QUALITY OF PINK LADY ® BRAND APPLE
Apple (Malus domestica Borkh, ‘Pink Lady ® brand’) fruit were harvested from one California orchard in 2002, 2003 and 2004 at two or three different maturity stages each year. Fruit were evaluated for background color, firmness, fruit size, percentage of blush, starch index (CTIFL chart), soluble solids, titratable acidity and carbon dioxide (CO2) production and immediately stored at 33 oF in air or in controlled atmosphere (CA). In 2003, additional treatments included 1 ppm of SmartFresh ® (1-MCP) or 2200 ppm of diphenylamine (DPA). Firmness, CO2 production, external condition and internal browning were determined after storage in CA or air and 5 days at 68 oF. Fruit stored in CA conserved higher firmness and produced less CO2. Internal browning was not seen in fruit stored in air, but appeared in fruit after two months storage in CA. The incidence did not increase after longer storage times. SmartFresh ® worked as well as CA in conserving the quality of the fruit. It did not affect the incidence of internal browning, but DPA inhibited internal browning completely. When comparing similar storage atmospheres for all three seasons, the incidence of internal browning was significantly different, being much higher in 2002 and 2004. A mineral analysis of the apple flesh showed differences among the seasons. Concentrations of calcium (Ca), boron (B) and magnesium (Mg) were significantly higher in 2003, corresponding with a lower incidence of internal browning.
Prediction of controlled atmosphere-induced flesh browning in `Fuji' apple
Abstract Rapid induction of internal flesh browning by exposure of fruit to high CO2, fruit maturity indices, respiration rates and CO2 permeances were assessed as predictors of flesh browning which developed in apple (Malus domestica, Borkh. cv. Fuji) during long-term controlled atmosphere storage. Fruit were harvested from eight orchards at 170, 190 or 210 days after full bloom and held at 20°C in 50 kPa CO2 (balance air) for 1–3 days, in 20 kPa CO2 (balance air) for 3–7 days or at 0°C in a controlled atmosphere of 2 kPa O2+2 kPa CO2 for 150 days. Flesh browning increased with greater exposure time in 20 kPa and 50 kPa CO2 and after 3 days of exposure, more browning developed in fruit exposed to 50 than 20 kPa CO2. Flesh browning in all atmospheres increased with harvest date but significant variability was present among orchards at any one harvest. Across all orchards and harvest dates, strong positive relationships were found between flesh browning after controlled atmosphere storage and that which developed after short-term exposure to 20 kPa CO2 at harvest. This relationship improved with decreasing exposure time at 20 kPa CO2. While substantial differences in fruit maturity indices (background colour, starch pattern index, watercore incidence, soluble solids concentration, titratable acidity, flesh firmness), fruit respiration rates and fruit permeances to CO2 determined at harvest were also found among harvest dates and orchards, they were at best poorly related to flesh browning. The best predictor of orchard and harvest date differences in controlled atmosphere-induced flesh browning was therefore assessment of flesh browning after exposure of fruit to 20 kPa CO2 for 3 days.
Effect of Soybean Cyst Nematode (Heterodera glycines) on Yield of Resistant and Susceptible Soybean Cultivars Grown in Ohio.
Soybean (Glycine max) producers in Ohio rarely use soybean cyst nematode (Heterodera glycines, SCN)-resistant cultivars because of concerns over limited yield potential and lack of resistance to Phytophthora sojae. A two-year study was initiated to determine grain yield and nematode population increase on soybean cyst nematode-resistant cultivars in maturity groups II and III in production fields. Sites differed in soil texture, nematode densities, and P. sojae infestation at a number of locations in Ohio. Soil was assayed for nematode densities before planting and at harvest. Yields of resistant cultivars averaged 0% to 18% higher than those of susceptible cultivars in fine-textured soils with average preplant populations ranging from 463 to 14,330 SCN eggs/100 cm(3) soil. In coarse-textured soils, yields of susceptible cultivars were 21% to 56% less than the resistant cultivars with average preplant densities ranging from 1,661 to 15,558 SCN eggs/100 cm(3) soil. The reproductive index ranged from 0.1 to 5.5 for resistant cultivars and 0.4 to 112 for susceptible cultivars. In 1993, yield of P. sojae-susceptible, nematode-resistant 'Asgrow A 3431' was as high as yield of the P. sojae-resistant, nematode-susceptible cultivar 'Resnik' in a Phytophthora-infested field. The nematode-resistant cultivars Madison Experimental 131527 and Asgrow A3431 had higher yields than AgVenture AV1341 and susceptible cultivars Resnik and Kenwood when compared over five nematode-infested sites. Nematode-resistant cultivars were found to be excellent alternatives to currently grown susceptible cultivars for managing SCN where group III cultivars are used. However, better cultivar alternatives may be needed for sites with combined Phytophthora root rot and cyst nematode problems.