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Brown spot (Stemphylium vesicarium) is a fungal disease widespread in European pear industry. The high number of fungicide applications required to control the disease can promote strains with fungicide resistance. The aim of the present study was to assess the effectiveness of soil- applied water solution of calcium chloride in combination with rootstock to control the incidence of brown spot in Abbé Fétel pear. Soil salinity, stem water and osmotic potential, along with fruit fraction of calcium and defence-mechanism related-enzymes such as peroxidase, polyphenol oxidase, phenyl-alanine ammonia-lyase, and β-1,3-glucanase were investigate in tree grafted on Fox 11 (Pyrus communis L.) and Sydo®, a quince (Cydonia oblonga) rootstock. Both grafting combinations were fertigated or not with calcium chloride. Sydo® showed a positive effect in reducing brown spot severity on Abbé Fétel. Compared to Fox 11, fruits from trees grafted on Sydo® showed higher calcium concentrations, fraction of calcium pectate, fruit firmness, polyphenol oxidase, phenyl- alanine ammonia-lyase and β-1,3-glucanase levels. Fruit calcium concentration was positively correlated with disease fruit tolerance. However, soil calcium applications were ineffective in promoting fruit calcium partitioning. Calcium chloride applications decreased leaf osmotic and stem water potential in trees grafted onto Sydo®, but this wasn’t found in those grafted on Fox 11. In conclusion, Sydo® rootstock promoted Ca acquisition, osmotic adjustment at leaf and fruit level, fruit synthesis of defence-related enzymes that all together reduced brown spot severity in Abbé Fétel pear.

Il volume contiene gli atti del convegno: Nocicoltura da frutto: Innovazione e Sostenibilità. Giornate tecniche nazionali SOI NOCE 2019, svoltesi a Bologna presso il Dipartimento di Scienze e Tecnologie Agro-Alimentari dell'Università di Bologna, 20-21 settembre 2019.

In the original publication of the article, the unit of measures in Table 7 was incorrect. In particular, SLW and macronutrient concentrations were reported wrongly in mg/m2, while micronutrients were wrongly indicated in microg/m2. The correct unit of measures is: g/m2 and mg/m2 for SLW, macro- and micronutrients, respectively. The correct Table 7 is provided in this erratum

The aim of this study was to evaluate the sustainability of an agro-industry sludge as a nitrogen (N) fertilizer in perennial crops by assessing its dynamics of release of: 1) N as ammonium (NH4+)- and nitrate (NO3−)-N, and 2) carbon as soil respiration. In incubation assay, application of agro-industry sludge promoted the maximum NH4+-N concentration (50 mg kg−1) 2 h after application, then it decreased with time until day 26. NO3−-N increased, reaching the maximum between day 60 and day 100, according to a second degree function. Agro-industry sludge showed a slower release of NO3−-N compared with urea. Soil basal respiration and cumulative amount of carbon dioxide were higher in sludge from day 71 on. In field, soil NO3−-N increased after fertilization treatments and was higher in Calcari Stagnic Cambisols soil. Sludge showed a potential lower environment impact in terms of mineral N release, than urea.

The aims of the present study were to verify that high mineral N, specifically nitrate, may reduce plant growth by inducing a toxic effect on plants. GF667 plants were fertilized with urea or compost at rising rates of N (mg kg ¡1): 0, 200, 500, and 1000. At 8, 37, and 94 days after fertilization, plant growth, tissue N, root starch concentrations, electrolyte leakage (E. L.), superoxide dismutase (SOD), and catalase (CAT) enzymes were measured. Unlike compost, urea application promoted a linear increase of soil nitrate and ammonium during the experiment. Plant growth responded to urea-N application rates according to a second degree function with the highest plant biomass found at a urea-N rate between 200 and 500 mg N kg-1; and higher rates decreased plant growth. SOD and CAT showed no response to source and rate of N, while E. L. was higher in roots fertilized with urea-N

