scholarly journals Growth Response to Weed Control and Fertilisation in Mid-Rotation Plantations of Eucalyptus pellita in South Sumatra, Indonesia

Forests ◽  
2021 ◽  
Vol 12 (12) ◽  
pp. 1653
Author(s):  
Maydra A. Inail ◽  
Eko B. Hardiyanto ◽  
Daniel S. Mendham ◽  
Erlanda Thaher
Keyword(s):  
Weed Control ◽  
Tree Growth ◽  
Nutrient Management ◽  
Acacia Mangium ◽  
Weed Competition ◽  
Young Tree ◽  
Wood Volume ◽  
High Productivity ◽  
Eucalyptus Pellita ◽  
Lower Productivity

We report on a study of mid-rotation weed control and nutrient management in Eucalyptus pellita plantations in South Sumatra. The study was established at two contrasting sites (representing high and low productivity for the region) that had previously carried three rotations of Acacia mangium. A combination of weed control, nitrogen (N), and phosphorus (P) fertiliser were applied at 1 and 2 years after establishment. We found that the addition of up to 250 kg N ha−1 applied either at 1 year or 2 years after planting did not improve growth. The application of P (30 kg P ha−1) at age 1 year (in addition to 12 kg P ha−1 applied at planting) did not enhance tree growth either. Keeping the plantation free from weed competition throughout rotation (full weed control) enhanced wood volume up to age 4 years at the high-productivity site, while it improved wood volume up to the end of rotation at age 6 years at the low-productivity site. An additional experiment assessing the effect of weed control in the early phase of plantation establishment revealed that weed competition reduced young tree growth of E. pellita substantially. The results of the studies support the current practice of plantation management of E. pellita in the region that applied only P fertiliser at planting time and that kept trees free from weed competition before canopy closure. Full weed control throughout rotation is worth practicing at lower-productivity sites to achieve maximum productivity.

Near infrared spectroscopy of Eucalyptus pellita for foliar nutrients and the potential for real-time monitoring of trees in fertiliser trial plots

2021 ◽  
pp. 096703352110079
Author(s):  
Agustan Alwi ◽  
Roger Meder ◽  
Yani Japarudin ◽  
Hazandy A Hamid ◽  
Ruzana Sanusi ◽  
...  
Keyword(s):  
Near Infrared ◽  
Acacia Mangium ◽  
Nir Spectroscopy ◽  
Nutrient Status ◽  
Significant Loss ◽  
Eucalyptus Pellita ◽  
Operational Decision Making ◽  
Fertiliser Application ◽  
Planting Distance

Eucalyptus pellita F. Muell. has become an important tree species in the forest plantations of SE Asia, and in Malaysian Borneo in particular, to replace thousands of hectares of Acacia mangium Willd. which has suffered significant loss caused by Ceratocystis manginecans infection in Sabah, Malaysia. Since its first introduction at a commercial scale in 2012, E. pellita has been planted in many areas in the region. The species replacement requires new silvicultural practices to induce the adaptability of E. pellita to grow in the region and this includes relevant research to optimise such regimes as planting distance, pruning, weeding practices and nutrition regimes. In this present study, the nutritional status of the foliage was investigated with the aim to develop near infrared spectroscopic calibrations that can be used to monitor and quantify nutrient status, particularly total foliar nitrogen (N) and phosphorus (P) in the field. Spectra acquired on fresh foliage in situ on the tree could be used to predict N and P with accuracy suitable for operational decision-making regards fertiliser application. If greater accuracy is required, spectra acquired on dry, milled foliage could be used to predict N and P within a relative error of 10% (R2c, r2CV, RMSEP, RPD = 0.77, 0.71, 0.02 g 100/g, 1.9 for foliar P and = 0.90, 0.88, 0.21 g 100/g, 3.0 for foliar N on dry, milled foliage). The ultimate application of this is in situ nutrient monitoring, particularly to aid longitudinal studies in fertiliser trial plots and forest operations, as the non-destructive nature of NIR spectroscopy would enable regular monitoring of individual leaves over time without the need to destructively sample them. This would aid the temporal and spatial analysis of field data.

