Journal of Horticulture and Postharvest Research
Volume:4 Issue: 1, Mar 2021

The experiment was conducted to investigate into the allelopathic potential of the aqueous extracts of different parts of Jatropha curcuson seven selected field crop species. 

Research method:

The leaf, stem, bark, twig, root, pericarp, seed and oilcake extracts of J. curcus at four different concentrations (1:5, 1:10, 1:15 and 1:20 (w/v)) were tested against jute, mungbean, mustard, radish, rice, wheat and tomato. Control i.e. distilled water without extracts was also maintained in each case. The experiments were conducted following completely randomized design with three replications.

Except few, the aqueous extracts of J. curcas plant parts significantly inhibited the seedling growth of all the test species at concentration more than 1:15 (w/v) whereas, at or below this level stimulated the seedling growth. Percent shoot and root growth inhibition of the test crops varied among J. curcus parts extract from 10 to 100, at 1:5 (w/v) concentration. At the same concentration, J. curcas oilcake extract completely (100%) inhibited the shoot and root growth of all the test crop species except rice. Similarly, seed extract completely inhibited (100%) the shoot and root growth of jute and mustard, whereas around or more than 70% inhibition of the shoot and root growth of all the test species except rice. These results confirm that J. curcushas allelopathic properties and may possess allelochemicals. Since oilcake of J. curcus extract had greater inhibitory activity than other parts, this could be used for isolation and identification of allelochemical(s). The results of this experiment will be helpful for the researchers to know the plant-plant interaction of J. curcus with its neighboring plant species or the intercrops introduce in Jatropha field. Limitations: There was no significant limitation to the report.

This research compares the allelopathic properties of different parts of Jatropha curcus on seven selected field crop species.

In Oasis areas, salinity becomes a real threat for sustainable agricultural production, and with the introduction of non-native varieties, salinity pressure is more expressed and has harmful outcomes to the local ecosystem and biodiversity. In this context the present study was conducted to compare salt stress behavior of local oasian and introduced cultivars.

 Research method:

Seeds of two local oasian cultivars namely Djerid (Dj) and Nefta (Ne) and one exotic cultivar namely Cayenne (Ca) were treated with four salt concentrations (0; 2.5; 5 and 7g/l NaCl). Salt stress responses were evaluated using germination parameters and early seedling growth.

Results revealed that the increase of salinity level had negatively effect on germination and early seedling for the three cultivars. However oasian cultivars were found to be the most tolerant to salinity. Ne cultivar showed the highest germination percentage and germination index and the lowest mean germination time at 7g/l NaCl concentration. Also, “Ne” performs better on seedling traits as indicated by the less effect of the high salinity on radicle and plumule length as well as plumule fresh weight, compared to the other cultivars. The introduced cultivar “Ca” was identified to be the most sensitive to salt stress. Limitations: No limitations were founded. 

Originality/Value:

 This study valorized the autochthone chili pepper cultivars by highlighting their salt stress tolerance. Thus, oasian genotypes could be very useful as genetic resources for the development of chili pepper cultivars with improved germination and seedling growth under salt-stress conditions.

A significant number of genetic resources of Camellia sinensis and its allied genotypes have been collected and preserved in Iran TRC. Information about them is mostly based on morphological data.

PCR-RFLP technique and morphological characters were used for the identification of organelle DNA (cpDNA) diversity in 25 tea genotypes. Twenty-one qualitative and quantitative characteristics were evaluated.

A pair-wise similarity among the samples ranged from 0.14 to 0.66 based on morphological data. The dendrogram was designed, and samples were grouped into three main clusters at 0.38 similarity. Using three universal primer pairs which introduced for chloroplast amplified about 4070bp of cpDNA, following the digestion of fragments with three restriction endonucleases (HinfI, AluI and PstI) and the result of this method was introduced six haplotypes. The most significant and widespread haplotype was H2 (frequency ≈ 28%). All of the detected mutations were insertion-deletions and they ranged from 30 to 60 bp. The calculated total cpDNA diversity in populations (hT), a major portion of it was within populations were (hS) and genetic differentiation among populations (GST) were 0.43, 0.17 and 0.61, respectively. It should have been noted that the calculated GST was low and no structure could be identified. Limitations: Applying allied species and using more potent markers such as cpSSR and sequencing can lead to more accurate results. 

Originality/Value:

 the results of this study indicate that the PCR-RFLP method and morphological characters are applicable in the identification of tea genotypes and cultivars. In studying Camellia genus phylogeny, the polymorphism in cpDNA has to be considered carefully.

In Bangladesh,mango fruit supply is limited in the local market as well as for export due to its short self-life and susceptibility to post-harvest diseases. This study aimed to evaluate the effects of CaCl2 in hot water on organoleptic and biochemical characteristics of mango fruits for extension of shelf-life. 

