Stalk Weight Research Articles

EFFECTS OF DIFFERENT WATER STRESS LEVELS ON BIOMASS YIELD AND AGRONOMIC TRAITS OF SWITCHGRASS (Panicum virgatum L.) CULTIVARS UNDER ARID AND SEMI-ARID CONDITIONS

This study was conducted to determine the effects of different water stress levels on biomass yield, plant height, number of stalks per unit area, single stalk weight, yield reduction ratios and irrigation water use efficiency (IWUE) values of switchgrass (Panicum virgatum L.) cultivars under Central Anatolia conditions. Experiments were conducted for two years (2016 – 2017) in randomized blocks – split plots experimental design with three replications under Konya ecological conditions. Six switchgrass cultivars (Shelter, Alamo, Cave in rock, Shawnee, Kanlow and Trailblazer) and five different irrigation treatments (water stress levels: S1: Full irrigation; S2: 75% of full irrigation; S3: 50% of full irrigation; S4: 25% of full irrigation and S5: Rain-fed without irrigation) were used in present experiments. Kanlow, Alamo and Trailblazer cultivars had greater biomass yields than the other cultivars in all water stress treatments. Under different water stress treatments, dry biomass yields varied between 48300 kg ha-1 (S5- Cave in rock) and 25120 kg ha-1 (S1- Kanlow); plant heights varied between 70 cm (S5) and 180 cm (S1); number of stalks per unit area (meter) varied between 221 (S5) and 356 (S1); stalk weights varied between 0.56 g (S5) and 2.25 g (S1). IWUE was calculated as 5.7 kg m-3 for the first harvest and as 2.1 kg m-3 for the second harvest. Considering the biomass yields from single harvest of rain-fed treatments (S5) and two harvests of the other irrigation treatments (S1-S4), IWUE values and water deficits of the region, it was concluded that single harvest was more suitable for switchgrass plants grown under ecological conditions

Ripening Response of Sugarcane Varieties to Chemical Ripeners and Economic Benefits during the Early Period of Harvesting at Wonji-Shoa and Metahara Sugarcane Plantations, Central Rift Valley of Ethiopia

Wonji-Shoa and Metahara sugarcane plantations experience reduced sucrose content (%) during the starting period of sugarcane crushing due to the combined influence of high (>27°C) temperature and the presence of high residual soil moisture. Studies elsewhere showed the potential of chemical ripeners in boosting the sucrose content (%), where natural ripening is deterred by these challenges. Accordingly, a field experiment was conducted to evaluate the responsiveness of selected sugarcane varieties to chemical ripeners at both plantations. The treatments consisted of a factorial combination of four sugarcane varieties (B52298, NCo334, C86-56, and SP70-1284) and six ripener treatments: (1) Ethephon™(720 g ai ha−1), (2) Fusilade Forte™(25.6 g ai ha−1), (3) Moddus™ (250 g ai ha−1), (4) Ethephon™ (720 g ai ha−1) + Fusilade Forte™ (25.6 g ai ha−1), (5) Moddus™ (250 g ai ha−1) + Fusilade Forte™ (25.6 g ai ha−1), and (6) Unsprayed (control). The experiment was laid out in a randomised complete block design in a factorial arrangement with three replications. The results showed a significant ( p = 0.025 ) and highly significant ( p = 0.001 ) variety by ripener interaction in stalk height and sucrose content, respectively, while the main effect ripener highly significantly affected stalk weight ( p = 0.001 ) and sucrose yield ( p = 0.003 ). The variety C86-56 sprayed with combinations of Ethephon™ + Fusilade Forte™ and Moddus™ + Fusilade Forte™ had the shortest stalk heights of 1.27 and 1.29 m, respectively, compared with the control. Ethephon™ + Fusilade Forte™ combination resulted in the highest reduction of stalk weight (8.36%), while the lowest was recorded in the sole Moddus™ treatment (6.31%). From the ripener treatments, the Moddus™ + Fusilade Forte™ combination and Ethephon™ + Fusilade Forte™ combination improved sucrose yield by 1.42 and 1.34 t ha−1, respectively, compared with the control. However, in economic terms, the Moddus™ + Fusilade Forte™ combination treatment resulted in the highest marginal rate of return of 1244%. Therefore, the Moddus™ + Fusilade Forte™ combination ripener treatment was found to be promising to be evaluated at a commercial scale on immature sugarcane varieties B52-298, NCo334, and SP70-1284.

