The most common measure of a successful harvest is the ‘yield’, the amount and quality of a crop that comes off the land. As it relates to wild blueberries, it means getting as many ripe berries off the field as possible and getting them off in one piece. Berries left behind, or crushed, are a loss to the farmer and a waste of what nature has provided.
At PEI Berries, by looking at new equipment and approaches to harvest, we are trying to accomplish three basic things for ourselves and other local farmers:
1) Capture from the plants a higher percentage of berries than is achieved with current harvesting equipment
2) Increase the amount of the fruit that is captured, transported and stored, as a whole berry (not crushed)
3) To minimize the negative impact mechanical harvesting can have on the soil and plants
Currently, a traditional wild blueberry harvester’s design consists of a reel-type picking head. This head is mounted on the side of a tractor (see image to the right) to allow the picking head to follow the contours of the ground. The reel rotates within the head in the same direction as the tractor’s wheels, with its rotation speed in ratio to the forward motion of the tractor. Comb type picking bars rake the blueberries from the plants and then they are carried around the reel and deposited in a conveyor. A series of conveyors carry the berries from the reel to a platform at the rear of the tractor.
A key issue of this design is that it rotates, not towards the fruit it is trying to pick up (in a forward motion), but backward to pick up the fruit it has just passed over. This can leave a lot of berries on the plant, or allowing them to fall to the ground. With this as a major area of yield loss, we are looking to build a ‘better mouse trap’, a harvester that leaves fewer berries behind.
The ‘Whole’ Blueberry
Wild blueberries that are broken or crushed during the harvest, in transit or while being stored can be of no value to a processor. In a perfect world, every single wild blueberry is harvested and every one of those is captured and stored as a whole berry.
But in many operations, large storage bins are used to move and hold wild blueberries. Given the volume and weight of the fruit inside these bins, excessive movement and vibration cause berries at the bottom to be crushed and their juices released. If one is looking to grow and deliver a high quality whole wild blueberry, this then becomes another area of yield loss and waste.
At PEI Berries we are encouraging local growers to return to the smaller baskets (see image to the left) used in the past. These place less weight and pressure on berries at the bottom and provide better aeration at all times. As a result, fewer berries are crushed and less juice is lost. And as growers are paid primarily by weight, they could get higher returns for their crop.
Soil & Plants
It is obvious that the movement of heavy equipment over farm land can lead to soil compaction and erosion. And that through these conditions there can be a reduction in the number of fruit bearing plants within a given field. This in of itself can significantly reduce the harvest potential per acre of wild blueberries, but it also has the additional negative effect of the potential loss of valuable topsoil. Once that soil is gone, it is gone.
And depending on the equipment, its size and how it is used, considerable plant damage can happen at harvesting time. Equipment can strip away the bark from the branches and stems of the plants, making it difficult for them later to return sap to the rhizome system (roots). They need to do this to promote better capacity to overwinter, which enables them to produce more plants in the coming years. This provides better crop stability year-to-year, and may increase the number of fruit producing plants within a field.
By looking at a redesign of the harvester, we are also looking at its impact on the soil and plants. Our objective is to find the best balance between crop yield and quality and the impact harvesting that crop has on the land and plants.