scholarly journals Floristic composition and growth of weeds under custard apple (Annona squamosa) progenies

2004 ◽  
Vol 22 (4) ◽  
pp. 529-537 ◽  
Author(s):  
P.S.L. Silva ◽  
Z. Barbosa ◽  
O.F. Oliveira ◽  
R.P. Antonio ◽  
P.I.B. Silva

Weeds have a negative influence on several fruit tree characteristics, such as yield, making it difficult to management practices in orchards. Alternative weed management methods, aiming to reduce the use of herbicides, have become attractive since herbicides are costly and cause environmental degradation. The use of cultivars with greater competitive ability against weeds has attracted international attention. The objective of this work was to evaluate the floristic composition and growth of weeds under the canopies of irrigated custard apple tree progenies. Twenty halfsibling progenies around three years of age were evaluated in a random block design with five replicates and four plants per plot. A circle with a 0.5 m² area was established around the trunk of each plant. Floristic composition, fresh matter, and dry matter mass of the above-ground part of the weeds, were evaluated in this area. Root collar and canopy diameters, as well as leaf area of the progenies were also evaluated. Fifty-eight weed species were recorded. The five weed families with the most species were Leguminosae, Convolvulaceae, Euphorbiaceae, Malvaceae and Sterculiaceae, in decreasing order. The number of weed species per plot ranged from 6 to 18, but there was no difference between the mean percentages of different weeds under the canopies of the progenies. The lowest weed fresh and dry matter masses occurred in progenies JG1 and SM8, respectively. There were no differences between progenies with regard to root collar diameter and leaf area; however, one of the lowest weed dry matter yields was observed under the canopy of progeny FE4, which showed the largest canopy diameter.

Author(s):  
KB Basnet

A field experiment was conducted during the winter season of 2001-2002 at Mangalpur, Chitwan, Nepal to evaluate the performance of rapeseed in different agronomic management practices. The experiment was conducted with 16 treatments in a randomized complete block design (RCBD) with three replications. The treatments included control without input and four agronomic inputs (NPK, FYM, micronutrient- Zn, B and S and weeding), six and four combinations of two and three inputs respectively and a full package with all inputs. Application of NPK fertilizers increased leaf area and total dry matter per plant significantly as compared to control and weeding practice at 55 and 40 DAS, respectively. Further, in two factor combinations, significantly higher leaf area and particularly total dry matter per plant was produced by the application of NPK fertilizers with FYM at all stages (25 to 85 DAS) of growth and development. Finally, exclusion of NPK fertilizers in the combination of three agronomic inputs significantly lowered leaf area and total dry matter per plant as compared to others which included it at 40 and 70 DAS. All above mentioned trends were reflected on rapeseed yield indicating its significant correlation with leaf area (r=0.971) and total dry matter per plant (r=0.976). In general, addition of NPK fertilizers to other combinations of agronomic inputs increased leaf area and total dry matter per plant significantly. Key words: Leaf area, dry matter, agronomic inputs, yield J. Inst. Agric. Anim. Sci. 26:51-55 (2005)


2018 ◽  
Vol 10 (11) ◽  
pp. 269
Author(s):  
Francisco de Assis de Oliveira ◽  
José de Souza Leite Neto ◽  
Mychelle Karla Teixeira de Oliveira ◽  
Luan Alves Lima ◽  
Luan Vitor Nascimento ◽  
...  

The quality of water used to prepare a nutritive solution is a fundamental factor for plants to express their maximum yield potential, however, due to an emerging water scarcity, the use of saline water is turning into a challenge for producers and scientists. The present study was developed to evaluate the effect of potassium nitrate in two arucula cultivars fertigated with saline nutritive solutions in semi-hydroponic system. It was used a randomized block design, in factorial scheme 2 × 4, with two arucula cultivars (Cultivada and Folha Larga) and four nutritive solutions [S1-standard nutritive solution; S2-standard nutritive solution + NaCl (7.5 dS m-1); S3-S2 + 50% of KNO3; S4-100% of KNO3], with three replicates, with each experimental unit represented by a gutter of 1.5 m filled with coconut-fiber based substrate and 30 plants per replicate. Plants were collected 40 days after planting and evaluated for following variables: height, amount of leaves, leaf area, above ground fresh matter, above ground dry matter, leaf succulence, percentage of dry matter, and specific leaf area. Cultivada is more productive than Folha Larga, but presented higher sensibility to salinity. Increase of salinity in the water for preparation of nutritive solution negatively affects arucula cultivars’ development in semi-hydroponic system. The use of potassium nitrate reduced the effects of salinity on the Folha Larga’s development, but did not inhibit negative effects of salinity in any cultivar. Growth of arucula, Folha Larga, using saline water in semi-hydroponic system is feasible with addition of 50% of KNO3.


CERNE ◽  
2010 ◽  
Vol 16 (3) ◽  
pp. 251-257 ◽  
Author(s):  
Reynaldo Campos Santana ◽  
Tiago Reis Dutra ◽  
José Pereira Carvalho Neto ◽  
Gilciano Saraiva Nogueira ◽  
Paulo Henrique Grazziotti ◽  
...  