Biochar is the solid C-rich matrix obtained by pyrolysis of biomasses, currently promoted as a soil amendment with the aim to offset anthropogenic C emissions, while ameliorating soil properties and growth conditions. Benefits from biochar seem promising, although scientific understandings are beginning to be explored. In this project, I performed a suite of experiments in controlled and in field conditions with the aims to investigate the effect of biochar on: a) the interaction with minerals; b) Fe nutrition in kiwifruit; c) soil leaching, soil fertility, soil CO2 emissions partitioning, soil bacterial profile and key gene expression of soil nitrification-involved bacteria; d) plant growth, nutritional status, yield, fruit quality and e) its physical-chemical changes as affected by long-term environmental exposure. Biochar released K, P and Mg but retained Fe, Mn, Cu and Zn on its surface which in turn hindered Fe nutrition of kiwifruit trees. A redox reaction on the biochar surface exposed to a Fe source was elucidated. Biochar reduced the amount of leached NH4+-N but increased that of Hg, K, P, Mo, Se and Sn. Furthermore, biochar synergistically interacted with compost increasing soil field capacity, fertility, leaching of DOC, TDN and RSOC, suggesting a priming effect. However, in field conditions, biochar did not affect yield, nutritional status and fruit quality. Actinomadura flavalba, Saccharomonospora viridis, Thermosporomyces composti and Enterobacter spp. were peculiar of the soil amended with biochar plus compost which exhibited the highest band richness and promoted gene expression levels of Nitrosomonas spp., Nitrobacter spp. and enzymatic-related activity. Environmental exposure reduced C, K, pH and water infiltration of biochar which instead resulted in a higher O, Si, N, Na, Al, Ca, Mn and Fe at%. Oxidation occurred on the aged biochar surface, it decreased progressively with depth and induced the development of O-containing functional groups, up to 75nm depth.

Biochar addition to soil has been suggested as a promising strategy to increase soil carbon storage with important side-effects on soil fertility and crop productivity. Understanding the effect of biochar on soil respiration partitioning into rhizosphere-derived (Fr) and soil organic carbon-derived (Fsoc) components and on plant root dynamics and microbial activity is a crucial issue in the prediction of the impact of biochar on soil organic carbon and nutrient cycles. Within this framework, an experiment was carried out in an apple (Malus domestica Bork) orchard located in the experimental farm of the Bologna University (Italy). In spring 2009, 10 t of biochar per hectare were incorporated into the surface 20-cm soil layer by soil ploughing. The trenching method was used in order to partition total soil respiration (Fs) into Fr and Fsoc components in both biochar-treated and control soil. Soil respiration measurements were performed from June 2009 to March 2011. To study root dynamics, polycarbonate boxes were built and buried into the soil. Soil profile pictures were collected fortnightly with a CCD sensor scanner inserted in the boxes and analysed with the WinRHIZO Tron MF software. Biochar addition increased Fsoc and reduced Fr, even if the root length intensity (La) increased in biochar-treated soils relative to that in the control. A decrease in root metabolic activity was postulated to explain these contrasting results.

l'applicazione al suolo in primavera di cloruro di calcio (8-10) interventi ogni 10 giorni, con concentrazioni saline non superiori a 8-10 g/l riduce la suscettibilità del pero alla maculatura bruna

Dopo 14 anni di sperimentazione, si chiude un’attività di ricerca iniziata nell’agosto 2001 presso l’azienda sperimentale “Marani” di Ravenna con l’obiettivo di valutare l’impiego di compost di qualità nella gestione della fertilizzazione del pesco al fine di rispondere alla necessità di ripristinare i livelli di sostanza organica nel terreno, e di recuperare i prodotti di scarto attraverso la produzione di compost e concimi organici (fanghi e digestati). La fertilità del terreno è aumentata a seguito della somministrazione di concimi organici con effetti benefici sulla produzione e qualità dei frutti, senza aumentare i rischi di inquinamento legati alla lisciviazione dell'azoto minerale.

