The agronomic performance data for the registered varieties grown in 2022 can now be viewed on the CTRF Plant Breeding website.
The CTRF established plots of the most commonly grown flue-cured tobacco varieties in Ontario to compare performance for 2022. A two-year (2021 + 2022) and three-year (2020 + 2021 +2022) average of these varieties are also presented. If you have questions about this handout, please contact the CTRF.
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Mailing Address: CTRF, P.O. Box 322, Tillsonburg, ON N4G 4H5
Telephone: 519-842-8997
Web Address: https://ctrf1.com
March 13, 2023
by CTRF Comments Off on Protected: Highlights from the Annual Meeting of the Ontario Recommending Committee for Flue-Cured Tobacco held on February 2023
The CTRF is holding an “Open House” on Wednesday, December 14, 2022, between the hours of 8:30 a.m. and 12:00 noon. Please stop by and look at the cured leaf samples of registered and promising varieties that will be on display. Handouts on the performance of the registered varieties will be available. The CTRF’s plant pathology and agronomy programs will have a display in CTRF’s lab that highlights some of the research that was conducted this year. Click here for the program and directions.
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Mailing Address: CTRF, P.O. Box 322, Tillsonburg, ON N4G 4H5
Telephone: 519-842-8997
Web Address: https://ctrf1.com
October 31, 2022
by CTRF Comments Off on Protected: CTRF Program Updates – October 2022
The majority of the crop was planted in late May and early June and crops are off to a good start, with cultivation now starting to occur. Problems observed in greenhouses this spring include chill injury, chemical injury, pH in float water, spiral roots, dry cells, and algae. In the field, there have not been many problems reported yet. However, there have been reported cases of plants showing damage due to environmental stresses, particularly low night temperatures soon after transplanting. As a result, we have started to see in certain fields plants that are forming suckers.
Figure A &B. Sucker formation in early stages of Tobacco transplants.
There have been a few growers asking about tray sanitation now that transplanting is finished. It is important to mention that unless Styrofoam trays are properly sterilized following use each year, it is not uncommon for fungi to build up in the trays and infect the plants. The CTRF has encountered Black Root Rot in Styrofoam trays over the past years when steam has not been used to disinfect them. As of today, sterilization of Styrofoam trays with steam is the only practice that will effectively control Black Root Rot. For more information on Black Root Rot and its control, please refer to the technical bulletin entitled “Tobacco Pests and Disorders in the Field – Black Root Rot” posted in the Plant Protection area of this website. Please see the technical bulletin “Tobacco Pests and Disorders in the Greenhouse-Damping Off” for more information.
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Mailing Address: CTRF, P.O. Box 322, Tillsonburg, ON N4G 4H5
Telephone: 519-842-8997
Web Address: https://ctrf1.com
April 11, 2022
by CTRF Comments Off on 2022-Progress of Seedling in the Greenhouses
The 2022 greenhouse season is underway with a cool and cloudy start. At this time, all greenhouses have been seeded. Overall, seedling stands in greenhouses should provide adequate transplants for this year’s crop. As the seed germinates and seedlings grow, pests, tray and greenhouse conditions, fertility, and contaminations due to drifting of pesticides may arise and affect the crop.
Based on the farm calls received and the greenhouses that the CTRF has visited, seedlings between farms do vary in size depending on the type of production method being used and the time of seeding. Thus far, there have been a variety of issues occurring in the greenhouses, including dry cells, slow seed germination, uneven seed germination and seedling growth and algae formation on the surface of media interfering with seedling emergence and growth.
1-Dry cells
Styrofoam dry cells were observed in some float greenhouses when some tray cells showed dryness after floating (fig 1). The exact cause of cell dryness is not clear, but it can be associated with debris in the soil mix or issues with soil wetting agent and filling up cells loosely. These factors may prevent water absorption and soaking of the growth media, which will result in slow seed germination. To mitigate cell dryness some growers mist the trays’ surface using a handheld hose equipped with a mist nozzle.
