Bunch disease in mango plants, also known as Mango Witches’ Broom (MWB), is a devastating phytoplasma-associated disease that affects mango trees worldwide. This disease poses a significant threat to mango cultivation as it causes severe yield reduction, leading to massive economic losses for farmers and impacting mango production on a large scale.
Bunch disease is caused by phytoplasmas, which are tiny bacteria-like organisms that reside within the phloem tissue of infected plants and are spread by various insect vectors such as leafhoppers and planthoppers. Once a mango tree is infected, the phytoplasma disrupts the tree’s normal growth and development, resulting in the characteristic symptoms of the disease.
One of the most noticeable symptoms of bunch disease is the formation of abnormally large, bushy, and compact clusters of shoots, resembling witches’ brooms. These brooms contain an excessive number of small, stunted, and chlorotic leaves, giving the tree a dense and unproductive appearance. Infected trees also exhibit delayed flowering, reduced fruit set, smaller and distorted fruits, premature fruit drop, and poor quality of the remaining fruits. These symptoms manifest progressively, and over time, the tree’s overall growth and productivity decline significantly.
Mango bunch disease has been reported in various mango-growing regions, including Asia, Africa, South America, and Australia. The severity of the disease can vary depending on several factors, including the mango variety, environmental conditions, and the presence of suitable insect vectors. Warm and humid conditions, coupled with a high population of leafhoppers and planthoppers, contribute to the rapid spread of bunch disease.
Effective management strategies are crucial to minimize the impact of bunch disease on mango production. Disease management primarily focuses on the control of insect vectors through integrated pest management (IPM) practices. IPM involves the use of mechanical, cultural, and biological control methods, along with the judicious application of insecticides when necessary. Regular monitoring of insect populations, timely pruning and destruction of infected plant parts, and maintaining orchard hygiene play a crucial role in preventing the spread of the disease.
In recent years, efforts have been made to develop resistant mango varieties through breeding programs. These efforts aim to provide farmers with resistant cultivars that can withstand or minimize the impact of bunch disease, reducing the need for intensive chemical control measures.
In conclusion, bunch disease in mango plants is a severe phytoplasma-associated disease that poses a significant threat to mango cultivation worldwide. Its impact on mango trees can be devastating, leading to reduced yields and economic losses for farmers. Effective disease management strategies, such as integrated pest management and the development of resistant cultivars, are essential for minimizing its impact and ensuring sustainable mango production.