Indian Institute Of Sugarcane Research Research Articles

Enumeration, Identification and characterization of endophytic bacteria isolated from sugar beet (Beta vulgaris L.) root for ethanol production

The bioethanol production from sugar beet is regulated by endophytic bacteria. Thus, the present investigation is aimed to isolate, identify and characterize endophytic bacteria from different varieties of sugar beet roots. The presence of specific bacteria in sugar beet roots plays vital role in bioethanol production. The ability to produce bioethanol through fermentation with the help of various microbes present in roots was studied in different varieties of sugar beet at Indian Institute of Sugarcane Research, Lucknow sub tropical regions of India. A total of 16 microbial isolates comprising of 12 bacterial and 4 fungal strains were studied for their potential to produce bioethanol from sugar beet root. Among them only 2 bacteria were more effective as fermenting agents. These isolated endophytic bacteria were characterised by molecular sequencing and were identified as Enterobacter hormaechei and Enterobacter cloacae. These isolates may also act as a good alternative agent for the bioethanol production.

Molecular identification of 16SrXI-B subgroup of phytoplasma related strain with yellow leaf disease of sugarcane (Saccharum officinarum) in India

In India, yellow leaf disease (YLD) is known to be caused by Sugarcane yellow leaf virus (SCYLV) and Sugarcane yellows phytoplasma (SCYP; 16SrI-B). Therefore, present study was conducted to confirm the association of specific phytoplasma with YLD in Co 0238 and CoS 510 sugarcane genotypes during 2019-2020 at Indian Institute of Sugarcane Research, Lucknow. The YLD affected genotypes were characterized by yellowing of leaf mid-ribs and leaf-lamina, leaf-tip necrosis, bunching of leaves at crown region and drying of plants with an incidence ranged from 28.26-35.81%. YLD symptomatic leaf samples were collected from the two genotypes and subjected to genomic DNA extraction by DNeasy Plant Mini Kit followed by nested PCR assay using universal phytoplasma primers (16S rDNA region). The nested PCR assays of samples from both the genotypes showed specific amplification. 16S rRNA gene sequence analyses of CoS 510 isolate (MN913611) revealed 100% identity with Sugarcane white leaf phytoplasma (SCWLP) belongs to 16SrXI-B subgroup. Similarly, virtual RFLP analyses revealed 1.00 similarity coefficient with 16SrXI-B subgroup. Thus, present study first time reports the association of SCWLP related strain with YLD of sugarcane in India. Phytoplasma infecting sugarcane are more diverse and needs systematic studies on their single or mixed infections in different varieties in India.

Evaluation of Phytotoxicity of Sulfantrazone 48% F to Sugarcane Saccharum officinarum L.

A field experiment was conducted at the Indian Institute of Sugarcane Research, Luchnow, under subtropical Indian conditions during the season 2012-2013 to study the evaluation of phytotoxicity of sulfantrazone 48% f to sugarcane variety CoSe 92423. The experimental design was Randomized Complete Block Design (RCBD) with four replications. The treatments used in the experiment are sulfentrazone PPI 720 g a.i.ha-1, sulfentrazone PPI 1440 g a.i.ha-1, sulfentrazone Pre-em: 3 DAP 720 g a.i.ha-1, sulfentrazone Pre-em: 3 DAP 1440 g a.i.ha-1 and untreated control(weedy). The results showed that sulfentrazone PPI 1440 g ai.ha-1 registered the highest increase of germination (56.9 %) that didn’t differ significantly from other treatments. The dry matter accumulation in weeds was the lowest (7.2, 10.6 and 22.8 g.m-²) in sulfentrazone PPI 1440 a.i.ha-1 treatment achieved highest inhibition proportion of dry matter (90.2, 88.9 and 83.5 % ) at the 60, 90 and 120 DAP respectively. Phytotoxicity was not significantly affected by use of sulfentrazone herbicide. a significant increase in average number of canes by using sulfentrazone PPI 1440 g a.i.ha-1 led to even the highest increase in this attribute at the 90,120,150, 210 and 300 DAP. The use of sulfentrazone PPI 1440 g a.i.ha-1 registered the highest cane yield (84.1 t.ha-1) that was significantly higher to the tune of 44.94 % over control. Addition of sulfentrazone treatments significantly affected sugar yield. Sulfentrazone PPI 1440 g a.i.ha-1 and sulfentrazone Pre-eme 1440 g a.i.ha-1caused highest increase in this character which reached to 13.850 and 13.500 t.ha-1respectively.