Figure 1. Dry cells (left, circles) in float trays. Note the seed pellets (right, arrows) in dry cells and the seedling size in wet cell.
2- Slow seed germination
Soil media in trays is essential for seed germination since it sustains seed germination and growth soon after seeding. If the soil media conditions are not adequate to ensure proper aeration, by not filling the trays too tight or too loose, media wetness, soil and water (float trays) and overall greenhouse temperatures, slow seed germination and seedling growth will occur. Greenhouse temperature is crucial for seed germination and growth. Cooler temperatures during seed germination will extend the number of days necessary to reach maximum germination and to decrease uniformity in the size of seedlings, and after germination, they can exacerbate seedlings’ chilling injury. A temperature of 24°C or 75°F is recommended for optimal seed germination and seedling growth and a temperature of at least 15°C or 60°F or higher be maintained during the first 14 days. However, some growers will maintain at least 21°C or 70°F for the first 14 days to maximize the speed of germination and plant uniformity. After the first 14 days, good rates of seedling growth can be achieved with an overnight minimum temperature of 10°C or 50°F without any injury to plants.
Figure 2: uneven seed germination and seedlings growth.
3- Algae
Algae may develop on the surface of either dry or float trays, especially under cool and dim conditions. Several distinct types of algae may form on trays depending upon what types were in the substrate used to fill the trays or which types were present upon the trays from previous seasons. Blue-Green Algae are the most common algae in greenhouses, and they affect tobacco seedlings by causing oxygen levels in the media to fall, thus inhibiting root growth, and competing with the plants for fertilizer. Two situations are usually seen in cases of algae infection, one where the seedlings are not able to emerge through the algae and the other being where the seedlings emerge but cannot establish themselves before succumbing to the algae and dying.
Figure 3. Uneven germination and mattes of algae covering cell, preventing seedlings emergence (left, arrows) and seedlings that emerged but succumb to algae (right, arrows).
There are no pesticides registered for algae control in tobacco greenhouses. Algae are best managed by providing conditions as favorable as possible for seed germination and early seedling growth, so that the seedlings will establish quickly and outpace the formation of the algae on the media surface. Following good tray fertilization practices is also essential since it encourages algae growth. Therefore, fertilizer should not be added to float tray water until the plants have reached the two-leaf stage. For dry trays, fertilizer applications should not start until three weeks after seeding. As seedlings grow, the canopy will close over and shade the media surface, therefore, reducing the negative effects of algae.
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Mailing Address: CTRF, P.O. Box 322, Tillsonburg, ON N4G 4H5
Telephone: 519-842-8997
Web Address: https://ctrf1.com
December 13, 2021
by CTRF Comments Off on CTRF Registered Variety Data (2021) Available Online
The agronomic performance data for the registered varieties grown in 2020 can now be viewed on the CTRF Plant Breeding website.
The CTRF established plots of the most commonly grown flue-cured tobacco varieties in Ontario to compare performance for 2021. A two-year (2020 + 2021) and three-year (2019 + 2020 +2021) average of these varieties are also presented. If you have questions about this handout, please contact the CTRF.
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Mailing Address: CTRF, P.O. Box 322, Tillsonburg, ON N4G 4H5
Farm visits and calls conducted by CTRF indicate that nitrogen deficiency is not uncommon in tobacco this season, which is not surprising considering the excessive rainfall experienced so far. For example, weather data from Environment Canada shows in the Tillsonburg area June brought in a total of 159.4 mm (compared to 88.8 mm normal) and July had 150.2 mm compared to 96.2 mm normal). Moreover, in some cases the rainfall was experienced daily during these two months. Under such conditions, nitrogen losses can occur through soil erosion or leaching below the root zone and soil type impacts the extent of these losses.
