ABSTRACT- Fruits and vegetables are mainly consumed for their nutritive value. India ranks high in the world in production of these commodities. But, a major part of the yield is lost due to a number of factors. Post harvest decay due to attack by a variety of pathogen is one of the main reason responsible for such losses. Most of the fruits and vegetable are prone to attack by post harvest pathogens. But, perishable fruits are at maximum risk due high moisture content present in them. Various control measures have been practiced against the fungal pathogens. Tradionally used methods like irradiation, use of chemical fungicides etc. have certain environmental and health hazards associated with them. Recent trends are shifting towards safe and consumer friendly strategies to control the post harvest decay of perishable fruits. Presently, trends are focusing on enhancement of the shelf life of perishables along with the minimization of the losses in quantitative as well as qualitative terms. In the recent past, a metamorphic change in the post harvest management scenario has been observed. Emerging trends are aimed at use of biological control measures to combat the post harvest losses.
Key-words- Post harvest decay, Perishables, Fungal pathogens, Biological control, Post harvest management, Emerging trends, Consumer friendly strategies

INTRODUCTION- Almost all crops are vulnerable to attack of some pathogen at all stages of life. However, the risk increases many fold after harvesting. Post harvest diseases result into reduction in both quality and quantity of the crop. Losses caused due to post harvest fungal pathogens are far more than realized [1-3]. A large number of pathogens attack various fruits and vegetables, but perishable fruits, due to their high moisture content are an easy prey to these pathogens.
A variety of strategies are evolved to enhance the shelf life of perishables by reducing chances of decay due to post harvest pathogens [4-9]. But, most of these have certain limitations associated with them. In today’s world, consumer’s concern over the presence of poisonous chemical residue, off taste or tissue softening resulting as after effects of some of control measures has prompted the search for some safe and consumer friendly strategies to deal with the issue.
Use of Biocontrol agents, microbial antagonists and natural fungicides are few of them to be named here. In the present paper, uses of biological control measures and natural fungicides to reduce the post harvest decay caused by various fungal pathogens have been reviewed [10-21]. This review describes key strategies underlying the development of Biocontrol of post harvest decay of fruits and possible approaches and prospects for future.

MATERIALS AND METHODS- A large number of post harvest pathogens cause decay of perishables. Some of these have been listed in Table 1. Use of various biological control measures, natural fungicides or some antagonistic compounds to control post harvest losses in a number of fruits were studied. Many of these were able to yield favorable responses as reported by a number of workers. Although, the exact mechanism is not clear but different types of interactions between the host and pathogen such as competition for site and nutrients, site exclusion or synthesis of some antagonistic compounds are thought to be responsible for the inhibitory role. Most of the studies involved use of biological control methods or use of natural fungicides to control post harvest decay caused by fungal pathogens.

Biological control: Growth of Rhizopus stolonifer has been reported to be checked by Enterobacter cloacae. Blue and green mold of citrus fruits was checked by Debaryomyces hansenii. Storage rot of ginger by Sclerotium rolfsii is reported to be controlled by Trichoderma species. Silver scurf of potato is controlled by different microorganisms like Pseudomonas putida, Nocardia globerula and Xanthomonas compestris. Blue mould of citrus fruit is reported to be checked by Pichia guilliermondii. Bacillus subtilis has been patented for the control of brown rot of stone fruits. Post harvest biocontrol of grey mould and blue mould of apple by Cryptococcus albidus has been reported. Pseudomonas syringae is reported to control post harvest decay of peaches. Biocontrol of grey mould , black mould and soft rots of grapes has also been reported Bacillus subtilis has been patented for biocontrol of brown rot of stone fruits caused by Monilia fructicola; Pichia guilliermondii strain US-7 and Hanseniaspora uvarum strain 138 have been used for biocontrol of citrus fruit rots. Growth of Helminthosporium solani causing silver scurf of potato is checked by Nocardia globerula, Pseudomonas putida, and Xanthomonas compestris. Biocontrol of post harvest diseases of peach by application of Pseudomonas syringae has been studied. Biocontrol of fruit rots of grapes caused by various fungal pathogens has also been studied.