Research Method:

Mangoes were treated with different concentrations (0.0, 0.5, 1, 2, 3, 4 & 5 %) of CaCl2 in hot water (50°C) for 10 min and kept at 25±2°C over 12 days. Each treatment included 20 mangoes with three replications. The physiological changes were observed and biochemical characteristics of mango fruits were analyzed.

Better skin color and aroma were observed at 0.5~4.0% CaCl2 and no fungal infection was found at 3~5% CaCl2 as compared with untreated control whereas taste and texture of mangoes increased significantly with the increasing concentration of CaCl2. The shelf life of treated mangoes increased 2~3 days with increasing concentration of 4~5% CaCl2 but slight skin shriveling and weight loss were observed. Higher concentration of CaCl2 treated fruits maintained higher values of moisture, ash, titratable acidity, vitamin-C, reducing sugar, starch, invertase activity whereas total soluble solid, total sugar, non-reducing sugar, total phenol, amylase, polyphenoloxidase activity decreased significantly. Limitations: In future, mechanism of CaCl2 in hot water for extending shelf life of mangoes will be elucidated using molecular approach.  

Originality/Value:

The treatment of 4% CaCl2 in hot water could be used to extend the shelf life of mangoes up to 2~3 days with consumer acceptance.

Maize output is decreasing in developing countries due to poor postharvest management despite the huge investments. The study is aimed at identifying and quantifying sources and causes of postharvest losses from farm to retail and suggest appropriate interventions for reducing these losses. 

Research Method:

Commodity system assessment on postharvest handling, storage and marketing of maize was conducted between July and August, 2017 in Nigeria, Rwanda and Punjab (India) using surveys, interviews, observations, measurements and quantification of losses along the value chain. Postharvest quality and economic loss assessments along the chain were based on physical damage, decay and weight loss.

Causes of postharvest losses at farm level are similar in all the countries studied, with sorting losses from 2 to 50% and drying losses from 10 to 40%. Damage and defects were extremely high in Rwanda at the farm level. Maize is stored for 5 to 10 months with 2 to 3.5% damage in Nigeria and 6% in Rwanda. Maize is stacked in sacks during wholesale and cleaning rejects obtained is 2 to 11% in Nigeria and India, little or no sorting in Rwanda at wholesale. Postharvest losses are 15%, 60% and 20% of total produce for Nigeria, Rwanda and Punjab, which account for economic losses of $720 million, $131.2 million and $8.2 million respectively. Limitations: The research is limited to major production areas in the three countries because of funding. 

Originality/Value:

 The study identified problems, sources and causes of post-harvest losses and suggests appropriate interventions, training needs and advocacy issues to reduce these losses.

Comparison and determination of ZEN production capacity of F. oxysporum, F. graminearum, and F. solani. The influence of low temperature stress and incubation time on the production of ZEN was also investigated. 

Research Method:

Production of ZEN was evaluated by incubating media cultures at a constant temperature of 25°C for a period of 14 days before being incubated at 8°C for 14 days (Low-temperature stress/ LTS). The second set of the samples was incubated at constant 25°C for 4 weeks’ time (constant- temperature/ CT). HPLC and a fluorescence detector were employed to measure the concentration of ZEN. The species-specific pair of primers was used to perform a PCR assay on the fungal DNA.

The higher levels of ZEN were seen at LTS compared with CT in three Fusarium species. The highest ZEN was produced in F. oxysporum media cultures. The significant production of ZEN was seen when F. oxysporum incubated at LTS compared with CT (P≤0.05). The highest and the lowest levels of ZEN were seen in F. oxysporum and F. solani and the difference of ZEN production by them were significant in CT and LTS, respectively (P≤0.05). ZEN production for the F. graminearum was in the intermediate level. Presence of PKS4 gene was confirmed by PCR in these Fusarium species. Limitations: Higher cost of ZEN detection by HPLC was a limitation. 

Originality/Value: 

Production of ZEN in LTS and CT by the Fusarium evaluated species was confirmed. However, LTS stimulate ZEN production in Fusarium media cultures, especially for F. oxysporum.

International agencies have advocated that monitoring food security and world food resources are necessary to meet the needs of growing populations and to minimize postharvest losses. This paper focuses on the biochemical and physiological bases of changes that causes post-harvest losses and ways to mitigate them. By controlling these metabolic changes, some degree of preservation is possible.

Postharvest losses are 30-50% in developing countries due to energy crisis and lack of proper handling procedures and refrigeration; in contrast to less than 15% in developed countries. Highly perishable commodities like fruits and vegetables are living entities which are characterized by life evolving activities like respiration, transpiration, ripening and metabolic changes. Various compositional changes, such as chlorophyll degradation, softening, and ascorbic acid losses can result in short shelf life. Total 63 species of vegetables are grown in Pakistan but onions, potatoes, tomatoes, garlic, green chilies, coriander, spinach, pumpkin and okra are mostly grown and consumed.

