Date thenar ( Phoenix dactylifera L. ) is known as “ tree of life ” plays an imperative function in the life of the people populating in adust parts of the universe. It is an antediluvian and valuable fruit, as the day of the month ‘s name has been and is mentioned in holy books like the Quran, Torah and Buddha ( Belarbi et al. , 2000 ; Falade and Abbo, 2007 ) . Prophet Muhammad ( PBUH ) is reported to hold said that the best assets is the day of the month thenar, that it is used for bring arounding many upsets, and He ( PBUH ) urged Muslims to devour day of the months ( Zaid and de Wet, 1999 ) . Muslims deem it as a virtuousness to eat day of the months at ‘Iftar ‘ in the month of ‘Ramadan ‘ . It has been cultivated in the Middle East since at least 6000 BC ( Al-Qarawi et al. , 2003 ) . At least 2000 or more different cultivars of day of the month thenars exist all over the universe ( Ali-Mohamed and Khamis, 2004 ) . The Date fruit provides a good beginning of saccharides, fiber, minerals, and vitamins, but it contains a minute sum of fat and protein ( Baloch et al. , 2006 ; Al-Farsi et al. , 2005 ; Mohamed, 2000 ) . Date fruit is besides suited for hypertensive individuals because of its high sum of K and low content of Na ( Al-Hooti et al. , 2002 ) . New surveies have reported that day of the month fruit has antimutagenic and antineoplastic action ( Ishurd and Kennedy, 2005 ; Vayalill, 2002 ) .
The maturation of the day of the month fruit is considered by four different stages/phases based on colour, softness, wet, and sugar content. ( 1 ) Kimri phase: at this stage the fruit is rather difficult, the colour is green and it is non fit for comestible intent. At this stage the fruit attains a rapid addition in weight, volume and construct up of cut downing sugars that will weaken at the terminal of this phase. ( 2 ) Khalal phase: at this phase, day of the month fruit additions its maximal weight and size. The day of the month ‘s entire sugar and sourness will hike as its H2O content decreases. At the terminal of Khalal phase, the fruit is physiologically mature and difficult. ( 3 ) Rutab phase: maturation of day of the month fruit starts at this phase. Its coloring material alterations and its texture become soft. It begins to lose astringence and starts geting a darker and less attractive coloring material than the old phase. ( 4 ) Tamar phase: the day of the month fruits are to the full mature at Tamar phase and texture of the flesh is soft. At this phase, day of the month fruit contains its maximal entire solids and it is in the best status for storage. Some mentions have mentioned another a really early phase named called “ Hababauk ” . This term is used for the female flower and besides used for the period after pollenation, in which the immature fruit is still creamy before bit by bit turning green at the Kimri phase. Generally, day of the month fruit is harvestable and marketable at three phases including Khalal, Rutab and Tamar that depend on cultivar features, particularly soluble tannic acids degrees ( Ismail et al. , 2001 ; Hong et al. , 2006 ; Awad, 2007 ) .
Although there are many cultivars of day of the months, some have become pre eminent in the universe market ( Krueger, 2001 ; Nixon, 1950 ) . ‘Deglet Noor ‘ , intending “ day of the month of the visible radiation ” in Arabic, comes from the Algerian Sahara and is one of the taking cultivars grown in North Africa and California. ‘Halawy ‘ , intending Sweet in Arabic, is a soft, high-quality day of the month with rich spirit from Iraq. ‘Khadrawy ‘ , intending green in Arabic, is a short and reasonably productive tree with soft fruit from Southern Iraq.