Clonal production of eucalyptus seedlings has made considerable progress in recent years. Significant developments have taken place in irrigation and fertilization systems as well as in management of clonal miniorchards. However, the proportion of leaf area in stem minicuttings remains almost the same as that used in macrocutting systems. This work aimed to evaluate the effect of leaf area reduction on seedling production of eight eucalyptus clones. The experiment was conducted over a period of 105 days using a randomized block design and three replicates in an 8 x 4 factorial arrangement, with eight clones and four leaf reduction levels (0%, 25%, 50% and 75%). Variables evaluated included height, root collar diameter, shoot and root dry matter and relationships between these variables. Experimental results demonstrated that clones behaved differently as to leaf reduction and that the 0% reduction level can be adopted in most clones being evaluated.


2010 ◽  
Vol 39 (8) ◽  
pp. 1666-1675 ◽  
Author(s):  
Marcio Mahmoud Megda ◽  
Francisco Antonio Monteiro

The objective of this work was to study morphogenic characteristics, and dry matter production of roots and shoots of marandu palisadegrass (Brachiaria brizantha cv. Marandu) submitted to combinations of nitrogen and potassium, in a nutritive solution, employing silica as substrate. The experiment was carried out in a greenhouse during the summer. It was used a 5² fractionated factorial scheme with 13 combinations of nitrogen and potassium, which were distributed in a randomized block design, with four replications. The nitrogen × potassium interaction was significant for the number of tillers and leaves, for leaf area, for shoots and root section dry mass, for total length and surface and specific length and surface in the roots. Production of aerial part dry mass positively correlated with the number of tillers and leaves and grass leaf area. Nitrogen rates modulated the root system development, and the root specific length and surface decreased when high rates of nitrogen and potassium were supllied. Nitrogen and potassium influence Marandu palisadegrass morphogenic characteristics, which are determinant for grass dry matter production.


CERNE ◽  
2011 ◽  
Vol 17 (2) ◽  
pp. 189-193 ◽  
Author(s):  
Thais Galhardo Godoy ◽  
Sebastião Carlos da Silva Rosado

The objective of this study was the selection of superior genotypes for growth traits, correlating them to initial height growth in the field, at age eight months. A random block design was used in the nursery, with eight clones, three replicates and four plants per plot. And a random block design was also used in the field, with eight clones, four replicate blocks and nine plants per plot. Data being analyzed in the nursery at age 120 days included: height of field seedling, at age eight months (Hc), height of nursery seedling (Hm), root collar diameter (Dc), shoot diameter (Db), shoot dry matter (PMSPA), root dry matter (PMSR), total dry matter (PMST), ratio of shoot dry matter to root dry matter (PMSPA/PMSR), Dickson quality index of root collar diameter (IQD-Dc), Dickson quality index of shoot diameter (IQD-Db). Analyses of variance showed that significant genetic differences exist among clones for all traits and, given the high heritability values found, the estimated genetic gains were generically very high. As for predicted indirect genetic gain, selection in nursery seedlings for Dc, PMSPA/PMSR, IQD-Dc provided the highest values of indirect gain in field seedling height.


2017 ◽  
Vol 14 (2) ◽  
pp. 147-154 ◽  
Author(s):  
MM Kamrozzaman ◽  
MAH Khan ◽  
S Ahmed ◽  
N Sultana

An experiment was conducted at Sadipur charland under Farming System Research and Development Site, Hatgobindapur, Faridpur, during rabi season of 2012-13 and 2013-14 to study the growth and yield performance of cv. BARI Gom-24 as affected by different dates of sowing under Agro-ecological Zone-12 (AEZ-12) of Bangladesh. The experiment was laid out in randomized complete block design with six replications, comprising five different dates of sowing viz. November 5, November 15, November 25, December 5 and December 15. Results reveal that the tallest plant, leaf area index, total dry matter, and crop growth rate were observed in November 25 sown crop and leaf area index, total dry matter and crop growth rate were higher at booting, grain filling, and tillering stages of the crop. Maximum effective tillers hill-1 (3.49), spikes m-2, (311), number of grains spike-1 (42.20) and 1000-grain weight (52.10 g) were produced by November 25 sown crop exhibited the highest grain (4.30 t ha-1) and straw yield (4.94 t ha-1) as well as harvest index (46.88%) of the crop. Lowest performance was observed both in early (November 5) and late sown crop (December 15). The overall results indicated that November 25 sown crop showed better performance in respect of growth and yield of wheat under charland ecosystem of Bangladesh.J. Bangladesh Agril. Univ. 14(2): 147-154, December 2016


2017 ◽  
Vol 35 (3) ◽  
pp. 425-427
Author(s):  
Jana Koefender ◽  
André Schoffel ◽  
Diego P Golle ◽  
Candida E Manfio ◽  
Alice PB Dambróz ◽  
...  

