scholarly journals Weed community and growth under the canopy of trees adapted to the brazilian semi-arid region

2010 ◽  
Vol 28 (1) ◽  
pp. 69-76 ◽  
Author(s):  
P.S.L. Silva ◽  
P.I.B. Silva ◽  
K.M.B. Silva ◽  
O.F. Oliveira ◽  
J.D.D. Jales ◽  
...  

The objectives of this work were to evaluate the floristic composition and dry biomass of weeds under the canopy of seven perennial species adapted to the Semi-Arid region of Brazil, and correlate these characteristics with growth traits of the perennial species. The following perennial species were evaluated in two experiments (E1 and E2): mesquite (Prosopis juliflora), jucá (Caesalpinia ferrea), white popinac (Leucaena leucocephala), mofumbo (Combretum leprosum), neem (Azadirachata indica), sabiá (Mimosa caesalpiniaefolia) and tamarind (Tamarindus indica). In E1, the seven species were evaluated in a random block design with four replicates and nine plants per plot. In E2, evaluation comprised four species (mesquite, jucá, white popinac, and tamarind) in a random block design with eight replicates and nine plants per plot. A circle with an area of 1.77 m² was established around the trunk of each plant, two years after they were transplanted to the permanent location. The weeds collected within this circle were cut even with the ground, classified and weighed. At this time, plant height, and crown and stem diameters were evaluated in all trees of each plot. In E1 there were no differences between tree species as to weed frequency under their canopies; however, weed growth was smaller under the canopy of sabiá trees. Mesquite and sabiá had the greatest plant height and crown diameter means, but only sabiá had the greatest stem diameter. In E2, the perennial species were not different with regard to weed frequency and growth under their canopies, but mesquite had the greatest growth, as measured by plant height (with significant results for jucá as well) and crown and stem diameter.

Author(s):  
Antônio Veimar da Silva ◽  
Carla Michelle da Silva ◽  
Caio Nunes Gonçalves ◽  
Manoel Cícero de Oliveira Filho ◽  
Caike de Sousa Pereira ◽  
...  

This study aimed to evaluate the growth and development of watermelon plants under different plant spacings in the Semi-arid region of Brazil. A randomized block experimental design was used with four treatments and eight replications. Data were submitted to analysis of variance and the Tukey test. The treatments were composed by the following spacings: T1: 3.0 x 0.8 m; T2: 3.0 x 0.6 m; T3: 2.0 x 0.8 m and T4: 2.0 x 0.6 m (spacings between rows and between plants, respectively). The plant length, number of leaves, stem diameter, leaf area, number of flowers, number of fruits per plant, average fruit weight, total fruit production, number of commercial fruits, average weight of commercial fruits, total weight of commercial fruits and percentage of commercial fruits were evaluated in this study. There was a significant difference in the growth traits: stem diameter and leaf area at 30 days after sowing (DAS), and plant length, stem diameter and number of leaves at 60 DAS, with no significant statistical difference in the remaining days and nor for the number of flowers. The watermelon plants showed adequate vegetative and productive development at the 2.0 x 0.8 m plant spacing in the edaphoclimatic conditions of the semi-arid region under study. This spacing is well suited to small producers in the semi-arid region, which are dependent on agriculture with small areas and can obtain good productivity with no need to use larger areas due to spacing


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.


2014 ◽  
Vol 36 (3) ◽  
pp. 693-703 ◽  
Author(s):  
Rodinei Facco Pegoraro ◽  
Bruna Aparecida Madureira de Souza ◽  
Victor Martins Maia ◽  
Uirá do Amaral ◽  
Marlon Cristian Toledo Pereira

