scholarly journals Factors affecting the sucrose content of sugarcane: iii, varieties

1969 ◽  
Vol 37 (1) ◽  
pp. 28-34
Author(s):  
M. A. Lugo-López ◽  
G. Samuels ◽  
F. Méndez

Data were obtained from 41 field experiments located throughout the Island. From the whole group of varieties tested, 20 were selected for evaluation of their sucrose production at harvesttime. The data were grouped according to three broad climatic areas, namely, humid, subhumid, and semiarid. Certain varieties were observed to produce better sucrose yields in a given climatic region, but in general, there were no significant differences among climatic regions for most varieties. P.R.'s 908, 907, 902, and 905, M.'s 330 and 28, and C.A.'s 38-102 and 38-74 produced the highest sucrose yields at harvesttime. The superiority in this respect of M.'s 336 and 28, and P.R.'s 907, 902, and 905 has been definitely established. Other promising varieties need further testing. Most of these canes yield more total sugar than the standard commercial P.O.J. 2878 and B.H. 10-12 canes, which cover more than 80 percent of the total land area where sugarcane is grown in Puerto Rico. The important bearing of seasonal variation on sucrose content of varieties is discussed. Seasonal differences in the performance of individual varieties have proved to be much greater than differences encountered between varieties in the same season.

1969 ◽  
Vol 36 (3) ◽  
pp. 194-202
Author(s):  
G. Samuels ◽  
M. A. Lugo López ◽  
P. Landrau Jr.

The results of over 150 field experiments with sugarcane conducted by the Agricultural Experiment Station of the University of Puerto Rico covering a wide range of varieties and soils of Puerto Rico revealed the following: 1. Nitrogen produced an increase in sucrose content with increased cane yields. When the percentage increase in cane tonnage is plotted against the percentage increase in sucrose percent cane, a highly significant regression is obtained. The equation obtained reveals that a significant increase in sucrose concentration occurs only after increases in yields are over 27 percent. 2. Different nitrogen sources, namely, ammonium nitrate, ammonium sulfate, and Uramon, produced no significant differences in influence on sucrose concentrations. 3. The application of phosphorus had no significant effect on the sucrose content of sugarcane. Cane tonnage responses were also slight. 4. The use of potassium fertilizers did not significantly influence the sucrose content of sugarcane. Where there was an increase in yield, there was generally an increase in sucrose content. Percentage increases in yield of cane, however, were very low, the majority being less than 10 percent. The soils seem to contain sufficient potassium for good sucrose concentrations, and the use of potash as fertilizer does not usually produce any significant increases in sucrose. 5. The minor-element fertilizers produced no significant increases in sucrose content. The use of copper, magnesium, zinc, boron, manganese, calcium, sodium, iron, and sulfur produced no appreciable increases in yield. The majority of percentage yield increases were less than 7, while percentage decreases or increases in sucrose content varied from —3 to +7.


1969 ◽  
Vol 62 (1) ◽  
pp. 48-55
Author(s):  
M. Pérez-Zapata ◽  
G. Ramírez-Oliveras ◽  
C. González-Molina

The performance of 34 new sugarcane varieties was evaluated in a plant crop and two ratoons at two sites in southwestern Puerto Rico. At Bonilla farm in Cabo Rojo the five leading varieties were PR 65-413, PR 65-339, PR 62-739, UCW 53-69, and PR 980. PR 980, which is the leading commercial variety of the Cabo Rojo area, ranked fifth in total sugar production per acre. PR 65-413 and PR 65-339 have the greatest potential as commercial varieties for the Cabo Rojo area, since they are high sugar yielders and suited to mechanization. In the humid valley of Central Eureka in Hormigueros, the most outstanding varieties were PR 1152, PR 61-902, PR 1140, CP 52-43, and NCo 310. PR 1152 is high in sugar content and cane tonnage production, and is suitable for mechanized harvesting. PR 1140 and PR 61-902 also had a good sucrose content, but their performance in subsequent crops was poor. NCo 310 and UCW 53-69 are not suitable for mechanized harvesting.


