Effect of Time of Sowing, Row Spacing and Variety on Summer Cluster Bean (Cymopsis tetragonoloba (L.)Taub.) Under Middle Gujarat Conditions

A field experiment was carried out at Agronomy Farm, B. A. College of Agriculture, Anand Agricultural University, Anand, Gujarat during the summer season of the year 2015 to study the effect of time of sowing, row spacing and variety on summer cluster bean under middle Gujarat conditions, in loamy sand soil. Eighteen treatment combinations comprised of three dates of sowing viz., D1: (21 st January); D2: (1 st February) and D3: (11 th February) as main plot treatments and combination of three different row spacing viz., S1: 30 cm; S2: 45 cm; and S3: 60 cm along with two varieties V1 (GG 1) and V2 (GG 2) as sub plot treatments, were laid out in Split Plot Design with three replications. Results revealed that treatment combination D3S1V2 (sowing on 11th February with 30 cm row spacing with variety GG 2) recorded significantly higher seed yield (1476 kg ha-1) which was found at par with treatment combination D2S3V2 (sowing on 1st February with 60 cm row spacing with variety GG 2). However, maximum net realization (Rs.50667 ha-1) and BCR (4.53) were obtained under treatment combination D2S3V2, followed by D3S1V2 with net realization of Rs.48511 ha -1 and BCR of 4.24.

Cluster bean (Cymopsis tetragonoloba (L.)Taub.) is an important self pollinated, multipurpose, drought resistant leguminous crop,cultivated in arid and semi-arid areas of about 23.30 mollion hectare in India producing 1.22 million tone of cluster bean with productivity of 584 kg ha -1 (Anon.,2014). Rajasthan is the largest Cluster bean producing states in the world as it dominates the Indian production scenario contributing to around 4.2 lakh tons i.e. over 70% of the total production in India. It is cultivated in 3.18 lakh hectares in Gujarat with 1.91 lakh tone production with productivity of 602 kg ha -1 (Anon., 2015). Its cultivation mainly confines the districts of Banaskantha, Sabarkantha, Kutch, Mehsana, Gandhinagar, Patan and Kheda. However, its productivity during kharif season is low due to uneven and erratic distribution of rainfall in these areas as well as incidence of pests and diseases. For exploiting yield potential of cluster bean its cultivation is shifted to summer season. Among the various management factors contributing to growth and development of cluster bean, nonmonetary inputs like time of sowing, row spacing and selection of variety play vital role in summer season. The cardinal range for cluster bean being 15-35 °C, early or late sowing may impact its germination and growth. The late sowing in summer may face the risk of rainfall during ensuing monsoon season at maturity. High or low density sowing may have lead to poor yield performances. Varieties of cluster bean viz. Gujarat Guar 1 (GG 1) and Gujarat Guar 2 (GG 2) have been released by G.A.U., S.K. Nagar, which have been found suitable for cultivation during summer season in north Gujarat conditions. But the performance of cluster bean varieties at varied time of sowing and row spacing have not been evaluated for middle Gujarat conditions in summer season. Therefore, this experiment was conducted.

MATERIALS AND METHOD
A field experiment was carried out at Agronomy Farm, B. A. College of Agriculture, Anand Agricultural University, Anand, Gujarat during the summer season of the year 2015 to study the effect of time of sowing, row spacing and variety on summer cluster bean under middle Gujarat conditions, in loamy sand soil, low in organic carbon (0.35%), medium in available phosphorous (43.28 kg P 2 O 5 ha -1 ) and high in available potash (388.17 kg K 2 O ha -1 ). Eighteen treatment combinations comprised of three dates of sowing viz., D 1 : (21 st January); D 2 : (1 st February) and D 3 : (11 th February) as main plot treatments and combination of three different row spacing viz., S 1 : 30 cm; S 2 : 45 cm; and S 3 : 60 cm along with two varieties V 1 (GG 1) and V 2 (GG 2) as sub plot treatments, were laid out in Split Plot Design with three replications.

Effect of time of sowing
A perusal of data presented in table-1 revealed that sowing on 1 st February (D 2 ) being at par with sowing on 11 th February (D 3 ) gave significantly higher plant height at 30 (32.31 cm), 60 DAS (56.47cm) and at harvest (82.97cm) and for test weight (38.90 g) of cluster bean over sowing on 21 st January (D 1 ). Conversely, crop sown on 11 th February (D 3 ) produced significantly the highest branches plant -1 (6.01), pods plant -1 (43.92), seeds pod -1 (7.96) and pod length (9.11 cm) over early sowing on 1 st February (D 2 ) and 21 st January (D 1 ). Better growth of plant in terms of plant height under late sowing on 1 st February (D 2 ) and 11 th February (D 3 ) reflected into better development of yield attributes. Moreover, congenial climatic conditions especially at reproductive phase also played vital role in development of yield attributes due to positive sink to source ratio wherein assimilates translocation to reproductive components. These Similar trend was observed for seed and stalk yield. The impact of different time of sowing on seed and stalk yield of cluster bean reported in table 2 indicated that 1 st February sowing (D 2 ), being at par with 11 th February sowing (D 3 ) produced significantly higher seed (1027 kg ha -1 ) as well as stalk (5043 kg ha -1 ) yield which were 21.12 % and 27.87 % higher over 21 st January sowing (D 1 ), respectively. Higher seed and stalk yield under treatments D 2 (1 st February) and D 3 (11 th February) over D 1 (21 st January) might be attributed to enhanced yield attributes in later sowing over early sowing under favorable weather conditions which might induced photosynthetic activity and translocation of assimilates which was reflected in augmentinggermination, plant height and ultimately had complimentaryimpact on number of branches plant -1 , pod development and seed formation (Kalyani ,2012).
Harvest index (Table 2) was found unchanged due to different time of sowing. However, maximum harvest index (19.56 %) was reported under sowing on 11 th February (D 3 ).