Nitrogen (N) is a critical nutrient for producing good yield and leaf quality of flue-cured tobacco. Stunted growth is the first signal for nitrogen deficiency, and is followed by phenotypic symptoms, including pale, green coloration of the lower leaves. Since nitrogen is a mobile element and the plant responds to a deficiency by moving the nutrient away from older leaves to younger leaves, the plant symptoms begin on the older lower leaves and progress up the plant if the deficiency continued. The color will change to a light yellow and will become progressively whiter (Figure.1 &2).
Figure 1. Nitrogen deficiency symptoms
Adding N as a corrective measure is the proper solution considering the plant stage, but soil type and previous crop management must be considered when you are making the decision to apply additional nitrogen to your crop since excessive amounts of nitrogen may show no yield benefit and can reduce cured leaf quality and produce cured leaf with unbalanced chemistry. Other negative consequences may be increasing soil acidity, delayed maturity, and increased weed and sucker problems.
Figure 2. Nitrogen deficiency symptoms
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Mailing Address: CTRF, P.O. Box 322, Tillsonburg, ON N4G 4H5
Telephone: 519-842-8997
Web Address: https://ctrf1.com
June 22, 2021
by CTRF Comments Off on 2021-Crop update and grower reported issues
The majority of the crop was planted in May, with some crops being planted in early June. Currently, most crops appear to be off to a good start, and cultivation is now occurring. Not many problems have been reported in fields yet, however, there have been a few reports of nematode, chill injury, and a case where one of the fertilizer bands at planting was too close to the plants and caused an injury.
There have been reports of Blue Mold occurrence on tobacco from the United States, where the disease has been recently reported in Pennsylvania.
There are no reports of Blue Mold occurrence here in Ontario, where the disease has not occurred since 2009. However, growers should routinely scout fields and any leftover plants in the greenhouse for signs of Blue Mold (please see photos below for some of the Blue mold symptoms). More detailed information about the identification of Blue Mold and its control can be found in the technical bulletin entitled “Tobacco Pests and Disorders in the Field – Blue Mold” posted in the Plant Protection , as well as in OMAFRA publications 842 and 843.
Yellow necrotic lesions on the upper surface of leaves at the bottom of the plant are an early symptom of Blue Mold.
Bluish-grey fuzz (Peronospora tabacina) spores on the underside of the leaf are another symptom of Blue Mold.
There have been a few growers asking about tray sanitation now that transplanting has finished. It is important to mention that unless Styrofoam trays are properly sterilized following use each year, it is not uncommon for fungi to build up in the trays and infect the plants. The CTRF has encountered Black Root Rot in Styrofoam trays over the past several years when steam has not been used to disinfect them. As of today, sterilization of Styrofoam trays with steam is the only practice that will control Black Root Rot. For more information on Black Root Rot and its control, please refer to the technical bulletin entitled “Tobacco Pests and Disorders in the Field – Black Root Rot” posted in the Plant Protection area of this website. Steam sterilization is also recommended for control of Pythium and Rhizoctonia Damping-off, please refer to the technical bulletin entitled “Tobacco Pests and Disorders in the Greenhouse – Damping off” for more information.
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Mailing Address: CTRF, P.O. Box 322, Tillsonburg, ON N4G 4H5
Telephone: 519-842-8997
Web Address: https://ctrf1.com
May 4, 2021
by CTRF Comments Off on 2021 Progress of Seedlings in the Greenhouses
The 2021 greenhouse season is progressing well, despite the cool and cloudy start. Overall, percent seed germination and uniformity of seedling stands in most greenhouses appear to be quite good. Based on the greenhouses that the CTRF has visited, seedlings between farms do vary in size depending on the type of production method being used and when seeding was started. In some greenhouses, clipping is started already. Only a few isolated problems have been reported to date with algae and chilling injury being the issues observed the most.
