Department of Food Production, Faculty of Agriculture and Natural Sciences, The University of the West Indies, St. Augustine, Trinidad and Tobago.
DOI: https://doi.org/10.37855/jah.2000.v02i02.23
Key words: chilling injury, cold resistance, cultivars, fruits, postharvest decay, ripening, storage decay, storage disorders, susceptibility, tomatoes, varietal reactions
Abstract: Studies on the sensitivity to chilling injury (CI) of 8 processing and 8 non-processing tomato cultivars stored at the table-ripe stage were examined. Fruits were stored for 21 days at 7 degrees C and upon transfer to 20 degrees C for 1 or 3 days, respectively. The low correlation coefficient between pitting and decay suggested that these two early manifestations of CI are not significantly related. The least sensitive tomato cultivars to CI were Advantage, Dorado, and Rio Grande among the processing types and Star Pak and Walters of the non-processing types. The least tolerant to CI were processing cultivars Caraibe and Cascade and non-processing cultivars Early Set, Carnival, and Capitan. The observed tolerance of table-ripe tomatoes after 21 days at 7 degrees C plus 3 days at 20 degrees C compared to control fruit stored continuously at 20 degrees C for only 8-11 days indicates that a longer marketing period could be obtained at temperatures lower than those currently recommended.
Department of Applied Biology, Horticulture, University of Helsinki, P.O. Box 27, FIN-00014, Finland.
DOI: https://doi.org/10.37855/jah.2000.v02i02.24
Key words: apples, calcium, calcium chloride, cold storage, crop quality, dry matter, endogenous growth regulators, ethylene production, firmness, fruits, heat treatment, magnesium, nitrogen, nutrient content, pH, phosphorus, plant growth regulators, postharvest dec
Abstract: 'Lobo' apple fruits were subjected to preharvest CaCl2 spraying treatment, pre-storage heat treatment, and CaCl2+heat treatment and were held at 2 degrees C and 90-95% RH for six months. Respiration and ethylene production rates were monitored and soluble solids, juice pH, firmness, total dry matter and macronutrient (P, K, Ca, Mg, and N) contents were determined. Additionally, the incidence of physiological disorder and pathological disease were recorded. Respiration and ethylene production rates slightly decreased in heat-treated apples and increased in CaCl2-treated apples. CaCl2 treatment did not increase fruit firmness or Ca concentration. Combined CaCl2+heat treatment and heat treatment increased pH. At the beginning of storage, the firmness of heat- and CaCl2+heat-treated fruits was lower but greater than that of the control fruits at the end of the storage period. After 6 months of storage, the lowest incidence of disorder and disease symptoms was observed in the CaCl2+heat treatment.
Plant Tissue Culture Division, National Chemical Laboratory, Pune - 411 008, India.
DOI: https://doi.org/10.37855/jah.2000.v02i02.25
Key words: 2,4,5 T, abscisic acid, in vitro culture, in vitro regeneration, pawpaws, somatic embryogenesis, somatic embryos, tissue culture
Abstract: A protocol for high frequency somatic embryogenesis in C. papaya was developed using immature zygotic embryo explant of cultivars Honey Dew and CO 2. Somatic embryos were induced in immature embryos, cultured on Murashige and Skoog's (MS) basal medium supplemented with 3 mg/litre of 2,4,5-T, and incubated in the dark for a period of 3-6 weeks. Loosely attached globular somatic embryos appeared from apical domes within 3-6 weeks of incubation. The development of somatic embryos was asynchronous, which passed through globular, heart, and torpedo shape stages. Embryos continued to proliferate with regular subculture and remained morphologically competent for up to one year. Maturation of the embryos was achieved in medium supplemented with ABA [abscisic acid] (0.1 mg/litre). The cotyledonary stage embryos germinated (71.33% in Honey Dew and 59.33% in CO 2) on phytohormone free MS basal medium. Regenerated plantlets were established in the greenhouse and hardened plants were transferred in soil.
Department of Horticulture, College of Agriculture, Acharya N G Ranga Agricultural University, Rajendranagar, Hyderabad - 500 003, India.
