scholarly journals TOLERANCE OF F 2 POPULATIONS OF COWPEA TO WATER DEFICIT

2018 ◽  
Vol 31 (1) ◽  
pp. 48-55
Author(s):  
ERINA VITÓRIO RODRIGUES ◽  
KAESEL JACKSON DAMASCENO-SILVA ◽  
MAURISRAEL DE MOURA ROCHA ◽  
EDSON ALVES BASTOS ◽  
ADRIANO DOS SANTOS
Keyword(s):  
Water Deficit ◽  
Development Stage ◽  
Incomplete Block ◽  
Grain Production ◽  
Full Irrigation ◽  
Average Decrease ◽  
Relative Production ◽  
High Production ◽  
Experimental Plots ◽  
Block Experiment

ABSTRACT Water deficit affects plant development and the overcoming of its effects depends on the genotype, duration of stress, severity of damage and development stage of the plant at water stress. Cowpea is considered tolerant to water deficit, however, studies have shown that its yield can be reduced under this condition. Thus, the objective of this work was to evaluate the effect of water deficit on F2 populations of cowpea and select tolerant genotypes. Thirty F2 populations of cowpea and their parents (BRS-Paraguaçu, Pingo-de-Ouro-1-2, BRS-Xiquexique, CNCx-698-128G, Santo-Inácio and MNC99-510F-16-1) were evaluated in two experiments, one under induced water deficit and other under full irrigation, in the experimental field of the Embrapa Mid-North, in Teresina, State of Piauí, Brazil. A triple lattice incomplete block experiment design was used, with three replications. The experimental plots consisted of six 2-m rows, with spacing of 1.0 m between rows and 0.50 m between plants. The grain production was evaluated and its decrease related to the relative production and tolerance to stress was calculated. The grain production of the genotypes had an average decrease of 29.83% under water deficit. The genotypes from the crosses BRS-Paraguaçu x CNCx-698-128G, BRS-Xiquexique x Pingo-de-Ouro-1-2, CNCx-698-128G x BRS-Xiquexique, CNCx-698-128G x MNC99-510F-16-1, Santo-Inácio x BRS-Xiquexique and MNC99-510F-16-1 x BRS-Paraguaçu had high production and high tolerance to water deficit.

scholarly journals PRODUTIVIDADE DE GRÃOS E PARÂMETROS FISIOLÓGICOS DE SORGO GRANÍFERO SOB DEFICIÊNCIA HÍDRICA E IRRIGAÇÃO PLENA

2017 ◽  
Vol 16 (3) ◽  
pp. 361
Author(s):  
MAURÍCIO CASTELO BRANCO SANTANA ◽  
EDSON ALVES BASTOS ◽  
MILTON JOSÉ CARDOSO ◽  
ADERSON SOARES ANDRADE JÚNIOR ◽  
FLÁVIO DESSAUNE TARDIN ◽  
...  
Keyword(s):  
Drought Tolerance ◽  
Grain Yield ◽  
Sorghum Bicolor ◽  
Leaf Area ◽  
Chlorophyll Content ◽  
Water Deficit ◽  
Irrigation Management ◽  
Grain Production ◽  
Full Irrigation ◽  
Area Index

