Number Of Millable Canes Research Articles

Effect of planting methods on growth pattern and productivity of sugarcane varieties

Results from an experiment consisting of 4 planting methods and 8 varieties of sugarcane revealed that cane yield under small pit method of planting (120cm x60cm spacing with 3 settlings per pit) was significantly the highest (149.5 t ha1 ) and registered an increase to the tune of 5.7, 9.9, and 16.2 % over those of Mega pit (150cm x 150cm 15 settlings per pit), Trench method (30cm width x 30cm depth with 12 settlings per pit) and conventional method ( 15cm width 15cm depth with 12 settlings per pit) of planting.The corresponding per cent increase with respect to number of milliable cane was 11.6, 16.0 and 22.7 %. Among the varieties, variety 87A298 recorded significantly the highest cane yield of 147.67 t ha-1 while variety CO 86V96 recorded highest number of millable canes (105.3). The growth parameters under small pit method were also higher as compared to other methods. It also registered maximum net return (Rs.178430ha-1) and per day productivity (443.6 kg ha-1). However, the B-C ratio was the highest (2.30) under conventional method of planting.

Effect of Caneplex on Growth, Yield and Quality of Sugarcane

Efficacy of Caneplex, a micronutrient combina tion of c alcium, magnesium, molybdenum, manganese, zinc, copper, iron and sulphur, was tested during spring planting season in three consecutive years-2005-06, 2006–07 and 2007–08, on growth, yield and quality of sugarcane at the research farm of UP. Council of Sugarcane Research, Shahjahanpur (UP.) using the variety CoS 97264. Application of Caneplex enhanced the germination, shoot population, NMC and consequently the yield of sugarcane. The results showed that the germination was significantly increased by the application of Caneplex @ 25 or 30kg/ha as basal whereas top dressing of the same doses did not affect the germination significantly. Application of Caneplex @ 25 or 30kg/ha as basal followed by the same amount as top dressing showed significant increase in germination by about 4–5% over untreated control. Application of Caneplex @ 25 or 30 kg/ha as basal followed by the same amount of Caneplex as top dressing increased the shoot population and number of millable canes significantly as compared to control. The cane yield was marginally increased due to the application of Caneplex as basal or top dressing alone, the basal application being slightly better. A significant increase in cane yield was recorded after application of Caneplex @ 25 or 30 kg/ha as basal followed by the same amount of Caneplex as top dressing. Sucrose percent in juice at 10th month crop age was not affected significantly by the application of Caneplex at any dose under various treatments. Conclusively, the application of Caneplex @ 25 or 30 kg/ha as basal followed by the same amount of Caneplex as top dressing increased the cane yield significantly, however, Caneplex did not show significant effect on the cane quality (sucrose percent) at any dose under various methods ofapplication.

Response of Summer Planted Sugarcane (Saccharum officinarum L.) to Tillage Practices and Planting Methods

A field experiment was conducted to study the effect of tillage practices and planting methods on the performance of summer planted sugarcane at GBPUA&T, Pantnagar. Ten treatments comprising two tillage practices (conventional and no pre-planting tillage) and five planting methods (flat, ridge & furrow, trench, dual row trench and pit planting) were laid out in factorial randomized block design with three replications. No pre-planting tillage significantly increased the emergence percentage over conventional tillage besides attaining the more plant height, leaf area index and number of green leaves. Among different planting methods, maximum emergence (36.48 %) was noticed in trench method. In terms of growth, viz; plant height, number of green leaves and LAI, dual row trench method showed superiority over the remaining methods of the planting . Trench planting gave the maximum number of shoots which in turn also reflected in the maximum number of millable canes (108448 ha -1 ). In spite of non significant differences, no pre-planting tillage produced 1.4 t ha-1 higher cane yield than conventional tillage. No pre planting tillage gave Rs. 10586 ha-1 and Rs. 13311 ha -1 , higher gross and net return, respectively than conventional tillage and also had 12.1 per cent higher benefit cost ratio than conventional tillage. Trench method produced the maximum cane yield (90.8 t ha -1 ) which was significantly higher than flat and dual row trench planting. It also gave the maximum gross (Rs. 272989 ha -1 ), net return (Rs. 189278 ha -1 ) and B:C ratio (2.26).