Market exits during the pandemic

2021 ◽  
pp. 113-133
Author(s):  
E. V. Bessonova ◽  
S. M. Myakisheva ◽  
A. N. Tsvetkova
Keyword(s):  
Growth Potential ◽  
Efficiency Enhancement ◽  
High Productivity ◽  
Young Firms ◽  
Lower Productivity ◽  
Fast Development ◽  
Negative Effect ◽  
Positive Effect ◽  
Substantial Rise ◽  
Stimulation Of

The new coronavirus pandemic has triggered an economic crisis different from other crises in the acuteness and non-uniformity of its impact on various sectors of the economy. This paper analyzes how the dynamics of firms entering and exiting the market have changed in this environment and which groups of firms have shown to be the most vulnerable to the negative effect of the crisis. Our analysis shows that the number of newly registered firms dwindled sharply in the period of the toughest restrictions imposed to curtail the infection spread in April — May 2020. The recovery which followed in the subsequent months has failed to compensate for the spring’s slump, which may suggest a “scarring impact” of the crisis. July and October 2020 saw a substantial rise in companies’ exits from the market. The crisis has hurt not only the hardest hit industries but also other areas of economic activity. Liquidations rose most extensively among young firms aged less than three years. Relatively higher productivity firms exited less often than lower productivity companies. This may suggest a “cleansing effect” of the crisis. But with the redundant labor being unable to move to more productive firms, the positive effect of the crisis may be brought to naught. Therefore, for the consequences of the crisis to be remedied, incentives should be provided to new firms’ entries and support for efficient companies, especially for young firms showing growth potential. Stimulation of growth in the number of high-productivity firms should go hand in hand with the creation of conditions for new entities’ fast development, expansion, and efficiency enhancement.

scholarly journals Herbicide Evaluation for Sweet Potatoes

1969 ◽  
Vol 66 (4) ◽  
pp. 254-260 ◽  
Author(s):  
Lii-Chyuan Liu ◽  
Edwin Acevedo-Borrero ◽  
F. H. Ortiz
Keyword(s):  
Weed Control ◽  
Sweet Potato ◽  
Tuber Yield ◽  
Potato Cultivar ◽  
Weed Competition ◽  
Sweet Potatoes ◽  
Minimum Rate ◽  
Potato Plants ◽  
Herbicide Treatments ◽  
Rate Controlled

Two herbicide experiments were carried out in 1980 to evaluate Alachor and Metribuzin alone or combined for weed control in sweet potato cultivar Miguela at the Isabela and Fortuna Substations, Metribuzin at 1.12 kg ai/ha rate controlled effectively both broadleaf weeds and grasses. A minimum rate of 6.73 kg ai/ha of Alachor was needed for acceptable weed control. Metribuzin at the 1.12 kg al/ha rate in combination with Alachor at the 3.36 kg ai/ha rate provided the best weed control. There was no visible herbicide injury to sweet potato plants at the Isabela Substation. Moderate crop injury as a consequence of Metribuzin application at 2.24 kg ai/ha was apparent at the Fortuna Substation. The highest tuber yield was obtained with Metribuzin at 1.12 kg ai/ha in combination with Alachor at 3.36 kg ai/ha at both Substations. Metribuzin at 1.12 kg ai/ha rate alone or in combination with any other herbicide also produced good tuber yield. Sweet potatoes with standard herbicide treatments, Diphenamid and Chloramben, yielded poorly because of weed competition.

Habitat relationships of the mahogany glider, Petaurus gracilis, and the sugar glider, Petaurus breviceps

2000 ◽  
Vol 27 (1) ◽  
pp. 39 ◽  
Author(s):  
Stephen M. Jackson
Keyword(s):  
Canopy Cover ◽  
Acacia Mangium ◽  
Adjacent Area ◽  
Entire Study ◽  
Fragmented Forest ◽  
Eucalyptus Pellita ◽  
Continuous Forest ◽  
Sugar Glider ◽  
Food Species ◽  
Petaurus Breviceps

Trapping data of the mahogany glider, Petaurus gracilis, and the sugar glider, Petaurus breviceps, in sympatry, in north Queensland, were analysed with vegetation variables to determine the habitat relationships of these two species. The study area contained a trapping grid (80 traps) within an area of continuous forest and trapping transects within an adjacent area of fragmented forest (44 traps). The mahogany glider was trapped more often at 43 of the 124 locations (38 in the continuous and 5 in the fragmented forest), with the sugar glider dominant at 46 locations (18 in the continuous forest and 28 in the fragmented forest). The remaining 27 trap locations where gliders were caught did not favour either species. Eight trap locations within riparian rainforest had no captures of either species. The presence of mahogany gliders was significantly correlated with the presence of Corymbia clarksoniana, Eucalyptus platyphylla, the absence of Corymbia intermedia and Acacia mangium, and a small mid and upper canopy cover. In contrast, the presence of sugar gliders was most correlated with a large number of stems. When the presence of the mahogany glider was compared with that of the sugar glider with respect to various habitat variables for the entire study area, the mahogany glider was most associated with the presence of C. clarksoniana, Eucalyptus pellita, Lophostemon suaveolens, Melaleuca dealbata and a reduced lower and upper canopy. In contrast, the sugar glider was most associated with C. intermedia, A. mangium, a large number of potential food species, rainforest species and a dense mid and upper canopy cover.

