Bangladesh Agron. J. 2023, 26(1): 9-17 EFFECT OF LEAF CLIPPING ON GROWTH AND YIELD OF BLACKGRAM (Vigna mungo L.) A. Sultana1, M.F. Karim1, M.H. Mahmud2*, S.C. Sarker1 and M.D. Hossain3 1Department of Agronomy, Sher-e-Bangla Agricultural University, Dhaka-1207, Bangladesh 2Project Implementation Unit-BARC, NATA-Phase-II Project, BARC, Dhaka-1215, Bangladesh 3Bangladesh Wheat and Maize Research Institute, Regional Station, Jamalpur, Bangladesh *Corresponding author, Email: h.mahmud193@gmail.com (Received: 18 April 2023, Accepted: 11 September 2023) Keywords: Pulse crop, source-sink relationship, leaf clipping, blackgram, seed yield Abstract An experiment was conducted at Sher-e-Bangla Agricultural University farm, Dhaka to investigate the effect of variety and leaf clipping on the growth and yield of blackgram (Vigna mungo L.) from March to June-2019. The experiment was laid out in a split-plot design with three replications. The treatments were Blackgram variety (3); V1: BARI Mash-1, V2: BARI Mash-2 and V3: BARI Mash-3, and leaf clipping (4); C0: No leaf clipping (control), C1: Clipping of 1st basal leaf, C2: Clipping of 2nd basal leaves and C3: Clipping of total apical leaves having no inflorescence. Growth, yield and yield contributing characteristics were compared under different treatments. Results indicated that variety and leaf clipping significantly affected most of the growth and yield contributing characteristics of blackgram. In the case of variety, mthe aximum value of the yield and yield contributing characteristics such as pod−1 length (8.99 cm), pods plant−1 (14.00), number of seeds pod−1 (9.78), 1000 seeds weight (48.58 g), and seed yield (1381.70 kg ha−1), were observed in var. BARI Mash-3. In the case of leaf clipping, maximum pod length (8.44 cm), pods plant−1 (15.18), seeds pod (9.32), 1000- seeds weight (48.33 g), seed yield (1306.7 kg ha−1), was recorded in Clipping of 1st basal leaf treatment. The blackgram var. BARI Mash-3 and clipping of 1st basal leaf was found superior in producing maximum pod length (9.32 cm), number of pods plant−1 (16.87), number of seeds pod−1 (10.80), 1000- seeds weight (51.67 g), and seed yield (1456.70 kg ha−1). So, var. BARI Mash- 3 and clipping of 1st basal leaf may improve the growth and yield of blackgram. Introduction Pulses constitute an integral part of the human diet and are a potential source of protein for the millions of people of Bangladesh. The per capita pulse consumption in Bangladesh is only 14.3 g day−−1, much lower than the WHO recommendation of 45 g day−1 and the Indian Council of Medical Research recommendation of 60 g day−1 (Afzal et al., 1999; HIES, 2010). Among the pulses, blackgram is very much popular in Bangladesh and ranks 3rd in terms of consumption and total area in which different varieties of this crop are cultivated (BBS, 2021). Bangladesh Agricultural Research Institute (BARI) developed several high-yielding varieties such as BARI Mash- 1, BARI Mash-2, BARI Mash-3, and BARI Mash-4 (BARI, 2019). But farmers generally grow the local varieties, which affects the seed yield. Cutting leaves from the plant is known as leaf clipping for better growth and development. Photosynthetic active radiation is the major factor regulating photosynthesis and other physiological processes in plants. The dry matter production and yield depends on it to a greater extent. Shading at both 50 and 75% of the full sunlight had significant negative effect on leaf area index (16 - 35%), total dry matter production (11 - 18%), grain yield (19 - 32%) of pulses over full sunlight (Monoj et al., 2019). Defoliation or leaf damage can decreases assimilate availability during grain filling, seed and biological yield (Echarte et al., 2006). 