Growth, yield and quality of mid late and late varieties of sugarcane (Saccharum spp complex hybrid) as influenced by row spacing and fertility levels

A field experiment was conducted to assess performance of newly developed five mid late and late sugarcane cultivars, i.e. Co 0121, Co 0123, Co 0124 and Co 0241 along with CoS 767(standard) with two row spacing (75 and 90 cm) under three fertility levels, i.e. 75, 100 (N150 P21.8 K41.5) and 125% of recommended dose of fertilizers (RDF) with plant-ratoon system. Varieties Co 0121 and Co 0241 recorded the maximum and significantly higher cane yield (69.1 and 67.2 tonnes/ha) and commercial cane sugar (10.22 and 9.00 tonnes/ha) in plant and ratoon crop, respectively. In ratoon crop number of millable canes (NMC) and cane yield increased substantially by 10.5 and 10.3 per cent, respectively with 75 cm row spacing. Closer spacing fetched maximum net return (` 24 810 and ` 47 820) with benefit: cost ratio of 1.42 and 2.27 with plant as well as ratoon crop, respectively. Fertility level of 125% RDF, being at par with 100% RDF registered improvement in yield attributes and produced increased cane yield and CCS both from plant as well as ratoon crop over 75% RDF. Except varieties, the quality parameters did not undergo significant variation due to change in row spacing and fertility treatments. Cultivar×fertility level interactions indicated that varieties Co 0121 and Co 0241 were equally productive at normal fertility level of 100% RDF.

Radiation-induced in vitro mutagenesis system for salt tolerance and other agronomic characters in sugarcane (Saccharum officinarum L.)

Gamma ray-induced in vitro mutagenesis and selection for salt (NaCl) tolerance were investigated in sugarcane (Saccharum officinarum L.). Embryogenic callus cultures were irradiated (10 to 80Gy) and subjected to in vitro selection by exposure of irradiated callus to NaCl (0, 50, 100, 150, 200, and 250mmolL−1). Increasing NaCl concentrations resulted in growth reduction and increased membrane damage. Salt-selected callus lines were characterized by the accumulation of proline, glycine betaine, and Na+ and K+ concentration. Higher accumulation of proline and glycine betaine was observed in NaCl stressed callus irradiated at 20Gy. Na+ concentration increased and K+ concentration decreased with increasing salt level. Irradiated callus showed 50–60% regeneration under NaCl stress, and in vitro-regenerated plants were acclimatized in the greenhouse, with 80–85% survival. A total of 138 irradiated and salt-selected selections were grown to maturity and their agronomic performance was evaluated under normal and saline conditions. Of these, 18 mutant clones were characterized for different agro-morphological characters and some of the mutant clones exhibited improved sugar yield with increased Brix%, number of millable canes, and yield. The result suggest that radiation-induced mutagenesis offers an effective way to enhance genetic variation in sugarcane.

English

Experiments were conducted during 2012-2013 with eight sugarcane genotypes along with four commercial checks to study the phenotypic stability and regression of cane yield, and its components under four environments. The G × E component of variation was significant for single cane weight, number of millable canes, commercial cane sugar percent, cane yield and sugar yield. The genotypes SNK 07680 and SNK 07337 was found stable for cane yield (132.60 and 105.66 t ha-1 respectively), sugar yield (14.44 and 12.70 t ha-1) its component characters such as sucrose (16.81 and 16.31% respectively), whereas SNK 07680 found stable for CCS (11.98%). Genotype SNK 07658 showed adoptability to unfavorable environment for single cane weight, number of millable canes and sucrose as evident by its deviation from regression and regression coefficient. Regression analysis concluded that 81.13% of total cane yield was contributed by single cane weight and number of millable canes.   Key words: Sugarcane, stability, G × E interaction, sucrose %.

