MAP extended those results to 120 days at 0°C. Ethylene treatment restored the ripening of MA fruit but not the 1-MCP-treated fruit stored for 60 days at 0°C or when it was packed in MA bags for 90 days at 0°C. Ethylene for 48 h prevented the ‘hard core’ texture observed in CA with 1-MCP treated fruit. CONCLUSIONS: Kiwifruit treated with 1-MCP and/or packed with MA requires a minimum time at 0°C before to induce ripening by ethylene treatment (100 μl l–1 for 12 h at 20°C). Ethylene treatment avoids ‘hard core’ development on 1-MCP treated fruit stored in CA. Show more

Keywords: 1-methylcyclopropene, hard core, fruit quality, ripening protocol

DOI: 10.3233/JBR-160117

Citation: Journal of Berry Research, vol. 6, no. 4, pp. 381-393, 2016

Authors: Tontou, Rodanthi | Giovanardi, Davide | Ferrari, Michele | Stefani, Emilio

Article Type: Research Article

Abstract: BACKGROUND: The bacterial canker, caused by Pseudomonas syringae pv. actinidiae , is the most severe disease of cultivated Actinidia spp. The pathogen is systemic and not easily controlled by agrochemical means. OBJECTIVE: Our aim was to search, select and identify, among kiwifruit bacterial endophytes, possible antagonists able to control Pseudomonas syringae pv. actinidiae . METHODS: Several kiwifruit production areas were inspected, in order to find host plants without any disease symptom inside severely affected orchards. From those plants, endophytes were isolated, selected, tested for their ability to inhibit the growth of the …pathogen and identified. RESULTS: A set of 65 different bacterial endophytes was isolated and tested: several of them were able to inhibit the growth of Pseudomonas syringae pv. actinidiae in vitro . None of the antagonists proved to possess either ice nucleation activity or transferable copper resistance. Taxonomically, antagonists belonged to the families of Pseudomonadaceae and Enterobacteriaceae . CONCLUSIONS: Effective bacterial antagonists were found as endophytes in kiwifruit plants and bearing features of safety of use and negligible risk for the crop. Such finding makes it possible to select the most prospective of them, in order to develop efficient biopesticides able control the bacterial canker in commercial orchards. Show more

Keywords: Kiwifruit, bacterial canker, endophytic microbiota, biological control

DOI: 10.3233/JBR-160118

Citation: Journal of Berry Research, vol. 6, no. 4, pp. 395-406, 2016

Authors: Collina, M. | Donati, I. | Bertacchini, E. | Brunelli, A. | Spinelli, F.

Article Type: Research Article

Abstract: BACKGROUND:  Pseudomonas syringae pv. actinidiae (Psa) is the etiologic agent of the bacterial canker of kiwifruit, the most severe disease of Actinidia spp. This pathogen was firstly recorded in Japan and in China. The initial occurrence in Italy dates back to 1992, but the most important outbreak was in 2008. From that year, Psa has spread worldwide with a devastating virulence causing substantial losses to kiwifruit production in China, Italy, New Zealand, Chile, France and Portugal. OBJECTIVE:  Screening the existing compounds with different mode of action for their efficacy in controlling Psa on Actinidia deliciosa …(cv. Hayward) grown in controlled conditions. METHODS:  Products were grouped according to their active ingredients and mode of action in the following categories: Copper compounds, plant extracts, disinfectants, resistance inducers, filming agents and biological control agents (BCAs). The experiments were performed on potted A. deliciosa (cv Hayward) vines grown in controlled greenhouse conditions. Inoculation was experimentally performed by spraying each plant till run off with a suspension of a highly virulent, biovar 3 Psa strain. Disease control and phytotoxicity were monitored for 15 and 30 days after inoculation. RESULTS:  Copper compounds and resistance inducers (acibenzolar-S-methyl, Fosetyl-Al) showed the most promising results. However, few other compounds, such as some plant extracts and disinfectants (Verdeviva), provided some protection. Also biological control agents (BCAs), containing living microorganisms, partially controlled the disease. CONCLUSION:  Copper compounds and resistance inducers can be possibly combined to develop a more robust and effective control strategy in open field. In addition, BCAs seem interesting, particularly in specific phenological stages when other control methods cannot be used, although results require further validation. Show more

Keywords: Actinidia spp. Psa, protective compounds, disinfectants, resistance inducers, BCAs

DOI: 10.3233/JBR-160128

Citation: Journal of Berry Research, vol. 6, no. 4, pp. 407-415, 2016

Authors: Tacconi, Gianni | Michelotti, Vania | Cacioppo, Ottavio | Vittone, Graziano

Article Type: Research Article

Abstract: BACKGROUND: Kiwifruit (cv. Hayward) artificial pollination is a crucial technique useful to increase fruit quality and size. However, artificial pollination efficiency depends on the timing of application and the pollination system. OBJECTIVE: The main objective is identify the best practices to be applied in the orchard to reach the best pollination by deciphering the relation between the floral stage and the pollination technique. METHODS: Many parameters were analyzed in different environments in Italy for many years, such as pollen quality (germinability, humidity, conservation at –18°C), pollination system (dry or liquid, using different machines) and flowering …stage. The interaction of the pollination systems and the flowering stage were evaluated by labeling flowers according to their flowering stage and weighting the fruit later. RESULTS: The petals fall and the early petal fall stages is the best moments for dry and liquid pollination respectively. The dry blower system gave the best results. The low pollination rate observed using the pollen-lycopodium mix is due to the interfering of the lycopodium on pistils. Pollen quality was achieved keeping it at low temperature during its harvesting and must have low humidity when stored at low temperature. CONCLUSIONS: The dry pollination with pure pollen reach the best result because at the end of flowering the pistil exudate increase the pollen adhesion. Show more

Keywords: Kiwifruit, pollination efficiency, pollination system, pollen quality, flowering stage

DOI: 10.3233/JBR-160138

Citation: Journal of Berry Research, vol. 6, no. 4, pp. 417-426, 2016

Article Type: Other

Citation: Journal of Berry Research, vol. 6, no. 4, pp. 427-430, 2016

Article Type: Other

Citation: Journal of Berry Research, vol. 6, no. 4, pp. 431-432, 2016