RESUMO - O presente trabalho objetivou avaliar híbridos de sorgo granífero em condições com (CDH) e sem restrição hídrica (SDH) em Teresina-PI, buscando identificar híbridos mais tolerantes ao déficit hídrico. Foram avaliados doze híbridos comerciais (DKB 599, BRS 330, AS 4610, BRS 380, BRS 309, AG 1040, BRS 310, DKB 551, 1 G 282, 50 A 50, BRS 305 e BRS 373), utilizando-se delineamento de blocos ao acaso, com quatro repetições, entre os meses de setembro e dezembro de 2012. Os tratamentos foram dispostos em esquema fatorial 2 x 12 (regimes x híbridos). O manejo de irrigação baseou-se na evapotranspiração da cultura. Foram determinados o índice de área foliar (IAF), o teor relativo de clorofila na folha (TCF), a eficiência de uso da água (EUA) e a produtividade de grãos. O cultivo de sorgo granífero CDH apresentou redução de 38,1% e 36,4% no IAF, nas leituras aos 63 e 98 dias após a semeadura, respectivamente; 9,3% no TCF e 33,1% na produtividade de grãos em relação ao sorgo sob SDH. Em média, a EUA na condição de déficit hídrico foi superior em 7,13%. Os híbridos BRS 305 e 1G 282 foram os mais produtivos na condição de restrição hídrico, mostrando-se também responsivos à melhoria do ambiente. Palavras-chave: Sorghum bicolor, tolerância a seca, área foliar, teor de clorofila. GRAIN PRODUCTION AND PHYSIOLOGICAL PARAMETERS OF GRAIN SORGHUM UNDER WATER DEFICIENCY AND FULL IRRIGATION  ABSTRACT - Twelve commercial sorghum hybrids were evaluated under two water regimes: water deficit (WD) and full irrigation (FI), at Embrapa Meio-Norte, in Teresina, State of Piauí, Brazil, from September to December 2012. The hybrids DKB 599, BRS 330, AS 4610, BRS 380, BRS 309, AG 1040, BRS 310, DKB 551, 1 G 282, 50 A 50, BRS 305 e BRS 373 were evaluated using complete randomized blocks with four replications. The irrigation management was based on crop evapotranspiration. The irrigation applied summed to the rainfall amounted 484 mm and 302 mm for FI and WD environments, respectively. The leaf area index (LAI), the relative chlorophyll content in the leaf (RCC), water use efficiency (WUE) and grain yield were determined. The sorghum under water deficit decreased by 38.1% and 36.4% in the LAI, respectively, in the readings at 63 and 98 days after sowing; 9.3% in the RCC and 33.1% in grain yield compared to sorghum under full irrigation. The WUE under water deficit was in average 7.13% higher than under full irrigation (FI). The hybrids BRS 305 and 1G 282 showed phenotypic characteristics of drought tolerance and responsiveness to irrigation for grain production. Keywords: Sorghum bicolor, drought tolerance, leaf area, chlorophyll content.

scholarly journals Evaluation of experimental designs in durum wheat trials

2015 ◽  
Vol 52 (2) ◽  
pp. 105-114
Author(s):  
Anastasios Katsileros ◽  
Christos Koukouvinos
Keyword(s):  
Durum Wheat ◽  
Block Design ◽  
Field Trials ◽  
Experimental Designs ◽  
Incomplete Block ◽  
Wheat Genotypes ◽  
Randomized Complete Block Design ◽  
Experimental Plots

Abstract Variability among experimental plots may be a relevant problem in field genotype experiments, especially when a large number of entries are involved. Four field trials on 24 durum wheat genotypes were conducted in 2013/14 in order to evaluate the efficiency of Incomplete Block, Alpha and Augmented designs in comparison with the traditional Randomized Complete Block Design (RCBD). The results showed that the RCBD can be replaced by an Alpha design, which provides better control of variability among the experimental units when the number of treatments to be tested in an experiment exceeds twenty. The ranking of the genotypes across the four designs was not constant.

Yield gap of the double-crop system of main-season soybean with off-season maize in Brazil

2020 ◽  
Vol 71 (5) ◽  
pp. 445 ◽  
Author(s):  
Rogério de Souza Nóia Júnior ◽  
Paulo Cesar Sentelhas
Keyword(s):  
Water Deficit ◽  
Zea Mays L ◽  
Sowing Date ◽  
Agricultural System ◽  
Grain Production ◽  
Yield Gap ◽  
Mato Grosso ◽  
Expansion Yield ◽  
Glycine Max L ◽  
Main Factors

The succession of main-season soybean (Glycine max (L.) Merr.) with off-season maize (Zea mays L.) is an important Brazilian agricultural system contributing to increased grain production without the need for crop land expansion. Yield-gap studies that identify the main factors threatening these crops are pivotal to increasing food security in Brazil and globally. Therefore, the aim of the present study was to determine, for the soybean–off-season-maize succession, the magnitude of the grain and revenue yield gap (YG) caused by water deficit (YGW) and suboptimal crop management (YGM), and to propose strategies for closing these gaps in different Brazilian regions. The ensemble of three previously calibrated and validated models (FAO-AZM, DSSAT and APSIM) was used to estimate yields of soybean and off-season maize for 28 locations in 12 states for a period of 34 years (1980–2013). Water deficit is the biggest problem for soybean and off-season maize crops in the regions of Cocos (state of Bahia), Buritis (Minas Gerais) and Formosa (Goiás), where the YGW accounted for ~70% of total YG. The YGM revealed that locations in the central region of Brazil, mainly in the state of Mato Grosso, presented an opportunity to increase yields of soybean and off-season maize, on average, by 927.5 and 909.6 5 kg ha–1, respectively. For soybean, YGM was the main cause of total YG in Brazil, accounting for 51.8%, whereas for maize, YGW corresponded to 53.8% of the total YG. Our results also showed that the choice of the best sowing date can contribute to reducing soybean YGW by 34–54% and off-season maize YGW by 66–89%.