1-Algae
Blue-green algae are the most common algae that colonizes mostly float trays, however in a couple of cases, red-orange algae were also found to be present. Algae formations depend upon what types were in the substrate used to fill the trays or which types were present on trays from previous seasons or and in greenhouses. Blue-green algae are the most common algae in tobacco greenhouses and produce an oily-looking, blackish-green slimy layer on the tray surface. Red-orange algae are less frequent in tobacco greenhouses, however they can also be found colonizing water systems and seeding soil substrates, such as soilless medium or muck soil beds.
Unlike blue-green algae, the red algae lack motility structures, this probably being the main reason for the algae to be less spread in float trays or muck soil beds, in which we have seen and found these algae often imbibed in the vermiculite layers on the muck bed. In float trays, the red algae tended to be attached to the sides of the Styrofoam tray cell, often staining them red-orange (Fig. 1).
Fig. 1.- Blue-green algae (arrow) and red-orange algae (circle).
Note the red/orange-stained Styrofoam surfaces under the red algae.
This because algae cause oxygen levels in the media to fall, and or promote formation of nitrites in the tray media which inhibits root growth as well as competing with the plants for fertilizer.
Fig. 2. a) Tray cells and seed covered with blue green algae and b) poorly established seedling due to algae.
Chilling injury was also of concern especially with some of the recent weather conditions. The initial symptoms of chilling injury are often a bright yellow color in the growing point of the seedling and upward cupping of the leaves, as shown in the image below (Fig. 3).
Fig. 3. Chilling injury
As the seedlings become larger and the leaves grow out, some leaves will be malformed, cupped, and have a distinct yellow/white discoloration. Seedlings do outgrow chilling injury without any ill effects on the seedlings when transplanted to the field.
Chilling injury is caused by exposure of the seedlings to a large variation in air temperature, such as when ventilation occurs on a very cool but sunny day or at night when the temperature outside is quite cold and the temperature drops significantly in the greenhouse because the heaters do not have enough capacity to maintain the set temperature. Also, some varieties are more susceptible than others to chilling injury. However, cold injury is not usually severe enough to be fatal to the seedlings, but it can delay growth and allow other problems, such as algae on trays, to be more damaging than they would otherwise be.
Clipping is underway in tray greenhouses. Bacterial Soft Rot (also known as Blackleg) is a common issue during this crop phase in the greenhouse.Bacterial Soft Rot is caused by several bacteria with Pectobacteriumcarotovorum (previously Erwinia carotovora) being the most important. As seedlings are clipped, leaf debris from the clipper fall back onto the seedlings foliage as shown in Figure 4, and when conditions are favorable, for example, high nitrogen levels, warmtemperatures, high humidity, long periods of leaf wetness, and plant injury (by stress or wounding), outbreaks of Bacterial Soft Rot will occur. Bacterial spread to healthy seedlings continues as more clipping is carried out, particularly when clipping is done on wet foliage.
Fig. 4. Leaf debris from clipper that has fallen back on to the seedlings.
Bacterial Soft Rot can become a serious seedling problem during extended periods of warm, wet, overcast weather conditions during the greenhouse season. The disease infects tobacco seedlings in both dry and float trays and has the potential to destroy large numbers of plants in a relatively short period of time. Initially, the bacteria colonize wounded tissues, organic matter, and debris in trays. Leaves touching the surface of a tray can become infected and the rot can spread through the petioles into the stem. Debris and leaves
Fig. 5. Seedlings in a tray infected with Bacterial Soft Rot
There are no control agents registered for control of Bacterial Soft Rot in tobacco greenhouses. Removal of trays with the diseased seedlings from the greenhouse and replacing them with blank trays is the best control in this situation. Other practices for control include trying to keep leaf debris from the clipper out of the beds, not clipping when the leaves are wet, not over-fertilizing, keeping the foliage of the seedlings as dry as possible, and ventilating the greenhouse adequately to keep the humidity level down.
Click here for more information on Bacterial Soft Rot
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