Make your move - First Quarter 2009
Hardy plants and working machinery key to successful transplanting
While growers must be diligent throughout the tobacco growing season, it is especially critical during the transplanting stage. Plants need to be healthy and strong in order to survive being uprooted and placed in the field. In order to make this process smooth and successful, there are several steps growers can take.
“Getting the plants off to a good start is very important to produce good yields of tobacco,” says Bob Pearce, Extension tobacco specialist at the University of Kentucky.
According to the 2008 Flue-Cured Tobacco Guide published by the North Carolina Cooperative Extension Service, “An ideal transplant is disease free, hardy enough to survive transplanting shock and available for transplanting on time.”
To ensure a successful transition, there are several key factors to consider. Dan Timmer, marketing manager for Mechanical Transplanter Co., says, “As far as the field transplanting, this is what I feel is important: proper field preparation; preseason maintenance on transplanters; proper training for new employees on the transplanter; and plants in proper condition to start transplanting.”
According to Timmer, a common mistake is that the transplants are not hardy enough. “Firm, well-mowed transplants always set better,” he says.
In transplanting, timing is everything. In general, early-transplanted tobacco yields more than late-transplanted tobacco. Although the historical last-frost date for a region serves as a good guideline for choosing a date for setting out transplants, according to the Flue-Cured Tobacco Guide, the five-day weather forecast is actually better. Tobacco that has been transplanted for several days is better able to tolerate frost than recently transplanted tobacco.
“For me, the key to successful transplanting and ultimately a good season is the quality of the transplant,” Pearce says. “Transplants should be healthy with a good, robust root system.”
For burley tobacco, Pearce says he likes to see a transplant that is about 5 inches in height from the top of the soil line. The transplant should have been clipped at least three times while growing in the float bed and be a very pale green in color (from lowered fertilizer levels during the last week or so of growth on the bed). Dark green transplants are tender and do not adapt to the stresses of the field as easily as pale plants.
Pearce also says that while transplanting, it is customary for growers to add water to the planting trench to aid in transplant establishment. The amount added varies from one grower to another, but approximately 300 gallons per acre is commonly used.
Growers also often deliver a systemic insecticide in the transplant water. Products such as Admire, Platinum or Belay are commonly used in the transplant water. Pearce says use of these products usually provides season-long control for aphids and flea beetles and is therefore an important part of a grower’s field management.
Some growers like to put a starter fertilizer in the transplant water as well, but Pearce says the university’s research has shown little or no benefit to the use of these starter fertilizers.
“Last year, we had very hot and dry conditions at transplanting time, and I visited several growers with significant stand loss,” he says. “And in most cases the growers had used a high rate of starter fertilizer in the transplant water. The additional fertilizer led to salt stress and ultimately stand loss.”
One of the mistakes he commonly sees is plants with low to moderate levels of pythium root rot being sent to the field. Such plants are vulnerable to greater losses if subjected to stress such as hot temperatures and dry conditions in the days immediately after transplanting.
For flue-cured tobacco, the greenhouse float-system method produces excellent-quality transplants with uniform stem lengths in a very predictable time period, according to the Flue-Cured Tobacco Guide.
However, growers should pay close attention to the weather, as it does play a role in greenhouse production. For example, cool, cloudy conditions can delay germination. Also, unseasonably warm temperatures in February and March can increase the rate of plant growth, causing problems with stem and root diseases, especially if the seeds are planted in the greenhouse too early.
“Successful transplant production in a greenhouse requires intensive management with great attention to details,” says the guide. “Little problems can become big problems very quickly.”
There are four major steps to take to produce healthy transplants in a float system. First, the grower should consider the materials. The water source should be analyzed and alkalinity managed. Growers should select a uniform, high-quality growing medium with a low, well-mixed nutrient charge. The tray design should also be considered and seeds with high germination rates and acceptable pelleting materials should be used.
Second, the grower should promote uniform emergence. This can be accomplished by sowing seeds during sunny periods, filling trays uniformly and placing seeds uniformly (in the center of the dibble). A warm temperature should be provided—68 to 70 degrees F at night. The grower should also reduce spiral rooting and control ants and mice.
Third, uniform growth should be promoted. The grower should monitor fertilizer salts in the medium and leach with water from overhead when necessary. The water should continue to be analyzed and the alkalinity managed when necessary. The grower should also clip properly and manage insects and diseases.
And finally, the grower should work to prevent stand loss. This can be achieved by providing proper ventilation and airflow to prevent heat injury. In addition, early seeding, high nitrogen rates and hot daytime temperatures that promote stem rot diseases should be avoided. Trays should also be fumigated with methyl bromide or new trays should be purchased.
There are a few mistakes that are made during transplanting that could be avoided if growers take proper steps. One common mistake is that transplanters are not properly maintained prior to transplanting.
“In preparing for transplanting, the grower should thoroughly lubricate and inspect the transplanter and replace any worn or broken parts,” Pearce suggests. “It can be very frustrating and expensive to have a whole crew of workers standing around while you try to fix a transplanter.”
He says another common mistake he sees is not transplanting deep enough. Recent research indicates that shallow planting affects quality.
“Since we have gone to mostly float plants, many growers believe that all they need to do is get the root ball covered,” says Pearce. “We have shown with some recent research that as little as ¾- to 1-inch deeper planting makes a big difference in growth and yield for burley tobacco. Our data shows that shallow-planted plants grew more slowly and had larger numbers of ground suckers than deep-planted plants.”
In order to transplant deeper, growers need to make an extra effort to make sure the transplanter is adjusted properly to get plants far enough into the ground. Thus, some growers are rethinking their transplanters in order to achieve the proper depth.
“The most recent innovation in transplanting was the move to carousel transplanters when we started growing float plants,” Pearce says. “The carousel planters require only one worker per row compared with the old finger-type planters that were used before. But, despite the reduced labor needs for carousels, some growers here are switching back to the finger-type planters because they are having difficulty adjusting the carousels to plant the plants deep enough.”
Growers should heed this advice regarding transplanting not only to produce high-quality tobacco but also to save on costs. Poor transplanting and mistakes made during the process lead to increased costs for the overall crop.
According to the Flue-Cured Tobacco Guide, “Transplant production costs per acre increase when the percentage of usable transplants decreases. Therefore, management practices that improve stands and promote uniform growth decrease production costs.”
More growth, less cost. Sounds like a sturdy business plan.