10 Sultana et al. Defoliation up to a certain limit may be useful to overcome this problem of excessive vegetative growth. Rao and Ghildiyal (1985) stated that the remaining leaves of defoliated plant had higher net photosynthetic rate (Pn) than intact plant improving yield. In Bangladesh, few studies have been conducted to determine the effect of variety and leaf clipping on the growth and yield of blackgram. Considering the above facts, the study was undertaken to find out the suitable variety and optimum level of leaf clipping on blackgram seed production. Materials and Methods The experiment was conducted in the Agronomy field of Sher-e-Bangla Agricultural University (SAU). The experimental site is geographically situated at 23°77ʹ N latitude and 90°33ʹ E longitude and the Agro-ecological zone (AEZ) of “The Modhupur Tract”, AEZ-28. The treatments were Blackgram variety (3): V1=BARI Mash-1 V2=BARI Mash-2 V3=BARI Mash-3 and Leaf clipping (5): C0=No leaf clipping (control), C1=Clipping of 1st basal leaf, C 2=Clipping of 2nd basal leaf and C3=Clipping of total apical leaves having no inflorescence. The experiment was laid out in a split-plot design having 3 replications. Blackgram varieties are assigned in the main plot, and leaf clipping treatment is in sub- plot. Fertilizers were applied in the doses of 45, 90, 40, 55, and 10 kg ha−1 for urea, TSP, MoP, gypsum, and boric acid, respectively. Seeds were sown at the rate of 35 kg ha−1 in the furrow 30cm apart rows at about 2-3 cm depth and treated with bavistin before sowing the seeds to control the seed-borne diseases. Leaf clipping was done at 30 DAS according to treatment variables. Harvesting was done once when 90% of the pods became brown to black in color. Harvest index was calculated on dry basis with the help of following formula. Harvest index (HI%) = Seed yield Biological yield × 100 The collected data were compiled and analyzed statistically using comuter package program Statistix 10 Data analysis software and the mean differences were adjusted by Least Significant Difference (LSD) test at a 5% level of probability (Gomez and Gomez, 1984). Results and Discussion Plant height Variety, leaf clipping and treatment combination has showed significant variation on plant height of blackgram at different days after sowing (DAS) (Table 1). The maximum plant height (11.88, 28.35, 47.75, and 53.75 cm at 15, 30, 45 DAS and harvest, respectively) was observed from var. BARI Mash-3 t, which was statistically similar to var. BARI Mash-2 at 30 DAS (26.99 cm) and at harvest (51.67 cm) respectively. Whereas the minimum plant height was observed from BARI Mash-1. The probable reason for this may be the varietal potentiality of the plant. The present study was similar to the findings of Siddikee et al. (2018). At 15 DAS maximum plant height (11.50 cm) was observed in clipping of 1st basal leaf treatment, at 30 DAS maximum plant height (27.80 cm) was observed in no leaf clipping treatment which was statistically similar to clipping of 2nd basal leaves and clipping of 1st basal leaf treatment, and at 45 DAS and harvest, respectively the maximum plant height (48.24 cm and 55.20 cm) was observed in clipping of 1st basal leaf treatment. Whereas the minimum plant height at 15 days (10.96 cm) was observed in clipping of 2nd basal leaves treatment which was statistically similar with clipping of total apical leaves having no inflorescence and no leaf clipping, and at 30, 45 DAS, and at harvest, respectively, the minimum plant height (25.51, 41.24, and 47.22 cm, respectively) was observed in clipping of total apical leaves having no inflorescence treatment. Removal of leaves in certain levels may influence growth if the old or bacterial or pest infested leaves or sunburned leaves were Effect of leaf clipping on growth and yield of blackgram 11 removed. The maximum plant height (12.19 cm and 29.32 cm) at 15 DAS and 30 DAS was observed in BARI Mash-3 with no leaf clipping and (53.07 cm and 58.23 cm) at 45 DAS and at harvest was observed in BARI Mash-3 with clipping of 1st basal leaf treatment combination. Whereas the minimum (10.07 cm) at 15 DAS was observed in BARI Mash-2 with no leaf clipping. At 30, 45 DAS, and harvest, the minimum plant height (24.03, 38.63, and 45.20 cm, respectively) was observed in BARI Mash-1 with clipping of total