The majority of the crop was planted in May and at this time, most crops appear to be off to a good start, with cultivation now starting to occur.  Plant problems observed in greenhouses this spring include chill injury, heat damage, chemical injury, pH in float water, some spiral root, and algae.  In the field, there have not been many problems reported as of yet.  However, there have been a few reports of fumigant injury.

There have been a few growers ask about tray sanitation now that transplanting has finished up.  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.

There have been no reports of Blue Mold in tobacco from the United States.  There has also been no reports of Blue Mold here in Ontario.  Growers should routinely scout fields and any leftover plants in the greenhouse for signs of Blue Mold.   Information about 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 area of this website and in OMAFRA publications 842 and 843.  If you find Blue Mold, please report it immediately.

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Mailing Address: CTRF, P.O. Box 322, Tillsonburg, ON  N4G 4H5

Telephone: 519-842-8997

Web Address: http://ctrf1.com

Progress of Seedlings in Greenhouses

The 2018 greenhouse season is underway with a cool, cloudy start. Most greenhouses appear to have good seed germination and seedling uniformity. 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.

A preventative application of fungicide has been made for the control of Rhizoctonia Damping-off in greenhouses that seedlings have reached the 1.5 cm leaf diameter growth stage.

Chilling Injury

Some concerns have been expressed regarding the amount of chilling injury being observed in some greenhouses, especially with some of the recent weather. The initial symptoms of chilling injury are often a bright yellow colour in the growing point of the seedling and upward cupping of the leaves, as shown in the image below.

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 it would otherwise be.

Effects of Certain Algae on Emerging Seedlings in Trays

Certain algae present on the surface of tray media can affect seedling emergence and establishment. Two situations are usually seen in these cases, 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 (as shown below).

Empty cells, stunted and brown seedlings caused by algae.

Seedling on the left (light brown in colour) has succumbed to algae.

Cool and cloudy weather conditions are ideal for algae growth. Some algae, such as the green algae, possess motile appendages that allow them to move in the presence of water in tray media as seen in a video in the plant protection area of the website.  This suggests that spread of algae in a tray can occur from cell to cell.

There are no chemical treatments for algae in tobacco greenhouses. Conditions that are optimum in the greenhouse for rapid seed germination and early seedling growth help seedlings to outpace the algae so that the seedlings become large enough that the algae can no longer affect them.  Not fertilizing for 2 or 3 weeks after seeding can also help to prevent an early buildup of algae in trays. As seedlings grow, the canopy will close over and shade the media surface, therefore, reducing the negative effects of algae.

Further information about algae and measures to reduce its effect on seedlings can be found in a technical bulletin in the plant protection area of this website.

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Mailing Address: CTRF, P.O. Box 322, Tillsonburg, ON  N4G 4H5

Telephone: 519-842-8997

Web Address: http://ctrf1.com

The 2018 version of OMAFRA’s Flue-Cured Tobacco Crop Protection Guide, Publication 843 is now available.  Growers who have not yet received a copy, can contact CTRF to request one by following this link.

Publication 843 contains recommendations on registered pest control products for flue-cured tobacco in Ontario.  There is a list of control products in the publication’s tables with a column that identifies whether a product is “TREC Approved”.  TREC stands for Tobacco Review and Evaluation Committee, which tests the acceptability of a product for use in flue-cured tobacco production.  Certain tobacco contractors require that control products used by their growers are TREC approved.  Check with your contractor as to their requirements.

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Mailing Address: CTRF, P.O. Box 322, Tillsonburg, ON  N4G 4H5

Telephone: 519-842-8997

Web Address: http://ctrf1.com

CTRF is pleased to announce the hiring of Mitchell Richmond as the Team Leader of CTRF. Mitchell is about to graduate from the University of Kentucky with a Ph.D. in Integrated Plant and Soil Science. His graduate work focused on agronomic research for all aspects of tobacco production from transplanting through curing.  Mitchell is replacing Dan Van Hooren, who is retiring.

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Mailing Address: CTRF, P.O. Box 322, Tillsonburg, ON  N4G 4H5

Telephone: 519-842-8997

Web Address: http://ctrf1.com

Reason^® 500 SC Fungicide has been granted registration for control of Blue Mold on field tobacco.  It is a liquid suspension concentrate that contains 500 g/L of the active ingredient (a.i.) fenamidone.  Reason^® 500 SC Fungicide is a broad-spectrum foliar fungicide that has both systemic and translaminar action, and belongs to the fungicide group 11. It is effective against several oomycetes including Peronospora tabacina, the pathogen that causes Blue Mold on tobacco.

Reason^® 500 SC Fungicide has both preventive and protective activity and it works by inhibiting the pathogen’s spore germination and acts as an anti-sporulant.  It must be applied on the plant foliage as soon as crop and/or environmental conditions become favourable for Blue Mold development.

For resistant management, no more than one application of Reason^® 500 SC Fungicide or other group 11 fungicide, such as Quadris Flowable Fungicide or Azoshy 250 SC, should be made before alternating with a fungicide from a different resistance management group registered and recommended for Blue Mold control.  Currently, the options are Aliette WDG, Actigard 50 WG and Presidio^® Fungicide.

The application rate for Reason^® 500 SC Fungicide is 400 to 600 mL/ha and should be applied on a 5 to 10 day interval depending upon disease conditions.  A maximum of 1600 mL/ha of Reason^® 500 SC Fungicide applied per season to tobacco is permitted.  When applying Reason^® 500 SC Fungicide, use sufficient water to guarantee good leaf coverage.

The re-entry interval (REI) after application is 12 hours and the pre-harvest interval (PHI) is 30 days.