1969 ◽  
Vol 37 (1) ◽  
pp. 44-51
Author(s):  
M. A. Lugo-López ◽  
G. Samuels ◽  
R. Grant

Data are presented here on the effect of applications of 2,4-D and maleic hydrazide to sugarcane at intervals prior to harvesttime. Field experiments were conducted at Río Piedras in northern Puerto Rico and at Colonia Río Grande, between Caguas and Gurabo, in east-central Puerto Rico. Daily fluctuations in Brix, polarization, purity, and available 96° sugar percent cane were followed for 46- and 72-day periods, respectively. No significant differences were observed between the mean available 96° sugar percent cane that could be ascribed to treatments. Seasonal variations and variations attributable to weather conditions were rather important factors at both locations.


1969 ◽  
Vol 54 (1) ◽  
pp. 110-127
Author(s):  
S. Alers-Alers ◽  
M. A. Lugo-López ◽  
R. Gandía Caro

The data presented in this paper are from field experiments conducted at Corozal and Barceloneta following a split plot design where sugarcane cropping cycles or age at harvest (12-, 18-, and 24-month) were the main plots and varieties were the subplots. The varieties studied were: P.R. 1028, P.R. 1016, P.R. 1013, P.R. 980, P.R. 975 and B. 4362. Six replications were used. Statistical analyses of the data revealed that under the conditions prevailing in Puerto Rico, with the sugarcane varieties now available, and under typical current soil and crop management practices, 12- and 18-month canes are more efficient sugar producers than 24-month cane. More cane tonnage and more total sugar per acre per month were obtained during the short cycles than during the 24-month cycle.


1989 ◽  
Vol 61 (2) ◽  
pp. 113-122
Author(s):  
Aino-Maija Evers

The effects of different fertilization practices on the glucose, fructose, sucrose, taste and texture of carrot cv. Nantes Duke Notabene 370 Sv were studied in field experiments carried out in southern Finland in 1985 and 1986. The effects of unirrigated and irrigated placement and broadcast fertilization, NPK fertirrigations without basic fertilization, NPK fertirrigations with NPK basic fertilization, and PK placement with N fertirrigations were compared. Further, the effects of single application were compared with those of split applications. Sugar analyses were made by high performance liquid chromatography, and sensory evaluations were performed for taste and texture. The results were analysed by contrast analysis. In 1985, fertilization and fertilization practices had no effects on sugar contents. In 1986, the unfertilized treatments had a tendency to yield higher glucose and fructose, and thus also total sugar contents than did the fertilized treatments on the average. Placement fertilization had a tendency to increase the glucose content as compared to NPK fertirrigations. No significant differences or tendencies were found in sucrose content. The glucose and fructose contents were higher in 1985 than in 1986. The sucrose content was mainly opposite, being higher in 1986.Weather conditions were more favourable for photosynthesis in 1986 than in 1985. The mean total sugar content in fresh weight was 7.8 % in 1985 and 6.7 % in 1986. Indicative results of taste and texture are presented. The sugar content in organically cultivated carrots did not differ from that of conventionally grown carrots, but the taste was worse.


1969 ◽  
Vol 38 (4) ◽  
pp. 170-178
Author(s):  
George Samuels ◽  
Pablo Landrau, Jr.

Critical analysis of the results of over 200 field experiments with potash fertilizers on sugarcane conducted by the Agricultural Experiment Station of the University of Puerto Rico, covering a wide ranges of cane varieties and sons types of Puerto Rico, revealed the following: (1) Potash increased cane yields mainly on the red and yellow podzolic soils of the humid area and on a planosol of the semiarid area. There was slight, if any, response to potash in the irrigated area. (2) The use of potash increased the sucrose concentration of the cane only if cane yields were also increased. Increases of 10 percent or more in tonnage were required if increases in sucrose content were to be expected. A linear relation Y = 0.12 x + 0.55 was obtained where Y was the percentage increase in sucrose-percent-cane and x the percentage increase in tons of cane yielded per acre. (3) When potash fertilizers significantly influenced the sucrose concentration of the cane, the polarization value of the cane juice increased. Brix and percentage extractability of juice were not appreciably affected. (4) The use of foliar diagnosis has proven to be of great value in Puerto Rico in determining when to apply potash fertilizers to sugarcane. Leaf values of 2 percent or more, on a dry-weight basis, indicate that no response to potash applications can be expected for soils and varieties in Puerto Rico. Values below 1.80 percent indicate that a response to potash fertilizers may be expected in the humid areas.