Performance evaluation of sugar cane cutter planter using different parameters

Sugarcane planting is a very labour intensive job and involves considerable human drudgery. Planting creates the foundation for a crop and plays a crucial role in its growth and yield. Study was undertaken to evaluate the performance of two different models of sugarcane planters. One model was Khalsa PE-630 type cuter planter manufactured M/S Punjab engineers, Meerut and the other was ITI make cutter planter designed by Indian Institute of Sugarcane Research, and manufactured by Indian Telephone Industries, Rai Bareli. In addition to this two different experimental test set ups based on different principals were developed for measuring cutting forces for sugarcane cutting. It was observed that field capacity of Khallsa make planter was 0.20 ha/hr with the field efficiency of 87.50% at effective working width of 1.34 m and a forward speed of 2.54 km/hr at 2 nd low gear. A set length of 32.96 cm with average.

Design and Development of a Tractor-Operated Disc-Type Sugarcane Ratoon Management Device

Ratoon occupies more than 50 % of sugarcane area. Productivity of sugarcane ratoon crop could be improved by performing cultural operations like stubble shaving, cutting of side old roots (off barring) and application of fertiliser near to root zone during initiation of ratoon after harvesting. Studies have indicated that leaving trash in the field after sugarcane harvesting improves soil health and sustain ratoon yield. The existing machinery can work only in trash-free fields due to the presence of tines and shovels for off barring which dragged the trash and got clogged. For performing cultural operations in ratoon field with trash, disc-type ratoon management device (Disc RMD) was designed and developed at ICAR- Indian Institute of Sugarcane Research, Lucknow, India. It was equipped with stubble shaving serrated blades mounted on a disc, two tillage discs for off barring (pruning of old roots) on either side of the stubbles and device for application of fertiliser at root zone. Performance of the equipment was evaluated in sandy loam soil of ratoon field within a week after sugarcane harvest during 2013–14 and 2014–15. The effective field capacity of the equipment was 0.28 ha h−1 at forward speed of 0.67 m s−1. Use of Disc RMD saved cost of operation of ratoon initiation by ₹ 800 (US$ 12.04) ha−1 (35 %) and ₹ 2300 (US$ 34.60) ha−1 (60 %) when compared to earlier developed machinery and conventional practice, respectively. Use of Disc RMD resulted in labour saving of 112 labour-h ha−1 which was 15 times effective than conventional practice. The use of developed Disc RMD significantly improved tillering by 10.6 and 8.6 %, millable canes by 19.8 and 16.2 % and sugarcane yield by 10.8 and 13.4 % as compared to earlier developed machinery and conventional practice, respectively. The corresponding cumulative benefits due to saving in cost of operation and increase in yield of sugarcane, in case of Disc RMD, were ₹ 16,700 (US$ 251.24) and ₹ 21,600 (US$ 324.96) ha−1, respectively.

Improving Stubble Buds Sprouting and Productivity of Winter-Initiated Ratoon in Subtropical Climatic Conditions of India