Gamma radiation, in vitro selection for salt (NaCl) tolerance, and characterization of mutants in sugarcane (Saccharum officinarum L.)

Gamma-ray-induced mutagenesis and in vitro selection of sugarcane (Saccharum officinarum L. Lam.) plants tolerant to NaCl was achieved using embryogenic calli of sugarcane var. Co740. Sensitivity to gamma radiation and NaCl was studied in vitro in embryogenic calli followed by characterization and evaluation of mutant clones. The results indicated that callus growth and plant regeneration were significantly affected by radiation dose (0, 10, 20, 30, 40, 50, 60, 70, or 80 Gy 60Co gamma rays) as well as NaCl exposure (0, 50, 100, 150, 200, or 250 mM). Salt tolerance was achieved by culturing irradiated callus on selection medium with different NaCl concentrations through stepwise in vitro selection. Salt-selected embryogenic callus lines were then analyzed for proline, glycine betaine, Na+, and K+ contents. Salt-selected plants were grown to maturity, and their agronomic performance was evaluated under normal and saline conditions. Twenty-four mutant clones were characterized for proline, glycine betaine, Na+, and K+ contents. The mutant clones exhibited improved sugar yield with increments in Brix%, number of millable canes, girth, and yield. The results suggest that in vitro culture and induced mutagenesis offer an effective way to enhance the genetic variation in sugarcane.

Nutrient uptake, sugarcane yield and economics of high sugar early genotypes of sugarcane (Saccharum sp hybrid complex) under various planting seasons and fertility levels in Bihar

A field experiment was conducted for 3 consecutive years (2006-2010) in two seasons (autumn and spring) on sandy loam soil of Bihar, Pusa (Samastipur), to find out the impact of early maturing high sugar genotypes and level of N-P and K fertilization on performance of sugarcane (Saccharum sp hybrid complex). The performance indicated significant superiority of CoSe 95422 to CoP 9301 in terms of germination (35.5 and 34.4 %), tillers (152 700 and 141 400/ha), cane length (204 and 201 cm) and cane diameter (2.32 and 2.25 cm) in autumn and spring season, respectively. CoSe 95422 exhibited significantly higher dry matter accumulation and leaf area index at all the growth stages during both the cropping seasons. Net assimilation rate increased substantially at the initial crop growth stages and declined thereafter. Genotype CoP 9301 achieved higher NAR (6.34 and 5.66 g/m2/day) during June- August, though it was failed to reach the level of significance during August-October. Number of millable canes exhibited marked variation among the genotypes in both the seasons. CoSe 95422 produced significantly highest cane yield during autumn (81.0 tonnes/ha) and spring season (73.2 tonnes/ha) respectively. The percentage increase in mean cane and sugar yield by autumn planted sugarcane over spring planted sugarcane was 9.7 and 11.27 %, respectively. However, maximum sugar yield was obtained by CoSe 95422. Further, it showed significantly higher N (206.8 and 176.5 kg/ha), P (18.5 and 16.9 kg/ha), K uptake (239.4 and 204.0 kg/ha), net return (` 55 430 and ` 46 500) and benefit: cost ratio (1.86 and 1.75) during autumn and spring season, respectively. Fertility level had significant impact on drymatter accumulation and leaf area index across the season as well as stages of growth. Significantly higher tillers (140 300 and 131 000/ha), cane length (208 and 204 cm), cane diameter (2.34 and 2.26 cm), millable cane (102 100 and 100 300/ha) and cane yield (85.2 and 77.6 tonnes/ha) were obtained with the application of 187.5 N + 46.4 P + 62.3 K kg/ha in autumn and spring season, respectively. Though all of these parameters except cane diameter in spring season were statistically similar to 150 N + 37.1 P + 49.8 K kg/ha. A significant increase in cane and sugar yield was observed up to 150 N + 37.1 P + 49.8 K kg/ha. The magnitude of increase in cane yield at 187.5 N + 46.4 P + 62.3 K, 150 N + 37.1 P + 49.8 K kg/ha over 112.5 N + 27.8 P + 37.4 K kg/ha were 37.6 and 30.9%, respectively, during autumn season. Whereas, these increased 35.7 and 28.0% respectively during spring season. Though, significant variation in sugar yield up to 150 N + 37.1 P + 49.8 K kg/ha was noticed during both the season. There was a significant increase in net return by increasing level of N+P+K/ha during both the season. Though, marked variation in benefit: cost ratio (1.87 and 1.75) was observed only up to 150 N + 37.1 P + 49.8 K kg/ha during autumn and spring season, respectively.