This study aimed to evaluate the growth characteristics of irrigated Vitória pineapple plants grown in semi-arid conditions and determine its developmental stages based on those characteristics. It was used a randomized block design with four replicates. The experimental treatments were: plant harvest at 270, 330, 390, 450, 510, 570, 690, 750, and 810 days after planting (DAP). The following variables were determined: plant height, stem diameter, D-leaf length, D-leaf fresh and dry mass, biomass production of plants and plant parts (organs), and vegetative biomass. Five phenological stages are proposed based on vegetative biomass production: < 20% biomass production (V1); 21-40% (V2); 41-60% (V3); 61-80% (V4); and > 80% (V5). The maximum growth rate for plant height, D-leaf length, and stem diameter was observed at the end of the phenological stage V1 (390-411 DAP), and at the end of stage V5 these plant traits had average values of 106, 82, and 7 cm, respectively. The maximum biomass accumulation rates were observed at stages V4 and V5, resulting in a final fruit yield and total fresh biomass of 72 t ha-1 and 326 t ha-1, respectively. Finally, we estimated that 80% of the accumulated biomass may remain in the field after fruit and slip harvest, and could be incorporated as plant residue into the soil.


Genetika ◽  
2016 ◽  
Vol 48 (1) ◽  
pp. 73-85 ◽  
Author(s):  
Jafar Ahmadi ◽  
Behroz Vaezi ◽  
Alireza Pour-Aboughadareh

The main goal of this study was to improve pure lines for low input agricultural areas of the semi-arid region of Iran and similar environmental conditions. Forty barley pure lines provided from ICARDA along with three check cultivars were evaluated under rain-fed conditions in a semi-arid region of Iran during two years (2011-2013). The experiments were conducted in a randomized complete block design with four replications to estimate genetic variation and heritability for agro-morphological traits. The highest values of phenotypic and genotypic coefficients of variation were observed for the number of grains per spike followed by peduncle length, early vigor and grain yield. The broad heritability estimates ranged from 24% for grain yield to 96% for the number of grains per spike. The highest and lowest expected genetic advance, observed for days to physiological maturity and the number of grains per spike, respectively. Results of stepwise regression and path analysis showed that hectoliter grain weight and thousand grain weight exhibited the highest direct effects on grain yield, respectively. Comparisons between the pure lines and check cultivars indicated that out of 40 pure lines, 27 lines had a higher grain yield. Also, the pure lines No. 29, 13, 9 and 33 were identified as the superior lines for semi-arid environmental conditions. Our results indicate that check cultivars could be improved by selecting for pure lines with taller peduncle and the number of grains per spike, but with heavier grains. Therefore, these lines can be used as genetic material to broaden the genetic basis of barley breeding programs all over the world.


2017 ◽  
Vol 16 (3) ◽  
pp. 449
Author(s):  
JOÃO PAULO NUNES COSTA ◽  
JOSÉ FRANCISMAR MEDEIROS ◽  
RAFAELA MENDES DE ANDRADE NUNES ◽  
EDMILSON GOMES CAVALCANTE JÚNIOR ◽  
JOSÉ FLAVIANO BARBOSA LIRA

