Mumbai, May 21 -- NCDEX Guargum futures fell today, giving up after recent gains as markets eyed possibility of an early start to the monsoon rainfall this season. The benchmark NCDEX Guargum futures had neared a one-month high of Rs 10000 per tone yesterday but saw a sizable correction today amid mostly downbeat moves in major agri coutners. The India Meteorological Department (IMD) has forecast an early arrival of the southwest monsoon in Kerala. Conditions are likely to become favourable for monsoon onset over Kerala during next 4-5 days, the IMD said in an update yesterday. This marks the earliest onset on the Indian mainland since 2009. Guar seed is primarily a rainfed crop and this positive update on monsoon has pulled both the Guarse...