apical leaves having no inflorescence. Table 1. Effect of variety, leaf clipping and combination of treatment on the plant height and branch no. plant−1 of blackgram at different DAS Plant height (cm) Branch no plant−1 15 DAS 30 DAS 45 DAS At harvest 30 DAS 45 DAS At harvest Variety V1 10.61c 25.83b 40.96c 48.19b 0.43c 3.27c 4.15c V2 10.91b 26.99a 44.58b 51.67a 0.57b 4.67b 5.68b V3 11.88a 28.34a 47.75a 53.75a 0.85a 6.28a 6.88a LSD (0.05) 0.52 1.55 2.11 2.34 0.05 0.18 0.35 Leaf clipping C0 11.06b 27.80a 44.77b 51.92b 0.53c 4.53b 5.33b C1 11.50a 27.46a 48.24a 55.20a 0.91a 4.91a 5.91a C2 10.96b 27.47a 43.48b 50.47b 0.64b 4.87a 5.60b C3 11.01b 25.51b 41.24c 47.22c 0.38d 4.64b 5.24c LSD (0.05) 0.40 1.21 1.67 1.83 0.04 0.14 0.29 Combination of treatment V1C0 10.93 cd 26.60 cd 40.00 ef 45.97 fg 0.47 ef 3.33 ef 4.13 e V1C1 10.73 de 26.11 c-e 43.70 cd 52.53 cd 0.53 e 3.53 e 4.33 e V1C2 10.36 de 26.60 cd 41.50 d-f 49.07 ef 0.40 fg 3.27 f 4.27 e V1C3 10.41 de 24.02 e 38.63 f 45.20g 0.33 g 2.93 g 3.87 e V2C0 10.07 e 27.49 a-d 45.90 bc 53.60 bc 0.67 d 4.73 cd 5.67 cd V2C1 12.05 a 27.11 b-d 47.97 b 54.83 bc 0.80 c 4.53 d 6.13 c V2C2 10.49 de 27.73 a-d 42.93 d 50.00 de 0.40 fg 4.87 c 5.73 c V2C3 11.03 b-d 25.67 de 41.53 de 48.23 e-g 0.40 fg 4.53 d 5.20 d V3C0 12.19 a 29.32 a 48.40 b 56.20 ab 0.47 ef 5.53 b 6.80 ab V3C1 11.73 ab 29.15 ab 53.0 7 a 58.23 a 1.40 a 6.67 a 7.27 a V3C2 12.03 a 28.09 a-c 46.00 bc 52.33 cd 1.13 b 6.47 a 6.80 ab V3C3 11.59 a-c 26.83 cd 43.55 cd 48.23e-g 0.40 fg 6.47 a 6.67 b LSD (0.05) 0.70 2.10 2.89 3.17 0.07 0.25 0.51 CV (%) 3.67 4.53 3.79 3.61 6.62 3.05 5.28 In a column means having similar letter(s) are statistically similar and those having dissimilar letter(s) differ significantly at 0.05 level of probability. V1: BARI Mash-1, V2: BARI Mash-2, and V3: BARI Mash-3, and C0: No leaf clipping (control), C1: Clipping of 1st basal leaf, C2: Clipping of 2nd basal leaves and C3: Clipping of total apical leaves having no inflorescence Branches plant−1 Variety, leaf clipping and treatment combination has showed significant variation on the branches plant−1 of blackgram (Table 1). The maximum number of branches plant−1 (0.85, 6.28 and 6.88) at 30, 45 DAS, and at harvest, respectively) was observed in BARIMash-3 treatment. Whereas numerically, the minimum number of branches plant−1 (at 30, 45 DAS, and at harvest, 12 Sultana et al. respectively) was observed from BARI Mash-1. Probably the varietal performance was responsible for the variation in branches plant−1 of blackgram. Sunil et al. (2020) was also found similar results which supported the finding. The maximum number of branches plant−1 (0.91, 4.91, and 5.91 at 30, 45 DAS, and at harvest, respectively) was observed in clipping of 1st basal leaf treatment, which was statistically similar to clipping of 2nd basal leaves treatment at 45 DAS. Whereas the minimum number of branches plant−1 (0.38) at 30 DAS was observed in clipping of total apical leaves having no inflorescence treatment, at 45 DAS, the minimum number of branches plant−1 (4.53) was observed in no leaf clipping, which was statistically similar with clipping of total apical leaves having no inflorescence and, at harvest, respectively, the minimum (5.24) was observed in clipping of total apical leaves having no inflorescence treatment, which was statistically similar with no leaf clipping (5.53) treatment during harvest. This could be that these lower leaves, only use photo assimilate for their maintenance apart from losing carbon for respiration. Their removal has certainly helped to get more assimilate on the other parts and thereby enhance plant growth and development, but clipping of total apical leaves having no inflorescence caused injury damages to the plant. As a result, energy was being lost to makeup the injury and plant growth became detritions as a result the number of branches became pore in this part. Ahmed (2017) was also found similar results. The maximum number of branches plant−1 (1.40, 6.67, and 7.27 at 30, 45 DAS, and at harvest, respectively) was