Variability in Breeding Pool of Sugarcane (Saccharum spp.) for Yield, Quality and Resistance to Different Biotic and Abiotic Stress Factors

The understanding on the available genetic variability in the breeding pool aids the breeder to choose better parental combinations for the desired genetic improvement in crop plants. The variability present in the National Hybridisation Garden (NHG) of sugarcane in India at Sugarcane Breeding Institute, Coimbatore with an assemblage of 606 clones of sugarcane cultivars and other elite hybrids were studied for cane yield components, juice quality parameters and their level of resistance against red rot. The data on smut resistance, tolerance to stalk borer and tolerance to different abiotic stresses like drought, salinity, water logging, low temperature, high temperature and winter ratooning ability of these clones to be used parental clones were collected from the available literature. Significant leptokurtic distribution for the cane characters and right skewed distribution for juice quality traits were observed in this breeding pool. Correlation studies indicated that selection of parents contributing to high cane height and high number of millable canes (NMC) would result in progeny with high single cane weight (SCW) and cane yield because, the SCW was negatively correlated with NMC and cane thickness. Clones with high per se performance for important yield contributing characters were identified which are potential parents for yield improvement. For sucrose content, a highly heritable trait in sugarcane, nineteen clones with high juice sucrose of more than 20 % were found to be suitable as parents for quality enhancement. One hundred and thirty-seven clones were found as either resistant (R) or moderately Rto the most virulent races of red rot pathogen by testing with mixed inoculum of Cf 671 and Cf 94012 isolates. Screening of the clones for pollen fertility inferred that NHG has higher number of clones that can be used as female parent than as male parent. The synchrony in flowering of female and male parental clones with desirable traits of interest and the combining ability of the clones are also discussed in this paper. The critical consideration of the different parameters in choosing suitable parental clones in crossing programme will help in rapid varietal improvement for cane and sugar yield as well as to enhance the resistance against different biotic and abiotic stresses for increased sugarcane productivity.

English

Three hundred and thirty-nine genotypes of sugarcane germplasm were planted during spring 2006-2007 and 2007-2008 to study the associations among 15 characters. The cane yield, considered as the most important character of sugarcane was positively and significantly correlated with germination percentage, number of shoots, number of millable canes, stalk diameter, stalk length, number of internodes, length of internodes, stalk weight, number of green leaves, while with the top weight, it showed positive but non-significant correlation. Cane yield was negatively correlated with brix at all the stages. Sugarcane is influenced by a number of characters to various degrees of relationship among themselves. Thus, the path coefficient analysis for cane yield, as dependent (or effect) and the other characters as independent (or causes) have been done at phenotypic level. Hence, the present study was conducted to elucidate the genetic association among different agronomic traits in sugarcane germplasm under sub-tropics.   Key words: Sugarcane, genotype, correlation and path coefficient analysis, cane yield. 

Stability analysis of cane and jaggery yield in elite sugarcane genotypes (Saccharumspp.)

