For many small vegetable operations, field packing directly into the shipping container or consumer package is the most cost-effective means for preparing many crops for market. Larger operations also field pack extremely perishable or delicate crops, such as berries, vine-ripe tomatoes and leafy vegetables. In both cases, the harvest crew member performs multiple functions, deciding the quality of each piece to harvest and how carefully to pick and pack it. Mechanized, mobile field-packing units are miniature packing lines, continuously performing cleaning, sorting/grading and packing as the crop is harvested. These units are typically custom-designed, and are efficient for a number of crops, notably pepper, summer squashes and cucumbers (Figure 1).

One indication of successful farming occurs when the size of the operation outgrows the ability to efficiently field pack the crop, making packing at a dedicated facility a viable alternative. Many markets demand that the crop be cleaned, have more rigorous sorting/grading, and/or be rapidly cooled, often necessitating the use of a packing facility.

Packinghouses can be designed in a variety of sizes and configurations for multiple uses. When properly planned and constructed, productivity can be greatly improved and postharvest life of the crop extended, thereby allowing shipment to more distant markets. However, to be successful, the planning stage must incorporate these basic concepts – functionality of the facility, product quality and worker safety.

The goal of this article is to provide an overview of factors that should be considered in planning the construction of a packing facility for small-to-medium sized operations.

1. Packinghouse Location

The facility should be located as close to the production area as possible for several reasons. Travel to and from the field requires a lot of time to transport workers, drop off picking containers, and pickup and deliver the crop. Shorter transport distances also reduce mechanical injuries to the crop, and minimize warming by shortening the delay between harvest and packing. Field lanes and roads should be smooth to minimize bumps and vibrations during hauling. Cuts, abrasions and bruises reduce yields and are cause for rejected loads upon arrival at destination (Figure 2).

The building should be raised above ground level to facilitate drainage and minimize standing water. This will also permit the use of raised loading docks that are most efficient for unloading field wagons and loading trucks (Figure 3a).

2. Packinghouse Design and Layout

Knowledge of current and projected product volume is necessary to properly size harvest, handling equipment and shipping operations. The packinghouse should be designed to facilitate product ‘flow’. In other words, for maximum efficiency, the crop should be unloaded at one end and handled toward the opposite end - the fewer the number of turns, the less likely the crop will be damaged. During packing, culls should be removed daily from the site to avoid accumulation of pathogens and insects.

The general layout below (Figure 4) incorporates several important features:

The facility can also be designed to be completed in stages. For example, the building could be constructed and used initially for receiving, packing and shipping. Later, as resources permit, more sophisticated packing equipment could be installed, hand lifts could be replaced by a fork lift to accommodate pallets, and a cold room could be added, along with a forced-air cooler or hydrocooler for rapid removal of field heat.

These guidelines are designed to provide background information that will assist growers in this critical planning process, leading to more productive and realistic discussions with commercial contractors. Then, the costs for each of these packinghouse components can be calculated to determine overall feasibility.

For further information regarding postharvest handling of fresh vegetables and sizing of packing equipment, see:

Figure 1. Delicate summer squash being washed, graded and packed on a mobile unit. 

Figure 4. Generalized packinghouse layout (top view).

Figure 6. Following packing, watermelons can be loaded directly into a refrigerated trailer.

Extension Vegetable Crops Specialists