Browsing Washington State University Extension by Author "Davidson, Roy M., 1939-"

Now showing items 1-20 of 52

  • Apple anthracnose (bull's eye rot) 

    Davidson, Roy M., 1939-; Byther, Ralph S. (Pullman, Washington : Washington State University. Extension., 1992-01)

  • Armillaria (Shoestring) Root Rot 

    Davidson, Roy M., 1939-; Byther, Ralph S. (Pullman, Washington : Washington State University. Extension., 1994-05)
    Shoestring rot is caused by a group of fungi known as Armillaria. Symptoms include stunting, yellowing or browning of leaves or needles, white growth on lower trunk and roots, and string-like strands in the soil surrounding ...

  • Armillaria (shoestring) root rot 

    Davidson, Roy M., 1939-; Byther, Ralph S. (1979-06)

  • Carrot rust fly 

    Davidson, Roy M., 1939-; Antonelli, Arthur L. (1979-05)

  • Club Root of Cabbage and Other Crucifers 

    Davidson, Roy M., 1939-; Byther, Ralph S. (Pullman, Washington : Washington State University. Extension., 1990-11)
    Crucifer plants [cabbage, cauliflower, Brussels sprouts, broccoli, kohlrabi, kale, collard, Chinese cabbage, mustard and some turnips, rutabagas, and radishes] are susceptible to the fungus Plasmodiophora brassicae. Authors ...

  • Common Causes of Plant Damage and Suggestion for Plant Care 

    Davidson, Roy M., 1939-; Byther, Ralph S. (Pullman, Washington : Washington State University. Extension., 1994-07)
    Parasitic diseases caused by fungi, bacteria, viruses, or nematodes are responsible for only about one-third of all plant problems. The rest are caused by such factors as climate, planting location or procedures, and ...

  • Common causes of plant damage and suggestions for plant care 

    Davidson, Roy M., 1939-; Byther, Ralph S. (Pullman, Washington : Washington State University. Extension., 1978-01)

  • Construction Damage to Trees 

    Davidson, Roy M., 1939- (Pullman, Washington : Washington State University. Extension., 1987-07)
    Many of those beautiful, well established trees left on a new construction site die within 2 to 8 years after construction. Here are ways to identify and avoid future problems, lessen existing problems, and care for those ...

  • Construction damage to trees on homesites 

    Davidson, Roy M., 1939-; Byther, Ralph S. (1980-03)

  • Dogwood anthracnose 

    Davidson, Roy M., 1939-; Byther, Ralph S. (1979-07)

  • Dooryard pests 

    Davidson, Roy M., 1939-; Antonelli, Arthur L. (1979-05)

  • Insect answers: carrot rust fly 

    Davidson, Roy M., 1939-; Antonelli, Arthur L.; Getzin, L. W. (Louis William), 1933- (Pullman, Washington : Washington State University. Extension., 1981-07)

  • Insect answers: dooryard pests 

    Davidson, Roy M., 1939-; Antonelli, Arthur L. (Pullman, Washington : Washington State University. Extension., 1983-06)

  • Insect answers: the cabbage maggot in the home garden 

    Davidson, Roy M., 1939-; Antonelli, Arthur L. (Pullman, Washington : Washington State University. Extension., 1981-11)

  • Insect answers: the cabbage maggot in the home garden 

    Davidson, Roy M., 1939-; Antonelli, Arthur L. (Pullman, Washington : Washington State University. Extension., 1984-01)

  • Insect answers: the cabbage maggot in the home garden 

    Davidson, Roy M., 1939-; Antonelli, Arthur L. (Pullman, Washington : Washington State University. Extension., 1989-04)

  • Lophodermium Needle Cast of Pine 

    Byther, Ralph S.; Davidson, Roy M., 1939- (Pullman, Washington : Washington State University. Extension., 1995-08)
    This disease is caused by a fungus and affects Scotch pine, red pine, and Monterey pine more than other Pinus species. Symptoms are spots on the needles and eventual needle death. Cultural and chemical control measures are ...

  • Lophodermium needle cast of pine 

    Byther, Ralph S.; Davidson, Roy M., 1939- (Pullman, Washington : Washington State University. Extension., 1979-07)

  • Marssonina Leaf and Twig Spot on Willow 

    Davidson, Roy M., 1939-; Byther, Ralph S. (Pullman, Washington : Washington State University. Extension., 1994-03)
    This fungal disease affects foliage on many kinds of willow. Although the foliage is unsightly, the growth of the tree is not affected. Good sanitation practices are the only recommended control, though spring fungicide ...

  • Marssonina leaf and twig spot on willow 

    Davidson, Roy M., 1939-; Byther, Ralph S. (Pullman, Washington : Washington State University. Extension., 1976-05)