Effect of Nitrogen Fertilization on Cranberry Fresh Fruit Keeping Quality

Abstract: In this research project we compared the keeping quality of fruits harvested in plots fertilized during the last three years with 0, 13, 27, 40 and 54 lbs of nitrogen/acre. The nitrogen treatments were applied on small plots of 10 X 13 feet and split into four applications during bloom. The treatments were replicated two times per site in each of one organic and three conventional sites. The nitrogen fertilization had an effect on the keeping quality in both conventional and organic sites, with the best keeping quality obtained with a nitrogen fertilization of 0 or 13 lbs/acre (10% cumulative defects after 12 weeks). The worst keeping quality was obtained with a nitrogen fertilization of 54 lbs/acre (10% cumulative defects after 6 weeks). Most of the differences in keeping quality between treatments were related to fruit rot. As expected, the total percent weight of fruits smaller than 13/32 inches decreased and the number of white fruits increased as the amount of nitrogen fertilization increased. The highest average yield in the conventional sites was obtained in plots treated with 54 lbs of nitrogen/acre (43195 lbs/acre). It was closely followed by the plots treated with 27 and 40 lbs of nitrogen/acre (40 954 lbs/acre 35 876 lbs/acre respectively). Considering the keeping quality and the yield, the best nitrogen fertilization for fresh fruits in Quebec, based on this trial, seems to be between 27 and 40 lbs/acre, which confirms the standard recommendation in fresh fruit fertilization

Impact of fertilization on the firmness of cranberry (Vaccinium macrocarpon AIT.)

Abstract. Québec is one of the leading cranberry (Vaccinium macrocarpon Ait.) or called ‘Atoka’ in the Iroquoian language, producers in the world. Fertilization is a key management tool to reach high fruit yield and good quality. For example, in blueberries, rates and application methods of fertilizers can affect fruit firmness. N showed the greatest effect on the development, flowering, and productivity of the cranberry plant. On the other side, hand harvesting is preferred for marketing of fresh fruit since the physical abuse of mechanical harvesting reduces fruit firmness and substantially reduces market life. The objective of this research was to study the potential of firmness reflectance TA.TX2 Texture Analyzer as a means for measurement of fresh fruit firmness. Four experimental sites were established since 2014 on podzolic acid sandy soils containing more than 90% sand at Notre Dame-de-Lourdes and St-Louis-de-Blandford in central Québec. The experimental design was a randomized complete block with cv. “Stevens” established on permanent plots comprised five N, three P, four K and S, and also two Mg, Cu and B doses. Berries were hand-harvested on 0.37 m2 areas, 2-3 weeks before commercial harvesting. The fruits from zero N treatment were best for firmness and economic profit. Although, These N application rates discourage a good relationship between commercial yield and fruit quality. In other hand, the zero N rate resulted in lowest yield production and high quality; the fruit had the greatest N (60 kg ha-1) rate was diminished significantly firmness of the cranberry fruit. Finally, the 45 kg N ha-1 rate produced high yield with the buildup and maintenance concept and poor fruit quality

Fertilization and Soil Nutrients Impact Differentially Cranberry Yield and Quality in Eastern Canada

High berry yield and quality of conventionally and organically grown cranberry stands require proper nutrient sources and dosage. Our objective was to model the response of cultivar “Stevens” to N, P, K, Mg, Cu, and B fertilization under conventional and organic farming systems. A 3-year trial was conducted on permanent plots at four production sites in Quebec, Canada. We analyzed yield predictors, marketable yield, and fruit quality in response to fertilization and soil properties. Cranberry responded primarily to nitrogen fertilization and, to a lesser extent, to potassium. Berry yield was closely related to the number of fruiting uprights (r = 0.92), berry counts per fruiting upright (r = 0.91), number of reproductive uprights (r = 0.83), and fruit set (r = 0.77). Nitrogen increased berry yield nonlinearly but decreased berry firmness, total anthocyanin content (TAcy), and total soluble solids content (°Brix) linearly, indicating a trade-off between berry yield and quality. Fertilizer dosage at a high-yield level ranged between 30 and 45 kg N ha−1 in both conventional and organic farming systems. Slow-release fertilizers delayed crop maturity and should thus be managed differently than ammonium sulfate. Berry weight increased with added K. Redundancy analysis showed a close correlation between marketable yield, berry quality indices, and soil tests, especially K and Ca, indicating the need for soil test calibration

Interplay of immune and kidney resident cells in the formation of tertiary lymphoid structures in lupus nephritis

Kidney involvement confers significant morbidity and mortality in patients with systemic lupus erythematosus (SLE). The pathogenesis of lupus nephritis (LN) involves diverse mechanisms instigated by elements of the autoimmune response which alter the biology of kidney resident cells. Processes in the glomeruli and in the interstitium may proceed independently albeit crosstalk between the two is inevitable. Podocytes, mesangial cells, tubular epithelial cells, kidney resident macrophages and stromal cells with input from cytokines and autoantibodies present in the circulation alter the expression of enzymes, produce cytokines and chemokines which lead to their injury and damage of the kidney. Several of these molecules can be targeted independently to prevent and reverse kidney failure. Tertiary lymphoid structures with true germinal centers are present in the kidneys of patients with lupus nephritis and have been increasingly recognized to associate with poorer renal outcomes. Stromal cells, tubular epithelial cells, high endothelial vessel and lymphatic venule cells produce chemokines which enable the formation of structures composed of a T-cell-rich zone with mature dendritic cells next to a B-cell follicle with the characteristics of a germinal center surrounded by plasma cells. Following an overview on the interaction of the immune cells with kidney resident cells, we discuss the cellular and molecular events which lead to the formation of tertiary lymphoid structures in the interstitium of the kidneys of mice and patients with lupus nephritis. In parallel, molecules and processes that can be targeted therapeutically are presented