Climate is one of the major factors that affect all facets of life and realistic harvests cultivation depends on proper apprehension of climatic status. Proper apprehension of climatic status can assist husbandmans in making cultivation at an opportune clip and provision works ‘s demands during growing period. The maturing season of day of the month thenar starts with the rise in summer temperature with July and August, which is the peak production period. Unfortunately, the monsoon rains besides falls within these months of the twelvemonth, which is a existent constriction for this harvest. Hillawi and Khadrawi are the major assortments cultivated in Punjab. These assortments are semi dry and ripened early in July and face a immense job of monsoon rains. The happenstance of day of the month maturing period with the monsoon season means the harvest receives heavy harm by rain and a few proceedingss of rain can destruct upto 80 % of the day of the month harvest ( ASF, 2010 ) The fruit during this period is at edible ( Khalal/Rutab ) phase and prone to infestation by insects/birds and diseases that invade at a rapid rate under the favorable clime of comparatively decreased temperature with high humidness. This inauspicious state of affairs persists for several hebdomads. The extent of the losingss contributes to roll up so long as the fruits stay on the trees for privation of Dong formation until the terminal of July ( Saleem et al. , 2005 ) . Rain and high humidness may do physical harm to the fruit in period predating the maturation. When this happens, clefts appear on the fruit surface through Fungis and bacteriums may come in doing agitation and souring of the fruit quickly ( Olin, 2002 ) . It is deserving adverting that the sum of any peculiar rain is of less importance than the conditions under which it occurs ( Nixon and Carpenter, 1978 ) .
Traditional methods of day of the month fruit ripening/curing are popular in many countries of the state, in which fruit at the Dong phase are spread on the mats or fictile sheets and exposed to sun in an unfastened air. The quality of Sun dried merchandise under dust-covered status becomes really hapless and non-uniform with a low output. Due to relentless rain and stormy conditions a big sum of the harvested day of the months become moldy, fermented, and dusty, damaged by the birds and insects.
The present survey will be hence conducted on the maturation facets and fruit quality of day of the month thenar with regard to monsoon rains, by measuring the potency of preharvest ethephon application on maturing sweetening and fruit quality of day of the month thenar at Kimri and Khalal phases, analyzing the function of different chemicals on the maturing behavior and fruit quality and maturation and quality appraisal of day of the month fruit will besides investigated by the influence of hot H2O intervention by reaping the fruit at the physiological adulthood ( Doka/Khalal ) phase.
V ) REVIEW OF LITERATURE:
Fruits should be harvested at the right physiological adulthood and province of ripeness ( Harman and Patterson, 1984 ) . They are self sufficient with their ain catalytic machinery to keep an independent life, even when detached from the parent works. Based on their respiratory form and ethylene biogenesis during maturation, harvested fruits have been classified as climacteric and non-climacteric based on the respiration form and ethylene production during maturing. Climacteric fruits, harvested at physiological adulthood, can be ripened off the parent works. The respiration rate and ethene formation though minimum at adulthood, raise dramatically to a climacteric extremum, at the oncoming of maturation, after which it declines ( Gamage and Rehman, 1999 ) . In climacteric fruit, oncoming of maturation is accompanied by a crisp addition in respiration and ethylene production. The climacteric ethene is thought to modulate fruit maturation by bring oning the look of many ripening-related cistrons responsible for autocatalytic ethene production, cellwall metamorphosis, chlorophyll debasement, synthesis of carotenoids and volatiles, and transition of amylum to saccharify ( Gray et al. , 1992 ; Theologis, 1993 ; Alexander and Grierson, 2002 ) . Non-climacteric fruits are non capable of go oning their maturation procedure, one time they are detached from the parent works. Besides, these fruits produce a really little measure of endogenous ethene, and do non react to external ethene intervention. Such fruits show relatively low profile and a gradual diminution in their respiration form and ethene production, throughout the maturation procedure ( Gamage and Rehman, 1999 ) . In non-climacteric fruit, there is no dramatic alteration in the rate of respiration, and ethylene production remains at a really low degree. However, in some works species, some facets of maturing, such as chlorophyll debasement and fruit softening, are controlled or at least partly controlled by ethene ( Goldschmidt et al. , 1993 ; Wills and Kim, 1995 ) . Ethylene is biosynthesized from methionine via a welldefined tract in which 1-aminocyclopropane-1-carboxylate ( ACC ) synthase ( ACS ) and ACC oxidase ( ACO ) map as cardinal enzymes.