In India, the ratoon cane productivity at national level stands at 58 t/ha against 85 t/ha for plant cane. Ratooning is a practice of growing full crop of sugarcane from sprouts of underground stubble buds left in the field after harvest of the plant (main) crop. In sugarcane farming, ratooning saves the cost of seedbed preparation, seed material and planting operations. Ratoons help in extending the crushing period of sugar mills as they mature earlier than the plant crop. However, most often, ratoon crop yields are lower than the plant crop. The major cause of low ratoon cane productivity in north-west Indian subtropics is the prevalence of severe winter conditions coinciding with harvesting of early-maturing high sugar varieties which inhibit the sprouting of subterranean stubble buds. Unsprouted stubble buds cause gaps in subsequent sugarcane (Saccharum sp Hybrid) ratoon crop resulting in lower initial plant stand and poor crop yield. Several agro-techniques viz., trash mulching, polyethylene mulching and intercropping have been applied to enhance the bud sprouting in winter-initiated ratoon, but all the efforts could not produce the desired results. To address these constraints, a field experiment was conducted during 2009–2010 and 2010–2011 for three consecutive seasons at the Indian Institute of Sugarcane Research, Lucknow, India, to assess the effect of cultural package practices and organic and/or inorganic sources of additions on yield and quality of winter-initiated ratoon in Indian subtropics. Results thus showed that application of sulphitation press mud cake (SPMC) at 20 t/ha or SPMC at 10 t/ha + 25 kg zinc sulphate improved the bud sprouting and significantly produced maximum number of shoots. Significant increase in the number of millable canes was noticed with the application of SPMC at 20 t/ha (103.1 thousand/ha) and SPMC 10 t/ha + 25 kg ZnSO4 (102.1 thousand/ha). Maximum cane yield (71 t/ha) was also recorded with the application of SPMC at 20 t/ha followed by SPMC at 10 t/ha + 25 kg ZnSO4 (69.3 t/ha). Thus, it clearly suggests that productivity of winter-initiated ratoon can be enhanced through the application of SPMC at 20 t/ha or SPMC 10 t/ha + 25 kg ZnSO4/ha since these applications at the time of ratoon initiation enhanced the ratoon cane yield by 16.34 and 14.29 %, respectively, than that of conventional package of practices for ratoon initiation in subtropical climatic conditions of India. Juice quality of ratoon cane was remained unchanged.

Sugar Beet: A Historical Perspective in Indian Context

Sugarbeet (Beta vulgaris L.) was introduced in India in 1950s. Exploratory trials for root and seed crop were carried out by Indian Institute of Sugarcane Research, Lucknow, India all over the country and suitable sites were identified. It was observed that sugarbeet could be grown in the rabi season in the plains of north India for its roots which contain 13–15 % sugar; and the seed crop could be grown in the hills above an altitude of 5,000′. An All India Coordinated Project was launched by the ICAR in 1971 to carry out multi-location research on sugarbeet and concurrent with this was the establishment of a sugarcane-cum-sugarbeet sugar factory at Sriganganagar in Rajasthan. The project and the factory were operational for nearly three decades and the crop was well established in that area. However, there was no expansion in the area as no new sugar factory with the additional machinery required to process sugarbeet came up. The situation has been confounded by no government policy of incentive for setting up a washing, slicing and diffusion plant in the existing sugarcane factories. The current scenario is no different except that there are now openings for production of ethanol from sugarbeet. The Indian Sugar Industry is getting sensitized to the feasibility of sugarbeet cultivation. The reason for sugarbeet not picking up commercially is mainly the lack of market. Since it is an industrial crop, no seed money or incentives have been given to the sugar industry for installing the additional machinery. The work done at IISR along with other partners from time to time (such as GBPAUT, RAU, YSPUFH, BCKVV, MPKVV, VSI, etc.), has left no doubt about the agricultural feasibility of sugarbeet in the country. Varieties, machines, agronomy and plant protection technologies have been developed for growing sugarbeet in the subtropical and tropical India. The IISR is actively involved in sugarbeet germplasm maintenance and limited seed production at its breeding outpost at IVRI, Mukteswar since 1976. India stands to gain from capitalizing on the potential of sugarbeet for sugar, ethanol and fodder. It offers to enhance the livelihood options of hill farmers by growing the required sugarbeet seed in India. Sugarbeet being a halophyte can bring under cultivation a large area afflicted with salinity in the country.

Iron, Manganese and Sulphur Uptake and Nutrients Availability in Sugarcane Based System in Subtropical India

A field experiment was conducted during 2007–2009 at Indian Institute of Sugarcane Research, Lucknow to assess the effect of iron, manganese and sulphur nutrition on growth, yield, quality, nutrient uptake and soil health in sugarcane based system. Eight treatments comprising combinations of iron, manganese and sulphur in different propositions were applied in sugarcane plant as well as ratoon crop subsequently. Among the various treatments, the highest sugar yield (9.25 ton/ha) was obtained with three foliar sprays of 1 % MnSO4 in sugarcane plant crop. However, sugarcane ratoon crop showed the highest sugar yield (10.73 ton/ha) with three foliar sprays of 1 % FeSO4 during tillering phase. Mean iron removal from sugarcane ratoon crop was higher (7.69 kg/ha) than plant crop (4.75 kg/ha). Sugarcane plant crop removed 1.25 kg/ha Mn as compared to 2.596 kg/ha removal by ratoon crop. However, the highest removal (3.67 kg/ha) of Mn from ratoon cane was observed under foliar application of 1 % MnSO4. It was observed that application of Fe, Mn or S increased the soil fertility status after completion of plant–ratoon crop cycle as compared to control (NPK alone). Thus, it was concluded that, sugarcane and sugar yield could be increased with three foliar applications of 1 % FeSO4/1 % MnSO4 during peak tillering phase (May) or through 60 kg S/ha (basal application).