Genetic diversity assessment of Indonesian sorghum germplasm based on agro-morphological traits

Sorghum is a multifunctional crop that has been traditionally cultivated in Indonesia, especially in the eastern part where marginal and drought prone areas dominate the region. To understand similarities and genetic relationship among various accessions, study of genetic diversity was conducted using agro-morphological data to differentiate accessions and to obtain its genetic variance component. This research was conducted in 2012 and assigned in randomized complete block design with 2 replications in 5 m plot. Genotypes were 38 accessions of sorghum collected from various regions in Indonesia and also introduction lines. Traits observed were according to sorghum descriptors released by UPOV. The results of this study showed that there was significant effect of genotypes across quantitative traits, and also specific trait such as total biomass, brix content and juice extract volume (p <0.01). Analysis of genotypic and phenotypic variance suggests that diversity among accessions were broad and heritability (H2) varies from middle to high. Genetic correlation showed that juice extract volume was highly correlate and significant with total biomass weight and stalk weight. Based on quantitative traits dendrogram of accessions was grouped to 12 different clusters at 0.20 coefficients, with the highest contain 7 accessions. Abundant and very diverse germplasm collection indicates high potential of possible heterotic pattern to be used further in breeding program in order to develop high yielding varieties for biomass (stalk) and food (grain).

Research on the Physical Characteristic Parameters of Banana Bunches for the Design and Development of Postharvesting Machinery and Equipment

In the operations of the banana postharvesting process, the design and development related to the dehanding machine, the cutting and crushing machine of bunch stalks, and the fiber extraction machine of bunch stalks are in the initial stages. In addition, with the development of society and urbanization, the aging populations in hilly and mountainous areas, where bananas are planted, are becoming a more and more serious problem. The basic physical characteristic parameters of banana bunches, banana hands, and bunch stalks are the basis for studying their biomechanical properties and designing and developing the corresponding mechanical equipment. We measured the diameter, thickness of rind, curvature, density, moisture content, diameter of vascular bundle, weight of bunch stalk, and axial distance and circumferential angle of Brazilian and plantain banana hands using experiments and statistical analysis. Through the combination of physical experiments and numerical statistics, we obtained the value range and changing law of the physical characteristic parameters of banana bunches.

Growth of Porang Plants by Cutting the Midrib Tip and Providing Various Types of Biochar as an Intercropping in Interspace Oil Palm

To increase the income of smallholder oil palm farmers through the developmentof a polyculture pattern, which is expected to increase the LER (land Equivalent Ratio) byplanting porang Plant, witch tolerant to low light intensity. This study aims to determine theeffect of cutting the tip of oil palm fronds to increase light interception and to evaluate varioustypes of biochar on the growth of porang plants, using a randomized block design (RBD)arranged in factorial with three replications. The first treatment factor is cutting the tip of thepalm frond (C), namely cutting 1 m (C1), cutting 2 m (C2), and cutting 3 m (C3). The secondtreatment factor is the type of biochar (B) namely rice husk biochar (B1), corn cobs biochar (B2), and coconut shell biochar (B3). The results showed that the interaction between thetreatments had a significant effect on plant height, the number of leaves, stem diameter, anddry weight of stalks. Overall, the results of this study provide hope for the development ofpolyculture oil palm plantations with porang plants to increase farmers' income and at the sametime become an alternative source of carbohydrates considering that porang is capable ofproducing tubers of up to 40-50 tons per ha.

