Journal of Horticulture and Postharvest Research

Abstract Purpose: Excessive nitrogen use for crop production leads to environmental damage, so nitrogen use efficiency (NUE) needs to be improved. Stabilized amine nitrogen (SAN) (Lono, Levity Crop Science) has been shown to increase quality and yield of several crops. This work assesses the use of SAN for tomato production. Research method: SAN was applied to experimentally and commercially grown tomato plants and compared to several industry standard forms of nitrogen. Plant growth characters and yield were recorded. Findings: SAN was compared to an industry standard (IS) nitrogen fertilizer, and it significantly increased the harvested yield due to significant increases in fruit on trusses M3, M4 and lateral shoots. SAN was compared to several conventional IS fertilizers resulting in significantly increased chlorophyll levels, fruit-bearing trusses and an increased yield, but there was a shorter growth habit suggesting more energy was put towards fruit production and less to vegetative growth. Finally, SAN was applied to commercial processing tomato (variety HZ1662) production where there was a significant increase in the perfect red fruit when compared to the standard nitrogen application regime. Research limitations: Further work could be done with other commercial tomato crops. Originality/Value: Results from glasshouse experiments and commercial production show that SAN increases the yield of tomato (Solanum lycopersicum) when compared to IS nitrogen applications.

Abstract Purpose: In Tunisia, Pyrus communis ‘Arbi’ is broadly imperiled by Erwinia amylovora. The breeding of resistant rootstocks is an effectual control strategy for disease management. Therefore, a sound protocol for micropropagation and for the extensive production of high-quality plantlets was developed. Research method: Three groups of LED treatments were carried out: (1) 100% blue (B) LED, (2) 100% red (R) LED and (3) 50% B + 50% R (=BR) LED. Stock plants were micropropagtaed on modified Murashige and Skoog (MS) medium with half concentration of NH₄NO₃ and KNO₃. Findings: Throughout the propagation stage, red LED displayed important advantages: it produced optimal shoot height and leaf surface. The least leaf area was obtained with fluorescent light. The blue / red combination yielded considerable amelioration. Shoot weight/callus weight was maximal, along with shoot number and shoot length. The root formation of in vitro grown pear plantlets was greatly influenced by the various light types and by the incorporation of a new root-promoting substance, phenyl acetic acid (PAA). When combining red light and PAA, 89 % of rooting was observed in pear plantlets. The acclimatized pear vitroplants achieved rapid growth without morphological anomalies. Research limitations: In order to improve the survival rates of the acclimatized vitroplants, the acclimatization stage needs to be further studied. Originality/Value: The study compared the impact of different combinations of monochromatic blue and red LED lights and phenyl acetic acid against that of fluorescent light during the micropropagation, rooting and acclimation of a resistant pear (Pyrus communis L., cv. Arbi).

Abstract Purpose: Moroccan saffron is considered among the best quality produce worldwide. Its main production zones in Morocco are Taliwine and Taznakht administrative districts, located in the semiarid and arid bioclimatic ranges. The present study objective is the chemical characterization of Moroccan saffron from the main producing counties in relation with climatic conditions, altitude, soil, and irrigation water. Research method: Saffron, soil and water samples were taken from 10 counties representing 80% of the production areas and underwent analysis using standard methods.  Findings: Results showed that 80% of saffron samples are classified in category I, regarding crocin, picrocrocin, and safranal contents, according to the international standard ISO 3632-1. Soils supporting saffron cultivation are coarse and low in organic matter; their pH is alkaline and the EC low. Irrigation water is generally alkaline with low to very low EC. Statistical analysis showed that moderate altitude (1650-1900m) in the semiarid bio-climatic range had a positive effect on saffron quality (higher picrocrocin and crocin contents). Safranal was not influenced by altitude or by the bio-climate. Water and soil did not show any influence on saffron quality. Research limitations: As some cooperatives had organizational problems, it was not possible to get saffron samples from high altitude in the arid bioclimatic range in 2017 and 2018. Originality/Value: The most important value of the present work is the large number of samples distributed over three years and covering 80% of the production territory, which enabled to distinguish an effect of bio-climate and altitude on picrocrocin and crocin.

Abstract Purpose: Although the area under pineapple [Ananas comosus (L.) Merr.] cultivation has been increasing over the years in Bhutan, information on the morphological characters and yield performances of the cultivars grown in the country are literally absent. In this study, three landrace cultivars of pineapple (Accession ID: PV1, PV2 and PV3) collected from Sarpang District in Bhutan were evaluated for their morphological and physico-chemical characteristics. Research method: The field experiment was carried out in Randomised Complete Block Design with five replications at Agriculture Research and Development Centre, Samtenling, Bhutan in 2018. Seventeen morphological characteristics and five physico-chemical parameters were evaluated to record the variation amongst three accessions. Findings: The mean fruit weight of PV1 (1.4 kg), PV2 (0.9 kg) and PV3 (0.5 kg) were statistically significant. The fruit yield of pineapple accession PV1 (47.9 t/ha) was significantly higher than that of PV2 (30.0 t/ha) and PV3 (16.7 t/ha). Accession PV1 (14.3 °Brix) and PV3 (14.4 °Brix) had significantly higher total soluble solid (TSS) than that of accession PV2 (10.4 °Brix). Sugar to acid ratio of PV2 (46.81) was significantly higher than that of PV3 (34.95) but not with that of PV1 (41.54). Research limitations: Absence of molecular technique in characterisation of pineapples accessions. Originality/Value: This is the first report of characterisation of pineapple cultivars in Bhutan. Based on the result of this study, National Seed Board of Bhutan released Accession PV1 and PV3 as pineapple variety ‘Samtenling Kongtsey 1’ and ‘Samtenling Kongtsey 2’ respectively in 2020 for cultivation in Bhutan.