ABSTRACT The purpose of this work was to evaluate the influence of cutting the apex of the main stem of marigold plants on floral capitula yield. The experiment was carried out in a randomized complete block design, with five replicates. The following removal stages of the main stem apexes were studied: control (without pruning), up to 10 leaves, up to 15 leaves and visible flower bud. Three harvest periods were also evaluated: July, August and September, composing a factorial experiment in a 4x3 arrangement. The diameter, number, fresh matter and the dry capitula were evaluated. The most significant effect of cutting the apex of the main stem on fresh and dry matter of the capitula was obtained when the technique was performed at the time the plants had up to 15 leaves and visible flower bud. The harvesting performed in September showed to be the most promising, since it presented the larger diameter, higher number and higher fresh matter and the dry capitula.


2016 ◽  
Vol 69 (3) ◽  
Author(s):  
Eleonora Wrzesińska ◽  
Anna Komorowska ◽  
Grażyna Nurkiewicz

The condition and degree of weed infestation were determined in a spring barely crop grown in a short-term monoculture after mulching the soil with plants grown as a stubble crop (the control treatment without cover crop – lacy phacelia, white mustard, sunflower). The field experiment was carried out in 2010–2013 on good rye soil complex using a split-block design in four replications. The obtained results (the mean from all years of the experiment) showed that the stubble crop, especially sunflower, reduced the diversity of weed species without causing at the same time changes in weed species dominance. In all the control treatments of the experiment, <em>Chenopodium album</em> and <em>Fallopia convolvulus</em> were the dominant species. The degree of spring barley weed infestation depended on the species grown in the cover crop. White mustard and lacy phacelia slightly increased the number of weeds but their fresh matter significantly increased. However, the sunflower cover crop significantly increased the number of weeds without any substantial differentiation of their fresh mass.


Author(s):  
Mara Lúcia Martins Magela ◽  
Reginaldo de Camargo ◽  
Regina Maria Quintão Lana ◽  
Melissa Cristina de Carvalho Miranda ◽  
Raquel Pinheiro da Mota

In the current world scenario of agriculture it is necessary to find technologies to reach high productivity that are effective in providing soil conditioning improvement for the plants. Thus, this study analyzed the efficacy of organomineral fertilizers formulated with different organic matter sources on growth factors of maize. The experiment was done in a greenhouse at Campus Umuarama, Federal University of Uberlândia-MG, in a randomized block design, as a 2 x 5 + 2 factorial, containing two sources of organic matter, biosolid and filter cake, five doses of P2O5 recommendation for the crop and two additional treatments: mineral fertilization (100% of P2O5 of the recommended dose) and a control (no fertilizer), with four replications. Plant height, stalk diameter, and chlorophyll a and b were determined at 35 days after sowing (DAS); plant height, stalk diameter, shoot and root fresh and dry matter were determined at 65 DAS. The organomineral sources with biosolid and filter cake yielded greater height and diameter at 35 DAS than those of mineral fertilization. Regardless of the fertilizer organic matter source, stalk diameter at 35 DAS presented linear increase with increasing doses of the fertilizer sources. The use of fertilizer based on biosolid resulted in greater shoot fresh matter than the filter cake source, regardless of dose applied. In general, greater results were obtained for root fresh and dry matter at the greater fertilizer doses in comparison with the mineral fertilization. Organomineral fertilizers can be a viable alternative for partial or total substitution of mineral fertilization, since similar or better results were found for maize growth characteristics.


2020 ◽  
Vol 2020 ◽  
pp. 1-9
Author(s):  
Samuel Maina ◽  
Rossa Nyoike Ng’endo

Maize (Zea mays L.) is a significant food security crop in Kenya and it serves as the main source of nutrition and calories among the small-holder farmers. The overall maize yields per hectare have been fluctuating in the past few years posing a great risk to food security. Among the stress factors associated with maize yield loss include plant-feeding nematodes. In this regard, this study was conducted to evaluate the impacts of plant-parasitic nematodes specifically Scutellonema spp. under field conditions on maize performance in Mwea, Kenya. The field trials were laid out in a randomized complete block design with each treatment comprising of four replicates. The treatments included maize plots without nematicide (MPWN) and control plots treated with nematicide. The experiments were conducted in two trials. Soil samples were taken at a 0–20 cm depth at monthly intervals during 2018–2019. During the two trials, MPWN recorded significantly lower plant height and number of leaves per plant. Correlation analysis revealed a significant negative relationship between Scutellonema abundance with leaf area index, plant height, and number of functional leaves in MPWN during the 2019 trial. This implies that high population of Scutellonema perhaps has the potential to affect leaf area index, plant height, number of leaves per plant, which are aspects that in turn influence maize productivity. Therefore, holistic sustainable management practices to control Scutellonema spp. in maize fields such as use of organic amendments, resistant maize cultivars, and antagonistic organisms are crucial in order to alleviate negative impacts linked to Scutellonema infestation.


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