scholarly journals SUGARCANE CROPS WITH CONTROLLED WATER DEFICIT IN THE SUB-MIDDLE SÃO FRANCISCO VALLEY, BRAZIL

2018 ◽  
Vol 31 (4) ◽  
pp. 963-971 ◽  
Author(s):  
WELSON LIMA SIMÕES ◽  
MARCELO CALGARO ◽  
MIGUEL JULIO MACHADO GUIMARÃES ◽  
ANDERSON RAMOS DE OLIVEIRA ◽  
MÍRIAN PAULA MEDEIROS ANDRÉ PINHEIRO
Keyword(s):  
Water Deficit ◽  
Block Design ◽  
Development Stage ◽  
Maturation Stage ◽  
Randomized Block Design ◽  
Sugarcane Yield ◽  
Maturation Stages ◽  
Crop Cycle ◽  
Technological Quality

ABSTRACT Sugarcane is one of the most affected crops by water scarcity. The efficient use of the irrigation water is an alternative to minimize this problem. The objective of this work was to evaluate biometric parameters, yield, and technological quality of sugarcane plants subjected to different controlled water deficit regimes in the sub-middle São Francisco Valley, Brazil. The experiment was conducted in a randomized block design, in two crop cycles, with three replications, with ten treatments consisted of three controlled water deficits (15%, 30%, and 45% of the crop evapotranspiration - ETc), applied at three development stages of the plant - sprouting and tillering (Stage I), grand growth (Stage II), and maturation (Stage III) - and a control with 100% of the ETc throughout the entire crop cycle. The controlled water deficit did not affect the technological quality of the sugarcane in any development stage. The sugarcane yield was higher when using a controlled water deficit of 30% of ETc in the sprouting and tillering stages of the plants. The water deficit of 15% of ETc is recommended for the grand growth, or maturation stages of the sugarcane plants for a greater water use efficiency of the production system.

scholarly journals DIALLEL ANALYSIS OF TOLERANCE TO DROUGHT IN COWPEA GENOTYPES

2018 ◽  
Vol 31 (1) ◽  
pp. 40-47 ◽  
Author(s):  
ERINA VITÓRIO RODRIGUES ◽  
KAESEL JACKSON DAMASCENO-SILVA ◽  
MAURISRAEL DE MOURA ROCHA ◽  
EDSON ALVES BASTOS ◽  
ADRIANO DOS SANTOS
Keyword(s):  
Water Deficit ◽  
Recurrent Selection ◽  
Diallel Analysis ◽  
Diallel Cross ◽  
Limiting Factors ◽  
Additive Effects ◽  
Negative Effects ◽  
Complete Diallel Cross ◽  
Brazilian Northeast ◽  
Block Experiment

ABSTRACT The low use of technologies by farmers and the occurrence of biotic and abiotic stresses are limiting factors for cowpea production in the Brazilian Northeast region. The tolerance of genotypes to drought is an alternative to decrease the negative effects of stresses on cowpea production. Thus, the objective of this work was to identify parents and combinations of cowpea genotypes with high probability of generating segregating populations with tolerance to drought. Six cowpea genotypes were crossed in a complete diallel cross design, totaling 30 F2 populations, which were evaluated together with their parents in an experiment under water deficit at the experimental field of the Embrapa Mid-North, Teresina, State of Piauí, Brazil. A triple lattice incomplete block experiment design was used, with three replications, with experimental plot consisting of six 2-m plant rows. Fifteen plants per plot were sampled to evaluate their agronomic characteristics, whose results were subjected to analysis of variance and means were used to estimate the general and specific combining abilities. The genotypes showed significant differences in all characteristics evaluated, denoting the genetic variability of the population. The additive effects were more important than the non-additive effects, and maternal inheritance was detected. The genotypes BRS Xiquexique, Pingo-de-Ouro-1-2 and MNC99-510F-16-1 were the most promising for use in recurrent selection programs for tolerance to water deficit. The hybrid combinations (1) BRS Paraguaçu X (4) CNCx-698-128G, (2) Pingo-de-Ouro-1-2 X (3) BRS Xiquexique, (3) BRS Xiquexique X (5) Santo-Inácio, (4) CNCx-698-128G X (6) MNC99-510F-16-1 and (5) Santo-Inácio X (4) CNCx-698-128G showed potential for generating superior lineages regarding bean production and tolerance to water deficit.