Abstract Purpose: The white mulberry tree (Morusalba) having a low water requirement, is native to Iran. Mulberry leaf extract is a rich chlorophyll source, and natural source of antioxidants and coloring pigments. White mulberry leaf extract was studied in terms of color production ability and antioxidant properties. Research method: The extracts of mulberry leaves were extracted by pure solvents of methanol, acetone, ethanol and 96% and 80% ethanol. Color extraction was investigated at beginning, middle and end of the production season. Antioxidant capacity, phenolic compounds, ferric reducing power and color stability were evaluated. Findings: 80% ethanol had a higher extraction rate and was cost-effective. In April and May, more total chlorophyll and carotenoid were extracted than in June. To determine the optimized antioxidant capacity, 100% ethanol solvent, sample to solvent ratio of 1 to 10, and microwave power of 500-watt were used. The leaves phenolic compounds extracted were highest in April (24.01 μg/ml) and lowest in June (19.13 μg/ml). The ferric reducing power was higher in the first samples of the season. Color stability decreased with pH from 6 to 3 and temperature increasing from laboratory temperature to 90°C and receiving light. Research limitations: The extracted color was not investigated in food products. Originality/Value: Chlorophyll, carotenoids, phenolic compounds and ferric reducing power were higher in the leaves at the beginning of the season. Color extraction from leaves harvested in April with 80% ethanol solvent had a higher value while maintaining pH and storage at room temperature in the dark.

Abstract Purpose: Mango is known as one of the most important fruits for its delicious taste, flavor and high nutritional properties. However, due to the perishability and short shelf life of fruit, safe treatments are needed for increasing shelf life of fruit. This experiment carried out to elucidate effects of postharvest UV-C and calcium ascorbate (CaA) on quality of mango fruit during cold storage. Research method: After preparing ‘Langra’ mango fruits were irradiated for 5 min in 5 or 10 kj/m² UV-C or dipped for 5 min in 1.5% (CaA) or combination of calcium ascorbate and UV-C. Postharvest parameters including firmness, catalase and phenylalanine ammonia lyase activities, total phenolic content and antioxidant activities, firmness, soluble solid concentrations, ascorbic acid and sensory parameters were evaluated throughout 21 days of storage at 12^◦C. Findings: At the end of shelf life, CaA alone (1.5%), UV-C alone ( 5 or10 kj m^‒2 ) or combination of UV-C with CaA maintained good firmness, increased catalase activity, phenylalanine ammonia lyase activity, total phenolic content and antioxidant activity but decreased soluble solid concentrations compared with the control. Sensory parameters, such as texture, flavor, appearance and overall quality were kept acceptable for marketability with these treatments. Research limitations: No limitations were encountered. Originality/Value: Both UV-C and CaA showed potential for increasing marketability of mango with their generally recognized as safe status for consumers.

Abstract Purpose: Button mushroom has short postharvest life due to high respiration rate, fast browning and high transpiration rate. Calcium is regarded as a suitable material in order to preserve the quality and increase the postharvest life of button mushroom, but, in the research conducted on the edible mushrooms, usually calcium chloride has been used as a calcium source. However, calcium chloride is of a negative effect on the taste of products and finding a suitable alternative is highly significant. In this study, the impact of other calcium sources has been studied in relation to the increased shelf-life of button mushroom in comparison to calcium chloride. Research method: Mushrooms were treated in calcium chloride, calcium lactate and calcium nitrate (Ca concentration equivalent to 0.5% calcium chloride) for 5 min and then were dried at room temperature and packed in polyethylene containers using cellophane film. The packed mushrooms were stored at 4°C and estimated during the cold storage up to the 14 days. Findings: Results indicated that all three calcium treatments led to the reduction of browning in mushrooms by reducing polyphenol oxidase enzyme activity as compared to the control, and also, treated mushrooms had higher firmness value and calcium content but lower phenol content. In addition, desired indices, the calcium lactate treatment was better than two other treatments in maintaining mushrooms quality during the cold storage. Research limitations: No limitations were encountered. Originality/Value: calcium lactate can be an appropriate alternative for calcium chloride treatment in terms of increased shelf-life of button mushrooms.

Abstract Purpose: Produced tubers with inferior quality are the main bottleneck for exporting surplus amount of potato to the importing countries. Applying nitrogen as prilled and super granule urea along with biochar may improve the yield and processing quality of potato. To generalize a partial solution, the study was conducted to find out the efficiencies of N forms and biochar towards the improvement of the processing quality of potato for export. Research Method: The experiment comprised two factors. Factor A:  Nitrogen form (2): Prilled Urea (Up) and Urea Super Granule (U_S), and Factor B: Biochar level (6): B₀-Control, B₁- 2 t/ha, B₂- 4 t/ha, B₃- 6 t/ha, B₄-8 t/ha, and B₅- 10 t/ha. The experiment was laid out in a split-plot design with three replications. Findings: Nitrogen form and/or biochar levels had shown significant influence on most of the parameters. The maximum tuber yield of potato (37.9 t ha^-1) was observed from U_sB₅ which was statistically similar to U_sB₄. The maximum dry matter content of tuber (21.8 %) and specific gravity of potato (1.098 g/ml) were observed from U_sB₄. So, it may be concluded that the application of urea super granule (U_S) plus biochar B₄ (8 t/ha) was found best combination for maintaining optimum yield and better processing quality of potato. Research limitations: No limitations to report. Originality/Value: Application of biochar improved the soil organic carbon status (data not shown) and exhibited better potato yield and qualities. Urea super granules (USG) are much economic and environmental friendly over prilled urea.