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Harvesting Fruit

Bruising in Fruit
Fresh-market fruit growers have long been concerned about bruising. Processing-fruit growers also have grown concerned because unbruised fruit commands the best prices. The vast majority of bruising in the harvest process falls into two categories: (1) picking bruises associated with rough handling and detrimental impacts, and (2) compression bruises associated with significant vibrations during transport.

Bruising is an ever-present problem. One study showed that bruising of fruit after harvest ranged from 0.6 to 13 percent, with an average of 7.1 percent. A study conducted of packing sheds indicated that bruising caused 8.1 percent of the culls, while another study found bruising to cause only 2.7 percent of the culls. At the retail level in supermarkets, bruising was found to range from 29 to 78 percent, averaging 61 percent.

While bruising is a concern, it must be regarded as a defect that can be controlled through basic management principles. We encourage growers to determine the quality of the product being produced and to determine the dollar value of defects in the product. Good management practices then dictate that production steps be modified if the cost of correcting the problem is less than the cost incurred by defects in the product.

Damage inflicted on fruit is related to the energy available for bruising and the characteristics of the product. The energy available for bruising is in turn related to:

1. the suspension characteristics of the vehicle transporting the fruit,
2. the energy input to the system (a function of roughness of the road and vehicle speed), and
3. a third engineering factor involving both the properties and the packaging of fruit.

The damage suffered by fruit is dependent on the number of individual shocks and their severity, and is directly related to the energy absorbed by the fruit.

We may think we cannot change the characteristics of the products we deal with, but this is not entirely so. Packers of Golden Delicious have learned that packing apples directly on removal from storage may produce more bruised fruit than if fruit is packed after being held at a relatively low humidity for a few days to create an outer layer of bruise-resistant cells. Reducing the amount of bruising in fruit appears to be attainable by reducing the amount of energy that fruit receives in handling.

In practical terms, bruising can occur during any of six operations in which fruit is removed from the tree and moved into storage. In several Pennsylvania harvest operations, some of these steps may be combined, but they are discussed here individually to show the complexity of an efficient, high-volume harvest operation. Listed below are seven locations of fruit and the six steps involved in moving the fruit from tree to storage:

The harvest season is a hectic time of year, but we strongly recommend that growers educate employees in the proper method of performing assigned tasks.

Proper harvesting involves the following:

• Wearing proper clothing and a hat.
• Adjusting the bucket. (Picking buckets with rigid sides and of a reasonable size are recommended)
• Checking all ladders before using.
• Carefully setting ladders and setting them at the proper angle.
• Keeping your body centered on the ladder.
• Handling fruit like eggs.
• For apples, using stem-on picking methods.
• Getting your hands in the bucket to prevent bruising.
• Picking a tree from the bottom up.
• Releasing fruit carefully and slowly into the bulk bin.
• Reporting all accidents to the grower.

In Step 1, we suggest that growers offer incentives to pickers who pick properly and that growers give disincentives or penalties to those who cause more bruising than the set limit. Offering both rewards and penalties does more to encourage pickers to harvest fruit properly than if either penalties or rewards are used alone. In addition, we recommend the use of an active supervision system for picking crews.

Major bruise-reducing practices in Washington State include the use of three-legged aluminum stepladders. Growers do not allow pickers to set straight ladders into trees because they find the resulting damage (bruising and dropped fruits) unacceptable. Another practice is to use bubble liners in bins to absorb energy and vibrations for cultivars such as Golden Delicious and other high-value crops, such as bagged Fuji.

Step 2 involves moving the fruit within the orchard to the end of the rows. This operation is performed by tractors. In Washington State growers prefer the use of low-profile orchard tractors with wide tires. These tires act like springs and can intercept energy to prevent it from transferring to fruit in a bin.

Most Pennsylvania orchard tractors, in contrast, have 12- or 16-inch-wide tires on 24- or 28-inch-diameter rims. These tires are normally inflated to be fairly hard and can therefore transmit more energy to the fruit in a bin as the tractor moves over rough terrain. We recommend using tractors equipped with 18.4 by 16.1 orchard tires.