The Canadian Tobacco Research Foundation (CTRF) evaluated Reason^® 500 SC Fungicide in several field experiments and found the fungicide to have no detrimental effects on tobacco yield and quality.  The Tobacco Review and Evaluation Committee (TREC) also found the fungicide to be acceptable for use on flue-cured tobacco.

Even though Blue Mold on field tobacco has not occurred in Ontario since 2008, it is important that products be available for control in the event the disease reappears.

Always read the label before applying a pest control product.

The label for Reason^® 500 SC Fungicide and other tobacco crop protection agents can be found on the Pest Management Regulatory Agency (PMRA) webpage: http://pr-rp.hc-sc.gc.ca/ls-re/index-eng.php

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Mailing Address: CTRF, P.O. Box 322, Tillsonburg, ON  N4G 4H5

Telephone: 519-842-8997

Web Address: http://ctrf1.com

Up until only recently, tobacco growers in Ontario have had to deal primarily with the root-lesion nematode (Pratylenchus penetrans) in their fields.  This past growing season another species of nematode, tobacco cyst nematode (Globodera tabacum = TCN), was found on two tobacco farms.  One farm in the vicinity of Delhi and the other in the Langton area.  This is not the first report of TCN in Canada.  In 1998, it was reported in Quebec.  TCN is also present in several other tobacco producing countries in the world.

Host plants of TCN include tobacco along with several other solanaceous crops and weeds, such as tomato, peppers, eggplant, jimsonweed and nightshades. TCN causes damage to tobacco roots that can result in significant economic losses if not managed properly.  TCN is difficult to control because of its ability to persist in the soil without a host for several years and its almost impermeable cyst.  Detailed information about TCN and its control can be found in the plant protection area of this website.

Female tobacco cyst nematode feeding on a tobacco root.

This upcoming growing season, CTRF plans to conduct a survey of the tobacco growing areas in Ontario to determine the extent of TCN.  Also, trials are planned to be started to look at the effectiveness of rotational crops, such as pearl millet, for control of TCN.  Pearl millet is already known to be an effective control of root-lesion nematode in Ontario tobacco fields.

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Mailing Address: CTRF, P.O. Box 322, Tillsonburg, ON  N4G 4H5

Telephone: 519-842-8997

Web Address: http://ctrf1.com

Agronomic performance data for the registered varieties grown in 2017 can now be viewed in the plant breeding area of the website.

Varieties on display at the CTRF Open House on December 14, 2017.

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Mailing Address: CTRF, P.O. Box 322, Tillsonburg, ON  N4G 4H5

Telephone: 519-842-8997

Web Address: http://ctrf1.com

CTRF is holding an “Open House” on Thursday, December 14, 2017 between the hours of 8:30 a.m. and 12:00 noon.  Cured leaf samples of registered and promising varieties will be on display.  Handouts on the performance of the registered varieties will be available.  There will also be a plant pathology display in CTRF’s research lab.  Click here for the program and directions.

Samples of registered varieties on display from a previous year’s open house.

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Mailing Address: CTRF, P.O. Box 322, Tillsonburg, ON  N4G 4H5

Telephone: 519-842-8997

Web Address: http://ctrf1.com

Harvesting is finished on the majority of farms with the remainder of farms needing up to another week.  Conditions remain dry for those growers still harvesting.  Irrigation is ongoing in some of these cases to help reduce bruising and assist with moisture levels while curing, especially now that it is getting cooler.

Over the harvest season, bruising of mid-stalk tobacco was a problem on some farms, as was pole rot (causal organism Rhizopus arrhizus).  Tobacco scrap infested with pole rot should not be spread on any fields used to grow tobacco.  The infested scrap should be burned.  Check with your local municipality regarding burning bylaws.  Any infested tobacco debris left in empty kilns and bins should be removed and destroyed as well.  Disinfecting kilns, bins and pins before using them again next season should also be undertaken in those situations where pole rot was an issue this year.

Similar to the past several years, there were no reports of Blue Mold in the Ontario tobacco crop in 2017.

Final harvesting pass in CTRF’s variety trials located near Aylmer, ON on September 28, 2017.

CTRF has now completed harvesting all of its variety trials for 2017.  These trials are conducted in cooperation with growers on several farms.  This year there were a total of 42 promising flue-cured varieties being tested in replicated trials, with some of these varieties being grown at multiple sites.  Also, a promising variety, 13AA27-4, was released on a small-scale basis to a dozen growers this year.  These growers will soon be surveyed as to their impressions of the variety.  This information will assist with the evaluation of the variety once the agronomic performance of the variety is known from CTRF’s field trials.

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Mailing Address: CTRF, P.O. Box 322, Tillsonburg, ON  N4G 4H5

Telephone: 519-842-8997

Web Address: http://ctrf1.com

Harvesting is now underway on farms either with the first pass or, in some cases, the start of the second pass.  So far, leaves from the bottom of the plant are curing quite clean.  Irrigation is a common site on several farms and a good rain would be welcomed.

Bottom of the plant following first pass with the harvester.

To date, Potato Virus Y (PVY) has been the most common disease observed on farms, however, in most cases it is not causing significant losses.  Other diseases currently being observed, typically at low incidence, have been Target Spot, White Mould and Pole Rot while curing.  No Blue Mold has been reported in any tobacco fields in Ontario so far this season.

Insect pressure from Green Peach Aphids is typical for this time of year.  Hornworm populations have been on the low side in most fields over most of the season.

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Mailing Address: CTRF, P.O. Box 322, Tillsonburg, ON  N4G 4H5

Telephone: 519-842-8997

Web Address: http://ctrf1.com