DOI: https://doi.org/10.37855/jah.2000.v02i02.26
Key words: acidity, ascorbic acid, benzyladenine, chemical composition, ethylene production, fruits, plant growth regulators, postharvest physiology, postharvest treatment, reducing sugars, sodium benzoate, storage life, sugar content, tomatoes, weight losses
Abstract: The effect of postharvest application of ascorbic acid, sodium benzoate, and benzyladenine at two levels of concentration on the days to ripening, shelf life, and various physicochemical properties was studied. Benzyladenine at 50 ppm improved the shelf life to 42 days, followed by benzyladenine at 25 ppm (37 days) and sodium benzoate at 1000 ppm (35 days), compared to the control (26 days). Physiological weight loss increased throughout the storage period while sugars, total soluble solids (TSS), and acidity increased up to the 14th day and then declined in the control and treated fruits. Treatments that improved the shelf life maintained better fruit quality in terms of higher reducing sugars, TSS, and acidity. Peak ethylene production reached the 14th (7.43 nl g-1 h-1) day in benzyladenine at 50 ppm and on the 11th day (6.75 nl g-1 h-1) in sodium benzoate at 1000 ppm when compared to the 11th day (8.15 nl g-1 h-1) in the control. The reduced and delayed peak ethylene production in benzyladenine- and sodium
Biotechnology Center, Punjab Agricultural University, Ludhiana - 141 004, India.
DOI: https://doi.org/10.37855/jah.2000.v02i02.27
Key words: bandages, benzyladenine, in vitro culture, in vitro regeneration, kinetin, leaves, micropropagation, plant growth regulators, shoots, strawberries, survival, tissue culture
Abstract: The rate of strawberry propagation through conventional technique is quite low and it is difficult to maintain plant material during the summer months. In the present investigation, the protocol for tissue culture propagation has been further improved by using liquid medium with four layers of surgical bandage. Fifteen milliliters of liquid Murashige and Skoog's (MS) medium enriched with BAP [benzyladenine] and Kinetin was used for the study. The proliferating shoots were longer, thicker, and borne with broader leaves in liquid medium. Studies on the survival of such plants were also conducted. The survival rate on various substrates varied from 66.67% in soil to 76.67% in soilrite mix. Seventy percent of plantlets transferred on sand survived well.
Division of Fruits and Horticultural Technology, IARI, New Delhi - 110 012, India.
DOI: https://doi.org/10.37855/jah.2000.v02i02.28
Key words: browning, disinfectants, guavas, hydrogen peroxide, in vitro culture, in vitro regeneration, mercuric chloride, micropropagation, phenolic compounds, shoots, silver nitrate, tissue culture
Abstract: A method was standardized for the quick establishment of aseptic cultures in guava from mature field-grown stock plants for micropropagation through enhanced axillary branching technique. The maximum number of aseptic explants with shoot proliferation was obtained by a combination of surface sterilizing agents involving hydrogen peroxide (10%), silver nitrate (0.25%), and mercuric chloride (0.05%) treatment of explants one by one for five, six, and three minutes, respectively. The problem of phenolic browning was also minimized to a great extent by leaching of phenolic compounds due to agitation in antioxidant solution as well as by proper drying of explant prior to inoculation.
Biotechnology Laboratory, Division of Horticulture, ICAR Res. Complex for NEH Region, Umiam, Meghalaya - 793 103, India.
DOI: https://doi.org/10.37855/jah.2000.v02i02.29
Key words: application rates, in vitro culture, in vitro regeneration, internodes, leaves, lemons, paclobutrazol, plant growth regulators, roots, shoots, survival, tissue culture
Abstract: In vitro-grown microshoots of Assam lemon (C. limon) and Sweet lime "sour mutant" (C. limettioides) were pulsed for one minute with paclobutrazol solutions at 5 levels (0, 1000, 2500, 5000, and 7500 ppm) under laminar flow followed by inoculation in Murashige and Skoog's (MS) Medium. Observations on shoot length, root length, number of leaves, length of internode, root diameter, shoot weight, root weight, and plant weight were recorded after five weeks of culture initiation. Increased concentration of paclobutrazol suppressed the root length and increased the root diameter of both species. However, there was no response on shoot growth. Paclobutrazol-treated plants showed better survival at the nursery stage than control.
National Research Centre for Arid Horticulture, Bikaner 334 006 (Rajasthan), India.