Ripening is defined as alterations that “ occur from the latter phases of growing and development through the early phases of aging and consequence in characteristic aesthetic and/or nutrient quality ” ( Watada et al. , 1984 ) . It is a extremely coordinated, genetically programmed, and an irreversible phenomenon affecting a series of physiological, biochemical, and organoleptic alterations that lead to the development of a soft and comestible ripe fruit with desirable quality properties. A broad spectrum of biochemical alterations such as increased respiration, chlorophyll debasement, biogenesis of carotenoids, anthocyanins, indispensable oils, and spirit and olfactory property constituents, increased activity of cell wall-degrading enzymes, and a transeunt addition in ethylene production are some of the major alterations involved during fruit maturation ( Brady, 1987 ) .
The colour alteration during fruit maturation is due to the expose of antecedently present pigments by debasement of chlorophyll and dismantlement of the photosynthetic setup and synthesis of different types of anthocyanins and their accretion in vacuoles, and accretion of carotenoids such as I?-carotene, xanthophyll esters, luteins, and lycopene ( Tucker and Grierson, 1987 ; Lizada, 1993 ) . The addition in spirit and olfactory property during fruit maturation is attributed to the production of a complex mixture of volatile compounds such as ocimene and myrcene ( Lizada, 1993 ) , and debasement of acrimonious rules, flavanoids, tannic acids, and related compounds ( Tucker and Grierson, 1987 ) .
The gustatory sensation development is due to a general addition in sugariness, which is the consequence of increased gluconeogenesis, hydrolysis of polyoses, particularly starch, reduced acid-ity, and accretion of sugars and organic acids ensuing in an first-class sugar/acid blend ( Lizada, 1993 ; Grierson, Tucker, and Robertson, 1981 ; Selvaraj, Kumar, and Pal, 1989 ) . The metabolic alterations during fruit maturing include addition in biogenesis and development of the maturing endocrine, ethene ( Yang and Hoffman, 1984 ) , addition in respiration mediated by mitochondrial enzymes, particularly oxidases and de novo synthesis of enzymes catalysing maturing specific alterations ( Tucker and Grierson, 1987 ) . Change of cell construction involves alterations in cell wall thickness, permeableness of plasma membrane, hydration of cell wall, lessening in the structural unity, and increase in intracellular infinites ( Redgwell, MacRae, Hallet, Fischer, Perry, and Harker, 1997 ) . Fruit softening is associated with cell wall disassembly ( Seymour and Gross, 1996 ) and alterations to the pectin fraction are some of the most evident alterations that take topographic point in the cell wall during maturing ( Marin-Rodriguez, Orchard, and Seymour, 2002 ) . The general observation is that softening is accompanied by solubilization of pectin, affecting the action of enzymes pectinesterase ( PE ) , polygalacturonase ( PG ) and pectate lyases ( PL ) ( White, 2002 ) and hydrolysis of amylum and other storage polyoses ( Selvaraj et al. , 1989 ; Fuchs, Pesis and Zauberman, 1980 ) . This impression was supported by studies of alterations in cell wall pectic stuff in maturing Mangifera indica ( Roe and Bruemmer, 1981 ) , tomato ( Besford and Hobson, 1972 ) and pear ( Ahmed and Labavitch, 1980 ) .
Fruit maturation and ethene:
The gaseous endocrine ethene regulates a figure of works growing and developmental procedures, including fruit maturation. Ethylene plays a major function in fruit maturation in a broad scope of works species ( Abeles et al. , 1992 ; Lelievre et al. , 1997 ; Giovannoni, 2004 ) . It is a fruit maturing plant hormone, in infinitesimal sums can trip many events of cell metamorphosis including induction of maturing and aging, peculiarly in a climacteric fruit. A figure of reappraisals have been published on the function of ethene in fruit maturation, peculiarly in Mangifera indicas every bit good as its biosynthesis ( Adams and Yang, 1979 ; Kende, 1993 ) . The tract for ethylene biogenesis has been elucidated in apple, and other fruits such as alligator pear, banana, and tomato ( Kende, 1993 ; Yang and Hoffman, 1984 ) . The first measure is the transition of S-adenosylmethionine ( SAM ) to 1- aminocyclopropane carboxylic acid ( ACC ) by the enzyme ACC synthase. At the oncoming of fruit maturation, look of multiple ACC synthase cistrons are activated, ensuing in increased production of ACC. In most instances, it is the ACC synthase activity, which determines the rate of ethylene biogenesis. ACC is so oxidized to ethylene by ACC oxidase.