Impact of Organic and Inorganic Sources of Nutrients on Post Harvest Life of Cut Flowers of Hybrid Gerbera (Gerbera jamesonii B.) cv. Shimmer

The present investigation was carried out in premises of Biotechnology cum Tissue Culture Centre, Odisha University of Agriculture and Technology, Bhubaneswar during 2015-16 and 2016-17. The objective of the study was to standardize suitable integrated nutrient management (INM) practices on post harvest life of gerbera cut flowers. Four leaved tissue culture plantlets of gerbera cv. Shimmer a hybrid suitable for protected cultivation were used for planting. Experiment was laid down in Completely Randomized Design (CRD) with eight treatments combination and three replications per treatment. The treatments of different combination of vermicompost, biofertilizer, chemical fertilizer and macro and micro nutrients spray were used. The biofertilizers were applied after incubation with vermicompost for 7 days. Recommended dose of fertilizer were applied 3 month after planting as top dressing and subsequently as per treatment. Treatment combination of 75% Recommended Dose of Fertilizer (RDF) + vermicompost + Phosphorus Solublising Bacteria (PSB) + Azotobacter/Azospirillum + macro and micronutrient spray recorded maximum percent gain in weight of flower stalk, maximum percent gain in stalk length in vase, maximum percent gain in flower diameter, highest solution uptake in vase and longest vase life.

Evaluation of some new somaclones of sugarcane for yield and quality

The study aims to determine the genetic variability among eleven somaclones of sugarcane obtained via immature leaves of the Egyptian commercial variety GT-54 9 at Agronomy Department, Faculty of Agriculture, Assiut University. Significant differences were found among the somaclones and also their donor, revealing to abundance genetic differences among them. The highest values of GCV and PCV were estimated in agronomic traits for cane yield (18.11 and 18.53%) and in technological traits for sugar yield (17.65 and 17.76%) over two ratoon crops, respectively. The heritability in agronomic traits ranged from 50.39 (stalk diameter) to 98.46% (cane yield) and in technological traits varied from 73.02 (purity) to 98.78% (sugar yield) over the both ratoon crops. The obtained significant differences coupled with GCV, PCV and heritability estimates explained the differences among the studied somaclones (somaclonal variation). The average over the two ratoon crops revealed that somaclones no. 7 and 8 surpassed the donor in highly significant values for most agronomic traits i.e. stalk height (14.35 and 9.48%), stalk weight (9.52 and 15.24%), stalk number/fed (21.00 and 31.25%) and cane yield (32.16 and 52.02%), respectively. Also, the somaclone no. 4 surpassed the donor in highly significant values for all technological traits i.e. sugar yield (23.52), brix (3.13), sucrose% (6.28), purity% (2.99), pol% (6.36) and sugar recovery% (7.72%). The results concluded that the In-vitro cultures exhibited genetic variability among the obtained somaclones (somaclonal variation), which could be used to invent new superior somaclones and overcome the accomplishments of traditional cane breeding.

Rendimento de cana-de-açúcar e graus Brix em função de diferentes formas de adubação

A adubação na cultura da cana-de-açúcar mostra-se essencial para atingir uma boa produção, tendo em vista a exigência nutricional da planta. Reutilizar os recursos da propriedade rural é uma forma consciente, ecológica e econômica de repor os nutrientes do solo. Com esta idéia de reaproveitamento, a pesquisa experimental teve o objetivo de avaliar a aplicação de cama de aves, vinhaça e adubação mineral para o rendimento da cana de açúcar e do grau brix. O experimento foi conduzido em Lacerdópolis/SC, em uma área onde a cana foi plantada em 2017 e o experimento implantado em 2019, no segundo ano de cultivo da espécie no local. A pesquisa utilizou delineamento de blocos ao acaso, com quatro tratamentos e quatro repetições. Os tratamentos consistiram em testemunha, adubação com cama de aves, vinhaça (resíduo da fermentação alcoólica) e fertilizante mineral (9-33-12). A aplicação foi realizada em outubro de 2019 e durante o desenvolvimento da cana foram feitos os tratos culturais necessários. Quando a cana atingiu a maturação foi colhida manualmente e avaliado o diâmetro do colmo na base e ápice, peso dos colmos, volume em litros de caldo e graus brix, em unidades de medida. Todos os resultados obtidos foram submetidos a análise estatística. Entre as relações testadas, a adubação que se mostrou mais eficiente foi a cama de aves, tendo em vista o aumento significativo da produção.