Effect of row spacing
Results given in table-1 and table-2 revealed that significantly the highest plant height at 60 DAS (55.96 cm) and at harvest (82.04 cm) and stalk yield (4859 kg ha -1 ) were obtained when crop sown at 30 cm spacing (S 1 ) over rest of the treatments. Nevertheless, crop sown at 60 cm spacing (S 3 ) being at par with 45 cm spacing (S 2 ) produced significantly higher pod length (8.24 cm) and seeds pod -1 (7.13) over 30 cm spacing (S 1 ). Plant height at 30 DAS, branches plant -1 , pods plant -1 , test weight (g), seed yield (kg ha -1 ) and harvest index (%) were found statistically at par due to different row spacing.Under wider spacing some of the yield components might have been increased on individual plant basis but would have been decreased on per unit area basis, while under narrow spacing though number of plants per unit area might have been increased, but the yield components might have been declined on individual basis and eventually the biological yield was reduced. A similar result was obtained by Machado et al., (2003).

Effect of variety
In the present experiment different varieties showed imperial impact on all the growth parameters, yield attributing characters and yield (Table 1 and Table-2). Variety GG 2 (V 2 ) proved statistically superior over variety GG1 (V 1 ) in all the aspects barring periodical plant height and stalk yield. Significantly maximum branches plant -1 (6.13), pods plant -1 (40.89), pod length (9.28 cm), number of seeds pod -1 (8.07),test weight (41.86 g), seed yield (1245 kg ha -1 ) and harvest index (26.59 %) were recorded under variety GG 2 (V 2 ) over GG 1 (V 1 ) . On the other hand, variety GG 1 (V 1 ) exhibited higher plant height at 30 DAS (34.38 cm), 60 DAS (60.12 cm) and at harvest (88.39 cm) and produced higher stalk yield (5392 kg ha 1 ) over variety GG 2 (V 1 ). Variety GG 2(V 2 ) produced 89 % higher seed yield over variety GG 1(V 1 ). This can be attributed to higher biomass accumulation coupled with effective translocation and distribution of photosynthesis from source to sink (Patel et al., 2010).

Interaction effect
Interaction effect between D X V was found significant (Table 3(a)) for plant height at 30 DAS, pod length, seeds pod -1 , stalk yield and harvest index. Treatment combination D 3 V 1 (sowing on 11 th February with GG 1) being at par with treatment combination D 2 V 1 (sowing on 1 st January with GG 1) reported significantly higher plant height (37.17 cm) as well as stalk yield (5589 kg ha -1 ). However, in case of pod length and number of seeds pod -1 , treatment combination D 3 V 2 (sowing on 11 th February with GG 2) out right produced highest pod length (10.95 cm) and number of seeds pod -1 (9.84). Significantly higher harvest index (28.96) was reported under treatment combination D 1 V 2, which remained at par with D 3 V 2 .
Interaction between D X S (Table 3(b)) were found significant for seed yield as well as harvest index, wherein treatment combination D 3 S 2 (sowing on 11 th February at 30 cm row spacing) gave significantly higher seed yield (1085 kg ha -1 ) and harvest index (22.05 %). Nevertheless, it remained at with D 2 S 2 and D 2 S 3 for seed yield and with D 1 S 3 and D 1 S 1 for harvest index.
Number of pod plant -1 , seed yield as well as harvest index were found significantly influenced due to interaction between S X V (Table 3 (c)) and treatment combination S 3 V 2 gave appreciably higher Number of pod plant -1 (42.51), seed yield (1245 kg ha -1 ) and harvest index (28.02 %).   The perusal of result given in table 3(d) revealed that treatment combination D 3 S 1 V 2 (cluster bean variety GG 2 sown on 11 th February with 30 cm row spacing ), being at par with D 2 S 3 V 2 (cluster bean variety GG 2 sown on 1 st February with 60 cm row spacing) produced significantly higher seed yield (1476 kg ha-1) over rest of the treatment combinations.This could be also attributed to higher biomass accumulation coupled with effective translocation and distribution of photosynthates from source to sink. The result was also supported by Sonaniet al. (2016).

Economics
Data pertaining to economics (Table-4) clearly indicated that the highest net realization Rs. 50667 ha -1 and BCR (4.53) were obtained under treatment combination D 2 S 3 V 2 , i.e. cluster bean variety GG 2 sown on 1 st February with 60 cm