scholarly journals Weed control under integrated nutrient management systems in faba bean (Vicia faba) production in Egypt

2008 ◽  
Vol 26 (3) ◽  
pp. 585-594 ◽  
Author(s):  
I.M. El-Metwally ◽  
M.T. Abdelhamid
Keyword(s):  
Weed Control ◽  
Faba Bean ◽  
Field Experiments ◽  
Nutrient Management ◽  
Weight Ratio ◽  
Nutrient Release ◽  
Growth And Yield ◽  
Yield Potential ◽  
Mineral Fertilizers ◽  
Net Assimilation

Two field experiments were conducted in two successive seasons, 2005/2006 and 2006/2007, to determine whether management can improve faba bean competitiveness with weeds, thus helping to achieve its yield potential. The experiment included five treatments, composed of organic and mineral fertilizers, alone and mixed at different rates, along with a control and six weed control treatments, including oxadiargyl, prometryn, hand hoeing treatments alone or mixed with the herbicides, and a nonweeded treatment (control).The herbicide treatments were not superior to the two hand-hoeing treatments. Using compost favored growth and yield of faba bean more than of weeds. Adding fertilizer also improved most yield parameters. Application of compost alone or combined with 50 or 100% of the recommended NPK rate improved faba bean growth in terms of net assimilation rate, specific leaf area, and leaf weight ratio as components of relative growth rate. This improvement in growth resulted in increase of seed yield, yield components and protein of faba bean. Faba bean yield performance improved under interactive fertilizer effects and weed control treatments as growth improved, as a result of nutrient release from fertilizers and weed control.

scholarly journals VIABILIDADE DE UM PROJETO FLORESTAL DE Eucalyptus grandis CONSIDERANDO O SEQÜESTRO DE CARBONO

FLORESTA ◽  
2004 ◽  
Vol 34 (3) ◽  
Author(s):  
Romualdo Maestri ◽  
Carlos Roberto Sanquetta ◽  
Sebastião Do Amaral Machado ◽  
José Roberto Soares Scolforo ◽  
Ana Paula Dalla Côrte
Keyword(s):  
Carbon Sink ◽  
Eucalyptus Grandis ◽  
Carbon Price ◽  
Empirical Models ◽  
Northeastern Brazil ◽  
Growth And Yield ◽  
Rate Of Return ◽  
Internal Rate Of Return ◽  
High Productivity ◽  
Lower Productivity

FLORESTA 34(3), Set/Dez. 2004, 347-360, Curitiba-PR 347 VIABILIDADE DE UM PROJETO FLORESTAL DE Eucalyptus grandis CONSIDERANDO O SEQÜESTRO DE CARBONO Romualdo Maestri1 Carlos Roberto Sanquetta2 Sebastião do Amaral Machado3 José Roberto Soares Scolforo4 Ana Paula Dalla Côrte5RESUMO Foram avaliados cenários econômicos para créditos do seqüestro de carbono em florestas de Eucalyptus grandis na região sudeste e nordeste do Brasil. Curvas de produtividade volumétrica e de carbono em diferentes frações foram obtidas. A análise identificou taxas internas de retorno (TIR) de no máximo 7,7% ao ano para sítios de alta produtividade (38,2 m3.ha-1.ano-1). Se a biomassa total da floresta (radicular e aérea) for considerada, a TIR acima de 6% ao ano são possíveis mesmo para produtividades menores (30 m3.ha-1.ano-1). Assim, seria necessária uma remuneração de US$ 25,00/t para que o empreendimento atingisse remuneração de 6% ao ano quando o seqüestro de carbono fosse objetivo de negócio e para produtividade volumétrica de 24 m3.ha-1.ano-1 ou US$ 15,50/t para produtividade de 38,2 m3.ha-1.ano-1. Se considerada a venda da porção lenhosa do tronco, então seria possível auferir a mesma rentabilidade ao preço de US$ 12,00/t para produtividades acima de 34,7 m3.ha-1.ano-1. FEASIBILITY OF A FOREST PROJECT OF Eucalyptus grandis TAKING INTO ACCOUNT CARBON SINK Abstract The purpose of this study was to investigate some economic scenarios for carbon sink through Eucalyptus grandis stands forest projects in southeastern and northeastern Brazil. Below and above ground stored carbon and biomass were obtained through dbh class growth and yield empirical models as functions of different environmental conditions. The analisys was identificed internal rate of return (IRR) above 7.7% per annum for stands at high productivity sites (38.2 m3.ha-1.year-1). If below and aboveground stored carbon is considered, an IRR greater than 6% pa. may be achieved even at lower productivity sites (30 m3.ha-1.year-1). It would be necessary a carbon price of US$ 25.00/t to match an IRR of 6% pa at low productivity sites (24 m3.ha-1.year-1) and US$ 15.50/t at high ones (38.2 m3.ha-1.year-1). Additionally, if stem biomass was also traded in the wood market, carbon price of US$ 12.00/t would allow to achieve the same IRR.