observed in BARI Mash-3 with clipping of 1st basal leaf treatment combination. Whereas numerically, the minimum number of branches plant−1 (0.33, 2.93, and 3.87 at 30, 45 DAS, and at harvest, respectively) was observed in BARI Mash-1 with clipping of total apical leaves having no inflorescence treatment combination. Above ground dry weight plant−1 The above-ground dry matter weight plant−1 of blackgram was not significantly influenced blackgram variety except for leaf clipping and treatment interaction (Table 2). The maximum above-ground dry-weight plant−1 (1.59 g) was observed from no leaf clipping treatment at 15 DAS, which was statistically similar to clipping of 1st basal leaf treatment (1.57 g), at 30 DAS, numerically the maximum above-ground dry weight plant−1 (4.78 g) was observed form clipping of 1st basal leaf treatment which was statistically similar with no leaf clipping. At 45 DAS and harvest, respectively, the maximum above-ground dry-weight plant−1 (6.48 and 8.73 g) was observed in no leaf clipping treatment, which was statistically similar to all other treatments except clipping of total apical leaves having no inflorescence treatment at 45 DAS. Whereas the minimum above-ground dry weight plant−1 (1.51 g) was observed from clipping of 2nd basal leaves at 15, 30, 45 DAS, and at harvest respectively, the minimum above-ground dry-weight plant−1 (4.61, 6.19, and 7.22 g) was observed form clipping of total apical leaves having no inflorescence, which was statistically similar with clipping of 2nd basal leaves at 30 DAS and at harvest respectively. Sultana et al. (2013) was also found similar results. The maximum above-ground dry weight plant−1 (1.67, 5.63, 8.03, and 10.13 g at 15 DAS, 30 DAS, 45 DAS, and at harvest, respectively) was observed in BARI Mash-3 with no leaf clipping treatment combination, whereas the minimum above-ground dry weight plant−1 (1.47 g) was observed in BARI Mash-2 with clipping of total apical leaves having no inflorescence at 15 DAS, at 30 DAS (4.07 g) was observed in BARI Mash- 2 with clipping of 2nd basal leaves, at 45 DAS (4.80) was observed in BARI Mash-1 with clipping of 1st basal leaf and at harvest (5.94 g) was observed in BARI Mash-1 with clipping of 2nd basal leaves treatment combination. Pod length plant−1 Variety, leaf clipping and treatment combination has showed significant variation on pod length of blackgram (Table 2). The maximum pod length of blackgram (8.99 cm) was observed in BARI Mash-3. In contrast, the minimum pod length plant−1 of blackgram (7.67 cm) was observed in BARI Mash-1 which was statistically similar with BARI Mash-2. The probable reason for this Effect of leaf clipping on growth and yield of blackgram 13 may be the genetically potential of the variety that has helped in increasing pod length of blackgram variety. Sunil et al. (2020) and Siddikee et al. (2018) found similar result. The maximum pod length of blackgram (8.44 cm) was observed in clipping of 1st basal leaf treatment which was statistically similar with no leaf clipping and the minimum (7.95 cm) in clipping of total apical leaves having no inflorescence treatment which was statistically similar with clipping of 2nd basal leaves. Leaf removal, may, therefore, influence yield and yield contributing characters through photosynthate production and its distribution into plant parts depending on the magnitude of clipping of leaves. (Biswas et al., 2005). The maximum pod length of blackgram (9.32 cm) was observed in BARI Mash-3 with clipping of 1st basal leaf, whereas the minimum pod length plant−1 (7.42 cm) was observed in BARI Mash-1 with clipping of total apical leaves having no inflorescence treatment combinations. Number of pods plant−−1 Variety, leaf clipping and treatment combination has showed significant variation on number of pods plant−−1 of blackgram (Table 2). Table 2. Effect of variety, leaf clipping and combination of treatment on the above ground dry weight/plant (g), pod length (cm) and pod plant−−1 of blackgram Treatment Above ground