RESUMO - Avaliou-se comportamento da rebrota de cultivares do sorgo sacarino e forrageiro no semiárido potiguar sob diferentes lâminas de irrigação. O ensaio foi realizado em março de 2015, nas condições de campo, em um argissolo no município de Upanema-RN, região Nordeste do Brasil. O experimento foi conduzido com delineamento experimental em blocos casualizados completos, em esquema de parcelas subdivididas 4 x (5 x 2), com quatro repetições, sendo quatro lâminas de irrigação (50, 75, 100 e 125% da ETc), e cinco cultivares (duas cultivares sacarinas, BRS 506 e BRS 511, e três forrageiras IPA 467-4-2, IPA SF-15 e BRS Ponta Negra) combinadas com duas densidade de plantio nas subparcelas. As variáveis avaliadas foram as produtividades de massa fresca e seca. Verificou-se que a lâmina de irrigação repondo 100% da ETc proporcionou maior rendimento de biomassa e que as cultivares sacarinas apresentaram baixa capacidade de rebrota, sendo as variedades IPA SF 15, IPA 467-4-2 e a BRS Ponta Negra as mais produtivas.Palavras-chave: Sorghum bicolor, semiárido, estresse hídrico. GROWTH AND PRODUCTION OF THE FIRST REGROWTH OF SORGO CULTIVARS UNDER DIFFERENT IRRIGATION BLADES  ABSTRACT - Behavior of re-growth of saccharin sorghum and forage sorghum cultivars in the semi-arid region of the State of Rio Grande do Norte (RN), Brazil, under different irrigation blades was evaluated. The experiment was carried out in March 2015 under field conditions in an argisol in the municipality of Upanema-RN, northeast region of Brazil. The experiment was carried out in a complete randomized complete block design with four replications (4 x 5 x 2), four irrigation blades (50, 75, 100 and 125% of ETc estimated from climatic data of Mossoró-RN) and five cultivars (two saccharin cultivars, BRS 506 and BRS 511, and three forage cultivars, IPA 467-4-2, IPA SF-15 and BRS Ponta Negra) combined with two planting densities in the subplots. Fresh and dry mass productivities were evaluated. The results were submitted to analysis of variance (F test) and the means were compared by the Tukey test at the 5% probability level, using the SAEG 8.1 software. It was verified that the irrigation blade replacing 100% of the ETc provided a higher yield of biomass and that the saccharin cultivars presented a low sprout capacity, with the varieties IPA SF 15, IPA 467-4-2 and BRS Ponta Negra being the most productive. Keywords: Sorghum bicolor, semiarid, water stress. 


2004 ◽  
Vol 79 (3) ◽  
pp. 505-511 ◽  
Author(s):  
R. A. S. Juárez ◽  
E. R. Montoya ◽  
C. G. Nevarez ◽  
S. M. A. Cerrillo ◽  
F. L. Mould

AbstractThree goats provided with oesophageal and ruminal cannulae were used to determine variations in dry matter (DM) and neutral-detergent fibre (NDF) degradability of the forage consumed when grazing thorn scrubland in the semi-arid region of north Mexico, during two consecutive dry and wet periods. Ingesta samples were incubated intraruminally, the data were fitted to the exponential equation P = a + b (l - e-ct) and statistically analysed using a randomized-block design. Organic matter and crude protein (CP) contents were higher (P < 0.05) in the wet seasons. Values of NDF were similar in dry and wet season of both years whereas higher numerical values of acid-detergent fibre (ADF), lignin and cellulose were registered in the dry seasons. DM and NDF degradabilities after 24 and 48 h of ruminal incubation were higher (P < 0.05) in the wet seasons. Higher values (P < 0.05) in DM and NDF bag losses at zero time (A fraction) were registered in the two wet seasons. The insoluble but fermentable DM and NDF (B fractions) were higher (P < 0.05) in the 1999 wet season and variable in the rest of the studied period. Numerically higher values of DM and NDF c fraction were found in wet periods, whereas DM and NDF potential degradabilities were higher (P < 0.05) in the wet season in 1999 and similar across seasons in 2000. Lowest (P < 0.05) contents of CP in grazed forage, DM and NDF degradabilities after 48 h of ruminal incubation, and A, and B, and c fractions were observed in the dry seasons. Thus, these results may be related to both the lower feeding value of forage consumed by the animals and lower performance of livestock during this period. Then, the DM and NDF degradability after 48 h, together with the insoluble but fermentable matter and the c fraction permit the nutritive value of the forage consumed by grazing goats to be accurately described.


2018 ◽  
Vol 24 (1) ◽  
pp. 22
Author(s):  
Ajoy Mandal ◽  
R. Behera ◽  
Saket Bhusan ◽  
P.K. Rout

2019 ◽  
Vol 10 (3) ◽  
pp. 376-383
Author(s):  
Wagner César Farias ◽  
Francisco Mickael Medeiros Câmara ◽  
Eduardo Castro Pereira ◽  
José Maria Costa ◽  
Gustavo Alves Pereira ◽  
...  

