Christmas tree pests and weeds The pathogen often makes Douglas fir trees unsalable as Christmas trees and affects the Christmas tree farming industry. Douglas firs are also affected by "Phaeocryptopus gaumanni" which causes Swiss needlecast. Red band needle blight is a fungal disease which affects coniferous trees, particularly pine, with a worldwide distribution. The disease is caused by the fungi "Dothistroma septosporum". Since the late 1990s its appearance in the United Kingdom has increased, among the most affected species is Corsican pine and the disease has been a significant problem in Thetford Forest. Though the disease spread rapidly during September 2007 Christmas tree growers remained
Search tree their node length, B-trees are optimized for systems that read large blocks of data. They are also commonly used in databases. The time complexity for searching a B-tree is O(log n). An (a,b)-tree is a search tree where all of its leaves are the same depth. Each node has at least a children and at most b children, while the root has at least 2 children and at most b children. a and b can be decided with the following formula: formula_1 The time complexity for searching an (a,b)-tree is O(log n). A ternary search tree is a type of