Potential of ethephon in fruit maturation:
Fruit maturation has been described as an oxidative phenomenon that requires a turnover of active O species, such as H2O2 and superoxide anion ( Jimenez et al, 2002 ) . Ethephon ( 2-chloroethylphosphonic acid ) , releases ethene in works tissues, has aroused involvement because of its physiological effects in many fruit species ( Cooke and Randall, 1968 ; Warner and Leopold, 1967 ) . The responses to ethephon look to be chiefly caused by the action of ethene ( Anderson, 1968 ) . Now ethephon is widely used in agribusiness for publicity of blossoming, fruit maturation, defoliation and so on. Orange, Citrus paradisi, tangerine and green lemon fruits dipped in ethephon solutions for a few seconds to several proceedingss developed satisfactory marketable colour in seven to ten yearss after intervention. ( Fuch and Cohen, 1969 ; Yong et al. , 1970 ) . In Punica granatums, nevertheless pre-harvest application of ethephon decreased the soluble solids, pH and vitamin C content of the fruit juice ( Shaybany and Sharifi, 1973 ) .
Rouhani and Bassiri ( 1977 ) reported that when day of the month fruits were treated with 0, 125, 250, 500, 1000 or 2000 ppm ethephon and stored in certain bags or bags with 10 holes. The per centum dry weights of mush and seed, titratable sourness, soluble solids and respiration rates increased, whereas pH, soundness and astringence decreased with greater adulthood. The application of ethephon increased respiration and titratable sourness significantly. Although ethephon concentration and bag type affected maturation, their effects were comparatively little ; endogenous factors commanding maturing were more of import. Ethephon application at 1500 ppm shortly after full bloom on ‘Zaghloul ‘ and ‘Samani ‘ day of the month thenars grown in Egypt advanced fruit maturation by about one month ( Kamal, 1995 ) . Musa ( 2001 ) reported that effectivity of ethrel in heightening the fruit maturation of ‘Mishrigi Wad Khatib ‘ and ‘Mishrigi Wad Lagi ‘ day of the months grown in Khartoum, Sudan, was 2-3 crease higher by shooting 2ml of ethrel ( 480 g/l a.v. ) into a cavity made in the peduncle compared with 1000 ppm of ethrel crop-dusting over the fruit.
Preharvest ethrel application significantly increased the Rutab fruit output per clump ( 7 kilogram ) as compared to the control ( 4.5 kilogram ) and postharvest dipping of fruit at khalal phase in ethrel at 4.2ml/l and abscisic acid at 1.0 millimeters significantly enhanced the maturation, compared to the control ( Awad, 2007 ) . Ethephon accelerates maturing and improves the Peel colour of the Mangifera indicas ( Lakshminarayana et al. , 1975 ) . Mixture of ethephon, Na hydro oxide and H2O, kept in the locality of Mangifera indica fruit, facilitate the maturation in natural manner ( Sudhakar, 2006 ) . Nair and Singh ( 2003 ) reported that fruit quality in footings of TSS, TSS/acid ratio, sugars and eating quality of Mangifera indica curriculum vitae. Bocado was found to better with ethrel at 2000 ppm. Increase in salt concentration increasingly increased the Dong/Rutab formation of khadrawi and shamran day of the month cultivars, and add-on of acetic acid enhanced the consequence, but acetic acid entirely was uneffective ( Kalra et al. , 1977 ) .