 Limitations:

 In Pakistan due to energy crisis and economic constraints no cold food chains/transport is available as a result of which fresh produce endured post-harvest losses.  There is a need to use production technologies supplemented with postharvest techniques to mitigate postharvest losses.

Directions for Future Research:

 Many new technologically viable preservation techniques like modified atmosphere packaging and controlled atmosphere storage should come into existence due to increased health consciousness, increased purchasing power and an increase in percentage of postharvest losses (25-80% fresh produce) which could be applied with such economic constraints.

Fruit ages (early, mid, and late harvest stages) of Haden, Kent, Palmer, and Keitt mango varieties were determined through age-control and established for physiological (early harvest) and eat-ripeness stages (mid and late harvests). This was followed by determining physicochemical properties at these stages that could be used as simple harvest indicators for export and local markets. 

Research Method:

Randomized Complete Block Design and Completely Randomized Design with four replications in each case were used. For each of the four varieties, five mango trees were sampled at random in each of the four replications of a mango plantation when fruits were physiologically matured.

Physiological and ripe maturity index values were 8.94, 6.88, 7.25, and 6.56 oBrix respectively, for soluble solids; 24.9, 8.5, 35.5, and 23.8 mg.100g-1 respectively, for ascorbic acid; 3.25, 3.50, 3.33, and 3.49 respectively, for pH; and 18.5, 17.5, 19.5, and 17.0 oBrix respectively, for total soluble solids; 8.05, 3.32, 5.52, and 3.66 mg.100g-1 respectively, for ascorbic acid; 5.11, 4.08, 5.00, and 5.80 respectively, for pH; respectively. Pulp colour (turning yellow) was nearly the same for the different varieties at physiological maturity but varied when ripe, with uniform consistent texture at both stages.Limitations: No limitations to report. 

Originality/Value:

 Fruit should be harvested after full maturity in order to develop the most adequate organoleptic quality and the longest post-harvest life, and before full ripeness but should never be over-ripe or immature for any purpose unless otherwise.

Recently, there are researches showed positive effects of nano-chitosan in prolonging the postharvest quality and shelf life of strawberry, however, influences of storage temperatures on the nano-chitosan coated fruit have been overlooked. Therefore, in this work, changes of physiological traits of strawberry (Fragaria × ananassa Duch.) coated with 0.2% nano-chitosan and stored at different temperatures were studied. 

Research Method:

Strawberry was coated with 0.2% nano-chitosan and stored at different temperatures (2°C, 5°C, 10°C and 25°C) for 12 days. The effects of temperatures on the coated fruits were tested by measuring visual quality, weight loss, antioxidant properties, malondialdehyde content, firmness, total soluble solid, polyphenol oxidase activity in three days intervals.

After storing 0.2% nano-chitosan coated strawberry at four different temperatures, 2°C showed the most effective one as maintaining the overall quality of strawberry higher than the acceptable/marketable level after 12 days; meanwhile, fruits stored at 25°C were quickly decayed after 3 days. The treatments at low temperatures (2°C, and 5°C) significantly reduced weight loss, maintained firmness, total soluble solid, polyphenol oxidase activity and malondialdehyde content of the stored fruits. Limitations: Nano-chitosan has not been widely traded. 

Originality/Value:

 Coating strawberry with nano-chitosan and storing at 2°C effectively maintained the postharvest quality of strawberry as well. This treatment is quite simple and would be useful for stakeholders in the strawberry supply chain.

The use of natural and organic products increases to produce a healthy product free of pollutants. Tea seeds contain 15-20% oil, which used as edible oil and an organic pesticide. In previous years, these seeds were used to produce tea seedlings. But now, cuttings are used for tea propagation and seeds are a byproduct of tea production. Therefore, this study aims to compare the effect of TSO with commercial wax on post-harvest quality of Citrus sinensis cv. Moro. 

Research method:

An experiment was done as Completely Randomized Design; fruits were coated with control (distilled water), commercial wax (XEDASOL- MX20), and tea seed oil. The fruits were stored for 60 days in cold storage. The weight of the fruit skin, the contents of juice, total soluble solids, titratable acidity, and anthocyanins of the fruit were measured.

The results showed that fruits coated with commercial wax and tea seed oil have the lowest fruit weight loss, the highest percentage of TSS (10.42%), the most top content of anthocyanins (15.17 mg/l) and flavonoids (196.17 mg/l) that there was a significant difference with control. The lowest titratable acidity (2.28%) was observed in fruits impregnated with tea seed oil, and there was a considerable difference with control. In general, the effect of tea seed oil was similar to commercial wax. Limitations: No limitations were founded. 

Originality/Value:

 These results indicate that the application of tea seed oil proved to be effective in extending the quality and storage time of Citrus sinensis (cv. Moro).