Search

Balanced supply of essential nutrients in fruit trees, such as “Rocha” pears, is an important tool to achieve maximum yield and fruit quality, yet under fertilization the interactions among nutrients accumulation may be positive (synergistic) or negative (antagonistic), being also possible to have no interactions. Through foliar spraying of “Rocha” pear trees with Ca, this study aimed to assess the interactions with other micro and macronutrients in the leaves, the related implications on the synthesis of photoassimilates and the subsequent kinetics of accumulation in the fruits at harvest. Between fruit set and 30 mm diameter, two times spraying, with fifteen days range, were carried out with Ca(NO3)2 or CaCl2 (0.1, 0.3 and 0.6 kg ha− 1 or 0.4, 0.8 and 1.6 kg ha− 1, respectively). Thereafter, with similar interval periods, for all treatments, trees were sprayed with CaCl2 (firstly at a concentration of 4 kg ha− 1 – second phase, followed by four with 8 kg ha− 1 – third phase). During fruit development, through the three spraying phases with Ca, the accumulation of Ca, K, P, S, Mg and Zn showed substantial variations in leaf tissues, which at fruit maturity determined some special and quantitative variations in tissues accumulation of C, H, O, K, Mg, Cl, Cu, Zn, Mn, Fe. Nevertheless, the functioning of the photosynthetic apparatus and the morphological and colorimetric parameters were not impaired. Considering that during fruits development, although Ca translocation prevails in the xylem, being its redistribution through the phloem strongly limited, it was concluded that accumulation depends of the type of Ca fertilizer and concentration, prevailing an oscillating balance among Ca K, P, S, Mg and Zn deposition in the leaves and its slow removal from the mesophyll cells to the fruits until maturity. Besides, as at fruit maturity xylem functionality can be minimal, the major accumulation of Ca in the peripheral layers of the fruits, resulted from Ca spraying, whereas translocation through the xylem favored its accumulation in the core in the early stages of fruit development. Following this behavior, C, H, O, K, Mg, Cl, Cu, Zn, Mn and Fe further showed complex accumulation interactions in the fruits. [ABSTRACT FROM AUTHOR]

Metamitron is an apple (Malus domestica Borkh.) fruit thinner that acts by reducing the photosynthetic capacity of trees. Relative humidity may influence thinning efficacy; however, the broadness of this effect is not yet fully understood. Trials were set in Sint-Truiden (Belgium) in 2018 and Lleida and Girona (Spain) in 2019, using 4-year-old cvs. Braeburn and Elstar trees in Belgium, and 16-year-old cv. Golden Reinders trees in Spain. Four treatments were implemented at the stage of 12-14 mm fruit diameter: (a) CTR--control, trees under natural environmental conditions; (b) HH--high humidity, trees submitted to artificially increased air relative humidity applied for 3 h prior to the beginning of the experiment; (c) MET--trees sprayed with 247.5 mg/L metamitron; (d) MET + HH--trees submitted to the combination of increased humidity (HH) and metamitron (MET) application. In Belgium, metamitron absorption by leaves was greater than in Spain. This might be related to morphological characteristics of the leaves which developed under greater natural relative humidity levels in Belgium than in Spain. Compared to MET alone, 'Braeburn' and 'Elstar' demonstrated significantly greater metamitron absorption, 59% and 84%, respectively, under MET + HH, accompanied by declines in leaf net photosynthesis (10% and 32%, respectively) and sucrose (31% and 26%, respectively). At harvest, MET + HH treatment reduced yield by 24% and 32% in 'Braeburn' and 'Elstar', respectively, when compared with MET alone. A large reduction (considered over thinning) in the yield of 'Elstar' occurred. In contrast, metamitron absorption by 'Golden Reinders' using MET alone was similar to MET + HH; however, there was a slight foliar sugar reduction in the latter treatment. In addition, both treatments enhanced shoot growth and increased fruit abscission with similar improvements in fruit weight and size. In this study, high relative humidity enhanced fruit thinning efficacy under certain circumstances, such as age or genetic predisposal, which left the tree more susceptible to a negative carbohydrate balance. For instance, 'Braeburn' and 'Elstar' were easier to thin when compared to 'Golden Reinders'. In addition, this study raises a question that requires further research regarding the impact of HH before and after spraying as well as its effect in combination with higher temperatures. [ABSTRACT FROM AUTHOR]

