Management of Soybean Virus Disease Transmitting Insects.

Yellow mosaic (viral) disease is a common issue affecting soybean crops annually. Below are the symptoms and remedies related to yellow mosaic disease:

Symptoms of Yellow Mosaic Virus (YMV):

In the early stages, small yellow spots appear on the leaves, which later develop into large bright yellow-green patches. The affected leaves eventually turn completely yellow. Infected plants remain stunted and droopy, flower late, and produce fewer pods. The disease primarily spreads through infected seeds, with secondary transmission occurring via whiteflies.

Symptoms of Soybean Mosaic Virus (SMV):

Although an outbreak of this disease has not been observed at present, it is important to recognize its symptoms and management strategies as a precautionary measure:

Affected plants exhibit stunted growth. The leaves become narrow, short, thick, wrinkled, and their edges fold downward. The leaves show excessive greenness, with some areas being green and others yellowish. Infected plants flower late and produce fewer pods. In cases of severe infection, the seed coat color changes to gray, brown, or black. The disease is primarily transmitted through infected seeds, with secondary transmission occurring via fruit borers.

Preventive Measures:

• If diseased plants are detected early, they should be removed from the field and destroyed.
• Effective weed control in crops and along field boundaries is essential.

Control Measures:

• Install yellow sticky traps (15 x 30 cm) in the field at a rate of 20-25 per acre, positioned at crop height, to prevent fly and maggot infestations.
• At the first sign of disease or pest outbreaks, apply chemical insecticides to control whiteflies and prevent further infestations.
• Spray one of the following insecticides per 10 liters of water: Imidacloprid 17.8 SL (2.5 ml), Flonikamid 50% W (2 g), Thiomithoxam 25% W (3 g), or Acetamiprid 25% + Bifenthrin 25 W (5 g). If necessary, a second spray should be applied after 15 days. Alternate insecticides should be used for subsequent treatments.

Note: The recommendations for chemical pesticides in these control measures are provisional and should be followed with caution.