Study of artificial irradiation arrangement and pinching age on chrysanthemum

The study was conducted to determine the effect of artificial irradiation setting time, pinching age, and their interactions on the growth and yield of chrysanthemum. The research method uses factorial Complete Randomized Group Design with 2 factors. The first factor is the treatment of growth cut point age (U) consisting of three age levels (1, 2, and 3 weeks after planting), and the second factor is the setting time of artificial irradiation (W) consisting of four levels (1, 2, 3, and 4 hours per 35 days). The results showed that the treatment of cutting point of growing age had significant effect to very real on all parameters observed except in secondary branch diameter, while the treatment of artificial exposure time was not significant on all parameters observed. The interaction had a significant effect on very real on all parameters observed except in the secondary branch diameter. The intercept between the cutting point of age 1 week after planting and artificial irradiation setting 4 hours per 35 days resulted in the average weight of flower stalk, flower diameter, and economic weight of the highest secondary branches respectively 127.398 g, 6.733 cm, and 122.489 g, increased by 29.63%, 30.69%, and 33.30%, respectively when compared with the lowest treatment.

Somaclonal Variation in Chrysanthemum × morifolium Protoplast Regenerants.

Chrysanthemum × morifolium protoplasts were isolated and regenerated to assess possible protoclonal variation in the regenerants. After a preliminary screening of the potential of different regeneration systems for protoplast regeneration, we produced a series of cut chrysanthemum ‘Arjuna’ leaf protoplast regenerants through liquid culture. Regenerants (54) were vegetatively propagated and grown under a commercial production system in 2 different seasons. All screened regenerants were significantly affected with regard to either flower number, flower size, flower weight, leaf weight, stalk weight, or plant size. A significant plant size reduction in 43/52 and 48/49 regenerants for both seasons was the most recorded effect. Also a reduction in flowering induction time up to 10 days, altered flower types and colors were observed. Differences between growing seasons were notable. Possible molecular backgrounds including genome size variation and commercial applications in breeding of chrysanthemum are discussed.

Formation of structure elements of winter wheat yield in landscape conditions of the Central Ciscaucasia

Relevance. The yield level significantly depends on the cultivation technique and landscape conditions. Therefore, knowledge of the mechanism of the relationship between these factors and the plant is relevant. Methods . The experiment was carried out in 2015–2019 at the “Agro landscape” training ground. The aim of the research was to study the influence of predecessors, the level of mineral nutrition and location in the relief on the formation of elements of the structure of the yield of winter wheat in the zone of unstable moisture in the Stavropol Territory. Results . The pea yield was formed in 2015 by the type of tall stalks, in 2017 by the mixed type, in other years by the spike type. On taxon A 1 , the yield depended on the grain weight per year in a strong ( r = 0.85), and on A 3 , in an average ( r = 0.60). For the halffallow, the formation proceeded in 2015 due to the productive stalk ( r = 0.78) and grain weight per ear ( r = 0.71), in 2016–2019. according to the spike type ( r = 0.76–0.96). In taxon A 1 , the yield was formed due to the weight of grain per ear ( r = 0.83), and in taxon A 2 and A 3 , due to the stem ( r = 0.84–0.85). For peas, a significant difference between the nutritional backgrounds was for all elements of the crop structure, except for the weight of grain per ear, and for half-fallow only in the number of productive stems. On average for predecessors, a significant difference in taxa was noted between A1 and A 2 in the number of grains and grain weight per ear, between A 2 and A 3 in the stem, between A 1 and A 3 in all elements of the crop structure. The strongest relationship between yield was noted with the weight of grain per ear ( r = 0.88), which is closely related to the weight of 1000 grains ( r = 0.83) and the number of grains per ear ( r = 0.82).

