Optimization of plug size for mechanical transplanting of solanaceous vegetables

Studies were conducted on raising plug type nursery of solanaceous vegetable crops i.e tomato, brinjal, and chilli in three different cell sizes and two different media at different stages of crop growth for mechanical transplanting. The cell volumes of the three cells (C) studied were: 63.8 cm3 (C1), 18.70 cm3 (C2), and 16.28 cm3 (C3). Coco-peat, vermiculite and perlite in the ratio of 3: 1: 1 on volume basis (M1) and another media (M2) developed by Punjab Agricultural University (composition undisclosed) were studied. Same level of all plant growth parameters of tomato; plant height and spread diameter of brinjal; and stem diameter of chilli was achieved one stage earlier by using larger size cell C1 as compared to smaller cells C2 and C3, for the same media. Although higher values of stem diameter of brinjal, plant height and spread diameter of chilli were observed with the use of larger cell C1 as compared to smaller cells C2 and C3 for the same media, yet the effect of the cell size on these parameters was less pronounced. The use of media M2 instead of M1 in similar cells advanced the plant growth of tomato, brinjal, and chilli in terms of: plant height by 24 days, 50 days and less than 20 days respectively; stem diameter by less than 24 days, 65 days and 40 days, respectively; and spread diameter by 24 days, 65 days, and less than 20 days respectively. Plucking rating was highest in lowest cell size (C3) with media (M2) at higher stage of plant growth for all the crops.