dry weight/plant (g) Pod length (cm) Pods plant−1 (No) 15 DAS 30 DAS 45 DAS At harvest Variety V1 1.52b 4.45b 5.03c 6.38c 7.66b 11.75c V2 1.51b 4.11c 6.40b 7.65b 7.82b 13.32b V3 1.62a 5.51a 7.84a 9.50a 8.99a 14.00a LSD(0.05) 0.08 0.18 0.30 0.52 0.38 0.54 Leaf clipping C0 1.59a 4.76ab 6.48a 8.73a 8.16ab 12.11c C1 1.57a 4.78a 6.40ab 7.98b 8.44a 15.18a C2 1.51b 4.63b 6.63a 7.45c 8.04b 12.91b C3 1.52b 4.61b 6.19b 7.22c 7.95b 11.89c LSD(0.05) 0.06 0.14 0.24 0.40 0.31 0.40 Combination of treatment V1C0 1.59 ab 4.51 cd 4.84 e 7.19 de 7.83 cd 11.47 de V1C1 1.49 bc 4.61 c 4.80 e 6.20 fg 7.92 cd 12.40 c V1C2 1.48 bc 4.31 d-f 5.57 d 5.94 g 7.49 d 12.13 cd V1C3 1.51 bc 4.39 c-e 4.89 e 6.17 fg 7.42 d 11.00 e V2C0 1.51 bc 4.14 ef 6.57 b 8.87 c 7.70 cd 12.40 c V2C1 1.58 a-c 4.17 ef 6.55 b 7.80 d 8.08 c 16.27 a V2C2 1.48 bc 4.07 f 6.49 b 7.19 de 7.56 cd 12.40 c V2C3 1.47 c 4.09 f 5.99 c 6.74 ef 7.79 cd 12.20 c V3C0 1.67 a 5.63 a 8.03 a 10.13 a 8.93 ab 12.47 c V3C1 1.64 a 5.55 ab 7.84 a 9.92 ab 9.32 a 16.87 a V3C2 1.57 a-c 5.51 ab 7.82 a 9.22 bc 9.09 ab 14.20 b V3C3 1.59 ab 5.35 b 7.68 a 8.75 c 8.63 b 12.47 c LSD(0.05) 0.11 0.25 0.42 0.70 0.53 0.70 CV (%) 4.17 3.07 3.84 5.20 3.82 3.14 In a column means having similar letter(s) are statistically similar and those having dissimilar letter(s) differ significantly at 0.05 level of probability. V1: BARI Mash-1, V2: BARI Mash-2, and V3: BARI Mash-3, and C0: No leaf clipping (control), C1: Clipping of 1st basal leaf, C2: Clipping of 2nd basal leaves and C3: Clipping of total apical leaves having no inflorescence The maximum number of pods plant−1 of blackgram (14.0) was observed in BARI Mash- 3 and the minimum (11.75) in BARI Mash-1 treatment. Siddikee et al. (2018) and Mane et al. (2018) was also found similar result. The maximum number of pods plant−1 of blackgram (15.18) 14 Sultana et al. was observed in clipping of 1st basal leaf treatment and the minimum number of pods plant−−1 of blackgram (11.89) was observed in clipping of total apical leaves having no inflorescence which was statistically similar with no leaf clipping. The result obtained from the study was similar with the findings of Mondal et al. (2011). The maximum number of pods plant−1 of blackgram (16.87) was observed in BARI Mash-3 with clipping of 1st basal leaf, whereas the minimum (11.00) was observed in BARI Mash-1 with clipping of total apical leaves having no inflorescence treatment combinations. Number of seeds pod−1 Variety, leaf clipping and treatment combination has showed significant variation on the number of seeds pod−1 of blackgram (Table 3). The maximum number of seeds pod−1 of blackgram (9.78) was observed in BARI Mash-3. In contrast, the minimum (7.93) was observed in BARI Mash-1. The probable reason for this may be the genetic potential of the genotype that has helped produce more seeds pod−1 on blackgram variety. The result obtained from the study was similar to the findings of Sunil et al. (2020). The maximum number of seeds pod−1 of blackgram (9.32) was observed in clipping of 1st basal leaf, and the minimum (8.31) was observed in clipping of total apical leaves having no inflorescence, which was statistically similar with no leaf clipping. Removal of leaves in certain levels may influence growth such as if the old or bacterial or pest infested leaves or sun burn leaves were removed, it helps the plant for saving energy, which may be translocated to the others part, which influences the yield contributing characters to plant, but if the sources were removed excessively then its cause detritions and low yield of the plant. The result obtained from the present study was similar to Sultana et al. (2013). The maximum number of seeds pod-1 of blackgram (10.80) was observed in BARI Mash-3 with clipping of 1st basal leaf, whereas the minimum (7.27) was observed in BARI Mash-1 with Clipping of total apical leaves having no inflorescence treatment combinations. 