Integrated selection criteria in sugarcane breeding programs using discriminant function analysis

BackgroundSelection indices help the plant breeders to discriminate desirable genotypes on the basis of phenotypic performance. Therefore, the present study was conducted to evaluate thirty sugarcane genotypes (clones) along with two check cultivars in two cropping seasons at Mattana Agricultural Research Station.ResultsThe results showed the studied traits observed in all genotypes were significantly different. The results could significantly discriminate between low and high sugar yield genotypes by describing eleven traits including sugar yield (ton/fed), cane yield (ton/fed), number of stalk/m2, stalk weight (kg), stalk height (cm), stalk diameter (cm), number of internodes, Brix %, sucrose %, purity %, and sugar recovery %. High sugar yield genotypes were selected by discriminant analysis. The discriminant score (DS) could explain 79.2% of sugar yield variations and had a significant canonical correlation (0.89**). Results of discriminant function analysis (DFA) indicated that the most important traits, in order of appearance, are stalk weight, stalk height, purity %, Brix%, and cane yields.ConclusionsGenotypes, G.2017-43, G.2017-42, G.2017-29, G.2017-33, and G.2017-44, showed the highest values of the discriminant score and were recognized as the highest yielder sugarcane genotypes. While the genotypes named Vis, G.2017-30, G.2017-10, G.2017-27, G.2017-25, G.2017-70, G.2017-41, G.2017-40, G.2017-35, and G.2017-58, recognized as the lowest yielder sugarcane genotypes which represent the lowest values of the discriminant score.

Performance and stability analysis of some sugarcane genotypes across different environments

Eleven genotypes of sugarcane (ten genotypes and one commercial variety G.T.54-9 as a control) were evaluated at twelve environments; three locations (Agric. Res. Stations of Kom-Ombo, Aswan governorate, El-Mataana, Luxor governorate and Shandaweel, Sohag governorate and two harvesting dates; 11 and 12 month-old in 2015/2016 (plant-cane) and 2016/2017 (first-ratoon).The differences among genotypes, locations and between harvesting dates were significant for all studied traits; stalk length, stalk weight, cane yield, brix, sucrose and sugar yield. The interaction of locations × genotypes was highly significant in plant-cane and first-ratoon for all studied traits. Locations × harvesting dates interaction was significantly for stalk length in plant-cane crop and for stalk weight, sucrose and sugar yield in first-ratoon crop. Mean squares due to interaction between genotypes, harvesting dates and locations were significantly for all studied traits, except cane and sugar yields in plant-crop and stalk length in first-ratoon. Mean cane yield ranged from 54.23 and 52.61 to 57.61 and 56.71t/fed at harvesting dates and from 46.66 and 50.12 to 60.71 and 58.69 t/fed under locations in plant-cane and first-ratoon, respectively. Late harvesting date increased cane yield and its components. The stability analysis of variance for cane yield showed that the intermediate yielding genotypes (G.2003-47, G.2004-27 and G.2011-82) were more stable than the rather responsive high yielding ones. However, the genotype G. 2004-27 was stable for cane yield and its components. In addition, it was considered to be superior for cane yield under different environments. However, the highest yielding genotype (G.99-103) was unstable.

Genotype-by-environment interaction analysis across three crop cycles in sugarcane

ABSTRACT Genotype-by-environment interaction (GEI) is encountered in multi-environment trials. In sugarcane (Saccharum spp.), GEI affects crop growth and cane yield and complicates the selection of superior genotypes. The objective of this study was to assess and analyze GEI for cane yield and stalk weight to identify high-yielding, stable genotypes. Thirteen Canal Point (CP) sugarcane clones and three check varieties were evaluated at five different locations (environments) across three crop cycles (plant cane, first ratoon, and second ratoon) on the Florida organic (muck) soils. At each location, the experiment was conducted as a randomized complete block design with six replications. Mean stalk weight and cane yield data were collected and analyzed via the additive main effects and multiplicative interaction (AMMI) and genotype main effect (G) plus genotype × environment interaction (GEI), i.e. GGE biplot. The AMMI analysis for mean stalk weight and cane yield revealed that variation attributable to genotypes, environments, and GEI for these traits was significant. The GGE biplot analysis indicated that the five locations formed two mega-environments, with different winning genotypes. Two locations, Okeelanta and Duda, were non-representative of the Florida muck-soils. Among all the genotypes, CP 12–1417 had the highest mean cane yield and had the most stable performance across crop cycles. We concluded that the application of GGE biplot in our final-stage sugarcane testing program could help us identify clones best adapted to specific locations and enhance selection efficiency by helping us identify locations that provide similar information.

