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The aim of the study was to evaluate the effect of type of irrigation and of amount of water supplied on vine growth, yield and fruit quality at harvest and after 2 and 4 months of cold storage. The study was carried out in 2019, in northern Italy, on kiwifruit Gold 3®(A. chinensis var. chinensis) grafted onto micro-propagated 'Hayward' (A. chinensis var. deliciosa) rootstocks in 2012, planted at a distance of 4.5×2 m apart. The investigated irrigation systems included: 1) control (T0); 2) drip irrigation with a single line (T1); 3) drip irrigation with double lines (T2); 4) sprinkler (T3); 5) drip irrigation with double lines + sprinkler (T2+T3). Water management in the control treatment was carried out with drip irrigation with a single pipeline according to the advisory service, based on daily evapotranspiration only. In T1, T2, T3, and T2+T3 water was applied according to the soil water content measured by potentiometric probes, located at two depths: 0.20 and 0.60 m, and two distances from the line of the trees: 0.20 and 1 m. Irrigation started when soil water content got down below the field capacity (-0.03 MPa) and returned the same amount of water lost the day before and measured by a PAN evaporimeter. Compared to the control, T1 reduced the volume of water applied by 34%, T2 by 3%, while T3 increased the irrigation volume by 14% and T2+T3 by 17%. Sprinkler application induced an excess of water in the inter row, where soil structure was impaired by the frequent passes of machines, reducing soil permeability. No effect of treatments on vine yield was observed, however, fruit soluble solid concentration and fruit dry matter at harvest was increased by T2 compared to the other treatments. A similar response was also found after 2 months of cold storage, but disappeared after 4 months. The incidence of storage break down (SBD) was higher in fruits of the control and T3 (22 and 40% of the fruits, respectively), while T2 and T2+T3 irrigation strategies showed the lowest percentage (5-8%, respectively). Finally, the incidence of SBD was negatively correlated with the fruit dry matter (r=-0.88; P≤0.05).

Fruit cracking caused by rainfall prior to harvest, a major problem in sweet cherry production, is being exacerbated by climate change. Currently, pre-harvest spraying with calcium salt solutions is the prevalent technique to reduce fruit cracking in cherry orchards not covered by plastic roofs. This study evaluated the effectiveness of canopy-applied silicon in the reduction of sweet cherry cracking under different field conditions. Four field trials were conducted on mature trees of the cultivars Van, New Star, and Emperor Francis. Treatments included water (control), calcium chloride, and sodium silicate. Multiple sprays (three) were applied weekly from fruit onset of color to approximately 1 week before harvest. The results showed that under conditions conducive to cracking, sodium silicate reduced the percentage of cracked fruits to a similar or larger extent than calcium chloride. This study highlights how canopy-applied silicon sources may effectively contribute to reducing cherry cracking, acting as an alternative technique to other preventive methods.

Obiettivo dello studio è stato di stabilire la dinamica di assorbimento dei nutrienti minerali e la loro ripartizione tra i diversi organi della pianta di kiwi a polpa gialla. La prova è stata condotta a Brisighella, in un frutteto impiantato nel 2014 su un terreno franco-argilloso di buona fertilità. Dal mese di maggio sono stati determinati periodicamente la lunghezza dei germogli e il numero di foglie, la crescita del frutto (diametro, peso e sostanza secca), mentre ogni quattro settimane sono stati prelevati campioni di foglie e frutti per la determinazione della composizione minerale. A fine stagione, infine, sono state raccolte e pesate le foglie abscisse e il legno di potatura, anch’essi analizzati per macro e micronutrienti. Alla raccolta, nei frutti erano presenti rispettivamente 77, 10, 74, 11, 5 e 6 kg ha-1 di N, P, K, Ca, Mg e S. Boro e Fe sono risultati i micronutrienti più presenti nei frutti alla raccolta (circa 100 g ha-1). L’accumulo di N, P e K nelle foglie e nei frutti è aumentato linearmente fino alla raccolta; l’accumulo di Ca nei frutti si è interrotto ad agosto, mentre nelle foglie è continuato fino alla senescenza fogliare. Tenuto conto dei diversi organi della pianta (frutti diradati, legno di potatura, frutti raccolti e foglie abscisse), le quantità di N, P, K, Ca e Mg assorbite durante la stagione sono state rispettivamente pari a 143, 16, 105, 202 e 38 kg ha-1.

Una sperimentazione triennale evidenzia l’adattabilità di questa coltura agli ambienti emiliano-romagnoli

The continuous use of copper-based fungicides in viticulture to contrast fungal diseases may result into an accumulation of Cu in the topsoil, reaching toxicity levels for plants and soil biota. A possible strategy to mitigate the negative effects of excess of Cu could involve the formation of insoluble molecules by the application of P to the soil. The aim of this study was to evaluate the effectiveness P soil application as a strategy to alleviate the toxic effect of excess of Cu on potted grapevines plants, with particular emphasis on the physiological response of plants. Micropropagated plants of 1103 Paulsen rootstock were grown according to a factorial experimental design with two factors: Cu (4 levels: 0, 100, 200, 300 mg kg−1 dw) and P (2 levels: 0 and 100 mg kg−1 dw) and three replicates. Net photosynthesis, efficiency of PSII photochemistry and linear electron transport rate decreased as soil Cu concentration increased. The addition of P increased net photosynthesis, improved the efficiency of PSII photochemistry and linear electron transport rate, but decreased stomatal conductance. As a consequence, shoot and root biomass declined with the increase of Cu concentration in soil, while the increment of P tackled this decline and improved nutritional status. CuEDTA extractable fraction in soil was increased by both the supply of Cu and P; this because the addition of P in combination with the highest Cu soil concentration determined a decrease of soil pH. In conclusion, the addition of P to the soil mitigated Cu excess toxicity symptoms in grape through a preservation of photosynthetic apparatus efficiency and an improvement of nutrient uptake.