Preharvest Interval and Best Postharvest Management

Introduction:

When it comes to agriculture, the term harvesting typically refers to the process of gathering crops from the field. After the crops are mature, a combine or other type of harvesting machine goes through the field, cuts the stalks of grain at the base, and gathers them up. 

The harvested crops are then transported to a storage area, such as a barn or silo, where they will be threshed and cleaned. During this process there are different factors involving Preharvest Interval and Best Postharvest Management that have to be considered very carefully to gain maximum yield and revenue.

Preharvest:

All the things that involve crop growth, development, biochemical components and physical characters are the preharvest factors. 

Factors:

These factors include:

• Light 
• Humidity
• Genetic
• Pests and diseases
• Rainfall
• Irrigation
• Nutrients
• Agrochemicals
• Temperature

Light:

Light is responsible for many physiological functions such as chlorophyll, stomatal opening and respiration. The quality of fruit and vegetables are highly affected by the intensity and light quality. 

The quality of fruits and vegetables is also affected by light. Exposure to light can cause fruits and vegetables to become discolored or develop spots. 

Light can also make fruits and vegetables taste bitter or sour. Fruits and vegetables that have been exposed to light can also spoil faster than those that have not been exposed to light.

Humidity:

The humidity level in the air can have a significant impact on the shelf life and quality of fruits and vegetables. In general, high humidity levels (above 85 percent) can cause fungus to grow on the product, which can lead to damage and a shorter shelf life. 

Low humidity levels (below 50 percent) can cause the product to lose moisture, which will reduce the quality by having a low juice rate. It is important to monitor the humidity level in order to ensure that fruits and vegetables are stored in a way that minimizes damage and extends their shelf life.

Genetic:

The quality, major characteristics, size of fruits and vegetables is largely determined by the genetics of the plant. Plant breeders work to develop new varieties that are resistant to pests and diseases, have a longer shelf life, and maintain good quality during storage. 

For example, the University of Florida has developed a new grape tomato variety that is resistant to the tomato leaf miner, a pest that can damage leaves and reduce yields. The new variety also has a longer shelf life than traditional grape tomatoes. 

Temperature:

Temperature is one of the most important factors affecting the postharvest life of fruits and vegetables. The lower the temperature, the longer the postharvest life. However, there is a limit to how low the temperature can be before it begins to affect the quality of the produce. 

For example, chilling injury can occur when fruit or vegetables are stored at temperatures below their optimum range. This can cause discoloration, off-flavors, and textural changes in the product.

 

The rate at which fruits and vegetables ripen is also affected by temperature. Generally, warmer temperatures will result in faster ripening. This is because enzymes that are responsible for ripening are activated by heat. However, too much heat can cause accelerated ripening and deterioration in quality.

Pests and diseases:

The quality and freshness of fruits and vegetables can be significantly impacted by pests and diseases. For example, pests can infest plants and damage their appearance, while diseases can cause ripening problems, reduce color intensity, and affect vase life. 

In some cases, the damage caused by pests and diseases can be so severe that the affected produce is no longer fit for human consumption. As a result, it is important for growers to take steps to protect their crops from these threats.

Rainfall:

The amount of rainfall affects the flavor, color, and ripening of the produce. If there is a high amount of rainfall, the produce will be juicy and have a good flavor. If there is a low amount of rainfall, the produce will be dry and have a poor flavor. 

 

Postharvest is the management of the harvested crop. The postharvest includes the cleaning, cooling, storing, sorting, packaging and transportation of the crop. 

As soon as the crop is harvested it starts to deteriorate quickly e.g. in the case of horticulture products such as flowers and fruits. 

To increase the quality and shelf life of the product the treatment plays a very important role. 

When the harvested crop starts to deteriorate the biochemical process causes damage to the quality of the product. There is a specific level of degradation of the product which is acceptable by the market. The minimum level at which a crop is acceptable by market is called the shelf life of the product. 

Importance of Postharvest:

• There are many major problems related to economic and social issues that can be solved by proper post harvest management.
• The issues of food security on a global level can be solved by taking adequate steps towards the post harvesting losses. 
• By protecting our produced commodities from different damage causing factors can empower the small farming communities. 
• In this ever growing world the loss up to 40-60% of produced commodities can not be sustainable for the agriculture sector as well for the economical point of view. 
• Post harvest plays a huge role in maintaining the nutritional values, flavor, texture and shape. If we are able to maintain these factors and prolong the shelf life of these commodities these can be used in off season and can be an economical boost for the farmers. 

Post harvest elements:

Harvesting:

Crop is harvested after it reaches the stage of maturity. The early harvesting can lead to having high moisture which can be a source of fungus attack or disease.

Harvesting crops after a while of mature stage can lead to wastage of commodities by separating from the stalk. 

For harvesting, having the right tool or instrument plays a huge role in getting maximum yield. Cereal crops can be harvested by using sickle, combine harvester, or other machinery. But in the case of flower hand picking or flower bulb harvester it can be useful. 

Drying:

Drying the harvested crop can increase the shelf life and economical value of the commodities. Leaving moisture in the grains can cause mold.

If cereals are too dry that can result in breaking of seed during harvesting or milling or losing weight. Which can also lead to insect pest attack and this will make the commodity unusable. 

Threshing:

The threshing of cereals is a process that removes the grain from the straw. This is done with a threshing machine, which can be either powered by animals or by engines. 

The yield of the cereal crop can be improved by using a threshing machine, as it separates the grain from the straw more efficiently than hand threshing.

Storage:

Storage is keeping the commodities in a protected place from the external environment, insect pests, rodents and giving them suitable humidity and temperature level. 

In order to ensure that cereals are safe for human consumption, they must be properly stored. Cereals can be stored in a pantry for up to one year, in a refrigerator for up to six months, or in a freezer for up to two years. 

The length of time that cereal can be stored depends on the type of cereal and the conditions of storage.

For example, oatmeal can be stored in a pantry for up to two years, while Rice Krispies can only be stored in a pantry for up to six months. It is important to store cereals in a cool, dry place where they will not be exposed to sunlight or moisture.

Transportation:

The transportation of cereals is an important process that has been taking place for centuries. The distance between the producer and the market can be great, and the transport of these goods needs to be done in a timely manner. 

Transportation of produced values in the market can be very economical during the off season. Always select those markets which are close to you and don’t cause a great toll on transport.