Search results
Results from the WOW.Com Content Network
a) underside of scale showing female and eggs, x24 b) scale upperside, x24 c) female scales on twig d) male scale, x12 e) male scales on twig. Female scale insects in more advanced families develop from the egg through a first instar (crawler) stage and a second instar stage before becoming adult. In more primitive families there is an ...
Blight is a rapid and complete chlorosis, browning, then death of plant tissues such as leaves, branches, twigs, or floral organs. [1] Accordingly, many diseases that primarily exhibit this symptom are called blights. Several notable examples are: [citation needed]
Kondrat says you typically need to water an orchid every 7 to 10 days, but he cautions that’s a general rule of thumb and your orchid might need a different watering schedule.
Sooty mold caused by scale on a Eucalyptus dives. Sooty mold (also spelled sooty mould) is a collective term for different Ascomycete fungi, which includes many genera, commonly Cladosporium and Alternaria. [1] [2] It grows on plants and their fruit, but also environmental objects, like fences, garden furniture, stones, and even cars.
It is one of the most common viruses affecting cultivated orchids, perhaps second only to the Cymbidium mosaic virus. [1] It causes spots on leaves and colored streaks on flowers. [ 1 ] If a plant is also infected with the Cymbidium mosaic virus , it can lead to a condition called blossom brown necrotic streak.
Orchids are one of the most diverse and stunning groups of plants you can grow. Here are a few of our favorites, along with care tips.
Scale leaves on the bud of a pear tree Scale leaves on the caulis of a Tussilago. A scale leaf is a leaf with a reduced blade which is mainly formed by the amphigastrium. It can be dry, membranous or coriaceous, but also sometimes green. Scale leaves protect with their bud scales the leaves and flowers inside the bud from drying out in winter ...
Black rot on orchids is caused by Pythium and Phytophthora species. [1] Black rot targets a variety of orchids but Cattleya orchids are especially susceptible. [1] Pythium ultimum and Phytophthora cactorum are known to cause black rot in orchids. [1] Pythium ultimum is a pathogen that causes damping-off and root rot on plants. [2]