PRUNING AND THINNING

Pruning results in the formation of reduced vegetative buds, alters the hormonal conditions, better intake of nutrients, and formation of an increased number of new shoots. Pruning and trimming also reduce the incidence of stem-end rot and anthracnose in many fruits and increases the quality and yield in some fruits (Asrey et ah, 2013). Pruning also helps to reduce the size of the trees and increased total soluble solid content in Ber (Khan and Hosain, 1992). It reduces the competition between fruits, controls the number of flowers, reduced size and increased total soluble solid content, and improvement in the quality of larger fruits (Cordenunsi et ah, 2005)

IRRIGATION

The effects of irrigation on the quality of fruits are difficult to quantify as water stress serves as an important factor in fruit production. Water stress can lead to different physiological disorders at different stages. If there will be no availability of water from flowering to the initial stage of the growing season this will lead to reduced fruit growth rate and the fruit size. The water stress declines crop productivity and also accelerates the ripening of fruits. There are various physiological factors that occur due to the water stress and one of them is postharvest browning in avocados (Robert and Jennifer, 1997). Moisture stress results in cracking and sunburn in apples, cherries, and apricots. High water stress may lead to the deterioration of fruit quality during storage. Mild water stress may lead to a reduction in moisture content in fruits during storage, which in turn may reduce the incidence of pathogen attack on the fruits, and when there is no water stress the yield may increase but with a poor quality of fruit is obtained (Robert and Jennifer, 1997). Low or high irrigation supply can also hamper the antioxidant capacity and lower weight loss of the fruits (Schaffer et al., 1994). In case of drought roots often produce a hormone (abscisic acid) that reduces the stomatal aperture of the shoots (Hartung et al., 2002). Studies also reveal that lack of irrigations results in the fruit drop to a greater extent (Schaffer et al., 1994).

PLANT GROWTH REGULATORS

These provide a significant advantage when used appropriately as they stimulate a number of quality parameters. These help in increasing the fruit set, fruit development thus increasing the yield. Most of the growth regulators are synthesized endogenously but for improving the fruit set yield and quality they have to be provided exogenously. Fruit set in apple and pear is found to improve by the application of gibberellic acid (Gill et al., 2012). It has been observed that the application of GA3 at 20 ppm reduces the seed number by 61%. These hormones are also used to increase the fruit size and increased number of flowers and firmness of fruits (Luries, 2010). Cytokines with added gibberellins causes cell division and cell elongation that increases the fruit strength (Emongor et al., 2001; Yu, 2001). Size of citrus fruits was found to increase due to the application of auxins as it increases cell expansion and results in the growing of the fruit quickly (Sembok, 2016). Plant growth regulators are used on a commercial scale that influences the quality attribute of fmits except few which are not used in a widespread maimer. A plant hormone called naphthalene acetic acid is applied as a gel which prevents regrowth of pruned areas and is also used to reduce the blossom in apples. The application of ethephone induces ripening while as retain restricts the formation of ethylene gas thus delaying the maturity and ripening of apples and pears (Watkins and Miller, 2003, 2005).

SEASON AND TIME

Harvesting at mild temperatures is necessary as respiration rates get increased at higher temperatures. It has been observed that harvesting at early day, that is, in the morning is preferred best time for the local market and for faraway places evening harvesting is considered to be best because of low moisture content and increased amount of carbohydrate content that helps in safe storage of fruits (Moneruzzaman et al., 2009). Seasons have a great effect on the storage of fruits as the fruits that are harvested in dry seasons contain less amount of moisture than those fruits that are harvested in rainy season and contain a lot of moisture and attracts a lot of pathogens and microorganisms (Kader, 2013).

MATURITY STAGE

Stage of maturity plays an important role in determining the safe storage of fruits (Beckles, 2012). Different harvesting stage in case of Climacteric fruits exhibits certain postharvest attribute (Moneruzzaman et al., 2009). Determining the harvesting stage is very difficult for a grower. Picker should be knowledgeable enough to know the best stage of maturity for harvest which is the most important factor for shelf-stable storage and eating quality of fruits (Watada et al., 1984). There are different maturity indices for different fruits that gives the best idea for harvesting. Most of the fruits have good eating quality when fully mature on trees but such fruits cannot be stored for a long time as they get deteriorated quickly as compared with the fruits harvested at mature stages (Kader et al., 2000). If the harvesting is done before maturity, appearance and nutritional quality may be affected. Immature stage harvesting result in the decreased content of sugars that hampers obtaining the best taste after storage. When harvesting is done in later stages after attaining full maturity more sugar gets accumulated which results in the mechanical bruising and reduced shelf life (Toivonen, 2007). It has been found that fruit, when harvested in mature stages, contain less amount of ascorbic acid than those harvested at the mature stage (Lee and Kader, 2000) and also the fruits that are harvested earlier become dehydrated and become susceptible to microbial attack. At different total soluble solids (TSS) levels fruits exhibit different eating quality in respect of color, flavor and overall acceptability scores. Acid index content affects the color, flavor of fruits to a great extent (Crisosto and Crisosto, 2001). Thus, a combination of different factors is necessary to decide the harvesting indices of fruits (Balibrea et al., 2006).

