Dear Mani ji,
I Use phosphate, but mostly rely on compost fertilizers. I also add a lot of manure (cow dung) to it, Seems to be fruiting well for last 3 yrs . Yes my pot is big one .
Dear Satish ji,
My plant is not at all infected with cranker it developed because the fruits were developing in the shade of the leaf in hindi we tell " Patte ki daag" ..I grow them on terrace garden hence some times they end up developing near the wall and get hold of such spots. Plants infected with citrus canker have characteristic lesions on leaves, stems, and fruit with raised, brown, water-soaked margins, usually with a yellow halo or ring effect around the lesion. Older lesions have a corky appearance, still in many cases retaining the halo effect. The bacterium propagates in lesions in leaves, stems, and fruit. The lesions ooze bacterial cells that, when dispersed by windblown rain, can spread to other plants in the area. Infection may spread further by hurricanes. The disease can also be spread by from contaminated equipment, and by transport of infected or apparently healthy plants. Due to latency of the disease, a plant may appear to be healthy, but actually be infected.
Citrus canker bacteria [Xanthomonas axonopodis]can enter through a plant's stomata or through wounds on leaves or other green parts. In most cases, younger leaves are considered to be the most susceptible. Also, damage caused by Citrus Leaf Miner larvae (Phyllocnistis citrella) can be sites for infection to occur. Within a controlled laboratory setting, symptoms can appear in 14 days following inoculation into a susceptible host. In the field environment, the time for symptoms to appear and be clearly discernible from other foliar diseases varies; it may be on the order of several months after infection. Lower temperature increases the latency of the disease. Citrus canker bacteria can stay viable in old lesions and other plant surfaces for several months.
Regards
tanay