September 2013. A little leaf symptom on mango from Karimnagar district, Andra Pradesh.
Members thought that it was caused by boron deficiency. Test the leaves. Dwarfed and clustered young leaves and blossom often indicate boron problems. There is no need to prune before spraying with boron.
Later, more photos were sent of the problem on 2-year old plants (photo, left). These were very similar to those first sent by the member from Karimnagar. In response, a member from India wrote the following:
The mango plants shown in the three photographs are suffering from Vegetative Malformation, of the dreaded Mango Malformation (MM) (photo, right). MM is known by two phases: Vegetative malformation, appearing generally on young seedlings but also on vegetative parts of trees, and floral malformation, appearing on floral parts (panicles) of bearing trees.
- Diseases seedlings should not be used any further but discarded.
- Using scion shoots during ‘off season’ from those branches of theadult trees which bore malformed panicles during ‘on’ year for the purpose of making veneer grafts always yield vegetatively malformed seedlings.
- No treatment exists for curing diseased seedlings.
- If possible, please refer to my article 100 years of mango malformation that appeared in Annual Review of Phytopathology (1992) for greater details of the malady.
Another suggestion was zinc deficiency which is seen in (North Western Victoria) Australia on alkaline, sandy soils. It is available at: http://www.soilzone.com/Library/Crops/Deciduous%20Fruit/Nutrition/Mineral%20deficiencies.pdf, or by clicking here. Typical zinc deficiency shows up as small leaves clustered together on short stem internodes. Leaves have bright yellow blotches with the main vein remaining green.
Later (October), a photo of vegetative malformation was sent from Orissa. It looked similar to the other photos, but did not take the matter further.