Volunteer potatoes pose a threat to carrot yield and are expensive and difficult to control in carrots due to the lack of effective herbicides labeled for use in carrots. We have determined the effect of volunteer potato plant density on carrot yield and quantified how much yield is lost with various times of removal. We have also determined volunteer potato and carrot response to two new herbicides that help suppress volunteer potato in carrots. These results provide growers with new information and tools to help suppress volunteer potatoes that will minimize crop losses and reduce hand weeding costs.
The ability to rapidly and accurately identify pathogens that cause plant diseases can greatly reduce losses and costs for disease management. Unfortunately, many pathogens responsible for plant diseases, including fungi, bacteria, and viruses cannot rapidly be identified using historically applied techniques of microbiology and the use of microscopes. We have developed DNA detection assays for several diseases of potatoes. These molecular tools provide growers with critical information for timing control measures, correctly selecting disease resistant varieties, and meeting phytosanitary requirements.
Powdery scab is among the most damaging emerging potato pathogens in the world. No soil or plant treatment has an economically beneficial effect on the level of damage caused by it. Economic loss occurs when skin pitting or when yield loss is caused by suppression of full root development through powdery scab's attacks on the roots. Resistance to the fungus that spreads powdery scab could be very beneficial to the profitability of the potato crop. This article examines research done from 2003 to present on resistant potato gemplasm.
The Columbia Basin potato purple top phytoplasma is a bacteria-like agent transmitted to potatoes by the beet leafhopper. The disease is called purple top because of the characteristic purple coloration produced on infected potato plants. We have found that all of the major potato varieties grown in the Columbia Basin are susceptible to the disease. Additionally, we have found that the tubers produced on infected plants are frequently infected with the phytoplasma and that these infected tubers can produce infected daughter plants. These findings have implications for control of the disease and stress the importance of using seed tubers free of the pathogen.