Hydro-Priming Effects as A Seed Pretreatment Technique on Early Growth, Development and Yield of Amaranthus thunbergii Accessions

Abstract

Two field experiment were carried out in Sebele (24^o33’S, 25^o54’E, 994 m above sea level) during summer 2021/2022. The treatments were two amaranthus accessions collected from South-Eastern region of Botswana as factor A while hydropriming (soaking in preheated water) for duration 0-control (no priming), 30 seconds, 60 seconds, and 90 seconds allocated as factor B. Hydro priming duration and accessions significantly (P < 0.05) influenced growth, phenological characteristics and development of amaranthus in both seasons of study. Amaranthus seed accessions and hydropriming significantly (P < 0.05) influenced the timing/duration of phenological stages. The time amaranthus seeds took from sowing to seedling emergence hastened with an increase in priming duration. This resulted with an average of  3-6.5 days to emerge from 90 seconds or control as the minimum or maximum days taken to reach emergence, respectively. However, when seeds were exposed to hydropriming for the longest time, days from sowing to branching, flowering and physiological maturity were significantly (P < 0.05) delayed. This means 90 seconds duration significantly (P < 0.05) resulted with the longest number of days from sowing to branching, flowering and physiological maturity whereas non primed seeds took the shortest time to mature.  There were many branches, largest leaf size, highest leaf fresh weight and seed yield when amaranthus seeds were primed for 90 seconds compared to control. In general, hydropriming for 90 seconds duration outperformed all other treatments producing total leaf fresh weight or seed yield of 10306 kgha^-1 or 3763 kgha^-1, respectively. Comparing accessions, the highest emergence percentage, growth and crop yield significantly (P < 0.05) resulted from accession 2 than 1. In conclusion, hydropriming had a significant role in improving phenology, early growth and yield of amaranthus accessions.