Ethephon intervention stimulated the decrease of titratable sourness, anthocyanin accretion and fruit softening four yearss after intervention in rabbit-eye blueberry blueberry. The maturing publicity consequence of ethephon on entire soluble solids content was observed merely eight yearss after intervention. Ethephon intervention did non impact the fruit expansion during the probe period. They concluded that ethephon application for rabbit-eye blueberry blueberry promote the fruit maturation, but the stimulatory effects of ethephon on fruit maturation were different in grade on each maturing characters ( Ban et al. , 2007 ) . The stimulatory consequence of ethephon on blueberry fruit maturation has been reported by some research workers ( Eck, 1970 ; Forsyth et al. , 1977 ; Lewis and Ju, 1993 ; Warren et al. , 1973 ) . The skin colour enhancement consequence of ethephon has been noted for apple and cranberry ( Eck, 1972 ; Murphey and Dilley, 1988 ) . In ‘Jonagold ‘ apple, ethephon application stimulated the anthocyanin accretion in the tegument, but did non impact the entire soluble solids content, sourness and fruit soundness ( Awad and Jager, 2002 ) . From these consequences, it is concluded that ethephon application for fruit promotes maturing, but the stimulatory consequence of ethephon on fruit maturing differs in grade for each fruit maturing character. Ethylene released by the dislocation of EthrelA® is the cause of softening of fruit and hastens the oncoming of maturation of several fruits, including Mangifera indica, as reported by research workers ( Rupinder, Poorinima, Pathak, Singh and Dwivedi, 2007 ) .
Role of hot H2O, Na chloride and acetic acid in fruit maturation:
Recently, broad international involvement in heat intervention for quality care and disease control has reflected in a scope of literatures. With exposure of fresh agricultural trade goods to high temperature, heat daze proteins transcripts and protein degrees in such trade goods have been shown to increase ( Lurie, 1998 ) . Further more, a broad scope of fruit maturation procedures are affected by heat, such as colour ( Cheng et al, 1988 ; Tian et al. , 1996 ) , ethylene synthesis ( Ketsa et al. , 1999 ) , respiration ( Inaba and Chachin, 1988 ) , fruit softening and cell wall metamorphosis ( Lurie and Nussinovich, 1996 ) , volatile production. Postharvest heat intervention besides can cut down chilling hurt in many sorts of fruits during subsequent low temperature storage every bit good as cut down pathogen degree and disease development. Agricultural trade goods are big and respond otherwise by applied heat intervention. Inappropriate heat intervention can besides take to maturing acceleration or heat harm ( McDonald et al. , 1999 ; Lurie, 1997 ) .
The influence of hot H2O intervention on the ripening/curing of Dhakki day of the months with 70 oC performed better than 35 and 93 oC supplying with 55 % merchandise output of acceptable quality. The output of improved quality merchandise is further increased to 70 % on the optimisation of intervention clip to 3 proceedingss. They concluded that Dhakki dates does non necessitate to remain on tree beyond to the full mature doka phase for privation of dong formation and hence saves at least two hebdomads hang-on period Saleem et Al. ( 2004 ) . When fruits of Khadrawi and Shamran treated with 2 % NaCl entirely achieved 72 and 75 % maturation by weight, similar surveies were besides conducted on Khadrawi, Shamran, Zaidi and Thoory day of the month assortments at the doka phase. Sodium chloride ( 0.5-3.0 % ) , actic acid ( 0.5-2.0 % ) , or Na chloride at 1.0 % + acetic acid. With Khadrawi and Shamran increased concentration of NaCl resulted in a progressive addition in the maturation per centum of fruits ( Kalra and Jawand, 1974 ; Kalra et al. , 1977 ) . Shamshiri and Rahemi ( 1999 ) reported that Na chloride and acetic acid either individually or combined, significantly increased the TSS and reduced fruit soundness and wet content. Acetic acid at 2 % had a better consequence on fruit maturation and Na chloride, but the fruits with Na chloride were better in visual aspect. Mirza and Meraj-ud-Din ( 1988 ) treated the fruits of Dhakki and Basra cultivars in doka phase with 3 % brine solution, 0.25 % acetic acerb solution and 0.25 % citric acerb solution for five proceedingss and sulphuring them for five hours. Different chemical interventions significantly enhanced the maturing per centum of fruits, brine solution was found to be superior maturing agent.