FRUIT MATURITY AND HARVEST

Transcription

1 PT E R 1 HA 7 C FRUIT MATURITY AND HARVEST L itchi is a non-cimacteric fruit and therefore it is advantageous to pick fruit soon after it reaches maturity. This aso ensures that fruit has the maximum shef ife. Fruit eft too ong on the tree, unti it has aready started to soften, does not trave we and acks shef ife. Immature harvested fruit shrives and softens but does not deveop favour, and is either rejected at the market pace or receives very ow prices. The standards of fruit maturity have been deveoped. Litchi harvest criteria can vary with oca consumption patterns and distance to the market. Time from fowering combined with funess of coour is the most common criteria. Producers must decide whether to harvest as soon as the market price ensures a reasonabe return, or to eave the crop in the fied to obtain maximum profit. However, itchi crop does not permit onger waiting period as it may drasticay shorten the marketabe ife of the produce and ower the sae price. This baance is a critica factor in determining the grower s income from the crop. In practice the tota harvest period is very short and the grower has very itte time to make the correct decision. Litchi takes about 3 months from the time of fruit set to mature and ripen. Some varieties may take months. More precisey, a heat unit submission of GDD has been found sufficient for itchi maturity. If picked immature, fruits deveop ower amounts of Brix, acid ratio, taste and favour, whereas over-mature fruits ose their storage ife. It is therefore, desirabe to pick the fruits at the correct stage of maturity to faciitate ripening, distant transportation and maximum storage ife, and thus to increase their quaity and market vaue. Maturity Indices Litchi harvesting is aways a deicate task. Since the fruit is not cimacteric and maturation virtuay stops as soon as it is harvested, therefore, if picked too eary, coour and sugar/acidity ratio, both vita factors where fruit marketing and favour are concerned, wi suffer. The ater the fruit is harvested the arger the edibe part and the higher the tota mass. Leve of acidity

2 THE 186 A Manua for Litchi Production PRODUCTION wi drop significanty and the fruit may become rather tasteess. Foowing criteria may be foowed to ascertain the itchi maturity. Skin coour is usuay a determinant of ripeness. The fruit is said to be ready for harvesting when the pericarp is a uniform red, (just when the orange coour has disappeared competey or amost competey, except in the case of cutivars which produce yeow or green fruit) and the protuberances have become smoother. In varieties which produce red fruit, these shoud be an even deeper red at harvest time. A usefu test of ripeness is to check the coour of the inner surface of the skin, which shoud aso be red. Cass of surface redness is prime method to judge the fruit maturity. The youngest fruit (<33 per cent red) and the odest fruit (100 per cent red) have ower ari concentrations of tota soube soids and higher pericarp superoxide dismutase activity than intermediate fruit. The youngest fruit aso have higher rates of water oss than oder fruit. Testing is another way of determining whether the fruits are ready for picking. As itchi fruit mature, the concentrations of sugars, principay those of sucrose, gucose and fructose increase, whie the concentrations of organic acids, predominanty maic acid decrease. Other criteria used to determine the correct harvest time are minimum fruit weight and the sugar/ acidity ratio. These two criteria vary depending on the cutivar and the country or cimatic area in which it is grown. The most reiabe guide to maturity is titratabe acidity (TA) or the ratio of tota soube soids ( 0 Brix) to titratabe acidity. Recommendations vary, but a TSS:TA of 40 or greater is recommended for commercia fruit. In practice, however, most orchards of itchi are harvested on the basis of taste and genera appearance. The fattening of the fruit segments on the skin is a good way of teing when the fruit are mature (Fig. 17.1). Over-ripe fruit are sweet, but band. Indices used to judge maturity incude fruit size, skin coour or texture, the ari sugar: acid ratio ( Brix), and favour. Harvesting The objective of harvesting is to get the crop without damage and to send it to the market in the best possibe condition. Thus, the objective is to move the crop from fied to market with the minimum number of handing operations compatibe with the quaity requirements of the buyer; and to minimize exposure of the crop to stresses such as extremes of temperature, or of compression pressures caused by over-oading. Athough the scae of production, avaiabiity of abour and type of produce may vary, certain basic factors must be taken into account in the panning of itchi harvest operation. Equipment must be obtained, abour organized, marketabe produce identified and provision of coection and remova from the fied is made. Each of these tasks must be panned, managed and impemented efficienty if the vaue of the crop is to be fuy reaized.

3 Fruit Maturity and Harvest 187 Fig. 17.1: A mature itchi bunch ready for harvest Good production panning to ensure that crop maturity coincides with market demand. This can be achieved by proper care whie seecting the variety and proper orchard management. Continuous communication with buyers to ensure exact requirements as harvest time approaches, and to et the buyers know the best time of harvest and expected quaity. Forward panning to coordinate equipment, abour and transportation faciities. Fied supervision to enhance the work efficiency at site. The efficiency of the harvesting operation itsef depends upon the use of experienced or trained staff, and the adoption of methods which wi meet the buyers requirements. Good management of the harvest operations is usuay refect in the speed at which produce moves from fied to market pace, packing station or storage centre.