Effects of Weed Control and Irrigation on the Growth of Young Pecans

1990 ◽  
Vol 4 (4) ◽  
pp. 892-894 ◽  
Author(s):  
Michael G. Patterson ◽  
Glenn Wehtje ◽  
William D. Goff
Keyword(s):  
Weed Control ◽  
Tree Growth ◽  
Chemical Control ◽  
Growing Season ◽  
Control Effect ◽  
Carya Illinoensis ◽  
Maximum Increase ◽  
Tree Diameter ◽  
The Third ◽  
Selective Chemical

The effect of irrigation and weed control by various mechanical and chemical means was evaluated over a 4-yr period on newly planted pecans [Carya illinoensis(Wang.) K. Koch]. Weed control effect on tree growth became evident in the second growing season, and became more pronounced after the third and fourth season. After the fourth season, the maximum increase in tree diameter (384%) was achieved with comprehensive, herbicide-based weed control. Mowing provided a 224% increase, which was equivalent to the untreated (229%). Disking and selective chemical control of grass weeds resulted in 339 and 292% increase, respectively. Cumulative increase in tree diameter was 316 and 271% with and without irrigation, respectively.

The Concept and Application of Early Economic Period Threshold: The Case of DCPA in Onions (Allium Cepa)

Weed Science ◽  
1995 ◽  
Vol 43 (4) ◽  
pp. 634-639 ◽  
Author(s):  
Claudio M. Dunan ◽  
Philip Westra ◽  
Edward E. Schweizer ◽  
Donald W. Lybecker ◽  
Frank D. Moore
Keyword(s):  
Weed Control ◽  
Critical Period ◽  
Crop Yields ◽  
Economic Feasibility ◽  
Control Measures ◽  
Economic Losses ◽  
Weed Competition ◽  
Critical Periods ◽  
Control Efficacy ◽  
The Impact

The question of when to control weeds traditionally has been approached with the calculation of critical periods (CP) based on crop yields. The concept of economic critical period (ECP) and early (EEPT) and late (LEFT) economic period thresholds are presented as a comprehensive approach to answer the same question based on economic losses and costs of control. ECP is defined as the period when the benefit of controlling weeds is greater than its cost. EEPT and LEFT are the limits of the ECP and can be used to determine when first and last weed control measures should be performed. Calculation of EEPT accounts for the economic losses due to weed competition that occur between planting and postemergence weed control. In this way it is possible to better evaluate the economic feasibility of using preplant or preemergence control tactics. The EEPT for DCPA application is analyzed in the context of onion production in Colorado. The EEPT for DCPA application was calculated from an empirical regression model that assessed the impact of weed load and time of weed removal on onion yields. The EEPT was affected by control efficacy, weed-free yield, DCPA cost, and onion price. DCPA application was economically advisable in only one of 20 fields analyzed because of the tow DCPA efficacy (60%).

scholarly journals Competition periods of crabgrass with rice and soybean crops

2014 ◽  
Vol 32 (1) ◽  
pp. 31-38 ◽  
Author(s):  
D. Agostinetto ◽  
L.C. Fontana ◽  
L. Vargas ◽  
L.T. Perboni ◽  
E. Polidoro ◽  
...  
Keyword(s):  
Environmental Impact ◽  
Grain Yield ◽  
Weed Control ◽  
Critical Period ◽  
Rice Cultivar ◽  
Weed Competition ◽  
Flooded Rice ◽  
Reducing Costs ◽  
And Control ◽  
Impact Of Pesticides

Determining the periods of weed competition with crops helps the producer to choose the most appropriate time to use weed control practices. This strategy allows for the reduction of the number of herbicide applications, reducing costs and the environmental impact of pesticides. The objectives were to determine the period before the interference (PBI) of crabgrass (Digitaria ciliaris) competing with flooded rice, the critical period of interference prevention (CPIP) of crabgrass with soybean and the effects of competition on the grains yield and their components. Experiments were conducted with the coexistence of BRS Querência rice cultivar with crabgrass, for periods of 0, 7, 14, 21, 28, 35, and 110 days after emergency (DAE) and Fundacep 53RR soybean cultivar, whose periods of coexistence and control of crabgrass were 0, 7, 14, 21, 28, 35, and 156 DAE. Rice can grow with crabgrass infestation until 18 DAE, while soybean should remain free from the presence of crabgrass in the period between 23 and 50 DAE. The grain yield and its components, in the crops studied, are affected when grown with crabgrass.

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