Post-veraison trimming practices for slowing down berry sugar accumulation and tuning technological and phenolic maturity

In the last years, particularly in the viticultural areas characterized by low soil fertility and water availability, when the skin berry colour of red-varieties is considered optimal for harvest, the juice sugar concentration is often too high, giving rise to wines with high alcohol levels which are not well accepted by modern consumers. On the other hand is not possible to anticipate the time of harvest because of the risk of incomplete poliphenols synthesis which is known to start at veraison. Late trimming, enabling to decrease leaf area/yield ratio during the last phase of berry maturation, may represent a cheap and simple agronomical practice for slowing down sugar accumulation. However is not clear if late trimming may also delay anthocyanins accumulation in berry skin. With the aim of testing such hypothesis a 3-year experiment (2008-2010) was conducted in a mature Sangiovese vineyard located in a hot hilly area of Emilia-Romagna Region (Tebano, Ravenna, Italy), treated with different intensity of late (post-veraison) shoot trimming. In August, when grape soluble solids reached about 15 \ub0Brix (40-45 days before expected harvest), spur-pruned vines were submitted to trimming maintaining 14 (light trimming) or 10 (severe trimming) nodes on the main shoot and compared with control non-trimmed vines. A randomized block design was adopted. Berry weight and their soluble solids, total acidity and pH were monitored several times after treatment, while skin anthocyans, fruit yield and cluster weight were determined at harvest. Berry quality data (berry weight, soluble solids, pH, total acidity and yeast assimilable nitrogen, skin anthocyans concentrations) collected during 2008 and 2009 indicate a slowing-down of maturation in the berries collected on trimmed vines. Nevertheless skin anthocyans levels at harvest did not show statistical differences with control vines. Trimming decreased bunch weight and yield. In 2010 year, characterized by different metereological conditions (lower summer temperatures), trimming did not change sugar accumulation while inducing a small decrease of berry skin anthocyanins concentration (peonidin). These results suggest that late trimming may represent an effective tool for slowing down sugar accumulation without changing phenolic maturity. Furthermore, data indicate that late trimming practices should be performed and finely adjusted to metereological conditions and berry maturation trend

Improvement of Grapevine Iron Nutrition by a Bovine Blood-Derived Compound

Iron (Fe) is essential for chlorophyll formation and plant growth. Iron-deficiency chlorosis is a major nutritional disorder in several fruit trees cultivated in calcareous and alkaline soils, reducing fruit yield and quality and causing heavy economic losses. Since chelated Fe, the most widespread fertilizers used for preventing or curing Fe deficiency, pose risks of environmental pollution, the development of sustainable agronomic alternatives represents a priority for the fruit industry. In this work, we investigated the effectiveness of a bovine blood-derived product (BB; 0,125% Fe) for preventing Fe-deficiency in grapevine plants. During the vegetative season 2011 potted plants of five graft combinations: Sangiovese/SO4, Cabernet Sauvignon/SO4 and Cabernet Sauvignon/140 Ruggeri, 140 Ruggeri/Cabernet Sauvignon, Vitis riparia/Cabernet Sauvignon were grown on calcareous soil. Soil treatments included: 1) Control; 2) Fe-EDDHA (Fe 6%); 3) Bovine-Blood (5 g/l); 4) Bovine-Blood (20 g/l). With the exception of Cabernet Sauvignon/SO4 plants, Fe-EDDHA increased SPAD units (leaf chlorophyll content). Bovine-blood at low concentrations had similar or higher SPAD units than Fe-EDDHA. Increasing concentration resulted in further increases in SPAD units only in some graft combinations. Data highlight the efficiency of Fe blood-compound in the prevention of grapevine Fe-deficiency over one growing season

Capacidade de enraizamento de estacas de Maytenus muelleri Schwacke com a aplicação de ácido indol butírico relacionada aos aspectos anatômicos Rooting capacity of Maytenus muelleri Schwacke cuttings with indolebutyric acid application related to anatomical aspects