INTRODUCING AUTUMN SUGARCANE AS A RELAY INTERCROP IN SKIPPED ROW PLANTED RICE–POTATO CROPPING SYSTEM FOR ENHANCED PRODUCTIVITY AND PROFITABILITY IN THE INDIAN SUB-TROPICS

SUMMARYField experiments were conducted for the three consecutive cropping seasons of 2003–05, 2004–06 and 2005–07 at the Indian Institute of Sugarcane Research, Lucknow, India, to explore the feasibility of planting sugarcane in autumn as a relay intercrop in standing rice. The cropping systems evaluated were: i) rice-potato-spring sugarcane; ii) rice + autumn sugarcane (planted as a relay intercrop in every sixth row devoid (skipped) of transplanted rice + potato after rice; iii) rice-autumn sugarcane (planted without preparatory tillage) + potato; and iv) rice-autumn sugarcane (planted with preparatory tillage) + potato. In each case, sugarcane was planted in rows 90 cm apart. Rice was transplanted in rows at 20-cm row spacing when followed by potato or sugarcane, but at 18-cm row spacing when intended for sugarcane planting as a relay intercrop in late September. The germination (60.4%) of cane buds, tillers (323 000 ha−1) and number (149 000 ha−1), length (225 cm), girth (2.44 cm) and weight (747 g) of millable canes were markedly better when autumn sugarcane was planted with rice as a relay intercrop in comparison to other cropping systems. Similarly, this cropping system produced the maximum cane (111.4 t ha−1) and sugar (13.2 t ha−1) along with sugarcane equivalent yield (216.4 t ha−1). In turn, relay intercropping system with maximum cane production efficiency of 420 kg ha−1day−1 fetched the highest economic returns (Rs. 258 ha−1day−1) and benefit:cost ratio (1.5). Compared with the rice-potato-spring sugarcane cropping system, the relay intercrop of autumn sugarcane in standing rice produced 35.4% more cane and 38.3% more sugar with 24.1% higher returns besides 79.1% energy saving. This practice will not only benefit cane growers and sugar mill owners in tropical and sub-tropical India, but also in other parts of the world where rice and sugarcane are extensively cultivated.

Effect of heavy metals on soil respiration during decomposition of sugarcane (Saccharum officinarum L.) trash in different soils

An experiment was conducted to study the effect of heavy metals (Cd, Cr and Pb), soil texture (sandy, loam and clay) and incubation periods (7, 15, 30, 60, 90 and 120 days) on soil respiration (CO<sub>2</sub> evolution) during sugarcane trash decomposition in laboratory conditions of the Indian Institute of Sugarcane Research, Lucknow, India. Surface soils (0–15 cm) were collected from agricultural fields and crop residue of sugarcane trash (<i>Saccharum officinarum</i> L.) was taken in the institute farm. Crop residue (10 t/ha) and heavy metals (10, 50, 100, 1000 μg/g) were mixed and incubated at 30°C ± 2°C in an incubator. The rate of soil respiration (CO<sub>2</sub> evolution) decreased with increasing heavy metals concentration. During the 120 days, the toxicity decreased but still remained significant. Maximum soil respiration was recorded at 7 days of incubation period; further, it decreased with increasing incubation period. The highest drop of soil respiration rate was caused by addition of 1000 μg/g Cd, Cr and Pb levels. Clay soils evolved maximum CO<sub>2</sub> followed by loam and sandy soil.

