Sprout suppression of potatoes (Solanum tuberosum Linn) by vapour heat treatment.

Four wk after harvest, potatoes were vapour heat treated with a RH of 95 plus/minus 5% at temp. of 60 degree C (15, 30 and 60 min), 65 degree C (15, 30 and 60 min) and 70 degree C (15 and 30 min). Treatments were given to (i) dormant tubers and (ii) 100% sprouted tubers. Treated tubers were stored in 0.2% ventilated polyethylene bags at 22-30 degree C and RH of 50-80%. The temp. of the peripheral zone of potatoes rose from 35.6 to 43.8 degree C within 5 min after treatment while the core temp. rose to 31.1 degree C from 26 degree C. Thereafter the temp. of core and periphery rose gradually reaching a max. of 46 and 50.1 degree C resp. in 60 min. Heat treatment did not markedly influence (i) but it suppressed the sprouting in (ii) for about 3 wk. Repeating the heat treatment after 3 wk resulted in further sprout suppression for 5 more wk.