Growth Analysis of Chickpea Cv. Bari Chhola-6 as Affected by Foliar Spray of Growth Regulators

Leaf area index (LAI), leaf area duration (LAD), crop growth rate (CGR), net assimilation rate (NAR) and above ground dry matter accumulation (AGDM) of a cultivar of chickpea (Cicer arietenum) were studied with the application of potassium naphthenate (KNap) and naphthalene acetic acid (NAA) as foliar spray in 2001-2002. The growth regulators had greater influence on plants which showed comparable values of LAI, LAD, CGR, NAR and TDM over control plants. Out of the growth regulator treatment, 1500 ppm KNap produced 26.7 to 37.5% more TDM at different stages of growth than those of control, and it was superior to other treatments with NAA. Other growth parameters also increased following 1500 ppm KNap treatment. LAI, CGR, NAR and AGDM had a significant linear relationship with seed yield. The combination treatments of KNap and NAA concentrations did not show any cumulative influence on any of the parameters. Introduction The leaf area and its duration are important consideration for photosynthesis of a plant. These are also the measurements of growth of plants and plant physiological processes. LAI and LAD control total dry matter production and subsequently yield attributes and yield (Katiyar 1980, Jirali et al. 1994). Khanna-Chopra and Sinha (1987) observed that leaf senescence which starts during pod formation stage eventually affect the development of pods of chickpea. Leaf area and other growth parameters were influenced by different growth regulators in pulse crops (Fattah and Wort 1970, Islam et al. 2006 and Ullah 2006). The present investigation was undertaken to study the effect of KNap and NAA on some physiological parameters of chickpea plants. Materials and Methods A field experiment was done during November to March (Rabi season) of 2001-2002 on a silty-loam soil of Sher-e-Bangla Agricultural University farm, Dhaka, Bangladesh. The eight foliar treatments were tested as follows: T0 = water spray (control); T1 = 1500 ppm KNap; T2 = 10 ppm NAA; T3 = 20 ppm NAA; T4 = 30 ppm NAA; T5 = 1500 ppm KNap followed by 10 ppm NAA; T6 = 1500 ppm KNap followed by 20 ppm NAA and T7 = 1500 ppm KNap followed by 30 ppm NAA. The foliar treatments were applied at 45 days after sowing (DAS). The experiment was laid out in a randomized complete block design (RCBD) with four replications. The unit plot size was 6 m × 4.4 m. Fertilizers were added as urea, TSP, MP, gypsum and boric acid at the rate of 20 kg N, 40 kg P2O5, 20 kg K2O, 20 kg S and 1kg B ha , respectively before sowing. Seeds of chickpea cv. BARI chhola-6 were sown on 25 November, 2001 in rows having a gap of 40cm. The seeds were sown continuously and plants in rows were maintained 10 cm apart by thinning seedlings at 15 DAS. This gave a plant density of 25 × 10 plants ha. Intercultural operations were done as and when needed. Separate spray machines were used for application of two growth regulators. During spraying plots were separated by thick polythene sheet to check contamination. Corresponding author. E-mail: [email protected], Department of Botany, University of Dhaka, Dhaka-1000, Bangladesh. 106 KARIM AND FATTAH