An investigation was carried out with eight sugarcane genotypes along with four checks to study the phenotypic stability of cane yield, jaggery yield and its components under four environments. The G × E component of variation was significant for single cane weight, number of millable canes, commercial cane sugar percent (CCS %), cane yield, sugar yield, jaggery yield and per cent jaggery recovery. The genotypes, SNK 07680 and SNK 07337 were found stable for cane yield (132.60 and 105.66 t/ha, respectively), sugar yield (14.44 and 12.70 t/ha, respectively) its component characters such as sucrose percentage (16.81 and 16.31, respectively). The genotype SNK 07680 was stable for CCS% (11.98). Genotype SNK 07658 showed adaptability to unfavorable environment for single cane weight, number of millable canes and sucrose percentage. SNK 07680 and SNK 07337 genotypes were stable for jaggery recovery (10.09 and 9.60% respectively) and jaggery yield (13.71 t/ha and 11.44 t/ha respectively).

Breeding sugarcane for photo-thermo insensitivity

Sugarcane flowering is a complex physiological trait sensitive to photoperiod and temperature. Though flowering is essential for breeding, it is undesirable for commercial cultivation, as it terminates vegetative growth and biomass accumulation. In peninsular India, most of the currently grown commercial varieties flower profusely leading to significant losses in cane, sugar and fodder (cane tops) productivity. Keeping these facts crossing was initiated at National Hybridization Garden, Coimbatore during 2007 and crossed material was planted at Sankeshwar during 2008–2009 to identify parents/crosses. Parents viz., Co 86032, Co 95021, CoC 671 and Co 740 were found proven as they produced high frequency of productive non/shy flowering progenies. Further, flowering, number of millable canes and single cane weight are highly repeatable and hence reliable for early generation selection. The identified productive non/shy and late flowering progenies could be exploited suitably for future breeding programmes after confirming their productivity potential.

Economic Assessment of Sugarcane (Saccharum officinarum L.) through Intercropping

Sugarcane has pronounced importance to provide sugar for more than half of the global population. World population is enhancing day-by-day and production land is in the worst situation. The cultivated land is diminishing rapidly due to urbanization, road construction, and land deterioration. This crisis demands alternate research to raise crop productivity and maximize the economic returns per unit land for feeding the gigantic population. Sugarcane is a long duration crop and gave late net economic return. Intercropping in sugarcane received much attention and need to properly manage for getting higher net return from same unit area. It is becoming popular among farming community due to resourcefully utilization of land. Intercropping has the potential to inspire the farmers to get maximum economic return per acre per annum. For intercropping, wheat, gram, soybean, and potato were used as an intercrop in September-sown sugarcane. Triple row strip planting geometry of sugarcane with four intercropped (SC + Wheat, SC + Gram, SC + Soybean, and SC + Potato) and check with sole SC was used. Sugarcane was planted during September 2011- 12 and 2012-13 at research area University College of Agriculture, University of Sargodha, Pakistan. Randomized complete block design with three replications were used. Results showed that number of millable cane, cane diameter; unstripped and stripped cane yield and crop growth rate was significantly higher in sole sugarcane when compared with different intercrop in 2011-12 while trend was same in 2012-13. Cane diameter and un-stripped cane yield were statistically at par of intercrops SC + Soybean and SC + Potato while stripped cane yield of Sole SC and SC + Potato was statistically at par in 2012-13. In both the year of study, intercrops gave higher land equivalent ratio and net return over sole sugarcane planted while sole sugarcane gave maximum benefit cost ratio compared with other intercrops.