FERTILIZER APPLICATION

Fruits require essential nutrients for normal growth and quality produce. These nutrients called as micro- and macronutrients are needed by plants in varying amounts and help in minimizing the harsh environmental conditions. The main aim of the application of fertilizers is to produce high productivity with high-quality fruits (Looney et al., 1996). One such example is the application of nitrogen, which is needed by plants for carrying different metabolic processes like flower growth and development, fruit set, and fertilization of ovules (Sanzol and Herrero, 2001; Tagliavini and Millard, 2005). Fertilizer application to different fruits will enhance different nutritional qualities and overall acceptability scores. Different fertilizers impair different quality traits of fruits such as TSS, pH, glucose-fructose ratio, the acidity of juice, and the color of the fruit. It has been observed that the application of nitrogen, phosphorus, and potassium at different combination results in the improvement of growth, yield, and quality attributes of aona (Singh et al. 2012)

There are a number of metabolic processes that are governed by phosphorus like protein synthesis, respiration metabolism, carbohydrate metabolism, etc. (Fregoni, 1980). In grapevines phosphorus application enhances the organoleptic quality, such as enhancement of flavor and aroma (Pommer, 2003). The fruit firmness, size, color, acidity, aroma, and juiciness are directly affected by the application of potassium. In case of pears, the ratio of K:Ca are important for stable storage as their imbalance may promote cork spot during storage. Calcium is present in fruits in very minute amounts than leaves and its absence may increase the incidence of bitter pit in apples and other fruits. The uptake of calcium by fruits occurs only during the early development of the fruits as after that its vascular mobility is low. Calcium plays an important role in the stability of cell membranes, cell physiology, and tolerance against several fungal infections. It is also involved in increasing both fruit firmness, tolerance for diseases in storage.

POSTHARVEST QUALITY OF FRUITS

Postharvest quality management of fruits starts from the field and continues till it reaches to the final consumption. The tissue of fresh fruits still remains functional and continues their biological processes even after harvest and then naturally deteriorates. Before reaching to final consumer the horticultural crops are deteriorated almost 40-50% because of loss of water, bruising, and successive damage of fruits during postharvest handling (Kitinoja 2002; Ray and Ravi, 2005). Fruits are vital component of a balanced and healthy diet but due to the limited shelf life there seems to be a nutritional loss if not consumed or properly preserved such as loss of phytochemicals, vitamins, and many other macro and micronutrients. Too late or too early harvested fruits are subjected to many physiological disorders and have a shorter span of life than those harvested at optimum maturity level. Another research suggests that about 30-40% of total fresh fruits produce is lost from the point of harvesting till final consumer (Salami et al., 2010). Fresh fruits quality is governed by so many factors and combination of all these effects decides the rate of spoilage (Siddiqui et ah, 2015; Barman et ah, 2015; Nayyer et ah, 2015). Fully ripe fruits attain good eating quality when harvested and mostly chosen at the mature stage, but when the fruit is not fully ripe it may not be picked, if picked it reduces the mechanical properties during postharvest handling. If these factors are not controlled properly it leads to loss of postharvest on a huge scale. Postharvest damage to the quality of fresh fruit includes the production of ethylene, respiration rate, transpiration, and also the impact of various environmental and other physical stresses, like relative humidity, temperature, ethylene, etc. (Kader, 2013). Therefore, the nature of fresh fruit falls in the categoiy of the highly perishable item. Producers and handlers should understand the technique to reduce the losses due to various environmental and biological factors. At the same time, good postharvest techniques, control of humidity, and temperature during storage, appropriate packaging, transportation, and maintenance of storage conditions (atmosphere) should be adopted in order to maintain the quality of fresh produce otherwise this lacuna may be considered one of the big issues for postharvest losses. In fresh produce, these developmental changes cannot be halted, though it can be slowed down by minimizing the factors that are responsible for deterioration. This step is important as it increases the shelf life of fresh produce and ultimately increases the market value by maintaining their quality during postharvest handling. Postharvest losses in fresh fruits can either be quantitative (like loss of water, physical bruising, physiological disturbance, and damage or decay) or qualitative, such as changes in acidity, color, flavor, and nutritive value) (Ibom and Asiegbu, 2007). Total time is another important parameter between harvesting and processing in maintaining the freshness and quality of produce. During postharvest handling, system delays should be minimized and postharvest technologies also minimize the loss of quality to a greater extent especially in high water content fruits. The postharvest qualities of fresh fruits are dependent not only on treatment methods or postharvest handling but it is also dependent on many preharvest factors, like environmental conditions, nutrient type, a supply of water, and many other harvesting methods that influence both pre- and postharvest quality of fresh fruits. Quality losses during postharvest are as a result of various preharvest factors. Before harvesting fruits are infected with pests, not properly irrigated and use of poor quality of fertilizers, etc.

It is therefore important to have knowledge of preharvest factors in order to reduce the spoilage and can enhance the quality of fruits during harvesting.

 
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