DOI: https://doi.org/10.37855/jah.2000.v02i02.30
Key words: air temperature, cultivars, flowering, phenology, relative humidity, varietal reactions
Abstract: The flowering of Z. mauritiana cultivars (Gola, Kaithali, Banarsi Kadaka, Umran, Mundia, and Seb) at six locations in India (Anantapur, Andhra Pradesh; Sardarkrushinagar, Gujarat; and Jobner, Jodhpur, Bikaner, and Hisar, Rajasthan) was studied. Irrespective of cultivar, flowering was completed by 5 September at Anantpur, while it continued up to 29 November at Hisar. In Rajasthan, flowering duration was, approximately, from 24 July to 10 November. The peak of flowering was observed between 17 June and 30 August in southern India and from 27 August to 22 October in northern India. Flowering was generally dependent on temperature and relative humidity, particularly on the variation between maximum and minimum temperature. A maximum temperature of 32.4-36.9 degrees C and a minimum temperature of 20.7-25.3 degrees C, along with a temperature difference of 8.6-13.3 degrees C and morning relative humidity of 70.6-82.5%, prevailing continuously for a minimum of 1 month induced profuse flowering in all cultivars acro
ARC, Institute for Tropical and Subtropical Crops, Private Bag X11208, Nelspruit, 1200, South Africa.
DOI: https://doi.org/10.37855/jah.2000.v02i01.01
Key words: crop quality, crop yield, fruits, grapefruits, light penetration, oranges, overcrowding, pruning, regrowth
Abstract: In this study different pruning methods were applied to higher density orange (cv. Navel), grapefruit (cv. Star Ruby) and orange (cv. Valencia) orchards (in South Africa, in 1996-99), which had become overcrowded five to six years after planting. A progressive decline in yield and fruit size was experienced with these orchards. Response to the different pruning actions, as well as yield variation and fruit size was assessed over three successive seasons. Corrective (severe) pruning and hedging resulted in a significant reduction in yield in the 1st year after pruning, but with an increase in fruit size. However, yield and fruit size improved substantially in the 2nd and 3rd year after the severe pruning. Light hedging as a maintenance pruning action was effective in restricting tree size without adversely affecting yield. Alternate bearing was substantially reduced by annual pruning. By creating a slanted, 20 degrees angle canopy with mechanical hedging and selective pruning, a greater portion of fruit is bor
Instituto Tecnologico de Tepic, Apdo. Postal 634, Tepic, Nay. 63000, Mexico.
DOI: https://doi.org/10.37855/jah.2000.v02i01.03
Key words: browning, chemical composition, colour, cutting, fruits, mangoes, pH, plant composition, plant pigments, ripening, storage, storage decay, titratable acidity
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Abstract: Kent mango slices at two different stages of ripening: 4 days (S1) and 6 days (S2) after harvest were kept under aseptic conditions at 13 and 23 degrees C to determine if normal ripening could proceed after slicing. Whole mangoes stored at 23 degrees C and 65% RH were used as control. Soluble solids of slices from all treatments did not show the same trend as whole fruits and remained unchanged at their initial values. Titratable acidity increased and pH decreased in all the slices and were in turn, different from the control fruit. Colour parameters indicated loss of yellow pigments and browning. Decay occurred between days 5 and 7 of storage in slices that were stored at 23 degrees C. Slices from S1 mangoes kept at 13 degrees C suffered minimal changes due to cutting; however, the slices did not show the same compositional changes as the naturally-ripened whole fruit.
Department of Food Production, Faculty of Agriculture and Natural Sciences, University of the West Indies, St. Augustine, Trinidad and Tobago.
DOI: https://doi.org/10.37855/jah.2000.v02i01.04
Key words: ascorbic acid, brix, carbon dioxide, crop quality, cultivars, ethylene, fruits, growth, hot water treatment, pawpaws, sensory evaluation, storage, storage decay, tastes, temperature
Abstract: The effects of hot water treatments and storage conditions on quality of fresh-cut papaya were investigated. A hot water treatment of 48-50 degrees C for 20 minutes was found to delay fungal storage rots in fruits of Tainung #2 and Red Lady cultivars without negatively affecting sensory quality. Fresh-cut slices from fruit of Tainung #2 and Red Lady cultivars were stored at 5 degrees C and 10 degrees C and evaluated for changes in physical, chemical and microbial quality over eight days. There was a decline in sensory quality and acceptability of Red Lady papaya slices after four days at both temperatures, while fresh-cut Tainung #2 fruit held at 5 degrees C and 10 degrees C was found to have high sensory quality and acceptability up to six days of storage. A storage temperature of 5 degrees C was more effective than 10 degrees C in reducing CO2 and ethylene accumulation, as well as suppressing microbial growth, while maintaining high sensory quality in fresh-cut papaya slices. Unacceptable microbial counts w
Division of Fruit Crops, Indian Institute of Horticultural Research, Hessaraghatta Lake Post, Bangalore 560 089, India.