2017 ◽  
Vol 1 (1) ◽  
Author(s):  
La Ode Jabuddin ◽  
Ayub M Padangaran ◽  
Azhar Bafadal Bafadal

This study aims to: (1) Knowing the dynamics of fiscal policy and the performance of the agricultural sector, (2) Analyze the factors that influence fiscal policy and the performance                   of the agricultural sector, and (3) Analyzing the impact of fiscal policy on the performance of the agricultural sector. The data used in this study were pooled 2005-2013 data in the aggregate. Econometric model the impact of fiscal policy on the performance of the agricultural sector is built in the form of simultaneous equations, consisting of 7 equations with 25 total variables in the model, 7 endogenous variables, 12 exogenous variables, and 6 variables lag. The model is estimated by 2SLS method SYSLIN procedures and historical simulation with SIMNLIN procedure.The results showed that: (1) The development of fiscal policy in Southeast Sulawesi from year to year tends to increase, (2) The performance of the agricultural sector from the aspect of GDP has decreased, from the aspect of labor is still consistent, in terms of investment to grow positively, and assign roles which means to decrease the number of poor people, (3) factors affecting fiscal policy is local revenues, equalization funds, other revenues, as well as the lag fiscal policy, (4) the factors that affect the performance of the agricultural sector from the aspect GDP is labor, direct expenditure and GDP lag; from the aspect of labor is the total labor force, investment, land area, direct expenditure, as well as the lag of labor; from the aspect of investment is influenced by GDP per capita, land area, interest rates and investment lag; as well as from the aspect of poor people, are affected by population, investments, direct expenditure and poverty lag, (5). Fiscal policy impact on the agricultural sector GDP increase, a decrease in the number of poor, declining agricultural laborers, and a decrease in the amount of investment in the agricultural sector.Keywords: Fiscal policy, the performance of the agricultural sector, the simultaneous equations


2019 ◽  
Vol 100 (4) ◽  
pp. 1340-1349
Author(s):  
Jaime A Collazo ◽  
Matthew J Krachey ◽  
Kenneth H Pollock ◽  
Francisco J Pérez-Aguilo ◽  
Jan P Zegarra ◽  
...  

AbstractEffective management of the threatened Antillean manatee (Trichechus manatus manatus) in Puerto Rico requires reliable estimates of population size. Estimates are needed to assess population responses to management actions, and whether recovery objectives have been met. Aerial surveys have been conducted since 1976, but none adjusted for imperfect detection. We summarize surveys since 1976, report on current distribution, and provide population estimates after accounting for apparent detection probability for surveys between June 2010 and March 2014. Estimates in areas of high concentration (hotspots) averaged 317 ± 101, three times higher than unadjusted counts (104 ± 0.56). Adjusted estimates in three areas outside hotspots also differed markedly from counts (75 ± 9.89 versus 19.5 ± 3.5). Average minimum island-wide estimate was 386 ± 89, similar to the maximum estimate of 360 suggested in 2005, but fewer than the 700 recently suggested by the Puerto Rico Manatee Conservation Center. Manatees were more widespread than previously understood. Improving estimates, locally or island-wide, will require stratifying the island differently and greater knowledge about factors affecting detection probability. Sharing our protocol with partners in nearby islands (e.g., Cuba, Jamaica, Hispaniola), whose populations share genetic make-up, would contribute to enhanced regional conservation through better population estimates and tracking range expansion.El manejo efectivo del manatí antillano amenazado en Puerto Rico requiere estimados de tamaños de poblaciónes confiables. Dichas estimaciones poblacionales son necesarias para evaluar las respuestas a las acciones de manejo, y para determinar si los objetivos de recuperación han sido alcanzados. Se han realizado censos aéreos desde 1976, pero ninguno de ellos han sido ajustados para detecciones imperfectas. Aquí resumimos los censos desde 1976, actualizamos la distribución, y reportamos los primeros estimados poblacionales ajustados para la probabilidad de detección aparente en los censos de Junio 2010 a Marzo 2014. Las estimaciones poblacionales en áreas de mayor concentración del manatí promedió 317 ± 103, tres veces más abundante que los conteos sin ajuste (104 ± 0.56). Las estimaciones poblacionales en tres áreas fuera de las áreas de mayor concentración del manatí también fueron marcadamente diferentes (75 ± 9.89 vs 19.5 ± 3.5). El estimado mínimo poblacional en la isla entera fue de 386 ± 89, similar al estimado máximo de 360 sugerido en el año 2005, pero menor a los 700 sugeridos recientemente por el Centro de Conservación de Manatíes de Puerto Rico. Documentamos que el manatí tiene una distribución más amplia de lo que se sabía con anterioridad. El mejoramiento de los estimados poblacionales locales o a nivel de isla requerirá que se estratifique a la isla en forma diferente y que se investiguen los factores que influencian a la probabilidad de detección. Compartir protocolos como este con colaboradores de islas vecinas (por. ej., Cuba, Jamaica, Española), cuyas poblaciones de manatíes comparten material genético, contribuiría a la conservación regional mediante mejores estimaciones poblacionales y monitoreo de la expansión de su ámbito doméstico.