A espinheira-santa (Maytenus muelleri - Celastraceae) é a planta medicinal nativa do Sul do Brasil, cujas folhas são tradicionalmente utilizadas pela medicina popular para o tratamento de úlceras e outros problemas gástricos. Existem poucos trabalhos publicados sobre a produção de mudas e técnicas de propagação vegetativa da espécie. A propagação de espinheira-santa por estaquia poderia ser um método eficiente para obtenção de material homogêneo, com características genéticas desejáveis, produzido a partir de plantas matrizes selecionadas. O presente trabalho teve por objetivo estudar os efeitos da aplicação de ácido indol butírico (AIB), em solução e em pó, no enraizamento de estacas de espinheira-santa coletadas nas quatro estações do ano (abril/2005 a janeiro/2006), bem como averiguar, por meio de análises anatômicas e histoquímicas das estacas, a presença de possíveis impedimentos à iniciação do enraizamento adventício. Estacas provenientes de ramos de plantas matrizes de seis anos cultivadas da Estação Experimental do Canguiri, Pinhais, PR, foram coletadas e tratadas com AIB (0, 1500, 3000 mg L-1 ou mg kg-1), em solução alcoólica (50% v/v) e em talco. Aos 365 dias foram avaliadas as porcentagens de estacas enraizadas e mortas, número e comprimento médio de raízes formadas por estaca. Análises anatômicas e histoquímicas com lugol e cloreto férrico foram realizadas. A estação mais promissora para o enraizamento foi o verão/2006 com 62,50% para o tratamento controle, devido à menor lignficação dos ramos no período de intenso crescimento vegetativo. O número médio de raízes formadas por estaca foi de 6,94 (solução) e o comprimento médio de raízes formadas/estaca chegou a 4,82 cm nesta mesma estação. As concentrações de AIB aplicadas não foram eficientes na indução radicial, independentemente do modo de aplicação. Foi detectada a presença de uma camada quase contínua de fibras e braquiesclereídes, a qual constitui barreira anatômica à indução radicial. Os testes histoquímicos revelaram a presença de amido e de compostos fenólicos nas estacas, em todas as estações do ano. A dificuldade ou demora no enraizamento não pode ser justificada pela falta de reservas de amido nos tecidos das estacas, mas pode ser justificada pela presença de compostos fenólicos, possivelmente do grupo dos monofenóis, que causam a degradação do AIA, interferindo negativamente na indução do enraizamento.<br>"Espinheira-santa" (Maytenus muelleri - Celastraceae) is a medicinal plant native to Southern Brazil, the leaves of which are traditionally used in popular medicine for the treatment of stomach ulcers and other gastric problems. There are few published studies about seedling production and vegetative propagation techniques for this species. The propagation of "espinheira-santa" by cuttings could be an efficient method to obtain homogeneous material, with desirable genetic characteristics, produced from selected mother plants. This paper aimed to study the effects of indolebutyric acid (IBA) application, in solution and in powder, on the rooting of "espinheira-santa" cuttings, collected in four seasons (April/2005 to January/2006), as well as to investigate, by means of cutting anatomical and histochemical analyses, the presence of possible impediments to adventitious rooting initiation. Cuttings from branches of six-year mother plants grown at "Estação Experimental do Canguiri", Pinhais, Paraná State, Brazil, were collected and treated with IBA (0, 1500, 3000 mg L-1 or mg kg-1) in alcoholic solution (50% v/v) and in powder. After 365 days, the percentages of rooted and dead cuttings, the number and mean length of roots/cutting were evaluated. Anatomical and histochemical analyses were performed with lugol and ferric chloride. The most promising season for rooting was Summer/2006, with 62.50% of rooting for the control treatment, due to the lesser lignification degree of branches in intense vegetative growth period. The mean number of roots/cutting was 6.94 (solution) and the mean length of roots/cutting was 4.82 cm in that same season. The applied IBA concentrations were not efficient in inducing root growth, regardless of the application method. An almost continuous layer of fibers and stone cells was detected, constituting an anatomical barrier for rooting induction. The histochemical tests revealed the presence of starch and phenolic compounds in cuttings, in all seasons. The difficulty or delay in rooting cannot be justified by the absence of starch reserve in the cutting tissues but by the presence of phenolic compounds, possibly of the group of monophenols, which cause IAA degradation, negatively affecting rooting induction