Natural fungicides: Fungicidal properties have been shown by a number of compounds produced naturally by certain fungi. Fungicidal role of Trichoderma spp. is reported against Botrytis cinerea, and Sclerotinia sclerotium. Chitosan, a compound naturally present in cell wall of certain fungi, posseses antifungal action against a number of fungal pathogens such as Alternaria alternata, Botrytis cinerea, and Rhizopus stolonifer etc.

RESULTS- Post harvest losses may occur at any point in the marketing process, from initial harvest through assembly and distribution to consumer. Perishables are at risk at any of these stages. A variety of fungal pathogens caused post harvest decay of various fruits showed in Table 1.

Table 1: List showing some common fungal pathogens responsible for post harvest fungal decay of various fruits

Name of fungal pathogen	Type of Rot/decay
Alternaria alternata	Fruit rot
Botrytis cinerea	Grey mold rot
Colletotrichum gloeosporoides	Anthrachnose
Geotrichum candidum	Sour rot
Penicillium spp.	Blue and green mold rot
Rhizopus stolonifer	Soft rot
Sclerotinia sclerotium	Cottony rot

Enormous losses are caused due to these types of decay. These losses are however, minimized to some extent by using various natural fungicides or by biological control measures. Various types of biological agents or bio active compounds employed to reduce post harvest losses caused by fungal pathogen have been given in Table 2.

Table 2: Showing various natural fungicides/Biological agents exhibiting antagonistic role against different fungal pathogens

Antagonistic compound /Microorganisms	Affected Fungal pathogen
Chitosan	Alternaria alternata, Botrytis cinerea, Rhizopus stolonifer
Enterobacter cloacae	Rhizopus stolonifer
Debaryomyces hansenii	Geotrichum citri- aurantii, Penicillium italicum
Trichoderma spp.	Sclerotium rolfsii
Psudomonas putida, Nocardia globerula, Xanthomonas compestris	Helminthosporium solani
Pichia guilliermondii	Rhizopus stolonifer, Penicillium italicum
Bacillus subtilis	Monilia fructicola
Cryptococcus albidus	Botrytis cinerea, Penicillium expansum

DISCUSSION- India ranks high in the production of fruits and vegetables. However, there is a considerable gap between the gross production and net availability of these commodities. A large number of factors are responsible for it. Some of these are unavoidable, while others can be avoidable to more or less extent. Post harvest losses, especially due to decay caused by fungal pathogens can be reduced to some extent by employing some suitable control measures. Post harvest management is necessary to be maintain the quality as well as quantity of fruits and vegetables. For this purpose, various post harvest practices aim at keeping the produce free from contaminants and improve its market value. It is felt that a large number of fruits suffer from post harvest decay, thereby lowering both their quality as well as quantity [22-25]. Commonly practicized control measures such as irradiation, chemical fungicides etc. pose certain kind of threat to the consumer as well as environment. So, trends are seen shifting towards some safer control measures like biological control. A number of studies have shown their positive outcomes. These types of control measures are also important for enhancement of shelf life of the commodities, especially perishables. Biological control has emerged as an effective and alternative approach to minimize the post harvest losses. However, limitations of these products should be addressed by improving their efficacy. It is also felt that integration of biocontrol with other alternative methods that alone do not provide sufficient protection against post harvest, show synergistic effect.

CONCLUSION- Most of the fungal pathogens attack various fruits and vegetables. However, perishables are under maximum threat from these pathogens. Various studies indicate that use of biological control methods is effective against most of the post harvest pathogens. Currently, trends are shifting towards this direction. These have almost little or no adverse effects as these are biodegradable. However, potential toxicity of these compounds needs to be evaluated properly. There is a huge potential to explore more of microbes with anti fungal properties. Emerging trends are focussing on enhanced spectrum of activity of biological agents to minimize post harvest losses and their future prospects.

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How to cite this article: Geetanjli: Emerging Trends to Minimize the Post Harvest Decay of Perishable Fruits. Int. J. Life. Sci. Scienti. Res., 2017; 3(2): 936-939. DOI:10.21276/ijlssr.2017.3.2.11 Source of Financial Support: Nil, Conflict of interest: Nil