Working rules for determining the plot size and numbers of plots per block in field experiments

1984 ◽  
Vol 103 (1) ◽  
pp. 11-15 ◽  
Author(s):  
C. S. Lin ◽  
M. R. Binns
Keyword(s):  
Analysis Of Variance ◽  
Field Experiments ◽  
Block Design ◽  
Incomplete Block ◽  
Plot Size ◽  
Incomplete Block Design ◽  
Empirical Law ◽  
Block Experiment ◽  
Working Rules

SummaryWorking rules for determining plot size and number of plots within a block in field experiments are proposed based on the value of the intrablock correlation (ρ), which can be obtained from the analysis of variance of a randomized-block experiment. The method uses Binns' (1982) equation to relate this correlation to Smith's (1938) empirical law. The rules are: (1) if ρ is greater than 0·5, use an incomplete block design or reduce the plot size in order to increase the number of replications; (2) if ρ is less than 0·1, an increase in plot size is effective; (3) if ρ is between 0·1 and 0·5, an increase in plot size and a decrease in the number of plots per block may be helpful in combination.

scholarly journals Water restriction in different phenological stages and increased temperature affect cowpea production

2021 ◽  
Vol 45 ◽  
Author(s):  
Juliane Rafaele Alves Barros ◽  
Miguel Julio Machado Guimarães ◽  
Welson Lima Simões ◽  
Natoniel Franklin de Melo ◽  
Francislene Angelotti
Keyword(s):  
Air Temperature ◽  
Water Availability ◽  
Abiotic Factors ◽  
Dry Mass ◽  
Development Stage ◽  
Grain Production ◽  
Water Restriction ◽  
Phenological Stages ◽  
Increased Temperature ◽  
Temperature Regimes

ABSTRACT Water deficit and high temperatures are abiotic factors that most limit plant growth and development. However, its effects depend on crop development stage and on stress duration and intensity. Thus, the objective of was to evaluate the development of cowpea subjected to water restriction in different phenological stages and to increase in air temperature. The experiment was conducted with the cultivar ‘Carijó’, in growth chambers, in a 4 x 3 x 2 factorial arrangement, corresponding to levels of water availability (25, 50, 75, and 100%,), phenological stages (vegetative, flowering and pod filling) and temperature regimes (T°1: 20-26-33 °C e T°2: 24.8-30.8-37.8 °C), respectively. Reduction of water availability in the vegetative and flowering stages caused decrease in grain production. The percentage of aborted flowers was higher in plants maintained under an increased temperature of +4.8 °C, with consequent reduction in grain production. Higher water availability values favored shoot and root dry mass production. Increase of 4.8 °C did not affect shoot and root dry mass but reduced water use efficiency by about 83%. The highest enzymatic activities of CAT, GPX and SOD were found in plants subjected to the temperature of +4.8 °C. Only APX showed lower enzymatic activity with increasing temperature. The cv. ‘Carijó’ is more sensitive to the 4.8 °C increase in air temperature than to water deficits.

Opposite changes in leaf dark respiration and soluble sugars with drought in two Mediterranean oaks

2011 ◽  
Vol 38 (12) ◽  
pp. 1004 ◽  
Author(s):  
Jesús Rodríguez-Calcerrada ◽  
Oula Shahin ◽  
María del Carmen del Rey ◽  
Serge Rambal
Keyword(s):  
Water Deficit ◽  
Dark Respiration ◽  
Leaf Gas Exchange ◽  
Soluble Sugars ◽  
Water Deficit Stress ◽  
Co2 Uptake ◽  
Opposite Pattern ◽  
Leaf Dark Respiration ◽  
Mediterranean Oaks ◽  
Relative Production

