Effect of plant growth substances, tuber sizes and removal of sprouts on growth, yield and multiplication rate of potato

Seed tubers of two sizes (61.1 and 156.8 g) were treated with plant growth substances (PGS) (GA₃-2 ppm, GA₃-2 ppm + thiourea-1% and water) before keeping them for sprouting under moist sand. Sprouts were detached either once, twice or thrice from the same tuber before planting on 1st Oct./1st flush, 16th Oct/2nd flush and 4th Nov./3rd flush. These tubers were compared with normal tubers and sprouts. Stems/hill decreased with increase in sprout flush number. Plant height and number or leaves were highest in 1st Oct./1st flush and lowest in 4th Nov./3rd flush. Haulm weight was highest in 16th Oct./2nd flush and lowest in 4th Nov./3rd flush. PGS did not influence growth and yield. Sprouts could not compete with tubers for growth and yield. Tuber yield was maximum in 16th Oct./2nd flush and minimum in 1st Oct./1st flush. Normal tubers performed better for growth and yield than those tubers from which sprouts were detached. Mulliplication rate (MR) increased with increase in flush number and seed size tubers recorded higher MR on weight basis than over-size ones. MR for seed size tubers was 8.8, 15.4, 17.1 times on weight basis where one, two or three flushes were taken, respectively, as compared to 4.2–7.2 recorded for normal tubers.