Influence of Rind Hardness on Sugarcane Quality

Sugar recovery in a factory depends upon regular crushing and quality of varieties besides various other working parameters. Strategies for increased productivity and sugar recovery, varietal improvement can bring out through selection of parents to get maximum gains. These are governed by sugar content, fiber, rind hardness and cane yield. In order to assess the breeding value of different traits including rind hardness, study was undertaken at Sugarcane Research Institute, Shahjahanpur, during 2011-2012. Phenotypic difference and correlations among agronomic characters, basic quality characters and rind hardness in 120 segregating genotypes derived from contrast bi-parental cross (UP9530 × Co86011) of sugarcane cultivar were studied in this experiment. All the traits observed were found statistically significant among the mapping populations. The mean value of rind hardness was 5.91 with a range from 2.08 to 12.10 among 120 segregating population including their parents. Rind hardness (RHD) showed significant positive genotypic correlation with sugar yield-related traits viz; cane weight (CW, r = 0.325), cane yield (CYLD, r = 0.380) and sugar yield (SUYLD, r = 0.248). Significant negative correlation was observed for rind hardness with commercial cane sugar percent (CCS%, r = -0.388), number of millable cane (NMC, r = -0.216), hand refractometer brix %-October (HBR, r = -0.154), Brix% in juice (BR, r = -0.119) and Sucrose% in juice (SUC, r = -0.080). The simple correlation analysis showed that RHD, CW, CYLD and SUYLD showed significant positive correlation for agronomic characters, but for basic quality characters had negative correlations. Result indicated that rind hardness was found to have economically important trait due to showing significant positive and negative correlation with sugar yield and sugar content, respectively. The study also revealed that with the reduction in rind hardness, sugar recovery may increase. Present findings indicated that the rind hardness could play as a key role in the selection of elite genotypes in breeding program to develop high sugar, high yielding, erect, non-lodging, disease and insect resistant varieties. The details of the study were discussed in the manuscript.

Production Potential and Soil Fertility Status of Ratoon Sugarcane (Saccharum officinarum L.) as Influenced by Time and Level of Earthing Up and Nitrogen Levels in North-Eastern Uttar Pradesh, India

<p>A field experiment was carried out during the spring seasons of 2008-09 and 2009-10 at Varanasi, Uttar Pradesh to find out exact time of earthing up with level of earthing up and optimum doses of nitrogen for getting higher productivity, monetary returns, and changes in the fertility status of soils after harvest of ratoon sugarcane (<em>Saccharum officinarum</em> L.). Twentieth fifth April earthed crop produced significantly more height of tillers, leaf area index at maximum tillering stage, grand growth stage and at harvest, dry matter/tiller at maximum tillering stage at grand growth stage and at harvest, cane length, cane diameter of top, middle and bottom, weight of cane, cane yield, monetary returns, B/C ratio, N, P and K uptake except number of tillers/ha, number of millable cane/ha and net available soil nutrient after the harvest of ratoon crops as compared to 25<sup>th</sup> May and 25<sup>th</sup> June respectively. Twentieth cm height of earthing up from the ridge also significantly increased all the above parameters such as height of tillers, LAI of maximum tillering stage, grand growth stage and harvest, dry matter/tiller at maximum tillering stage, grand growth stage and at harvest, cane length, weight of cane and cane yield than that of 10 cm earthed crop in both the ratoon crops. Application of 210 kg N/ha linearly and significantly increased number of tillers/ha at 60 and 120 days after ratooning, height of tillers at 120 days after ratooning, LAI at maximum tillering stage, grand growth stage, and at harvest, dry matter/tiller at maximum tillering stage, grand growth stage and at harvest, number of millable cane, cane length, cane weight, cane yield, monetary returns, B/C ratio and N, P, K uptake followed by 180 kg N/ha. Ratoon crop showed that there was a build up of nitrogen and phosphorous but depletion in potassium content of the soil. 210 kg N/ha with earlier earthed at 25<sup>th</sup> April to a level of 20 cm was found optimum for obtaining higher yields and monetary returns.</p>

Improving bud sprouting, growth and yield of winter initiated sugarcane ratoon through tillage cum organic mediated rhizospheric modulation in Udic ustochrept under subtropical Indian condition