The pruning allows fruit harvest in different periods, according to the grower decision, being economically viable. The harvest can be scheduled according to the agronomical traits and due to the market price. The experiment was conducted in the didactic orchard of the Federal University of the Semi-Arid Region (UFERSA), from April 2013 to December 2014, in the municipality of Mossoro-RN. It was carried out in a randomized block design, with treatments arranged in a split-plot, which were composed by pruning periods, conducted in April (2013), November (2013) and July (2014). The subplots consisted of pruning intensities (short, medium and long); with four repetitions, where the experimental unit consisted of two plants that was pruned with 8 marked branches. From pruning to harvest, the the following botanical characteristics were evaluated in the marked branches: number of emitted sprouts by branches pruned at the day 15th (NBE); number of established branches by branches pruned at the day 50th (NRE); number of productive branches (NRP); vegetative number (VRN) and the total number of fruits (NFT). The evaluated characteristics presented a significant effect. The long pruning resulted in a higher number of fruits for all evaluated seasons. The best months for pruning was November and July. The guava tree ‘Paluma’ cycle, from pruning to harvest can vary according to the period of pruning, with 132 days in July and 150 days in April. durando entre 132 em julho a 150 dias em abril.  


AGRICA ◽  
2020 ◽  
Vol 7 (2) ◽  
pp. 87-100
Author(s):  
Josina Irene Brigetha Hutubessy

The study aims at revealing the impact of Tiens Golden Harvest organic liquid fertilizer on the growth and the yield of clove seed and optimum dose of Tiens Golden Harvest liquid fertilizer leading to the growth and the optimal yield of clove seed. The design used in this study was random block design with the treatment of T0 = Tiens Golden Harvest fertilizer 0 g/seed T1 = Tiens Golden Harvest 45 ml/seed, T2 = Tiens Golden Harvest fertilizer 90 ml/seed, T3 = Tiens Golden Harvest fertilizer 135 ml/seed, T4 = Tiens Golden Harvest fertilizer 180 ml/seed. Observation variables in this study were plant height, total leaves, leaf width, total fresh weight of brangkasan plant-1 and total dry oven weight of plant-1. The analysis result indicated that giving a different dose of Tiens Golden Harvest fertilizer may impact the plant height of 44,27%, fresh weight of plant-1of 32,58%, dry oven weight of plant-1of 48,92%. The optimum dose of Tiens Golden Harvest fertilizer contributing to the optimal growth of the clove seed is 180ml seed-1.


2020 ◽  
Vol 33 (4) ◽  
pp. 1111-1123
Author(s):  
LAUDICEIO VIANA MATOS ◽  
SÉRGIO LUIZ RODRIGUES DONATO ◽  
BISMARC LOPES DA SILVA ◽  
MARCOS KOITI KONDO ◽  
JOÃO LUIZ LANI

ABSTRACT The adaptation capacity of forage cactus (Opuntia ficus-indica Mill) plants to edaphoclimatic conditions and plant responses to changes in management systems contribute to increase the use of this species in agriculture and the exploration of its productive potential in semi-arid regions. The objective of this work was to evaluate the structural characteristics and cladode yield of forage cactus plants grown under different agroecosystems in the semi-arid region of Bahia, Brazil. Structural characteristics of plants and soils attributes were analyzed. The traditional information on the crop management and its correlations with cladode yield were used to identify the best yield indexes, considering the peculiarities of each agroecosystem. Plant height, cladode thickness, and number of cladodes of the forage cactus plants evaluated were less affected by the agroecosystem than by the production systems. Cladode width, length, and area were more affected by the agroecosystems. The forage cactus crop yields, expressed by the annual cladode fresh matter yield, were positively correlated with the plant structural characteristics: plant height and thickness, and cladode width and length. The cladode weight per plant and fresh matter yield per area were the yield components most affected by the management system adopted by traditional producers.


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