Search Results (5)

CH201/FRED^® is a novel red-blush pear cultivar with long-term storage potential and a prolonged shelf life. However, it is prone to controlled atmosphere (CA)-related disorders, particularly cavities. This study explored the impact of the balance between vegetative growth and crop load on the development of CA-related disorders during storage. Treatments involving the removal of two-thirds of floral bouquets (Fl_Th) and the shortening of branches by two-thirds (Pr) at the bud stage (late balloon stage) promoted the growth of 1-year-old shoots, which correlated with an increased incidence of cavities and reduced calcium levels in the pears. The Fl_Th treatment resulted in larger fruits with a higher total soluble solid content, a greater force required to puncture the skin and flesh, and a higher incidence of cavities than the Pr treatment. These findings demonstrate that both crop load and the leaf area-to-crop load ratio significantly influence the susceptibility of CH201/FRED^® pears to CA-related disorders during storage. Full article

Red-skinned pears with a bright red color and abundant health benefits are favored by consumers. However, fruit coloration and inner quality are usually affected by adverse factors, which lead to a decline in fruit quality and commerciality. Methyl jasmonate (MeJA) has been reported to be involved in many plant processes, including anthocyanin accumulation, while the value of MeJA application for fruit coloration and quality improvement in red-skinned pears is still largely unclear. The application of 0, 0.5, 1.0, or 2.0 mM MeJA at different fruit development stages significantly promoted red coloration in ‘Danxiahong’ pears. Moreover, MeJA treatment increased the fruit soluble solids, improved the total sugar content, decreased the fruit acid content, and significantly increased the total sugar/total acid ratio. However, no significant effect was observed on the fruit’s shape or longitudinal or transverse diameters. RT-qPCR analysis indicated that the expression of anthocyanin biosynthetic regulatory and structural genes, including PbrMYB10, PbrbHLH3, PbrWD40, PbrPAL, PbrCHI, PbrDFR, and other genes, was induced by MeJA treatments. Overall, our findings demonstrate that the application of MeJA plays a significant role in promoting anthocyanin accumulation in pear peels, leading to enhanced fruit coloration. Furthermore, MeJA treatment also positively impacts the improvement of the inner fruit quality. These results not only provide valuable insights into the mechanism of MeJA-mediated coloration but also contribute to a better understanding of the overall role of MeJA in pear fruit development and quality enhancement. Full article

The diploid Celina/QTee^® (‘Colorée de Juillet’ × ‘Williams’), one of the most promising pear cultivars developed by the Norwegian breeding program Graminor, was launched in 2010. In Norway, the flowering is medium to late, while the fruits ripen in the beginning of September. The fruits are attractive with an intense red blush (50%) on a green background. Although, ‘Celina’ is cultivated in the most climatically suitable regions for fruit cultivation, present in Norway, unfavorable environmental conditions for pear pollination can have a very negative effect on fruit set and consequent yield. The aim of this study was to determine the S-alleles of ‘Celina’, as well as its frequently used pollinizers, and, through paternity testing of ‘Celina’ seeds, give a recommendation regarding the most important pollinizers of this pear cultivar. In order to accomplish this, ‘Celina’ and its potential pollinizers were all S-genotyped. After harvest, seeds collected from ‘Celina’ fruit in 2017 and 2018 were genotyped using eleven microsatellite markers. Genomic DNA was also extracted from leaf material collected from ‘Celina’, as well as from five pear cultivars used as pollinizers in the three examined orchards, and analyzed using the same marker set. Subsequently a simple sequence repeat (SSR) database was constructed and used for gene assignment analyses with the aim of quantifying pollen donor contribution from individual pollinizers. The obtained results indicate that ‘Anna’, the only examined pollinizer that was fully cross-compatible with ‘Celina’, together with ‘Fritjof’, the genotype which had the highest flowering overlap with ‘Celina’, proved to be the most successful pollinizers across all seasons and orchards. Although both cultivars were ubiquitous in the examined orchards, either as planted trees or as branches introduced during the flowering period, they were the most abundant pollinizers in only one orchard each. It is therefore possible to conclude that pollinizer abundance has a secondary significance in pollinizer success within investigated ‘Celina’ orchards. Full article

Some cultivars of Pyrus communis develop mature fruit with a distinctive red blush. Investigating the patterns of pear colour development in response to sunlight has implications for orchard management of these pears. The objectives of these experiments are to study the seasonal patterns of colour development and investigate the influence of shade and sunlight exposure on the red colour and harvest quality of blush pears “ANP-0118” and “ANP-0131”. Several long, medium and short shading treatments were applied at different stages of fruit development from 28 (“ANP-0131”) and 29 (“ANP-0118”) days after full bloom (DAFB) until harvests at 119 DAFB (“ANP-0118”) and 175 DAFB (“ANP-0131”). Fruits were measured every three weeks for colour parameters (a*, hue angle, chroma) and at harvest for quality parameters (fresh weight, visual assessments of percentage blush coverage and blush intensity, flesh firmness and soluble solids concentration). In the unshaded control, red colour increased during the growing season (increase in a* value and decrease in hue angle), as well as increasing in chroma value. Periods of shading during the season negatively affected red colour in both cultivars, as evidenced by significant decreases in a* value and increases in hue angle. Shaded fruits that were subsequently re-exposed to sunlight reacted with a dynamic increase in a* value and decrease in hue angle. Fruit shaded for the length of the experiment or prior to harvest had significantly lower a* values than the control at harvest. Visual assessment at harvest of percentage blush coverage and blush intensity were significantly affected by shading in both cultivars. Shading treatments applied early in the experiment had a negative effect on the fresh fruit weight of “ANP-0118”. Full article

Site-specific crop management (SSCM) is one facet of precision agriculture which is helping increase production with minimal input. It has enhanced the cost-benefit scenario in crop production. Even though the SSCM is very widely used in row crop agriculture like corn, wheat, rice, soybean, etc. it has very little application in cash crops like fruit and nut. The main goal of this review paper was to conduct a comprehensive review of advanced technologies, including geospatial technologies, used in site-specific management of fruit and nut crops. The review explores various remote sensing data from different platforms like satellite, LIDAR, aerial, and field imaging. The study analyzes the use of satellite sensors, such as Quickbird, Landsat, SPOT, and IRS imagery as well as hyperspectral narrow-band remote sensing data in study of fruit and nut crops in blueberry, citrus, peach, apple, etc. The study also explores other geospatial technologies such as GPS, GIS spatial modeling, advanced image processing techniques, and information technology for suitability study, orchard delineation, and classification accuracy assessment. The study also provides an example of a geospatial model developed in ArcGIS ModelBuilder to automate the blueberry production suitability analysis. The GIS spatial model is developed using various crop characteristics such as chilling hours, soil permeability, drainage, and pH, and land cover to determine the best sites for growing blueberry in Georgia, U.S. The study also provides a list of spectral reflectance curves developed for some fruit and nut crops, blueberry, crowberry, redblush citrus, orange, prickly pear, and peach. The study also explains these curves in detail to help researchers choose the image platform, sensor, and spectrum wavelength for various fruit and nut crops SSCM. Full article