| 1572640 |
Seed(s) |
Bulk sudangrass seed. January 1997 |
| 0908073 |
Equipment |
Georgia Forestry Commission nursery, in 1985 |
| 1429001 |
Harvesting |
hand lifting operations |
| 1429002 |
Equipment |
transport from field to grading shed |
| 0010025 |
Management |
At the end of the crop cycle, the seedlings are ready for harvest. Harvesting, or "lifting", is done during the dormant period when the seedlings are in a state of maximum hardiness, or resistance to stress. This time period is known as the "lifting window" and occurs during the late fall, winter, or early spring. In nurseries where the ground freezes, there are two narrow lifting windows: one in the fall, and another in the spring. Because the weather is often too wet in the spring, some nurseries lift a significant portion of their crop in the fall. |
| 0010026 |
Equipment |
Lifting consists of drawing an inclined, vibrating blade under the seedlings, usually at a depth of about one foot. The inclined blade lifts the seedlings out of the seedbed and the vibrating action loosens the soil from around the roots. |
| 0010027 |
Harvesting |
Hand lifting consists of pulling the seedlings from the soil by hand, shaking the loosened soil from the roots, and placing them in a box. The lifting boxes are lined with wet burlap to keep the seedling roots from drying out. |
| 0010028 |
Harvesting |
Several different types of mechanical harvesters are also used to lift seedlings. Most use a digger blade to lift the entire seedbed width onto a moving, vibrating belt that shakes the soil from the roots. They are then placed into boxes for transport to the pre-storage cooler. |
| 0010029 |
Harvesting |
The time period from when the seedling are lifted until they are outplanted is one of the most critical in the entire reforestation sequence. The tiny fibrous roots are especially prone to drying and can be killed by a few minutes of exposure to heat or direct sunlight. The lifting crew includes several people that are assigned to keep the seedling boxes wet until they can be moved to the pre-storage cooler. |
| 0010030 |
Monitoring |
Progressive nurseries monitor seedling quality during the seedling harvesting to outplanting operation. The pressure chamber directly measures seedling moisture stress and is used to determine when weather conditions are too dry to lift, and to identify potential problems. |
| 0010031 |
Inspection |
Boxes of seedlings are brought into the packing shed where the seedlings are graded and counted. The workers visually rate each seedling according to predetermined grading standards. |
| 0010032 |
Monitoring |
Bundles of "shippable" seedlings are placed on a moving belt, and "culls" are discarded onto the floor and destroyed. Seedlings that have been grown especially for transplanting are also graded in this manner, and some nurseries use a multiple grading system: shippable, transplants, and culls. |
| 0010033 |
Display or Sign |
Grading standards are determined by the customer, depending on their intended use. Larger seedlings are needed for moist planting sites where planting competition is severe, or on sites where animal damage is serious. Shorter, stockier seedlings with a proportionally larger root system are required for harsher, drier planting sites. Often, the nursery manager negotiates these standards with the customer when the seedling order is taken. Grading standards usually consist of a range of acceptable shoot heights, a minimum acceptable caliper (stem diameter), and the length and fibrosity of the root system. Of course, the seed code for the specific seed lot is also carefully monitored during the grading process. |
| 0010035 |
Equipment |
Storage containers are transported to a cooler where they are kept at temperatures near freezing to maintain dormancy and cold hardiness. Each box is marked with the proper seed source code which describes the origin of the seedlot. |
| 0010036 |
Monitoring |
Cold storage facilities keep the ambient temperature near freezing, but it is important to monitor the temperature inside the storage container. For long term storage of more than 3 months, some nurseries utilize coolers that keep the storage temperature at slightly below freezing. Research has shown that frozen storage can maintain high seedling quality for over 6 months, and also retards the development of storage molds. |
| 0010037 |
Management |
Hardwood seedlings are sometimes "heeled-in" in outside beds until they can be outplanted. This process is normally only used where refrigerated storage is not available. Heeling-in is effective because dormant hardwoods have lost their leaves and therefore loose little moisture through transpiration. Seedling dormancy cannot be maintained under these conditions, however. |
| 0010074 |
Management |
Some nurseries store their container seedlings outside overwinter, being particularly careful to place the seedlings on the ground and insulate the root systems against cold. |
| 4798094 |
|
bareroot pine seedlings in bags being transported to delivery or planting sites. Bags are not stacked on top of each other which prevents damage and heat build-up. |
| 4798095 |
|
Storage racks with bareroot seedlings in bags. |