Sorprendente la crescita produttiva del noce nell’ultimo decennio. In Piemonte, Veneto ed Emilia-Romagna le più interessanti realtà che hanno deciso di puntare su questa specie per rilanciare la frutticoltura del territorio, diversificando l’offerta con un prodotto di alta qualità, assai ricercato dal mercato. Aumentano le richieste commerciali e i consumi pro-capite. Accurate tecniche agronomiche e materiale di propagazione di qualità: sono questi i punti chiave per ottenere buone performance produttive.

Biochar is a highly heterogeneous product derived from pyrolysis of biomass, and is considered to be a stable form of carbon, highly recalcitrant. Recently, the use of biochar has been indicated as a valuable strategy for long-term C sequestration in soil, contributing to reduce greenhouses gases (GHGs) emissions into the atmosphere. This potential is attracting research as well as political interests. Biochar is a highly heterogeneous product that, when applied to the soils, may affect agronomic responses. The application of biochar in agricultural land is reported to improve soil structure, nutrient use efficiency and water retention, reduce CH4 and N2O emissions, and increase soil microbial colonization and diversity. Therefore, most of the published evidences have been obtained on annual plants growing in tropical and subtropical environments, characterized by acidic soils. Results of the impact of soil-applied biochar on perennial plants growing in the Mediterranean basin are limited; hence long-term investigations are desirable before this approach can be widely adopted by growers.

Ottimizzazione delle strategie di applicazione del calcio per migliorare lo stato nutrizionale del pero e aumentare la tolleranza alla maculatura bruna (Stemphylium vesicarium) Maurizio Quartieri, Giovambattista Sorrenti, Elena Baldi, Moreno Toselli, Marina Collina, Alessandro Ciriani Dipartimento di Scienze Agrarie. Università di Bologna, Viale Giuseppe Fanin 46 - 40127 Bologna Parole chiave: Pyrus communis, Abate Fétel, cloruro di calcio, potenziale idrico, conducibilità elettrica La maculatura bruna (Stemphylium vesicarium (Wallr.) Simm.) è una delle principali avversità biotiche del pero. Colpisce principalmente foglie e frutti, sui quali compaiono tacche necrotiche che tendono ad estendersi e, nel caso del frutto, a provocare marciumi. Studi precedenti dimostrano come la tolleranza del pero ai patogeni può essere migliorata mediante l’aumento della concentrazione di calcio nei tessuti. Con l’obiettivo di incrementare il contenuto di calcio nelle foglie e nei frutti, e quindi migliorare la tolleranza del pero alla maculatura bruna, è stato condotto un biennio di studi per ottimizzare le strategie di applicazione del calcio. Le prove sono state condotte su alberi di pero della cv Abate Fetél/cot. MC allevati in vaso (30 l), confrontando le seguenti strategie: a) tipo di sale (CaCl2 e CaSO4); b) dose (due concentrazioni); c) epoca di somministrazione (primavera e estate); d) modalità di applicazione (terreno e chioma). L’effetto dei trattamenti sulla tolleranza alla malattia è stato valutato effettuando l’inoculazione sperimentale del patogeno sui frutti. I sali CaCl2 e CaSO4 hanno abbassato il pH e aumentato la conducibilità del suolo; tuttavia, il potenziale idrico fogliare è stato abbassato solo dal CaSO4. Tra i sali testati, il CaCl2 è risultato il più efficace nell’aumentare la ripartizione di calcio verso le foglie ed i frutti; tale effetto, tuttavia, tende a ridursi nel corso della stagione. Negli alberi trattati con CaCl2 al terreno alla concentrazione più alta (11,2 g/l di CaCl2), sono emersi gravi sintomi di fitotossicità, riconducibili probabilmente non alla concentrazione della soluzione distribuita, ma all’eccessiva salinità nel terreno. L’applicazione di CaCl2 al terreno, inoltre, è risultata più efficace di quella alla chioma, soprattutto se eseguita in primavera, nell’incrementare il calcio nell’albero. La tolleranza alla maculatura bruna del pero, tuttavia, non è stata migliorata da nessuno dei trattamenti a confronto.

