Bacterial soft rot
Erwinia carotovora
Also Known As - Bacterial soft rot and blackleg,Seed piece decayWhat is Bacterial soft rot (Erwinia carotovora)?
Bacterial soft rot, caused by Erwinia carotovora, is a plant disease affecting various fruits and vegetables. It is distributed worldwide and can infect a wide range of host plants. Symptoms include soft, watery decay of taproots, often leaving the outer layer intact, accompanied by a foul odor. Aboveground signs may include yellowing, wilting, and collapse of foliage.
How does Bacterial soft rot (Erwinia carotovora) occur?
Soft rot and blackleg-causing bacteria enter tubers through pores, waterlogged tissues, stem ends, and wounds. Infected vines spread bacteria to new tubers through soil water. Bacteria persist in soil, plant debris, and seed tubers. Infection happens through wounds or contaminated seed pieces. Moist conditions on wounded tissue enable infection, while high humidity and warm temperatures promote disease progression.
Symptoms
1 - On plants
Bacterial soft rot can cause significant damage to plants, reducing their ability to photosynthesize and leading to stunted growth and poor flowering. In severe cases, the disease can kill the plant. In addition, the disease can also make plants more susceptible to other diseases and pests.
2 - On soil
Bacterial soft rot does not directly affect soil, but the bacterium can survive in the soil and on plant debris for long periods of time. This can lead to the spread of the disease to other plants.
Solutions
1 - Cultural Methods and Preventions
• Rotate planting locations annually to minimize the buildup of bacterial pathogens in the soil. Additionally, control weeds, especially nightshades and buffalo bur. • Choose well-drained sites and avoid practices that lead to water accumulation, as excess moisture encourages disease development. In addition, keep the storage well-ventilated. • Opt for certified disease-free seed pieces of high quality, as they are less likely to develop blackleg in the field. • Harvest mature tubers with set skin, instead of cutting pieces to minimize decay and potential entry points for bacteria whenever possible. Furthermore, pack tubers in ventilated bags with air holes. • Store seeds at 40°F (4°C) and allow them to warm up at 65-70°F (18-21°C) for 2 to 3 weeks before planting. If using cut seed pieces, plant them immediately into warm and moist soil.
