~ 802 ~ International Journal of Chemical Studies 2018; 6(6): 802-805 P-ISSN: 2349–8528 E-ISSN: 2321–4902 IJCS 2018; 6(6): 802-805 © 2018 IJCS Received: 21-09-2018 Accepted: 24-10-2018 Bharati Upadhaya M.Sc Scholar, Department of Agronomy, Dr. Rajendra Prasad Central Agricultural University, Pusa, Samastipur, Bihar, India Navnit Kumar Assistant Professor -cum- Junior Scientist, Department of Agronomy, Sugarcane Research Institute, Dr. Rajendra Prasad Central Agricultural University, Pusa, Samastipur, Bihar, India Correspondence Bharati Upadhaya M.Sc Scholar, Department of Agronomy, Dr. Rajendra Prasad Central Agricultural University, Pusa, Samastipur, Bihar, India Yield, quality and profitability of sugarcane ( Saccharum spp. Hybrid complex) as influenced by plant growth regulators in sub-tropical India Bharati Upadhaya and Navnit Kumar Abstract A field experiment was carried out during the spring season of 2017-18 at Research farm of Sugarcane Research Institute, Dr. Rajendra Prasad Central Agricultural University, Pusa Samastipur, to study the influence of plant growth regulators on yield, quality and profitability of sugarcane (Saccharum spp. hybrid complex). The experiment was laid out in a randomized block design comprising of ten treatments with three replications. The results revealed that planting of setts after overnight soaking in 50 ppm ethrel solution + GA3 spray @ 35 ppm at 90, 120 & 150 DAP showed significantly higher cane and sugar yield, and consequently higher juice recovery as compared to rest of the treatments. Planting of setts after overnight soaking in 50 ppm ethrel solution + GA3 spray @ 35 ppm at 90, 120 & 150 DAP also registered higher gross returns (₹ 2,95,220.0/ha), net returns (₹ 1,67,988.0/ha) and benefit: cost ratio (1.32) followed by planting of setts after overnight soaking in 50 and 100 ppm ethrel solution and planting of setts after overnight soaking in 100 ppm ethrel solution + GA3 spray @ 35 ppm at 90, 120 & 150 DAP. Keywords: sugarcane, ethrel, gibberellic acid, yield, quality, profitability Introduction Sugarcane (Saccharum spp. hybrids) is an important cash crop and more than 70% of the world’s sugar production comes from it. India is the largest consumer and second largest producer after Brazil producing nearly 15 and 25% of global sugar and sugarcane, respectively (Mohan and Kanaujia, 2017) [3] . In India, it occupies about 2.53% (4.9 million ha) of the gross cropped area of the country with an annual production of 303.6 million tonnes. In Bihar, it occupies an area of 0.3 million ha with the production of 14.7 million tonnes (ISMA, 2017) [1] . Typically sugarcane is a tropical crop, however more than 50% sugarcane area in India falls in the sub-tropical zone, hence, demarcation with respect to physiology and yield is bound to happen. The productivity of sugarcane in Bihar is far below (50 t/ha) as compared to tropical areas (80 t/ha). Extremes of climate and use of sub-optimal agro-technologies are mainly responsible for low sugarcane productivity in sub-tropical India. In this direction, plant growth regulators like ethrel and gibberellic acid in judicious integration have been found useful to ameliorate these constraints and thus have been effective in improving productivity and profitability of sugarcane. Considering the above facts, an attempt was made to find out the combined effects of ethrel and gibberellic acid on yield, quality and profitability of sugarcane in sub-tropical India. Materials and Methods The field experiment was conducted during the spring season of 2017-18 at Dr. Rajendra Prasad Central Agricultural University, Pusa, Bihar (25⁰59′ N, 85⁰40′ E, and 52.1 m above mean sea level). Soil of the experimental field was sandy loam, calcareous in nature (28.5% CaCO 3 ), pH 8.2 with electrical conductivity 0.28 dS/m, low in organic carbon (0.41%), low in available nitrogen (220 kg/ha) and medium in phosphorus (28.3 kg/ha) and potassium content (141.5 kg/ha). The crop received 1,134.6 mm of rainfall of which maximum was received in the month of July. The crop was planted on 18 th March, 2017 and harvested on 30 th January, 2018. Sugarcane variety ‘BO 153’ was grown maintaining row to row distance of 90 cm using furrow method of planting. To check the fungal infection, setts were treated with 0.1% solution of carbendazim for 10 minutes. Thimet 10 G (an insecticide) was applied in furrows