Diseases & Disorders
All Diseases & Disorders Content
Plant Disease Management Decisions to Make Before Planting
For most plant diseases, in-season management choices are very limited. In fact, there are no in-season management options available for diseases caused by nematodes, viruses, and bacteria.
Soybean Vein Necrosis Virus Detected in South Dakota Soybeans
A new soybean virus called Soybean vein necrosis virus (SVNV) was detected in South Dakota soybean fields in Davison and Union counties. Symptomatic plants were sporadic and found along the field borders. Infected plants showed mild to moderate severity.
White Mold Development: Is your soybean field at risk?
According to USDA-NASS crop progress report for the week of July 17, 49% of the soybeans in South Dakota are at flowering. The flowering growth stage is also the time when white mold infection is initiated. The white mold pathogen infects the soybeans through the flowers that are senescing after pollination.
Wheat Stem Maggots Observed in S.D. Wheat
While scouting wheat fields throughout South Dakota, we have started noticing the presence of bleached heads scattered throughout many different fields. These discolored heads are the result of an infestation of the wheat stem maggot.
Barley yellow dwarf developing in winter wheat.
Barley yellow dwarf is starting to develop in winter wheat. Barley yellow dwarf is caused by the Barley yellow dwarf virus (BYDV). This disease usually becomes more distinct at flag leaf emergence. A typical symptom of Barley yellow dwarf is the purplish-yellow color of infected leaves, especially the flag leaf.
Winter Wheat Breaking Dormancy Early
A threshold indicator for winter wheat emergence is to consider average temperatures over a 14-day period. When that 14-day average temperature is equal to or above 5°C, or 41°F, then hard red winter wheat can break dormancy.
Late-Season Soybean Diseases: Know what’s killing your soybeans
Late-season soybean diseases can sometimes be mistaken for natural senescence. A closer look at the stems and roots of dying plants and the pattern displayed by dead plants in the field may reveal root or stem rots going on. In order to devise effective management practices for future soybean seasons, it is important to determine the cause of early soybean plants death.
Wheat Streak Mosaic Virus Management: Plan ahead before planting this fall
Have you had a history of moderate wheat streak mosaic disease in your field? Do you plan on planting wheat into wheat stubble or wheat fallow? Have your neighbors had wheat streak mosaic disease outbreaks in the recent past? If you answered yes to any of these questions, you need to incorporate wheat streak mosaic control principles into your management plan before planting winter wheat this fall.
Soybean Diseases Update
A few soybean fields scouted had between low to moderate levels of brown spot (also known as Septoria leaf spot). Soybean planted into soybean stubble had elevated levels of brown spot.
The Small Grains Disease Forecasting System Could Save Producers Money
The South Dakota State University Small Grains Plant Pathology program has partnered with the Small Grains Plant Pathology program at North Dakota State University to deploy a small grains disease forecasting system for South Dakota. The system uses weather variables including rainfall, temperature, and relative humidity to predict the likelihood of disease development. This new tool has the potential to save growers money by helping them avoid unnecessary fungicide applications, or knowing when to apply a rescue fungicide treatment.