Atmosphere ◽  
2021 ◽  
Vol 12 (7) ◽  
pp. 809
Author(s):  
Sen Wang ◽  
Wanyu Liu ◽  
Jun Li ◽  
Haotian Sun ◽  
Yali Qian ◽  
...  

Microorganisms existing in airborne fine particulate matter (PM2.5) have key implications in biogeochemical cycling and human health. In this study, PM2.5 samples, collected in the typical basin cities of Xi’an and Linfen, China, were analyzed through high-throughput sequencing to understand microbial seasonal variation characteristics and ecological functions. For bacteria, the highest richness and diversity were identified in autumn. The bacterial phyla were dominated by Proteobacteria, Actinobacteria, Firmicutes, and Bacteroidetes. Metabolism was the most abundant pathway, with the highest relative abundance found in autumn. Pathogenic bacteria (Pseudomonas, Acinetobacter, Serratia, and Delftia) were positively correlated with most disease-related pathways. Besides, C cycling dominated in spring and summer, while N cycling dominated in autumn and winter. The relative abundance of S cycling was highest during winter in Linfen. For fungi, the highest richness was found in summer. Basidiomycota and Ascomycota mainly constituted the fungal phyla. Moreover, temperature (T) and sulfur dioxide (SO2) in Xi’an, and T, SO2, and nitrogen dioxide (NO2) in Linfen were the key factors affecting microbial community structures, which were associated with different pollution characteristics in Xi’an and Linfen. Overall, these results provide an important reference for the research into airborne microbial seasonal variations, along with their ecological functions and health impacts.


2021 ◽  
pp. 1-39
Author(s):  
Nathan H. Haugrud ◽  
Thomas J. Peters

Abstract The invasion of waterhemp into northern sugarbeet growing regions has prompted producers to re-integrate inter-row cultivation into weed management programs as no currently registered herbicides can control glyphosate-resistant waterhemp POST in crop. Inter-row cultivation was a common weed control practice in sugarbeet until the release of glyphosate-resistant sugarbeet cultivars in 2008 made the use of inter-row cultivation unnecessary. In the late 2010s, producers began again to use inter-row cultivation to remove weeds that glyphosate did not control, but producers need information on the effectiveness and safety of inter-row cultivation when used with soil residual herbicide programs. Efficacy and tolerance field experiments were conducted in Minnesota and North Dakota from 2017 to 2019. Results from the efficacy experiment demonstrated cultivation improved waterhemp control 11% and 12%, 14 and 28 DAT, respectively. Waterhemp response to cultivation was dependent on crop canopy and precipitation after cultivation. Cultivation had minimal effect on waterhemp density in three environments, but at one environment, near Galchutt, ND in 2019, waterhemp density increased 600% and 196%, 14 and 28 DAT, respectively. Climate data indicated Galchutt, ND in 2019 received 105 mm of precipitation in the 14 days following cultivation and had an open crop canopy which likely contributed to further weed emergence. Results from the tolerance experiment demonstrated root yield and recoverable sucrose were not affected by cultivation timing or number of cultivations. In one environment, cultivating reduced sucrose content by 0.8% regardless of date or cultivation number, but no differences were found in three environments. In-season cultivation can damage/destroy leaf tissue which is likely responsible for the reduction in sucrose content. Results indicate cultivation can be a valuable tool to control weeds that herbicide cannot, but excessive rainfall and open crop canopy following cultivation can create an environment conducive to further weed emergence.


Sign in / Sign up

Export Citation Format

Share Document