Plant height
Table 1 represents that at harvest, plant height was maximum in the treatment of CaCl2 2% seed hardening + 1% foliar spraying at 30 DAS (T
11) (37.00, 40.67 and 38.83 cm) and remained at par with NAA 50 mg/L seed hardening + spraying at 30 DAS (T
15) (35.67, 39.33 and 37.50 cm), NAA 25 mg/L seed hardening + spraying at 30 DAS (T
14) (34.67, 37.50 and 36.08 cm) and CaCl
2 1% spraying at 30 DAS (T
6) (33.67, 37.00 and 35.33 cm). While Cycocel 1000 mg/L spraying at 30 DAS (T
8) recorded significantly less plant height (23.67, 26.00 and 24.83 cm) during the year 2016, 2017 and pooled basis, respectively.
Plant height was increased due to treatments of CaCl
2 and NAA, while decreased due to Cycocel at harvest in green gram. The decrease in plant height with cycocel may be attributed to anti-gibberellic activity of Cycocel mainly by blocking certain steps of gibberellin biosynthesis so that gibberellin is not made available for participation in plant growth (
Jain, 2013). The mechanism of reduction of plant height by spraying with Cycocel also appears due to reduced cell size and cell wall thickening (
Ginzo et al., 1977). Similarly,
Dighe et al., (1983) also observed that 500 ppm cycocel significantly reduced the plant height in wheat.
It was observed that NAA showed a positive effect on plant height. The application of auxin in plant has a role in the stimulation of RNA and protein synthesis and greater enhancement in photosynthesis rate, increased in cell elongation as well as cell division and cell wall plasticity, which ultimately showed the enhancement in various growth parameters. The above finding were in agreement with the results reported by
Ananthi and Mallika (2014) in green gram,
Sunil Jadhav (2016) and
Kinjal (2017) in black gram,
Upadhyay et al., (2016) in soybean,
Pothalkar (2007) in pigeon pea,
Amarjeet Singh (2014) in turmeric,
Sujatha et al., (2017) in chickpea.
Number of branches
At harvest, the number of branches per plant found statistically non significant during both the years. However, in pooled mean basis the treatment Cycocel 1000 mg/L seed hardening + spraying at 30 DAS (T
13) recorded significantly higher (8.67) than untreated absolute control with minimum number of branches per plant (6.67).
The reduction in plant height due to growth retardants is mainly seems to have released the apical dominance and diversion of the plant metabolites from vertical growth to horizontal growth and thereby more number of branches per plant. These results are in conformity with the findings of
Sen (1983) in wheat,
Sharma et al., (2003) in pigeon pea,
Manjunath and Dhanoji (2011) and
Sujatha (2014) in chickpea.
Leaf area
Leaf area per plant gradually decreased towards harvesting stage in green gram. The data reported in Table 1 indicated that the treatment CaCl
2 2% seed hardening + 1% spraying at 30 DAS (T
11) registered higher values of leaf area (362, 428 and 395 cm
2) over all other treatments. It was followed by T
13 (355, 418 and 387 cm
2), T
15 (344, 404 and 374 cm
2) and T
12 (341, 395 and 368 cm
2) during 2016, 2017 and in pooled analysis, respectively. Whereas, the treatment absolute control (T
16) recorded significantly lower value of leaf area per plant (223, 264 and 244 cm
2, respectively).
The increased in leaf area by seed hardening and foliar spraying with CaCl
2 and NAA might be due to increase in cell division, cell enlargement as well as induce more extensive and denser network of veins and ribs and there by increased foliar leaf area. These results are conformity with the finding of
Thirumalaiswamy and Rao (1977) in pearl millet,
Ginzo et al., (1977) and
Josana (2015) in chick pea,
Shinde and Jadhav (1995) in cowpea,
Pothalkar (2007) in pigeon pea,
Prakash et al., (2013) in rice and
Kinjal (2017) in black gram.
Days to 50% flowering
The data indicated in Table 2 showed non significant differences due to various treatments in both the years but in pooled basis differences were significant. In pooled analysis, the treatment T
11 (36.67) significantly taken minimum days to 50 per cent flowering followed by the treatments T
13 (37.00), T
15 (37.17), T
12 (37.50) and T
14 (37.83). While untreated absolute control (T
16) recorded significantly maximum number of days (42.00) to 50 per cent flowering. This might be due to early and faster emergence. Flower initiation is an important phonological development stage which determines the plant productivity.