4 THE 188 A Manua for Litchi Production PRODUCTION Training Workers for Harvesting Training and supervision of abour are critica to a successfu harvesting operation. Constant supervision is necessary to maintain quaity and reduce subsequent spoiage of produce. Training is required in both genera principes and crop specific techniques reating to maturity seection, maintenance of equipment, fied hygiene and division of abour. Some of the more important areas are: Teams of workers must work systematicay through a pot or fied, experienced staff removing the crop and others carrying it to coection points. If crops are reativey inaccessibe, as with oder itchi, great care must be taken by pickers cimbing on the trees if fruit is to be harvested free of damage. For this, panting densities and pruning techniques shoud be foowed which minimize tree size. It is essentia that crops shoud be harvested at the correct size and maturity for the market. The workers must be given strict specifications before entering the fied and their performance supervised carefuy. During ong harvesting sessions, some individuas deveop habits of sapping, pressing and rubbing produce. Others become tired and start to throw or drop produce into fied containers. Such practices can cause damage to the produce and shoud be controed by checking performance, by restricting the engths of work shifts and by promoting comfortabe working conditions. Sharp edges on rings and braceets, and ong fingernais, are significant cause of post harvest abrasions and shoud be removed before harvesting starts. Unmarketabe produce must not be eft in the fied to rot and contaminate heathy standing crops. Routine coection of waste is an important part of the harvesting operation and a workers can contribute to this. Ceaning, steriization or repacement of picking containers must be carried out reguary to prevent the buid-up of infection. Each individua shoud be issued once ony with necessary equipment and given cear instruction and training in its maintenance. It shoud then become that individua s responsibiity to keep knives and cippers both cean and sharp and to keep other equipment such as boxes, poes, nets and bags in a good state of repair. Harvesting Time The time harvest of itchi in a particuar day depends on the avaiabiity of transport and other faciities, weather and environmenta conditions as we as market demands. The factor which assumes greatest importance depends upon the crop and the oca situation. Most favourabe condition for harvesting is eary in the morning. In some areas, where markets need night transportation, it may be advisabe to avoid harvest during the midde of the day. Keeping harvested produce in the fied for ong time eads to deteriorate rapidy uness speciaized faciities are avaiabe.

5 Fruit Maturity and Harvest 189 If the crop is to be transported to a reativey distant market, storage centre, packing station or processing faciity and harvesting shoud be timed to aow for deivery at a convenient time. Harvesting can ony take pace when sufficient abour of the required ski and strength is avaiabe therefore manpower shoud be arranged adequatey. Harvesting eary in the morning or ate in the afternoon maximizes fruit water content and reduces the risk of desiccation. Fruit Picking To obtain the best quaity fruit, trees with proper ripening must be seected. In peak season, most fruits can be picked from a tree in one harvest and a trees of one cutivar in an orchard may be harvested within 8-10 days. If fruits are aowed to reach a good state of ripeness or if bags have been paced around the custers, each panice can be cut from the tree as one. Harvesting may be carried out by removing whoe panices using secateurs. Fruits are best harvested using cippers, and paced in harvesting bags carried by the harvester. Picking patforms and adders are used to reach higher fruit, and where trees are propped up, the props coud be used as supports to hep workers engaged in harvesting. Litchis shoud aways be handed with care, athough the skin is fairy rough, the sightest bemish coud mean a oss of commercia vaue. Puing out of bunches during harvesting has to be avoided because broken skin at the point of attachment of the branches is particuary susceptibe to a decay condition. Injury caused by rough handing contributes to fast rotting and fungus infection. If harvested cean, the produce shoud be kept cean and not stacked on the soi, even momentariy. Cean the crates and equipments reguary in detergent. After rain, postpone harvesting for at east three hours of sunshine to dry out fruit as skin is susceptibe to handing marks after rain. Crates and Containers Harvested produce may be transferred from the harvest containers into fied containers, for transport to a packing house, or to oca markets. Wooden crates are made of boards or sats, with a capacity of up to 25 or 50 kg for manua handing, can be used to shift the produce. Pastic crates are now in common uses. Most are made from high density poyethyene which contains utra-vioent inhibitor (UVI), which extends the ife of the container when it is exposed to sunight. Pastic returnabe crates have a onger ife than wooden ones Sacks, pastic bags and net bags made from natura or synthetic fibres are aso used where produce is transported directy from grower to market. They are reativey cheap

6 THE 190 A Manua for Litchi Production PRODUCTION and require itte storage space and usuay provide good ventiation to their contents. However, they give itte protection to their contents and when made from synthetic fibres tend to disintegrate when exposed to sunight. Harvesting Period in India Litchi distribution in India has cascading production pattern commencing from the east, and spreading to the west. Litchi production commences during the first week of May in Tripura, whie itchi in Bihar matures by the third week of May and continues up to the second week of June. Litchi in Uttar Pradesh and Punjab is ready for harvest during the 2-3 rd week of June, whie in Himacha, it comes to harvest by the ast week of June, thereby extending the tota season of its avaiabiity to over two months in a year. Fig depicts the harvesting period of itchi in India. STATE/UT S JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC Tripura Assam West Benga Bihar and Jharkhand Uttarakhand Punjab and Himacha Pradesh Fig. 17.2: Harvesting period of itchi in India