Field experiment was conducted during 2007–2010 at research farm of Indian Institute of Sugarcane (Saccharum officinarum) Research, Lucknow. The findings of the investigation revealed that tillage operation performed by Ratoon Management Device (RMD) involving earthing-up from both the sides of sugarcane stubble protects the subterranean buds from cold injury and provides congenial rhizospheric environment for survival and sprouting of buds. Tillage through RMD superimposed with composted trash regulates the soil microbial activities (ex situ soil respiration – 29.52mg CO2-Ckg−1soil day−1 and soil microbial biomass carbon (SMBC) – 187.3mg Cmicrobkg−1soil day−1). These in turn enhance the sprouting of stubble buds which otherwise fail to sprout under the influence of extremely low temperature. The tillage cum organic treatments creates congenial soil–water–air relations which produce viable and vigorous sprouts.Translated into practice, it means that the fact ‘Tillage is manure’ is quite pertinent in winter initiated sugarcane ratoon as mechanical manipulations of soil (tillage) at its optimum moisture level creates favourable physical environment (soil tilth) in root zone (bulk density – 1.35Mgm−3 at 0–15cm soil depth and infiltration rate – 5.5mmh−1). Addition of organics further provides congenial substrate/s to soil microbiota and enhances their metabolic activities which along with new activated roots maintain better soil–water–air relations and enhancing their sprouting in cold conditions. This ensures synchronized, early formed adequate number of millable canes (135,000ha−1), consequently resulting in higher ratoon cane (94.1Mgha−1) and sugar yields (8.75Mgha−1). The tillage cum organic technology is of immense significance to cane growers by increasing sugar yield in early crushing season from ratoon.

Effects of Gluconacetobacter diazotrophicus on seed cane produced through micro-propagated plantlets in sugarcane (Saccharum spp hybrid complex) under sub-tropics

Field experiment was conducted to evaluate the performance of micropropagated plantlets inoculated in vitro with Gluconacetobacter diazotrophicus on the population counts of diazotroph, plant growth, yield, quality and ultimately planting material of sugarcane cultivar CoS 96268. Maximum cell counts (5.8 × 105 cells/g fresh weight) was obtained in the in vitro, treated micropropagated plantlets-followed by untreated micropropagated plantlets (4.7 × 104 cells/g fresh weight) while it was only 3.7 x104 cells/g fresh weight in conventionally grown plants. The highest cell counts of Gluconacetobacter diazotrophicus was recorded at grand growth stage which decreased at maturity. Inoculation with diazotroph improved dry matter accumulation specially in roots accompanied by higher uptake of nitrogen and potassium in micropropagated plantlets. There was significant increase in number of millable canes, cane length, number of nodes, cane diameter and cane yield. Besides, treated plantlets produced 5.45 and 1.52 times higher planting material (3 budded setts) over conventionally grown plants and un-treated micropropagated plantlets, respectively. Results signify the use of inoculation with diazotrophic bacteria in micropropagated plantlets for faster multiplication of disease-free healthy seed cane of sugarcane varieties for their adoption.

Effect of Sources and Levels of Phosphorus with Zinc on Yield and Quality of Sugarcane

A study was conducted to ascertain the effect of sources and levels of phosphorus along with zinc on yield and quality of sugarcane for three consecutive years from 2004–2005 to 2006–2007 on sandy loam soil of Regional Agricultural Research Station, Anakapalle. The results of the study indicated that, application of phosphorus through diammonium phosphate (97.9 t/ha) or single super phosphate (95.8 t/ha) registered more or less similar cane yield. The effect of 100% recommended P2O5 (97.7 t/ha) or 125% recommended P2O5 (98.8 t/ha) was statistically non significant but found significantly superior to 75% recommended P2O5. However, significantly higher cane yield (98.1 t/ha) was recorded with application of 50 kg ZnSO4/ha as compared to lower level of 37.5 kg ZnSO4 (92.5 t/ha) due to higher number of millable canes. Hence, it can be concluded that application of 100 kg P2O5/ha through SSP or DAP and 50 kg ZnSO4/ha along with 112 kg nitrogen/ha was found optimum for sugarcane under sandy loam soils.