The decline in net photosynthetic CO2 uptake (An) caused by drought could reduce the availability of soluble sugars and thus limit leaf dark respiration (Rd). We investigated the response of leaf gas exchange and nonstructural carbohydrates to drought by stopping watering to 2-year-old plants of Quercus ilex L. and Quercus pubescens Willd. grown in large pots. An declined with increasing water deficit more rapidly than Rd, and Rd declined slightly more steeply in Q. ilex than in Q. pubescens. Soluble sugars increased in drought-treated plants relative to control well watered plants, and the opposite pattern was found for starch. After rewatering, Rd returned to pre-drought rates within 2 days and An within 1 week. Soluble sugars tended to recover pre-drought values after rewatering but continued to be significantly higher in drought-treated than control plants of Q. pubescens, for which the increase in the concentration of soluble sugars had been higher. These results suggest that the relative production of soluble sugars is upregulated when An is limited, and that soluble sugars do not control respiratory rates in response to and recovery from water deficit. Rather, we suggest that the decline in Rd contributes to drought tolerance by reducing the consumption of soluble sugars, which play an important role as osmoprotectants during water deficit stress.

scholarly journals Thermal and Soil Moisture Amplitude of Intercropped Crops

2020 ◽  
pp. 1-13
Author(s):  
João Danilo Barbieri ◽  
Paulo Sérgio Lourenço de Freitas ◽  
Rivanildo Dallacort ◽  
Cornélio Alberto Zolin ◽  
Diego Fernando Daniel ◽  
...  
Keyword(s):  
Zea Mays ◽  
Soil Moisture ◽  
Soil Temperature ◽  
Zea Mays L ◽  
Dry Mass ◽  
Development Stage ◽  
Grain Production ◽  
Lower Amplitude ◽  
Thermal Amplitude ◽  
Soil And Water

Conservation systems of production are promoting yields and profitability, intercropping systems aim at sustainable maximization of soil and water use, and have become an alternative for regions characterized by relatively short rainy periods and high temperatures. The objective of this work was to evaluate the influence of the intercropping system between maize (Zea mays L.) and C. juncea (Crotalaria juncea L.) on soil temperature and humidity for the municipality of Tangará da Serra in Brazil. The treatments consisted of the single crop of maize and crotalaria, as well as their intercrop cultivation, the soil temperature was evaluated at depths of 0.10, 0.20, 0.30 and 0.40 m and soil moisture at depths of 0.20 and 0.40 m. The components of grain production and yield of maize were also evaluated, for crotalaria, height, diameter and dry mass of the plants were evaluated. The highest soil temperature occurred at 14 h with an average of 21°C for all three treatments. The intercropping of maize with crotalaria gave the soil a lower amplitude of the soil temperature and kept the soil moisture high with values of 0.3 m3 m-3 in the depth of 0.20 m. The development stage presented the lowest mean thermal amplitude and higher humidity for the intercrop system. The yield of maize in an intercrop was reduced by 42.7% compared to a single crop.

Some physiological aspects of growth and yield in wheat crops: a comparison of a semidwarf and a standard height cultivar

1976 ◽  
Vol 16 (81) ◽  
pp. 578 ◽  
Author(s):  
JJ Walcott ◽  
DR Laing
Keyword(s):  
Field Experiment ◽  
Water Deficit ◽  
Grain Growth ◽  
Growth Analysis ◽  
Photosynthetic Activity ◽  
Growth And Yield ◽  
Grain Production ◽  
Lodging Resistance ◽  
Nitrogen Levels

A field experiment showed the semidwarf cultivar Penjamo 62 to outyield the taller Australian cultivar Gamenya at nitrogen levels up to 896 kg N ha-1. This was attributed primarily to a faster rate of grain growth particularly in the later stages. Lodging resistance of Penjamo 62 accounted for only 16-58 per cent of the differences observed at the lower nitrogen levels. Although these two cultivars showed only small differences in both photosynthesis and in the duration of photosynthetic activity of microplots in the greenhouse, large differences in the efficiency of utilization of post-anthesis photosynthesis for grain production were inferred from growth analysis. Moreover, grain growth of Penjamo 62 was far more sensitive to a post-anthesis drought than that of Gamenya, even though similar levels of water deficit and reductions in photosynthesis were recorded in microplots of both cultivars.

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