Step 3 involves moving fruit from the edge of the orchard to a loading area. If the haul distance is short it may be desirable to combine this step with Step 2. Special straddle vehicles or four-bin trailers may be useful. In some areas the trailers are operated in reverse and are attached to the front of the tractors. Using a multibin conveyance system may be more efficient than hauling bins singly on tractors. To lessen bruising, all orchard roads should be as smooth as possible to reduce the energy transferred to fruit during transport. Most loading areas should be smooth and paved, if possible, or at the very least covered with gravel. Muddy loading areas add a significant risk of spreading spores and soilborne decay organisms. Organic material and dirt caught in bin runners can defeat sanitation procedures used at the warehouse in storing and packing fruit.

Step 4 is loading straight trucks or tractor-trailers for further bin movement. When this operation is performed on paved surfaces, using conventional rubber-tired forklifts may maximize efficiency and may be necessary for handling large volumes of fruit.

Step 5 is trucking the fruit from orchard to storage. Drivers should be instructed to follow the smoothest roads and to travel at reasonable speeds, especially over rough roads. Special trailers with "air-cushioned rides" will absorb more road shock than conventional trailers.

The final step, Step 6, is moving the fruit from the trailer to the storage itself. In this phase, loading areas should be as smooth as possible and shock-absorbing forklifts should be used, especially on rough loading areas.

Bruising may be looked upon as a profit-reducing phenomenon and a manageable problem. Bruise-producing operations can be corrected for less money than the reduction in profit caused by the bruising. Remember, bruising is usually caused by only a few procedures. Growers may want to evaluate their present practices in view of the ideas presented here.

Excessive Heat and Worker Safety
A combination of very high temperatures (significantly above normal) and a higher-than-normal humidity can severely reduce the body's ability to maintain a proper internal temperature. Prolonged exposure to these conditions can lead to heat cramps, heat exhaustion, and heat stroke. For some, especially the old and infirm, it can lead to death.

The Heat Index (HI), also referred to as the "apparent temperature," is a measure of how humidity acts along with high temperatures to reduce the body's ability to cool itself. The HI is the temperature (in degrees) the body senses, based on normal humidity levels. For example, if the actual temperature is 100°F with 40 percent relative humidity, the effect of these conditions on the body is the same as 110°F with normal humidity (about 20 percent). The basic assumption in computing HI is that the person is in the shade, at sea level, with a wind speed of 6 mph. Exposure to full sunshine can increase the HI about 5 to 15°F. Various wind speeds can also alter the HI but usually have small effect.

The following table shows heat index, or apparent temperature, based on current air temperature and relative humidity.

To use this table find the current air temperature in the lefthand column; follow that row across until you reach the appropriate humidity column. The number you find there is the heat index (HI) or the apparent temperature.

The degree of heat stress may vary with age, health, and body characteristics. Listed below are some heat stress symptoms associated with several apparent temperatures. Symptoms of heat stress include a feeling of weakness, fatigue, giddiness, and nausea. Headaches and cramps are also signs of heat stress. Symptoms of heat stroke include mental confusion, loss of consciousness, convulsions, body temperatures of 106 degrees or higher, loss of coordination, and hot, dry skin that may be red, mottled, or bluish.

Preventing Heat Stroke Among Farm Workers

Employers should take the following steps:

• Learn to spot the signs of heat stroke, which can be fatal.
• Provide frequent rest breaks for the workers.
• Consider a workers’ physical condition when assigning work in extreme heat.
• Make available plenty of drinking water (about a quart per hour per worker).
• During extreme heat and humidity, schedule work during the morning and late-afternoon hours where possible.
• Provide shade, such as awnings and canopies, if natural shade is not available.

Workers should do the following:

• Get used to the heat for short periods and then follow with longer periods of work.
• Alternate work and rest breaks, with longer rest breaks in cooler areas.
• Wear hats to protect them from the sun.
• Dress in lightweight, loose-fitting, light-colored clothing, such as cotton.
• Drink plenty of water, even if they are not thirsty.
• Do not drink beer and alcohol or take cold medications.
• Take frequent breaks and get out of the sun, if possible.
• Know signs of heat stroke and fatigue and get immediate medical attention.