page_title: Pinus elliottii
section_title: Fusiform rust
hierarchical_section_title: Pinus elliottii / Diseases and pests / Fusiform rust
caption_attribution_description: Pitch canker (Symptoms)on slash pine (Pinus elliottii Engelm.) Fusarium circinatum Nirenberg &amp; O'Donnell Image location: United States This image contains digital watermarking or credits in the image itself. The usage of visible watermarks is discouraged. If a non-watermarked version of the image is available, please upload it under the same file name and then remove this template. Ensure that removed information is present in the image description page and replace this template with {{metadata from image}} or {{attribution metadata from licensed image}}. Caution: Before removing a watermark from a copyrighted image, please read the WMF's analysis of the legal ramifications of doing so, as well as Commons' proposed policy regarding watermarks. If the old version is still useful, for example if removing the watermark damages the image significantly, upload the new version under a different title so that both can be used. After uploading the non-watermarked version, replace this template with {{superseded|new filename|version without watermarks}}. العربية&#160;| català&#160;| čeština&#160;| Deutsch&#160;| Ελληνικά&#160;| English&#160;| español&#160;| eesti&#160;| فارسی&#160;| suomi&#160;| français&#160;| galego&#160;| עברית&#160;| hrvatski&#160;| magyar&#160;| italiano&#160;| 日本語&#160;| македонски&#160;| മലയാളം&#160;| Plattdüütsch&#160;| Nederlands&#160;| polski&#160;| português&#160;| română&#160;| русский&#160;| slovenščina&#160;| svenska&#160;| ไทย&#160;| українська&#160;| 中文&#160;| 中文（简体）‎&#160;| 中文（繁體）‎&#160;| +/−
context_page_description: Pinus elliottii, commonly known as slash pine, is a conifer tree in the Southeastern United States. Slash pine is named after the "slashes" – swampy ground overgrown with trees and bushes – that constitute its habitat. Other common names include swamp pine, yellow slash pine, and southern Florida pine. Historically, slash pine has been an important economic timber for naval stores, turpentine, and resin. Slash pine has two different varieties: Pinus elliottii var. elliottii and Pinus elliottii var. densa.
context_section_description: Starting in the late 1950s the emergence of Fusiform rust on South Eastern pine trees including slash pine (Pinus elliottii), loblolly pine, (Pinus taeda), and longleaf pine, (Pinus palustris) led to massive tree mortality within the pine industry. This obligate parasitic pathogen is notorious for infecting young trees in newer planted areas within the first 1–5 years of growing. The pine industry was still rather new at the time of this initial outbreak, therefore, many newly planted forests had large-scale mortality because the trees were not yet old enough to be resilient to the disease or harvested. Florida’s pine industry in particular was booming with an increase in plantation acreage from 291,000 acres (118,000 ha) in 1952 to upwards of 5.59 million acres (2,260,000 ha) in 1990. Because of the complicated lifecycle of Cronaritum quercuum f. sp. fusiforme, the fungal causal agent of Fusiform Rust, the management strategies of pruning diseased stems, reducing fertilization, and discarding infected seed were not sufficient enough to prevent million dollar annual loses.
  Rust pathogens are difficult to manage because of their complicated reproductive life cycles. Cronaritum querecuum f. sp. fusiforme is heteroecious, requiring two different plant hosts for reproduction, and is macrocyclic, meaning it contains all five spore stages typical for rust infections: basidiospores, teliospores, urediniospores, aeciospores, and spermatia. Oak trees are the secondary host for this pathogen. The primary inoculum on pine are basidiospores which infect the pine needles in spring between March and May. The basidiospores germinate and grow into the stems of the tree where the fungus can overwinter for 4–6 months in the wood. In the fall, the spermatia forms and fertilizes the aceiospores in the following spring. The aceiospores are released from the pine and are the primary inoculum that infect the oak trees in the following growing season. Aceiospores grow through the oak leaves producing urediniospores on the underside of the oak leaves. These urediniospores can reproduce clonally, asexually, and can continue to infect oak plants as a secondary inoculum. Within two weeks of the primary urediniospore inoculation on the oak tree, teliospores are formed which germinate into basidiospores that infect the pine trees and complete the life rust cycle. Symptoms on the pine include gall formation, stem swelling, cankers, bushiness, and dieback. The cankers in the stem allow secondary fungal infections or other pests to enter the trees easily.
  Understanding the climate conditions that can lead to rust outbreaks is an important component for management strategies, but this was not well understood in the early decades of this epidemic. More recent information has shown that certain weather patterns such as high humidity, wet pine needles, and temperatures around 15–29 °C (59–84 °F) for approximately 18 days can increase the spread of basiodiospores and therefore increase disease severity.  
  The secondary host, oak, is another economically and ecologically important tree in the south east. Therefore, eradication of the secondary host is not only not possible but also not effective because basidiospores can travel up to a half mile, easily infecting pine trees that are far away. Therefore, a combination of management strategies such as reducing fertilization treatments (which can benefit the pathogen), planting more rust-disease resistant trees in plantations and reintroducing fire to reduce the oak trees within the forest may help to reduce disease incidences.
caption: Example of Pitch Canker symptoms on a slash pine tree
exif: {}