EVALUATION OF PLANT GROWTH AND YIELD OF PAKCHOI UNDER DIFFERENT LED-LIGHT SPECTRUM IN VERTICAL GROW-HOUSE

Abstract

The present study was carried out at the roof top (indoor structure) of Dr. M. Wazed Mia Central Laboratory, Sher-e-Bangla Agricultural University, Dhaka. during the period from November 2020 to December 2020 to study the improvement of plant growth and yield of Pakchoi under different LED-light spectrum in vertical farming. Six treatments of the experiment viz. (i) T (Fluorescent light – Full; control), (ii) T W (White - Full), (iii) T R (Red - Full), (iv) T FL-T5 ii B (Blue - Full), (v) T (Red and Blue - 4:1) and (vi) T RBG RB (Red, Blue with Green - 4:1:1) were laid out in a Randomized Complete Block Design (RCBD) with three replications. PPFD of different LED light was maintained at 115 µmol/m 2 /s and duration was 16 hrs per day. Results showed that the highest plant height (24.41 cm), number of leaves plant -1 (14.33) and leaf breadth (9.10 cm) were found from the treatment T (Red and Blue - 4:1) but the highest leaf length (18.23 cm) was from the treatment T RB (White - Full) whereas the lowest plant height (17.68 cm), number of leaves plant -1 W (9.00), leaf length (16.50 cm) and leaf breadth (4.22 cm) were found from the treatment T (Red - Full). Treatment T RB R (Red and Blue - 4:1) also registered the highest stem diameter (1.20 cm), average diameter of whole plant (8.24 cm), leaf base breadth (1.92 cm), fresh weight plant (336.67 g), total yield (1.29 kg) and total soluble solids (9.24 °Brix) but the highest vitamin-C content (41.81 mg/100g) was achieved from T (Red, Blue with Green - 4:1:1) whereas T B RBG (Blue - Full) gave the highest SPAD value (42.04) and moisture content (94.12%). The lowest stem diameter (0.70 cm) was recorded from the treatment T (Blue - Full) but the lowest diameter of whole plant (6.08 cm), fresh weight plant B -1 (120.00 g), leaf base breadth (1.36 cm) and total yield (0.18 kg) of the experimental area were recorded from the treatment T (Red, Blue with Green - 4:1:1). T W (White - Full) showed lowest SPAD value (34.60) but T RBG (Red - Full) gave the lowest vitamin-C content (38.24mg/100g). From the above results, the treatments of different LED-light spectrum in vertical farming, T RB R (Red and Blue - 4:1) can be considered as the best treatment followed by control treatment T (Fluorescent light - Full) among all the treatments.