Character association and path analysis for cane yield, juice quality and their component traits in sugarcane over the environment

Pooled analysis for correlation coefficient revealed that cane yield was found to be significantly and positively correlated with CCS (t/ha) followed by germination % at 45 days, stalk height at 360 days, stalk diameter at 360 days, internodes/stalk at 360 days, stalk weight at 360 days and NMC at harvest at both genotypic and phenotypic levels while, CCS t/ha had highly significant and positive correlation with almost all the characters except tillers at 120 days, shoots at 240 days, juice purity % at 360 days and fiber % cane. These yield contributing characters also possessed highly significant and positive association among themselves. Path analysis showed low residual effect (0.028) indicating that there were negligible components left out other than those included in present study which influence cane yield. Further, path analysis revealed that for improving cane yield and quality of juice parameters in sugarcane, weightage in selection should be given to pol % cane at harvest, juice brix % at 360 days, fibre % cane, CCS (t/ha) or sugar yield (t/ha), juice purity % at 360 days and NMC at harvest because they have positive and highest direct effect on cane yield.

Effect of municipal wastewater irrigation and well water on plant and soil characteristics

In order to investigate the effect of treated wastewater on forage yield, nutrient elements and heavy metals in corn plants (Zea maize, 704 single cross), a field experiment was conducted in RCBD with three treatments in four replications in 2017. Irrigation with well water as first treatment, irrigation with wastewater as second treatment and irrigation with well water and wastewater was alternately applied as a third treatment. The results showed that the highest amount of forage corn yield, stalk and ear dry weight, plant height and leaf number and spade index were obtained in irrigation with wastewater. The highest nitrogen content of leaf and stalk and corn grain was obtained in irrigation with wastewater treatment and the least amount in irrigation with well water treatment was obtained. The amount of phosphorus and potassium measured in leaf and stalk of corn in all three treatments were not significantly different. Also, the highest amount of iron and zinc in leaf and stalk of corn was obtained in irrigation with wastewater treatment. The results showed that the amount of heavy metals including lead, cadmium and nickel in soils were not significantly different in all three treatments. According to the results, the use of urban wastewater not only does not cause soil and plant pollution to heavy elements, but also increases plant yield and nutrition.

Genetic Variability and Heritability among Sugarcane Genotypes at Early Stage of the Advanced Selection for some Agronomic Traits in Ferké, Northern Ivory Coast

Selection in sugarcane from true seed was recently implemented in Ivory Coast with the aim to increase the genetic variability of crop material used and, therefore, improve significantly sugar yields with a positive impact on the competitiveness of the Ivorian sugar industry. The objective of study was to determine the best performing cane genotypes among 29 clones tested under sprinkler irrigation, in comparison with a check variety (R579). It was carried out on R3-002 commercial sugarcane plantation of Ferké 2 sugar estate, in northern Ivory Coast. The experimental design used was a randomized complete block with 30 cane genotypes in three replications. Each plot comprised two dual rows of five meters with 0.5 and 1.90 m of inter-row spacing, i.e. 19 m² per plot and about 600 m² for the whole experiment. Based on sugar yields, four promising genotypes namely RCI12/15, RCI12/19, RCI13/121 and RCI13/136 were equivalent to the check variety which performed 15.6 t/ha. They are due to undergo the advanced selection stage during the 2020-21 cropping season for three more years for determining the first new sugarcane varieties of RCI origin to be tested commercially in Ferké sugar estates. Their yield performances ranged from 12.8 to 13.8 t sugar/ha, i.e. from 134.0 to 144.8 t cane/ha compared to 161.3 t/ha for the control variety. Although a relatively high level of stem-borer infestation rate recorded, with 15.6% on average (almost three times the tolerable threshold value of 5%), reasonable values of sucrose percent obtained with the promising genotypes, ranged from 12.7 to 13.9% over both crop cycles, compared with 13.6% for the check. Higher heritability values ranging from 61 to 80.5% were observed in traits like sugar yield, sucrose content (62.6%), recoverable sucrose (60.6%), fiber content (72%), stem-borer infestation rate (80.5%), number of internodes/stalk (67.7%), and flowering rate (79.6%). In contrast, lower and moderate values of heritability were observed for Pol juice (59.8%), juice purity (50.5%), cane yield (53%), millable stalk number/ha (29.5%), single stalk weight (36.7%), single stalk height (45%), and single stalk diameter (38.7%).

