Brinjal prices increase to Rs 40 a kilo in July 2018

In July 2018, the brinjal prices have increased rapidly and reached Rs 40 a kilo in panaji, goa
The cheaper round variety of brinjal, which cost Rs 15-20 a kilo or 5-7 small brinjals for Rs 20 are not available in the market
Only the longer and thin variety of brinjal is available
However one small brinjal is costing Rs 8
It would be interesting to find out why the smaller brinjals have disappeared from the market