Control of Morningglories (Ipomoeaspp.) in Sugarcane (Saccharumspp.)

Morningglories are summer annual or perennial dicots, and are troublesome weeds in sugarcane cultivated in northern India. If not controlled, they may compete with sugarcane, interfere in the harvest operation, and reduce yields. Managing morningglories in sugarcane continues to be a serious challenge for sugarcane growers. Field experiments were conducted during the 3-yr period from 2007 to 2009 to evaluate herbicides applied PRE and POST for control of morningglories in sugarcane. The herbicides applied PRE included diuron, metribuzin, and atrazine at 1.6, 1.4, and 1.0 kg ai ha−1, respectively, applied alone or followed by 2,4-D amine salt (0.58 or 1.16 kg ae ha−1) or 2,4-D sodium salt (0.8 or 1.6 kg ae ha−1) applied POST. Herbicides applied PRE controlled morningglories ≤ 87% at 15 d after treatment (DAT); however, control reduced to ≤ 56% at 90 DAT. Control improved when herbicides applied PRE were followed by POST application of 2,4-D amine or sodium salt. For example, diuron applied PRE followed by 2,4-D amine salt applied POST at any rate provided 100% control of morningglories at 15 and 30 DAT. At 90 d after POST application, control ranged from 68 to 82% with the PRE followed by POST herbicides, compared to 0% control when metribuzin or atrazine were applied PRE alone. The density and biomass of morningglories was also reduced to zero in treatments that included 2,4-D amine salt. The number of millable canes, cane height, and single cane weight was superior in PRE followed by POST herbicide treatments compared to herbicides applied PRE alone. Maximum cane yield was recorded for the treatments that included 2,4-D amine or sodium salt compared to only PRE treatments, and it was usually comparable with the nontreated weed-free control. It is concluded that a combination of PRE and POST herbicides were effective for control of morningglories; however, more research is required to evaluate other herbicides and their tank mix partners for control of morningglories in sugarcane.

Cultural-practice packages and trash management effects on sugarcane ratoons under sub-tropical climatic conditions of India

SUMMARYSugarcane (Saccharum spp.) ratoon crops comprise more than 0·50 of India's sugarcane acreage and reduce the cost of cultivation by 25–30%. However, ratooning is seldom practised beyond 1–2 ratoons because the yield declines in successive ratoons due to compacted soils with decreased fertility restricting root development and plant growth. Therefore, a field experiment on sugarcane was conducted from 1998 to 2003 at the Sugarcane Research Institute, Muzzaffarnagar (Uttar Pradesh), India to evaluate the effects of combinations of trash management with key cultural practices (stubble shaving, ridge dismantling, sub-soiling along stubble rows, trash mulching and earthing-up) on growth and yield of sugarcane up to the third ratoon. Two treatment combinations (ridge dismantling+stubble shaving+sub-soiling along stubble rows+trash mulching at 8 t/ha (T5) and all these plus earthing-up in June (T6)) showed similar growth, yield and economics of ratoon crops. Both these treatments produced significantly higher shoot populations, leaf area index (LAI), dry matter (DM) accumulation, net assimilation rate (NAR), number of millable canes, ratoon cane yield and sugar, soil organic carbon (SOC) content at harvest and higher net returns besides lowering weed density, weed dry weight and bulk density of soil compared with other treatments. T6 produced the highest cane yield of 77, 72 and 65 tonnes (t)/ha, which was 23, 27 and 29% more than trash burning alone (T1) in first, second and third ratoon crops, respectively. Although T6 had the same yield as T5, it led to significantly lower soil bulk density at 0–150 mm depth, higher SOC contents and greater benefit: cost ratios in the first, second and third ratoon crops, respectively compared with trash burning only. Adoption of the crop management components, separately or in combination, improved on trash burning only (the control treatment). Trash mulching sustained the improved yield and economic returns of sugarcane ratoon crops.