Can tea pruning litter biochar be a friend or foe for tea (Camellia sinensis L.) plants' growth and growth regulators?: Feasible or fumes of fancy

A mammoth amount of tea pruning litter (TPL) is generated through the pruning of the tea plant and kept on the soil surface which makes the soil sick due to the accretion of allelochemicals from it. Therefore, appropriate management of TPL is very much crucial. This study was conducted to assess the role of tea pruning litter biochar (TPLBC) as a soil conditioner towards the growth and regulations of two popularly grown tea cultivars (TV23 and S.3A/3) in India. Altogether twenty-nine (29) parameters comprising functional groups, plant biomass, and physiological and biochemical properties have been reported in this study to understand the feasibility of TPLBC for tea cultivation. TPLBC amendment of 400 kg ha−1 was best suited for the used cultivars, leading to an increase in chlorophyll content, photosynthetic rate, stomatal conductance, transpiration rate, and water use efficiency by 25.68%, 49.61%, 84.00%, 126.93%, and 3.87% respectively. The maximum increase in plant total biomass, shoot biomass, and root biomass was attended at 110%, 31%, and 117%, respectively at 400 kg TPLBC ha−1 over control. The results also revealed an increase in the content of sugar, starch, phenol, total polyphenol, and amino acids with an increasing dose of TPLBC up to 400 kg ha−1. However, with 500 kg ha−1 TPLBC, plant biomass, and polyphenol content were decreased but oxidative stress was increased. Considering all the 29 variables it can be concluded that the soil amendment with 400 kg TPLBC ha−1 was most promising for both TV23 and S.3A/3 clones.