Posts in the ‘Plant Health Care’ Category
Topping trees is bad for tree health!!
Topping trees lead to the decline of the trees health and eventually it can die. Topping is the indiscriminate cutting of tree branches to stubs or lateral branches that are not large enough to assume the terminal role. Other names for topping include “heading,” “tipping,” “hat-racking,” and “rounding over.”
It is a common fallacy that trees in Hawaii can survive the worst butchering that you can give them and they will always return. People assume that if the tree comes back to life and it is green that it is a healthy tree.
The truth is that a tree can appear to look healthy to the untrained eye and it can really be in a state of decline. It is just like a person that can have a disease and appear normal and healthy. These pictures are further proof that topping trees leads to their demise. These were once beautiful and healthy trees that should have been properly trimmed by a Certified Arborist.
For more info click here: http://www.treesaregood.org/treecare/topping.aspx 
Palm diseases threaten Hawaii’s coconut trees By Norman Bezona(in West Hawaii Today)
Palm diseases threaten Hawaii’s coconut trees
By Norman Bezona
Sunday, April 4, 2010 7:31 AM HST
A rash of palm deaths in Kona and Hilo has some folks fearing we may have a new disease on the island.
The state Department of Agriculture is always on the alert for pests like the one that hit South Florida several years ago. This disease killed most coconut and other susceptible palms in Florida and many other areas of the Caribbean.
We have been hearing a lot about a possible threat to Hawaii’s palms, as well as other tropical and subtropical regions. Our office receives frequent calls from fearful residents reporting sighting of the disease. After checking them out, most of the reports end up being palms with nutrient deficiencies, drought stress and poor pruning practices. Examples of this may be seen at the Palani entrance to the Makalapua shopping center and several areas around Keauhou. The problems appear to be caused by severe pruning practices in which too many leaves are removed. This combined with water stress is killing the trees.
So far, we have not found one case of lethal yellowing disease in Hawaii and hope that continued vigilance on the part of the Department of Agriculture and Hawaii’s citizens will ensure our freedom from this devastating disease.
Palms here have few serious diseases at present. Hawaii’s palms may be affected by bud rot or stem bleeding disease, which is often caused by physical damage such as unsanitary pruning equipment or climbing spikes. Most palms showing yellow or stunted growth have been found to be suffering from lack of fertilizer or water. For example, a recent report came from concerned citizens calling about the sickly palms at Crossroads Shopping Center area in Kailua-Kona. The trees simply need a balanced fertilizer plus minor elements, applied three to four times per year, and regular irrigation. All these problems are correctable, but if lethal yellowing ever gets in Hawaii, there’s no practical way of stopping destruction of our island’s palms. Not only would the coconut palm be destroyed, but more than 100 species of native and exotic palms would also die.
To realize the full potential threat of lethal yellowing, picture the streets of Waikiki and Kahala with tens of thousands of dying coconut palms in all stages of the disease, from the early brassy yellowing of the lower fronds through the collapsing of the crown and the final “telephone poling” when there is nothing more than a naked trunk.
This disease, originally thought to be a disease exclusively of coconut palms, occurs in the West Indies, Florida, Texas, Mexico and Africa. A similar disease occurs in the Philippines.
Lethal yellowing hit Key West, Fla., in the middle 1950s. After a number of years and killing three-fourths of the coconut palms, it stopped. In the early 1970s, it was found in the Greater Miami area. Since the Jamaica tall coconut palm is the one that had been planted almost exclusively in Florida, the disease ran rampant. By 1980, most coconut palms in south Florida were dead.
Research at the Coconut Industry Board in Kingston, Jamaica, has shown that all varieties of coconuts are susceptible to lethal yellowing. The degree of susceptibility has been the point for developing varieties that are resistant. On the one end of the scale, the Jamaica tall coconut is about 100 percent susceptible. On the other end, the dwarf types are slightly susceptible. Crosses of the dwarf and tall are fairly resistant.
When lethal yellowing hit the Florida mainland, it was discovered that many other palms are also susceptible to the disease in varying degrees. According to the University of Florida Lethal Yellowing Research Station in Fort Lauderdale, hundreds of other palms are susceptible, like the Manila, fishtail, loulu, date, oil and many others.
Mycoplasma-like organisms, which occupy a niche between a virus and a bacteria, are the cause of lethal yellowing. Mycoplasma-like cells have been found in tissues of all diseased palms examined by the University of Florida scientists. They appear to be transmitted by a leafhopper. Remember, neither the disease or leaf hopper have been found in Hawaii.
Florida began a two-stage program to replant the affected areas. Over half a million Malayan dwarf seed nuts were planted. The Malayan, while highly resistant to the disease, requires more care and is more subject to scale infestation in Florida. It also does not grow without adequate watering. To overcome this difficulty, Florida researchers started a hybridization project crossing Malayan palms with Panama talls that have shown resistance to lethal yellowing in Jamaica. The resulting Maypan is highly resistant and also grows with more vigor similar to the Jamaica talls.
Another approach is the addition of other species of palms which have shown resistance to lethal yellowing. The International Palm Society and University of Florida cooperated on a project to use more palms not susceptible the disease. One of the promising palms is Heterospathe elata, the Sagasi palm, which shows complete resistance so far and thrives in south Florida. It is a beautiful palm with a silhouette similar to a small-sized coconut and tiny pea-sized fruit. Other resistant palms so far seem to be royals, Ptychospermas, Arecastrum, Dypsis, Washingtonias, Sabals and Rhapis.
What is the threat to Hawaii? Transporting plants, especially palms from affected areas, could introduce the disease. It is essential to work with the Department of Agriculture and Plant Quarantine folks to have all imported plants inspected. Above all, do not smuggle in plants. This is how we got the spiraling whitefly, banana bunchy top disease and many other serious pests.
So be sure to follow the rules and regulations developed to protect our islands. Also be aware that there are very stiff fines for bringing plants or animals into the islands without the proper permits and inspection.
If you are interested in learning more about palms, contact the Hawaii Island Chapter of the International Palm Society. The president is Don Hemmes at the University of Hawaii at Hilo. For membership, call Grace Kissell at 963-6707. A meeting and tour is scheduled for April 11 at Bill Austin’s Garden and nursery.
Also in April is the International Palm Society meeting in Brazil. May 16 will be a tour of palm gardens in Kona. July 25 is a tour and meeting on palms and cycads at Panaewa Rainforest Zoo.