DOI: https://doi.org/10.37855/jah.2000.v02i01.05
Key words: crop quality, cultivars, fruits, length, sapodillas, weight
Abstract: An attempt was made to evaluate sapota (Achras zapota [Manilkara zapota]) cultivars based on their fruit characteristics. Twenty-two cultivars, viz. Badam, Badami, Bombay, Calcutta Round, CO1, CO2, Cricket Ball, Dwarapudi, Guruvayya, Gavaraiah, Pilipatti, Gutti, Hybrid, Jhumakiya, Kirtibarti (big), Kirtibarti (long), Krishna Rao, Mohangooti, Oval, Pakala Oval, Seedless and Vavilvalasa, were studied under Bangalore (Karnataka, India) conditions. Fruit weight was maximum in Krishna Rao and least in Pilipatti. The length of the fruit was maximum in CO1. Fruit breadth was maximum in Cricket Ball. Total soluble solid was highest in Kirtibarti (big) and Pakala Oval. The average number of seeds per fruit was least in Guruvayya, Gavaraiah and Pakala Oval. The study indicates that considerable variability exists in the cultivars and there is good scope for breeding varieties for dwarfness or reduced vigour.
Central Soil and Water Conservation Research and Training Institute, Dehradun (UP) - 248 195, India.
DOI: https://doi.org/10.37855/jah.2000.v02i01.06
Key words: agroforestry systems, crop yield, income, juvenility, multipurpose trees, peaches, soil depth, survival, toria, trees, trickle irrigation, vigour
Abstract: The investigation revealed that peach orchard can be raised successfully even on degraded land by adopting site specific agrotechnique. The porous profile with only 60 cm top soil depth (T3) favoured better vegetative vigour of peach plants as compared to those sites having soil only throughout the profile (T4 and T5). The drip system of irrigation had good response on plant survival but overall plant vigour was not influenced much in juvenile peach plants compared to rain fed control under humid subtropical climate. Introduction of urd (Phaseolus vulgaris cv. T-9) in kharif and toria (Brassica campestris [B. campestris var. toria] cv. Pant-303) in rabi season was a compatible combination with peach plantation but growing of annual crops particularly rabi season crop was uneconomical on highly gravely sites (80% gravels distributed throughout profiles-T2). The yield of groundstorey crops were affected by rainfall distribution pattern during crop growing period coupled with canopy cover of the overstorey compo
Ethiopian Agricultural Research Organisation, P.O. Box 2003, Addis Ababa, Ethiopia.
DOI: https://doi.org/10.37855/jah.2000.v02i01.07
Key words: adventitious shoots, benzyladenine, callus, culture media, IAA, in vitro culture, in vitro regeneration, kinetin, micropropagation, plant growth regulators, shoot tip culture, tissue culture
Abstract: Callus cultures were initiated from the shoot tip explants of aseptically grown C. forskohlii. A rapid initiation and proliferation of callus was obtained in MS basal medium containing 1.0 mg IAA/l and 1.5 BAP [benzyladenine] mg/l. Adventitious shoots (17.33) were obtained from compact greenish callus on passage to MS basal medium containing various concentrations and combination of IAA and kinetin. But, the best response was in the medium containing 1.0 mg IAA/l and 2.0 mg kinetin/l. On further subculturing of individual shoots onto hormone-free MS medium, shoots developed into normal plantlets.
Department of Horticulture, Punjab Agricultural University, Ludhiana - 141 004, India.
DOI: https://doi.org/10.37855/jah.2000.v02i01.08
Key words: benzyladenine, callus, culture media, cytokinins, epicotyls, explants, hypocotyls, in vitro culture, in vitro regeneration, limes, micropropagation, plant growth regulators, shoot tip culture, tissue culture
Abstract: Callus was induced from different explants of in vitro raised seedlings of C. aurantifolia to study the response of explants and medium composition on frequency of callusing and to develop reliable protocol for high frequency of plant regeneration from callus cultures. Shoot tip, epicotyl and hypocotyl were found superior explants for callusing in terms of amount of callusing, days to callus and callus induction frequency. Addition of cytokinin was found indispensable for regeneration and MS medium enriched with BAP [benzyladenine] (5 mg/l) resulted in highest per cent of callus regeneration. Regenerants were rooted in vitro and hardened in plastic pots containing autoclaved soil.