Trichoderma inoculation and trash management effects on soil microbial biomass, soil respiration, nutrient uptake and yield of ratoon sugarcane under subtropical conditions

A field experiment was conducted during 2003–2005 and 2004–2006 at the Indian Institute of Sugarcane Research, Lucknow, India to study the effect of Trichoderma viride inoculation in ratoon sugarcane with three trash management practices, i.e. trash mulching, trash burning and trash removal. Trichoderma inoculation with trash mulch increased soil organic carbon and phosphorus (P) content by 5.08 Mg ha−1 and 11.7 kg ha−1 over their initial contents of 15.75 Mg ha−1 and 12.5 kg ha−1, respectively. Soil compaction evaluated as bulk density in 0- to 15-cm soil layer, increased from 1.48 Mg m−3 at ratoon initiation (in April) to 1.53 Mg m−3 at harvest (in December) due to trash burning and from 1.42 Mg m−3 at ratoon initiation (in April) to 1.48 Mg m−3 at harvest (in December) due to trash mulching. The soil basal respiration was the highest during tillering phase and then decreased gradually, thereafter with the advancement of crop growth. On an average, at all the stages of crop growth, Trichoderma inoculation increased the soil basal respiration over no inoculation. Soil microbial biomass increased in all plots except in the plots of trash burning/removal without Trichoderma inoculation. The maximum increase (40 mg C kg−1 soil) in soil microbial biomass C, however, was observed in the plots of trash mulch with Trichoderma inoculation treatment which also recorded the highest uptake of nutrient and cane yield. On an average, Trichoderma inoculation with trash mulch increased N, P and K uptake by 15.9, 4.68 and 23.6 kg ha−1, respectively, over uninoculated condition. The cane yield was increased by 12.8 Mg ha−1 with trash mulch + Trichoderma over trash removal without Trichoderma. Upon degradation, trash mulch served as a source of energy for enhanced multiplication of soil bacteria and fungi and provided suitable niche for plant–microbe interaction.

Indian Institute of Sugarcane Research, Lucknow: Envisioning improved sugarcane production technology for high yields and high sugar recovery in India

The Indian Institute of Sugarcane Research (IISR) is a leading crop science research institute of India conducting research on fundamental and applied aspects of sugarcane cultivation as well as to coordinate the research work on sugarcane in different states of the country. Established on February 16, 1952, the Institute has expanded considerably in terms of infrastructure. The Institute has 5 full-fledged Divisions and carried out pioneering research work on crop improvement, crop production, crop protection, crop mechanization and crop quality management aspects of the sugarcane crop. The Institute has all requisite modern facilities and is all set to share its research facilities and professional manpower with other agencies/institutions working on the cause of sugarcane development in India. To impart a still bigger role, the institute is thinking of a need for a key shift from sugarcane research systems to sugarcane innovation systems that need to have a guiding agenda ‘developmental’ rather than ‘scientific’, relations involved ‘diverse and consultative’ rather than ‘narrow and hierarchical’, and the partners in various combinations of scientists, entrepreneurs, farmers, developments workers and policy actors from the public and private sectors rather than scientists in other public agencies.

Potassium nutrition for improving stubble bud sprouting, dry matter partitioning, nutrient uptake and winter initiated sugarcane ( Saccharum spp. hybrid complex) ratoon yield

A field experiment was conducted for two crop cycles during 2003–2005 and 2004–2006 at Indian Institute of Sugarcane Research, Lucknow to improve bud sprouting, dry matter accumulation (DMA), nutrient uptake and ratoon yield by using potassium fertilizer. Potassium (K) fertigation in standing plant cane increased the number of buds per stubble and number of stalks in ratoon cane. K content of stubble increased by 16.7% with K fertigation. The content of reducing sugars in buds at the time of ratoon initiation improved significantly with K fertigation. It improved dry matter accumulation, number of millable canes, individual cane weight, ratoon cane and sugar yields. Thus, it could be concluded that application of 66 kg K ha −1 with irrigation water in standing plant cane before harvest improved bud sprouting, dry matter accumulation and nutrient uptake in ratoon crop. Irrigation in standing plant cane increased ratoon cane (69.9 t ha −1) and sugar yields (7.6 t ha −1). This increase for ratoon cane and sugar yield was 8.7 and 5.55%, respectively over the control. Further, it increased ratoon cane yield by 15.21% (74.1 t ha −1) and sugar yields by 13.9% (8.2 t ha −1) with K fertigation over the control. Thus, K nutrition holds great promise for improving growth of ratoon cane and sugar yields.