The amount of nutrients present in husks and beans from Conilon coffee fruits directly influence the crop nutritional management, as well as its use as a complement to conventional fertilization. The present study aimed to quantify the concentration and accumulation of nutrients in husks, beans and whole fruit in irrigated and non-irrigated plants from the cropped genotype C. canephora cv. Conilon Clone 02, from clonal variety EMCAPA 8111. The experiment consisted of two treatments (irrigated and non-irrigated) in a completely randomized design with 28 replicates under field conditions, in southern Bahia, Brazil. During harvesting stage, 50 fruits per plant, in two consecutive harvests, were collected to quantify the dry matter and accumulation of nutrients in the husks, beans and fruits. The fruits from irrigated coffee plants showed higher N, P, K, Ca, Mg, Cu and Mn accumulation than non-irrigated plants. The huskand beans from irrigated coffee plants showed higher Ca, Zn and Cu and N, P, Ca, Mg, S, Cu and Mn accumulation, respectively, than non-irrigated coffee. Regarding the nutrient accumulation, K followed by N, and Ca were the most represented macronutrients in coffee husk. N followed by K and P, and N followed by K and Ca were the most represented macronutrients in beans and fruit, respectively. Fe and B were the micronutrients found in higher contents in husk, beans and fruits from Conilon coffee. [ABSTRACT FROM AUTHOR]

The economic and financial crisis has increased the number of urban horticulture on lands close to present or past industrial areas. "Tronchuda" or the Portuguese cabbage (Brassica oleraceae L var. costata DC) was studied because of its importance in Portuguese diet. It belongs to a number of economically significant horticultural crops (Brassica species), which are also known to be nutritionally well-balanced vegetables. "Tronchuda" produced in urban horticultures from 4 regions of mainland Portugal was studied for its nutritional profile along with elemental soil analysis of each sampling site. This study revealed significant interactions between essential elements in soil and plant leaves - the edible part of the plant for human nutrition. In general, these organs contained poor concentrations of Fe and Si, while Mn is absent, regardless of the sampling sites. Conversely, Ca levels were abundant with values ranging between 3.3% and 3.9%. Soils from CAP showed a soil nutrient exhaustion of Fe, Mn and Mo, although the highest protein and sucrose contents in the leaves was observed in plants growing in those soils. Protein, lipids and carbohydrates concentrations differed according to sampling site, reflecting different production practices. [ABSTRACT FROM AUTHOR]

Understanding the responses of cork oak (Quercus suber L.) to actual and predicted summer conditions is essential to determine the future sustainability of cork oak woodlands in Iberia. Thermal imaging may provide a rapid method for monitoring the extent of stress. The ecophysiology of cork trees was studied over three years. Three treatments were applied by means of rainfall capture and irrigation, with plots receiving 120%, 100%, or 80% of natural precipitation. Despite stomatal closure, detected using both thermal imaging and porometry, leaf water potential fell during the summer, most drastically during the third year of accumulative stress. The quantum efficiency (ΦPSII) and the maximum efficiency FV′/FM′ of photosystem II also fell more intensely over the third summer, while non-photochemical quenching (NPQ) increased. The reduced precipitation treatment sporadically further reduced leaf water potential, stomatal conductance (gs), IG (an index of gs derived from thermal imaging), ΦPSII, and FV′/FM′, and increased leaf temperature and NPQ. It is concluded that these are very resilient trees since they were only severely affected in the third year of severe drought (the third year registering 45% less rainfall than average), and removing 20% of rainfall had a limited impact. [ABSTRACT FROM PUBLISHER]

Andina is a conilon coffee variety originated from a selection of clones discovered by farmers. It was cultivated and evaluated for yield and plant vigor an altitude of 850m asl. Five genotypes (A1, NV2, NV8, P1 and Verdim TA), with a mean yield of 51.3 bags per hectare per year. [ABSTRACT FROM AUTHOR]