We evaluated, in the long term (8 years), the effect of different organic fertilization strategies on yield, fruit quality, and nutritional status of nectarine (Prunus persica var. nectarina) Stark RedGold trees grafted on GF677 peach × almond hybrid. The experiment was carried out in a commercial orchard, where since their plantation, trees were subjected, according to a complete randomized block design (4 replicates), to the following treatments: 1. unfertilized control, 2. mineral fertilization including P (100 kg ha-1) and K (200 kg ha-1) applied at planting and N (70-130 kg ha-1 year-1) split in two applications at 40 days after full bloom (60%) and in September (40%); 3. cow manure supplied at planting (10 t dw ha-1) and then, from the 4th year, at the rate of 5 t dw ha-1 per year in spring; 4. compost supplied as for Treatment 3; 5. compost applied at a rate of 5 t dw ha-1 year-1, and 6. 10 t dw ha-1 year-1, both split as described for N application in treatment 2. Compost was obtained from the domestic organic wastes (50%) mixed with pruning material from urban ornamental tree and grass management (50%) after a 3-month stabilization. Foliar and fruit mineral concentrations (evaluated in summer) and fruit quality were not affected by treatments, however yield was higher in trees fertilized with 10 t dw ha-1 year-1 of compost, compared to unfertilized control. This result indicates that leaf mineral concentration is not always related to fruit yield

As técnicas adotadas no cultivo das frutas de caroço ou drupáceas devem ser definidas com uma visão de sustentabilidade ecológica e econômica. Tal visão sugere que os aspectos produtivos, voltados ao aumento da qualidade, sejam compatíveis com o ambiente, mantendo e, se possível, aumentando a qualidade dos recursos ambientais e garantindo, ao mesmo tempo, um adequado retorno econômico aos fruticultores. No presente trabalho são discutidos aspectos da fertilização e manejo do solo das drupáceas, assumindo como modelo o pessegueiro, espécie mais estudada, sendo evidenciados alguns resultados obtidos recentemente em outras espécies do grupo, com ênfase na Itália, mas que podem ser aplicados, na maioria dos casos, em qualquer situação. The agronomic techniques adopted for stone fruit trees cultivation should be ecologically and economically sustainable. This implies that production processes, apart from improving fruit yield and quality, mantain or increase the value of natural resources, guaranteeng satisfactory incomes to growers. The paper discusses fertilization and soil management aspects for peach, fruit crop largely investigated, and other stone fruit species, with emphasis on the Italian fruit industry.

Indirizzi produttivi e innovazioni tecniche delle più importanti specie frutticole a foglia caduca: actinidia, albicocco, ciliegio, melo, pero, pesche e nettarine, susino. Miglioramento genetico e diffusione varietale, tecniche di propagazione, portinnesti, impianto del frutteto e gestione del suolo, biologia fiorale, potatura e forme di allevamento, controllo della fruttificazione, strutture protettive, indici di maturazione, composizione del frutto, conservazione, confezionamento e packaging, utilizzazione industriale dei frutti.

For its beneficial effect on soil chemical, physical and biological characteristics, organic matter (OM) is the factor most tightly related to soil fertility. Moreover, soil the repeated incorporation of OM over time allow the sequestretion of a considerable amount of organic C, with benefit for the agroecosystem. The first aim of a correct and strategic tree nutrient management is the increase of soil OM. The best way to achieve this goal is the use of: 1. raw or stabilized manures (i. e. compost obtained from the controlled biological decomposition of organic material); 2. floor permanent grass management; 3. mulches; 4. abscised leaves, and pruned wood, etc. Attention must be paid when fresh OM is incorporated into the soil, because it may create anoxia conditions. OM should be tilled into the soil to achieve not only a net release of N, but also an improvement of soil physical and biological fertility. If OM with a C:N ratio > 30 is incorporated into the soil, microbes use available soil N to break down organic residues and a soil N depletion is expected as well as an increase in soil humus content. With a C:N ratio < 20 a release of N is expected, although the timing depends on the chemical composition of organic material. A potential effect of the addition of OM is the ‘priming effect’ that is a sudden increase of microbial activity with a release of nutrients in their mineral form that promote both root uptake and shoot growth.