It is inferred that, both the phenological stages
viz., flower initiation and pod initiation were early due to seed hardening followed by the use of plant growth regulator’s spray. Similar reports have been also made by
Garai and Datta (2003) in green gram and
Varma et al., (2004) in pigeon pea. The results in present investigation showed that minimum days taken for 50 per cent flowering in combined effect of seed hardening + foliar spraying followed by only foliar spraying and then only seed hardening treatments. In general, combined effect of seed hardening and foliar spraying was more effective in early flowering as compared to their individual effect.
Days to maturity
The data indicated non significant differences due to various treatments during both the years but in pooled analysis differences were significant. The treatment T
11 (73.17) taken minimum days to maturity followed by the treatments T
13 (73.50), T
15 (73.83), T
12 (74.33) and T
14 (74.67). The untreated absolute control (T
16) (79.00) taken significantly maximum number of days to maturity.
Similar observations on advancement of flowering and harvest times were also reported by
Pawar et al., (2003) and
Narayanareddy and Biradarpatil (2012) in sunflower,
Pothalkar (2007) in pigeonpea,
Manjunatha (2007) and
Sujatha (2014) in chickpea.
Chlorophyll content of leaves
The chlorophyll content of leaves gradually decreased towards harvesting stage in green gram. The treatment T
11 registered significantly highest values of chlorophyll content of leaves-SPAD values (13.32, 14.80 and 14.06) over absolute control (T
16) (9.30, 10.47 and 9.88) and remained at par with T
13 (13.22, 14.68 and 13.95), T
15 (12.85, 14.43 and 13.64), T
12 (12.68, 14.32 and 13.50) and T
14 (12.20, 14.00 and 13.10) during 2016, 2017 and on pooled basis respectively.
From the data it is clear that continuous increase in chlorophyll content was noted up to 60 DAS, thereafter it decreased during both the seasons at senescence stage. The agrochemicals and growth substances such as CaCl
2, Cycocel and NAA had a positive effect on cell division and cell elongation leading to enhanced leaf expansion, leaf area and thereby chlorophyll content also. The increase in chlorophyll content due to growth regulators and agrochemical may be attributed to decreased chlorophyll degradation and increased chlorophyll synthesis. These results are in accordance with
Jayakumar and Thangaraj (1998), Shinde and Jadhav (1995),
Dashora and Jain (1994),
Pothalkar (2007) and
Kinjal (2017) in groundnut, cowpea, soybean, pigeon pea and blackgram respectively. In the present investigation, the chlorophyll content showed a positive correlation with grain yield indicating its importance in yield determination.
Seed protein content (%)
The data presented in Table 2 indicated that even though, the statistically non significant differences observed for the seed protein content during both the years but protein content was improved due to the different treatments. The two years pooled data revealed that the seed protein content recorded maximum (25.76%) in the treatment T
11 and it remained at par with the treatments T
13 (25.34%), T
15 (25.13%), T
12 (25.05%), T
14 (24.88%) and T
6 (24.56%) in pooled. While, the untreated absolute control treatment (T
16) recorded significantly lowest (22.82%) seed protein content.
From the above results, it is clear that there was increase in seed protein content in all the treatments like seed hardening, foliar spraying singly or their combined effect as compared to control. Similarly, the higher seed protein content was reported by
Sujatha (2014) in chickpea.
Avijit and Misra, (1987) in wheat,
Doijode (1975) in garden peas,
Bora and Sarma (2005) in pea.
Shukla et al., (2018) in chickpea and
Kumar et al., (2015) in field bean and
Damor and Patel (2018) in mung bean.
Total number of pods per plant
The data regarding total number of pods per plant influenced due to different treatments during both the years and on pooled basis were recorded and analyzed are recorded in Table 3. The significantly highest total number of pods per plant (33.73, 35.67 and 34.70) were recorded by the treatment T
11, while lowest observed in absolute control (22.00, 23.33 and 22.67) and remained at par with the treatments T
13 (32.80, 34.93 and 33.87), T
15 (32.13, 34.47 and 33.30), T
12 (31.60, 33.67 and 32.63) and T
14 (31.00, 33.07 and 32.03) during 2016, 2017 and in pooled, respectively.
Pod length
The significantly highest pod length (8.45) was recorded in the treatment CaCl
2 2% seed hardening + 1% spraying at 30 DAS (T
11) in pooled analysis. The treatment T11 was also remained at par with the treatments T
13 (8.40), T
15 (8.33), T
12 (8.03) and T
14 (7.98). The treatment untreated absolute control (T
16) recorded significantly the lowest pod length (7.10).
Number of seeds per pod
The treatment T
11 recorded significantly higher number of seeds per pod (11.93) on pooled basis and remained at par with the treatments T
13 (11.83), T
15 (11.57), T
12 (11.43), T
14 (11.33), T
6 (11.08) and T
8 (11.00). While, the treatment absolute control (T
16) recorded significantly lowest (9.73) number of seeds per pod.