1000-seed weight Variety, leaf clipping and treatment combination has showed significant variation on 1000 seeds weight of blackgram (Table 3). The maximum 1000-seed weight of blackgram (48.58 g) was observed in BARI Mash-3, and the minimum (39.0 g) was observed in BARI Mash-1 treatment. The probable reason for this may be the genetic potential of the genotype that has helped in producing more seeds pod−1 on blackgram variety. The maximum 1000-seed weight of blackgram (48.33 g) was observed in clipping of 1st basal leaf, and the minimum (40.33 g) was observed in clipping of total apical leaves having no inflorescence treatment. Removing these relative sinks probably reduced this competition, resulting in a significant increase in 1000-seed weight (Sultana et al., 2013). The maximum 1000-seed weight of blackgram (51.67 g) was observed in BARI Mash-3 with clipping of 1st basal leaf, whereas the minimum was observed in BARI Mash-1 with clipping of total apical leaves having no inflorescence treatment combination. Seed yield Variety, leaf clipping and treatment combination has showed significant variation on grain yield (kg ha−1) of blackgram (Table 3). The maximum grain yield of blackgram (1381.70 kg ha−1) was numerically observed in BARI Mash-3, and the minimum (1115.50 kg ha−1) was observed in BARI Mash-1 treatment. This increase in seed yield of blackgram varieties might be due to the higher production efficiency that has been reflected through improvement in different yield attributing characters. Sunil et al. (2020), Mane et al. (2018), and Jadhav et al. (2014) also found similar results in the study. The maximum grain yield of blackgram (1306.70 kg ha−1) was observed in clipping of 1st basal leaf, and the minimum (1127.30 kg ha−1) was observed in clipping of total apical leaves having no inflorescence treatment. Seed yield was greater in basal 2 leaves defoliated plant (5.95 t ha−−1) than the top defoliated ones (0.90 t ha−−1) i.e., defoliation of basal four leaves Effect of leaf clipping on growth and yield of blackgram 15 caused a reduction of only 35.3% seed yield than control. In contrast, the top four leaves defoliation caused a 61.6% yield reduction. These results indicate that upper leaves contribute more assimilate to the sink than the basal leaves. This is possible because upper leaves are younger, capture more sunlight than the basal leaves, and produce more assimilation. Rao and Ghildiyal (1985), and Mariko and Hogetsu (1987) was also found similar results. The maximum grain yield of blackgram (1456.70 kg ha−1) was observed in BARI Mash-3 with clipping of 1st basal leaf treatment combinations and the minimum (982.00 kg ha−1) was observed in BARI Mash-1 with clipping of total apical leaves having no inflorescence. Stover yield Variety, leaf clipping and treatment combination has showed significant variation on stover yield (kg ha−1) of blackgram (Table 3). The maximum stover yield of blackgram (3620.50 kg ha-1) was observed in BARI Mash-3, and the minimum (3290.80 kg ha−1) in BARI Mash-1 which was statistically similar to BARI Mash-2. Mane et al. (2018) found similar result which supported the study. The maximum stover yield of blackgram (3651.10 kg ha−1) was observed in no leaf clipping, and the minimum (3233.30 kg ha−1) was observed in clipping of total apical leaves having no inflorescence, which was statistically similar to the clipping of 1st basal leaf treatment. The maximum stover yield of blackgram (3953.30 kg ha−1) was observed in BARI Mash-3 with no leaf clipping, and numerically the minimum (3073.30 kg ha-1) was observed in BARI Mash-1 with clipping of total apical leaves having no inflorescence combination. Biological yield Variety, leaf clipping and treatment combination has showed significant variation on biological yield of blackgram (Table 3). The maximum biological yield of blackgram (5002.20 kg ha−1) was observed in BARI Mash-3, and the minimum (4406.30 kg ha−1) was observed in BARI Mash-1 treatment which was statistically similar to BARI Mash-2. The higher biological yield of BARI Mash-3 as compared to BARI Mash-1 might be due to the accumulation of more dry