Lavender can be affected by a number of insect pests, but only a few cause economic damage to the crop on a regular basis, such as the four-lined plant bug. However, under the right conditions, other insect pests can reach damaging levels. That is why it is important for growers to constantly scout fields and identify localized pest issues before they become a major issue.
In one of the provincial lavender cultivar trial locations, we noted major damage over the past week by garden fleahoppers (Figure 1). A section the trial containing about 100 plants had significant damage to almost all of the leaves on the plant. When the plants were shaken, hundreds of small green nymphs and a few adults fell out of the plant. Damage from garden fleahoppers has been noted on lavender before, but not at the damaging levels noted in this field. Continue reading
Weather conditions have been favourable for ginseng growth over the past few weeks, and there are no reports of major disease or insect issues. However, the standard issues for this time of year are showing up. This includes Cylindrocarpon on isolated plants or patches of plants in older gardens, Phytophthora root rot in saturated areas of the garden, Alternaria within the canopy where fungicide coverage is difficult to achieve, and Pythium in some fields. Continue reading
By Rebecca Shortt, Water Quantity Engineer, OMAFRA and Sean Westerveld, Ginseng and Medicinal Herbs Specialist, OMAFRA
With variable rains across the ginseng growing region it can be difficult to know when it is necessary to irrigate. Even if soil moisture is slightly lower than optimum for a week, yield can be impacted. Furthermore, seed yield and quality will be significantly affected by low soil moisture, especially if combined with a period of high temperatures, low humidity and/or windy conditions. There are many tools that can be used to improve water management decisions and avoid both wasting water and unnecessary yield losses. Continue reading
Basil downy mildew has been confirmed in the field in Norfolk County. The affected basil was infected in the field and was not directly exposed to previously infected potted basil plants. This suggests that airborne spores were widespread over the past week and the disease is likely to begin showing up throughout southern Ontario fields. Growers need to apply fungicides preventatively before symptoms are widespread in the field. Growers also need to scout fields regularly to identify symptoms before they become widespread. Continue reading
Laboratories in Ontario offer a range of DNA-based pathogen tests designed to identify issues in soil or other substrates. Some tests that they offer can identify a range of general pathogens in one test, while other tests can identify pathogens specific to certain crops. Because these tests can be expensive, it is important to understand the benefits and limitations of different tests.
Recently I submitted a soil sample from an area of a ginseng field that was completely destroyed by Cylindrocarpon root rot, which is caused by the fungus Cylindrocarpon destructans, and a separate sample from a healthy area of the garden nearby. The cause of the rot in the diseased area of the field was confirmed to be Cylindrocarpon destructans by plating at the University of Guelph – Simcoe Research Station. Samples were submitted for a DNA test that identifies multiple pathogens at once. Researchers at AAFC and in other countries had identified a ginseng-specific special form of Cylindrocarpon destructans in ginseng called Cylindrocarpon destructans f.sp. panacis, and the soil sample was also submitted for a PCR test (also DNA-based) that can identify this specific strain. Continue reading
The heavy rains over the past few days have resulted in standing water in many gardens. This will increase the risk of Phytophthora root rot as swimming spores (zoospores) move through the water to new plants. The biggest risk with standing water is the potential for splashing of the spores in the water onto leaves, which would lead to a foliar infection. Foliar infections lead to airborne spores that can travel great distances on wind currents and lead to infections in new areas of the garden, neighbouring gardens, or many kilometres down the road. Growers should take the opportunity after heavy rains to identify drainage issues and correct them before the next heavy rain. This is especially true for new gardens that have not been seeded yet. It is much easier to correct issues before the garden is in place than to wait until the seedling year. Continue reading
The final report of the 2013 lavender research trials is now complete. The report is comprehensive and discusses the results of four main research trials in great detail. The four research trials include cultivar trials at 6 sites across southern Ontario, row cover trials at 4 sites in southern Ontario, a plastic weed barrier trial and an oil distillation trial. Over the next few months, highlights of the results will be written in a series of articles. The detailed report will be posted to the Ontario Lavender Association website at www.ontariolavenderassociation.com within the next few weeks.
In this article, bloom characteristics of the 27 cultivars included in the cultivar trials will be discussed. Characteristics such as bloom height, bud spacing and flower and bud colour are important for determining whether a cultivar is suitable for different value-added products. For example, tall flower stems are more suitable for bundles, while shorter stems may still be suitable for oil distillation or other purposes. Different flower colours provide contrast in the field if the farm is open to the public, but white flowered cultivars may not be as useful for product development. Continue reading