Performance Evaluation of Two Pan Furnace with Forced Draft Combustion for Jaggery Making

Performance Evaluation of Two Pan Furnace with Forced Draft Combustion for Jaggery Making

Improving rhizospheric environment and sugarcane ratoon yield through bioagents amended farm yard manure in udic ustochrept soil

A field experiment was conducted for two crop cycles during 2003–2005 and 2004–2006 at the Indian Institute of Sugarcane Research, Lucknow in subtropical India. Trichoderma viride and Gluconacetobacter diazotrophicus amended farm yard manure (FYM) increased organic carbon (19.44 Mg ha −1) and available nitrogen (260 kg N ha −1) content of soil from 14.78 Mg ha −1 (OC) and 204 kg N ha −1 observed under farmer's practice (sole N application). Application of bioagents amended FYM improved soil porosity and reduced compaction (bulk density—1.39 Mg m −3 over 1.48 Mg m −3 under farmer's practice). Sugarcane ratoon crop removed the highest amount of nitrogen (N—165.7 kg ha −1), phosphorus (P—24.01 kg ha −1) and potassium (K—200.5 kg ha −1) in the plots receiving FYM with Trichoderma and Gluconacetobacter. Inoculation of FYM with bioagents improved population of ammonifying and nitrifying bacteria in the soil. Phosphorus and potassium uptake of the crop was greatest in the plots receiving FYM, Trichoderma and Gluconacetobacter. Bioagents ( Trichoderma and Gluconacetobacter) amended FYM increased ratoon cane (70.2 Mg ha −1) and sugar yields (7.93 Mg ha −1) compared with control (62.3 and 7.06 Mg ha −1 ratoon cane and sugar yields, respectively).

SSR markers associated with seed longevity in soybean

1 National Research Centre for soybean, Khandwa Road, Indore, India 452017 2 Department of Genetics & Plant Breeding, G.B. Pant University of Agriculture & Technology, Pantnagar (Uttranchal), India 3 National Research Center on Plant Biotechnology, IARI, New Delhi, India 110012 * Present Address and author for correspondence: Division of Crop Improvement, Indian Institute of Sugarcane Research, Lucknow, India 226002 (E-mail: ikrps@yahoo.com)

Enhancing efficiency of fertilizer n use in sugarcane by ring-pit method of planting

Nitrogen use efficiency of sugarcane variety CoS767 was measured in terms of partial factor productivity (PFP) and agronomic efficiency (AE) of applied N through a field experiment conducted during spring season in a sandy loan alluvial entisol soil at the Indian Institute of Sugarcane Research, Lucknow (26.50 N, 80.50 E and 120 m amsl). For this purpose, ten treatment combinations (2 methods of planting i.e. conventional flat and ring-pit method x 5 levels of N i.e. O, 75, 150, 225 and 300 Kg N ha-1 through urea) were tested in a randomized block design with 3 replications. In general, cane yield, PFP and AE were significantly greater in ring-pit method than that in conventional flat method. The optimum doses of N were 441 Kg N ha-1 in conventional flat method and 356 Kg N ha-1 in ring-pit method. To produce one tonne of cane yield, the crop required 8.481 Kg N in conventional flat method and 2.3421 Kg N in ring pit method of planting.

Tillering pattern, growth and productivity of promising sugarcane genotypes under various planting seasons and nitrogen levels in subtropical India