matter and higher biomass potential. Mane et al. (2018) and Siddikee et al. (2018) was also found simila results. The maximum biological yield of blackgram (4868.20 kg ha−1) was observed in no leaf clipping, which was statistically similar to clipping of 2nd basal leaves and the minimum (4360.70 kg ha-1) in clipping of total apical leaves having no inflorescence treatment. The maximum biological yield of blackgram (5313.30 kg ha−1) was observed in the BARI Mash-3 with no leaf clipping treatment combination, whereas the minimum in BARI Mash-1 with clipping of total apical leaves having no inflorescence. Excess removal of source (Leaves) reduced dry matter production, ultimately reducing yield. As biological yield is the combination of grains and stover yield, excess removal of leaves alters the growth, which influences the yield contributing characters as a result yield and growth were reduced. Harvest index Variety, leaf clipping and treatment combination has showed significant variation on harvest index (%) of blackgram (Table 3). The maximum harvest index of blackgram (27.66%) was observed in the BARI Mash-3 whereas the minimum (25.30%) in BARI Mash-1 which was statistically similar to BARI Mash-2. Jadhav et al. (2014) also reported that black gram varieties differed significantly in harvest index. The maximum harvest index of blackgram (27.80%) was observed in clipping of 1st basal leaf treatment. The minimum harvest index of blackgram (24.97%) was observed in no leaf clipping treatment, which was statistically similar to clipping of total apical leaves having no inflorescence (25.77%) treatment. Biswas et al. (2005) was reported that the effect of defoliation on the harvest index varied significantly with the clipping treatments. It was higher in 33 and 66% defoliation (average of 24.5%) than in control and 100% defoliation (average of 22.7%). The maximum harvest index of blackgram (28.81%) was observed in the 16 Sultana et al. BARI Mash-3 with clipping of 1st basal leaf treatment combination, whereas the minimum harvest index of blackgram (23.91%) was observed in the BARI Mash-1 with no leaf clipping treatment combination. Table 3. Effect of variety, leaf clipping and combination of treatment on the seeds pod−1, 1000 - seed weight (g), seed yield (kg ha−1), stover yield (kg ha−1), biological yield (k g ha−1) and harvest index (%) of blackgram Treatment Seeds pod−1 (no.) 1000 -seed weight (g) Seed yield (kg ha−1) Stover yield (kg ha−1) Biological yield (kg ha−1) Harvest index (%) Variety V1 1.52b 4.45b 5.03c 6.38c 7.66b 11.75b V2 1.51b 4.11c 6.40b 7.65b 7.82b 13.32b V3 1.62a 5.51a 7.84a 9.50a 8.99a 14.00a LSD(0.05) 0.08 0.18 0.30 0.52 0.38 0.54 Leaf clipping C0 1.59a 4.76ab 6.48a 8.73a 8.16ab 12.11c C1 1.57ab 4.78a 6.40ab 7.98b 8.44a 15.18a C2 1.51b 4.63b 6.63a 7.45c 8.04bc 12.91b C3 1.52b 4.61b 6.19b 7.22c 7.95c 11.89c LSD (0.05) 0.06 0.14 0.24 0.40 0.31 0.40 Combination of treatment V1C0 7.73 ef 37.33 gh 1096.70 g 3490.00 b-d 4586.70 cd 23.91 e V1C1 8.40 de 44.00 c-e 1223.30 ef 3266.70 de 4490.00 cd 27.26 a-c V1C2 8.33 de 40.00 fg 1160.00 fg 3333.30 b-e 4493.30 cd 25.82 b-d V1C3 7.27 f 34.67 h 982.00 h 3073.30 e 4055.30 e 24.22 de V2C0 9.00 cd 46.33 b-d 1194.70 ef 3510.00 b-d 4704.70 c 25.39 de V2C1 8.77 cd 49.33 ab 1240.00 de 3296.70 c-e 4536.70 cd 27.33 ab V2C2 7.93 ef 43.00 df 1206.70 ef 3486.70 b-d 4693.30 c 25.71 b-d V2C3 8.87 cd 41.67 ef 1100.00 g 3290.00 de 4390.00 d 25.06 de V3C0 9.40 bc 47.00 bc 1360.00 bc 3953.30 a 5313.30 a 25.60 c-e V3C1 10.80 a 51.67a 1456.70 a 3600.00 b 5056.70 ab 28.81 a V3C2 10.13 ab 51.00a 1410.00 ab 3592.00 bc 5002.00 b 28.20 a V3C3 8.80 cd 44.67 c-e 1300.00 cd 3336.70 b-e 4636.70 cd 28.04 a LSD (0.05) 0.74 3.99 70.03 301.21 291.56 1.72 CV (%) 4.88 5.26 3.33 5.11 3.64 3.81 In a column means having similar letter(s) are statistically similar and those having dissimilar letter(s) differ significantly at 0.05 level of probability. V1: BARI Mash-1, V2: BARI Mash-2, and V3: BARI Mash-3, and C0: No leaf clipping (control), C1: Clipping of 1st basal