Bridging boundaries: Exploring vineyard, management and variety characteristics influencing long-term infection of grapevine pathogens

Globalisation, climatic changes, and increasing consumer demand have forced the intensification of agricultural production. Thus, vineyards have crossed the boundaries of the original production zones and extended towards suboptimal areas, increasing the potential risk of damaging disease outbreaks. Therefore, there is a rising need for a complex and empirical revision of the interfering effects between grape infection and other external, large-scale factors such as environmental conditions and management practices. Although external abiotic and biotic factors could determine the infection levels of grape disease in a complex way, existing studies focus on the short-term effects of only a single or very few potential factors. In this large-scale study, we aimed to reveal the long-term impact of specific factors regarding vineyard characteristics, applied crop management and grape variety features, which could determine the infection severity of primary grape diseases (grey mould, downy mildew and powdery mildew) using a citizen science approach in Hungary, a traditional wine- and grape-producing country. The present study has revealed that some vineyards (e.g., inclination, row orientation) and variety features (e.g., bunch structure) were considered crucial. At the same time, other factors were found to be less relevant in the present complex comparison, suggesting that the role of these factors might be overemphasised in the literature. In conclusion, the susceptibility or tolerance of grapevines to pathogens appears to be an integrated effect of several factors and cannot be assigned to a single characteristic. The global changes urge the revision of conventional agricultural traditions and deepen our knowledge about the infection process and pathogen-host-environment interactions

Severity of symptoms of European stone fruit yellows on different apricot varieties

Apricot is an important fruit crop in Hungary. There are large growing areas consisted of orchards of different sizes. These orchards are highly affected by a disease complex the so cold apoplexy with its characteristic symptoms. In this study, the effect of rootstocks and scion varieties on the severity of symptoms was investigated in an apricot orchard near Budapest. Symptoms were assessed in autumn at their most characteristic appearance on the combinations of 5 different scion varieties and 3 different rootstocks in 3 consecutive growing seasons. According to the results of the assessments in most cases, symptoms proved to be more frequent and stronger on trees grown on wild apricot rootstock than on plum intergrafted or myrobalan rootstocks. The variety Mandulakajszi proved to be consistently the least affected variety particularly on plum intergrafted rootstocks. Severity of symptoms observed on other investigated varieties deviated depending on the different rootstocks and growing seasons. To reduce the effect of growing seasons monitoring should be continued. &nbsp

Severity of symptoms of European stone fruit yellows on different apricot varieties

Apricot is an important fruit crop in Hungary. There are large growing areas consisted of orchards of different sizes. These orchards are highly affected by a disease complex the so cold apoplexy with its characteristic symptoms. In this study, the effect of rootstocks and scion varieties on the severity of symptoms was investigated in an apricot orchard near Budapest. Symptoms were assessed in autumn at their most characteristic appearance on the combinations of 5 different scion varieties and 3 different rootstocks in 3 consecutive growing seasons. According to the results of the assessments in most cases, symptoms proved to be more frequent and stronger on trees grown on wild apricot rootstock than on plum intergrafted or myrobalan rootstocks. The variety Mandulakajszi proved to be consistently the least affected variety particularly on plum intergrafted rootstocks. Severity of symptoms observed on other investigated varieties deviated depending on the different rootstocks and growing seasons. To reduce the effect of growing seasons monitoring should be continued

The efficacy of essential oils against Venturia inaequalis (Cooke) G. Winter and Podosphaera leucotricha (Ellis & Everh.) E. S. Salmon in vivo

Though profitable crop production can be more simply achieved by using synthetic pesticides, the research of alternative plant protection solutions is necessary. The effect of the volatile oils of cinnamon, thyme, and a copper ingredient fertilizer were tested for their activity against apple scab and powdery mildew in apple orchards in 2014 and 2017. Oils applied alone or in combination were effective against apple scab in 2014 and in 2017 and against powdery mildew on leaves in 2017. The copper ingredient fertilizer product improved the efficacy of the oils. The results of these trials show that the tested volatile oils are suitable candidates for further research and for the development of organic fungicides against the diseases of apple

Detection of ‘<i>Candidatus</i> Phythoplasma prunorum’ in Apricot Trees and its Associated Psyllid Samples

‘Candidatus Phytoplasma prunorum’ is causing ever increasing economic losses through the decline of apricot trees in European countries, e.g., Hungary. In this study, the pathogen was identified from plant tissues and insects by nested-PCR. The insect species were identified via morphology and molecular methods. The incidence of the pathogen was 29.6% in randomly selected apricot trees. Most of the infected trees with symptoms died within a year. These results show that phytoplasma is significantly present and causes damage in the investigated plantations. The only known insect vector of this phytoplasma is the plum psyllid, Cacopsylla pruni, which was regularly encountered in the sampled apricot orchards and in their surroundings. In a two-year study, several adults among the sampled specimens were observed to be infected by the pathogen. This observation further confirms the role of the plum psyllid in vectoring the phytoplasma. All the sampled plum psyllid adults belonged to the ‘B’ biotype. Besides C. pruni, Cacopsylla crataegi was abundant in the samples. Several adults of the latter species were also infected by the pathogen ‘Ca. Phytoplasma prunorum’. The rates of occurrence of this phytoplasma in male and female adults of the two psyllid species appeared to be similar. The examined C. crataegi individuals showed genetic differences from each other and from specimens included in a previous investigation