Effect of silicon and gibberellic acid on growth and flowering of gladiolus

Effect of silicon and gibberellic acid on growth and flowering of gladiolus

Long-Term Effects of Different Nitrogen Levels on Growth, Yield, and Quality in Sugarcane

Nitrogen (N) plays an important role in sugarcane (Saccharum spp. hybrids) growth and development; however, long-term effects of N application levels on cane and sugar production in different sugarcane cultivars under field conditions remain unclear. In this study, we investigate the agronomic, yield, and quality traits in three sugarcane cultivars (GT11, B9, and ROC22) under different N levels (0, 150, and 300 kg/ha urea) from 2015 to 2019. Continuous four-year field experiments of plant and ratoon crops were carried out by using two-factor split-plot design. The results showed that N fertilizer application improved the tillering rate, stalk diameter, plant height, stalk weight, millable stalks/ha, cane yield, sugar yield and juice rate of cane, and the difference between N application and non-N application was significant. The cane yield, millable stalks/ha, juice rate, and juice gravity purity increased with the increase of N application, but the milled juice brix and sucrose % cane decreased with the increase of N application. The sugar yield was the highest at 150 kg/ha urea application, while the cane yield was the highest at 300 kg/ha urea application. Different N fertilizer application levels significantly regulated the activities of glutamic pyruvic transaminase (GPT) and glutamic oxaloacetic transaminase (GOT) and the contents of chlorophyll and nitrate N in plant leaves, which reflected the regulation in nitrogen metabolism and alteration in dry matter production and distribution, cane yield and sugar accumulation in different sugarcane cultivars. During the four-year experiment duration, the cane yield and sugar yield generally showed ROC22 &gt; B9 &gt; GT11. These data suggested that 300 kg/ha urea application was suitable for the plant and first ratoon crops, and 150 kg/ha urea application was suitable for the second and third ratoon crops. Both cane and sugar yields could be the highest in a four-year production cycle under this circumstance.

Effect of different levels of potassium on the growth and yield of sugarcane ratoon in inceptisols

The production of sugarcane in Indonesia has been decreased from a year to another, because its growth is less than optimal due to potassium content in the soil is low. Potassium is an activator of several enzymes of generative growth and synthesis of sucrose in sugarcane, therefore adding KCl fertilizer is expected to increase the growth and productivity of sugarcane. The research aimsed to determine the effect of potassium fertilizer on the growth and productivity of sugarcane. Research has been conducted from September 2015 until July 2016 in Karangploso Experimental Station, Malang. The study used PSJK 922 ( a middle ripening variety) and arranged in a randomized block design (RBD) with 4 replications. The treatment consisted of five doses of K2O fertilizer, ie: 0, 60, 120, 180, and 240 kg/ha. The results showed that increasing the potassium fertilizer dose from 0 kg K2O/ha to 240 kg K2O/ha did not significantly affect plant height (average 3.36 m) and number of the stalk (average of 13 stalk/m). However, 180 kg K2O/ha increased sugarcane stalk diameter from 28.20 mm to 30.53 mm, sugarcane stalk weight increased from 0.67 kg/m to 0.78 kg/m, so sugarcane yield also increased from 109.58 to 138.18 ton/ha.