Test weight (g)
The treatment CaCl
2 2% seed hardening + 1% spraying at 30 DAS (T
11) recorded significantly maximum (53.80 g) thousand seeds weight in pooled analysis and remained at par with the treatments
viz., T
13, T
15, T
12, T
14, T
6, T
8, T
10, T
7 and T
9. Whereas, the treatment of absolute control (T
16) recorded significantly the minimum (49.27 g) thousand seed weight.
Seed yield per plant (g plant-1)
The treatment CaCl
2 2% seed hardening + 1% spraying at 30 DAS (T
11) recorded significantly higher values of seed yield per plant (13.07, 14.20 and 13.63 g) and remained at par with T
13 (12.60, 13.93 and 13.27 g), T
15 (12.47, 13.60 and 13.03 g) and T
12 (12.13, 13.27 and 12.70 g) during 2016, 2017 and on pooled basis, respectively. Whereas, the treatment of absolute control (T
16) recorded significantly the lowest seed yield per plant (8.07, 9.40 and 8.73 g, respectively).
Seed yield (kg ha-1)
The significantly highest seed yield per hectare (949, 1006 and 978 kg ha
-1) was recorded by the treatment T
11 while significantly the lowest was observed in the absolute control (639, 679 and 659 kg ha
-1) during 2016, 2017 and in pooled analysis, respectively and remained at par with the treatments T
13 (922, 964 and 943 kg ha
-1) and T
15 (893, 917 and 905 kg ha
-1).
Harvest Index (%)
The treatment CaCl
2 2% seed hardening + 1% spraying at 30 DAS (T
11) recorded significantly highest harvest index (30.15%) in pooled analysis and remained at par with the treatments T
13 (30.01%), T
15 (29.84%), T
12 (29.49%), T
14 (29.27%), T
6 (28.80%), T
8 (28.66), T
10 (28.35%) and T
7 (28.34%). While, the treatment of absolute control (T
16) recorded significantly the lowest (26.84%) harvest index.
Grain yield is the manifestation of morphological, physiological, biochemical, biophysical and growth parameters. Improvement in yield according to
Humphries (1979) could happen in two ways
i.e., by adopting the existing varieties to grow better in their environment or by altering the relative proportion of different plant parts so as to increase the yield of economically important parts. The influence of plant growth regulators and seed hardening chemicals significantly increased the seed yield.
In the present investigation, it is observed that the number of pods per plant, pod length, seed yield, number of seeds per pod, 1000-seed weight increased due to seed hardening or foliar spraying alone and/or in combination of both by agrochemical CaCl
2 and growth regulators NAA and Cycocel.
The present study also revealed that increase in seed yield was significantly higher in seed hardening + spraying with CaCl
2 (2% seed hardening and 1% spraying) followed by Cycocel 1000 mg/L and NAA 50 mg/L. This could probably be due to beneficial effects of agrochemical and plant growth regulator treatments which help in enhancement of photosynthesis and nitrogen metabolism which are the major physiological process influencing plant growth and development. The treatments of CaCl
2 was significantly superior as compared to other treatments in enhancing the plant height, days to flowering, chlorophyll content, number of seeds per plant, 1000-seed weight and thereby seed yield. The increase in the higher yield may be due to better carbon assimilation, better accumulation of carbohydrates and reduced respiration in plants. These results are in agreement with the findings of
Singh and Rajodia (1989) in soybean,
Singh and Dohare (1964),
Das and Prusty (1982) and
Pothalkar (2007) in pigeon pea. The present studies also indicated that growth regulators were very effective in increasing yield and yield attributes as compared to control.
The present study also indicated that seed hardening + spraying, only foliar spraying and only seed hardening treatments with CaCl
2, CCC and NAA significantly increased the number of pods per plant, seed yield per plant, 1000-seed weight and harvest index, which are most important yield determining components in green gram. The increase in seed yield with respect to above treatments was probably due to maximum water absorbing capacity of seeds, more intense photosynthetic activity and more tissue hydration and thereby enabling the plant to resist soil moisture stress more efficiently. This is in conformity with the findings of
Mehrotra et al., 1970 in okra,
Arjunan and Srinivasan, 1989 in groundnut,
Masood Ali (1985) in chickpea,
Sen and Misra (1987) in wheat,
Patil (1987) in sorghum,
Shinde et al., (1991) in cowpea,
Singh et al., (1991) in chickpea,
Bora and Sarma (2005) in pea,
Shinde and Jadhav (1995) in pigeonpea,
Amaregouda et al., (1994) in wheat,
Jirali (2001) in turmeric and
Prabhu (2000) in black gram.