An experiment was conducted at the Indian Institute of Sugarcane Research, Lucknow, Uttar Pradesh, during 2000 2001 and 2001 2002 with 2 planting seasons (spring and summer), 3 genotypes ( Co H 94202 , CoLk 9606 and CoLk 9617 ) and 3 nitrogen levels (1 12.5, 150 and 187.5 kglha). Higher tiller number, vigour and re tention along with mean cane length (176.7 and 236.9 cm), cane diameter (2.46 and 2.23 cm) and cane weight (91 6.3 and 11 06 g) were observed with spring planted cane than summer cane during both the cropping sea sons respectively. Mean tiller population increased from 89,350tha to 21 8,600tha and 85,250 to 197,800tha dur ing first and second cropping seasons respectively. Thus higher tiller retention (66.6%) was observed during the first year than second year (52.9%). Genotype CoLk 961 7 produced highest number. of millable canes (1 53,5001 ha and 114,02O/ha during both the cropping seasons respectively), cane yield (92.1 9 and 109.4 tonnestha) and commercial cane sugar (10.72 and 12.95 tonnestha) and found superior to CoLk 94202 and CoLk 9606 . Spring planting produced highest cane (92.81 and 11 0.67 tonnestha) and commercial cane sugar (1 1.07 and 12.89 tonnestha) yields compared with the summer planting. The highest level of nitrogen also resulted in better tiller vigour, number and retention, besides better expression in growth parameters, cane (90.92 tonnestha and 103.75 tonnestha) and commercial cane sugar yields (10.69 and 12.59 tonnestha) during both the cropping sea sons.

Productivity and economics of sugarcane (Saccharum officinanrm) based production systems in subtropical India

A field experiment was conducted at the Indian Institute of Sugarcane Research, Lucknow, during 1996 98 and 1998 2000 with 3 cropping systems, viz. wheat (Triticum aestivum L. emend. Fiori Paol.) sugarcane (Saccha rum officinarum L.), sunflower (Helianthus annuus L.) sugarcane and sunflower sugarcane, and 3 planting ma terials for sugarcane (conventional 3 bud setts setts obtained from 750 ppm a.i. ethephon sprayed solution in seed cane 10 days before planting and polythene bag raised settlings PBS). The highest number of millable canes (158,70Olha), cane yield (116.9 tonneslha) and cane equivalent yield (145.9 tonneslha) were obtained when sugarcane (ethephon sprayed) was planted with spring sunflower. Sugarcane intercropping with sunflower increased 41.43% cane yield (1 11 tonneslha) over sunflower sugarcane system. Sunflower t sugarcane (CP) system produced taller cane (214 cm) than other systems. Use of polythene bag raised settlings increased the cane yield by 17% in wheat sugarcane system. The variation in cane yield was observed due to variation in date \ of planting under different systems. Sugarcane sunflower (ethephon sprayed) system also produced the highest number of millable canes (1 59,000) and cane yield (72.9 tonneslha) in subsequent ratoon. Sugarcane (ethephon sprayed) sunflower system fetched highest net return (Rs 78,000lha) and benefit :cost ratio (3.27). However, for .late planting conditions in wheat cane system the use of polythene bag raised settlings was found quite remu nerative (Rs 69,596lha net return and benefit : cost ratio 3.16)

Enhancing productivity and sustainability of sugarcane plant-ratoon system through planting geometry, dual-porpose legume intercropping and nitrogen nutrition

An effect of intercropped dual-purpose legumes in spring sugarcane plant-ratoon system was studied during 1997-98 to 1999-2000 at the Indian Institute of Sugarcane Research, Lucknow. The yield of sugarcane inter- cropped with cowpea [Vigna unguiculata (L.) Walp.] (67.0 tonneslha) and greengram (Phaseolus radiatus L.) (68.5 tonneslha) was comparable to that intercropped with Sesbania for green-manuring (72.2 tonneslha). Sig- nificantly highest cane-equivalent yield (80.3 tonneslha), sugar-equivalent yield (9.47 tonneslha), net monetary returns (Rs 33,341lha) and nitrogen addition (71.6 kglha) to the soil through incorporation of green biomass was recorded with sugarcane + cowpea intercropping system. Population density of 125% gave significantly higher number of millable canes (1 19,40O/ha), cane yield (73.7 tonneslha) and cane-equivalent yield (78.7 tonneslha). However, normal planting was found remunerative (Rs 36,696lha). The growth and yield parameters of sugar- cane as well as monetary returns significantly increased by application of 150 kg Nlha. Sugarcane + cowpea in- tercropping system proved highly productive and most economical. Cropping system x N level interaction indi- cated that sugarcane + cowpea as well as sugarcane + greengram were equally productive at higher level of N (1 50 kg Nlha). There was significant increase in number of millable canes, cane yield and sugar yield of ratoon from counter part plant crop intercropped with cowpea and greengram. Key words : ' I . Intercropping, Dual-purpose legumes, Nitrogen nutrition, Planting density