leaf, C2: Clipping of 2nd basal leaves and C3: Clipping of total apical leaves having no inflorescence Conclusion From the above findings, it can be concluded that most of the growth, yield, and yield- contributing characteristics of blackgram gave the best performance from var. BARI Mash-3. Again, Leaf clipping of 1st basal leaf showed the best performance regarding most yield and yield- contributing characteristics. In the case of combined effect, var. BARI Mash-3 and clipping of 1st basal leaf gave the best result in producing the maximum pod length, number of pods plant-1, number of seeds pod-1, and 1000- seeds weight, which ultimately influences seed yield. The highest seed yield was obtained from BARI Mash-3, and clipping of 1st basal leaf of blackgram treatment combination can be treated as the best treatment combination in this study. Effect of leaf clipping on growth and yield of blackgram 17 References Afzal, M.A., M.A. Baker and M.L. Rahman. 1999. Lentil cultivation in Bangladesh. Lentil, Blackgram and Mungbean Development Pilot project, Pulses Research Station, BARI, Gazipur-1701, Bangladesh. Ahmed, M.F. 2017. Effect of leaf clipping and variety on growth and yield of mungbean. M. S. Thesis, Department of Agronomy, Sher-e-Bangla Agricultural University, Dhaka−1207, Bangladesh. BARI (Bangladesh Agricultural Research Institute). 2019. ‘Krishi Projukti Hathboi’. Bangladesh Agricultural Research Institute, Joydebpur, Gazipur, Bangladesh. p.68. BBS (Bangladesh Bureau of Statistics). 2021. Statistical pocket book of Bangladesh. Mins. Planning Govt. Peoples Repub. Bangladesh. p.143. Biswas, M.I., M.A. Hossain and M.S.A. Fakir. 2005. Effect of defoliation at vegetative stage on dry mass production and yield in cowpea. J. Bangladesh Agril. Univ. 3(1): 13-20. Echarte, L., F.H. Andrade, V.O. Sadras and P. Abbat. 2006. Kernel weight and its response to source manipulations during grain filling in Argentinean maize hybrids released in different decades. Field Crops Res. 96(2): 307-312. Gomez, M.A. and A.A. Gomez. 1984. Statistical Procedures for Agricultural Research. John Wiley and Sons, New York. pp.97–129, 207–215. HIES. 2010. Preliminary report of Household Income and Expenditure Survey. Bangladesh Bureau of Statistics, Ministry of Planning, GoB, Dhaka, Bangladesh. Jadhav, P.B., D.R. Kamble, K.T. Jadhav and D.L. Gadpale. 2014. Performance of black gram (Vigna mungo L. Hepper) varieties to different sowing dates. Adv. Res. J. Crop Improv. 5(2): 166-171. Mane, R.B., B.V. Asewar, Y.E. Kadam and K.V. Deshmukh. 2018. Correlation studies in weather parameters and yield of black gram varieties under changing weather conditions. Bull. Env. Pharmacol. Life Sci. 7: 37-42. Manoj K.N., M.R. Umesh, Y.M. Ramesh, S.R. Anand and S. Angadi. 2019. Dry matter production and radiation use efficiency of pulses grown under different light conditions. Bangladesh J. Bot. 48(1): 9-15. Mariko, S. and K. Hogestu. 1987. Analytical studies on the responsed of sunflower (Helianthes annus) to various defliation treatments. Ecol. Res. 2: 1-17. Mondal, M.M.A., M.A. Rahman, M.B. Akter and M.S.A. Fakir. 2011. Effect of defoliation during reproductive stage on yield in mungbean (Vigna radiata Wilczek). Legume Res. 34(3): 222 - 225. Rao, T.R.K. and M.C. Ghidiyal. 1985. Analysis of photosynthetic source and sink relationship in mungbean (vigna radiata (L) wilezck). Indian J. Plant Physiol. 28: 135-144. Siddikee, M.R., R. Sultana, M. Hasan, T. Rahman, A.B. Siddique and A.K.M.R. Amin. 2018. Effect of nitrogen sources on the yield of different blackgram (Vigna mungo) varieties. Asian Res. J. Agric. 10(3): 1-8. Sultana, M., B. Ahmed, M.M. Rahman, S. Sultana and M.M. Haque. 2013. Growth and seed yield of mungbean as influenced by leaf clipping and fertilizer doses. Bangladesh Res. Pub. J. 9(2): 78-86. Sunil, C., P. Mahadevu, G.S. Yogesh, C. Hanagi and A.B. Mohankumar. 2020. Performance of blackgram varieties under rainfed conditions of Chamarajanagar district in Karnataka. J. Krishi Vigyan. 8(2): 215-218. Blank Page