questions: query about disease(yellow  leaf disease) of arecanut. 
 answers: 1. spray bordeaux mixture 1%.
2. application of npk fertilizers as per schedule along with lime and zinc @ 8.5 g each per palm.
3. physical condition of the soil should be improved by deep digging and adding sand/organic matter. in heavy sticky soils, gypsum @ 500 kg / ha may not be incorporated, once in two years prior to normal fertilizer application.
4. adequate drainage should be provided, especially during monsoon season.