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

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.

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Identification of drought-tolerant corn genotypes by multivariate analysis1

Pesquisa Agropecuária Tropical ◽

10.1590/1983-40632018v4852122 ◽

2018 ◽

Vol 48 (3) ◽

pp. 204-211 ◽

Cited By ~ 1

Author(s):

Ricardo Silva de Sousa ◽

Edson Alves Bastos ◽

Milton José Cardoso ◽

Diléia Rocha Pereira

Keyword(s):

Drought Tolerance ◽

Grain Yield ◽

Water Deficit ◽

Block Design ◽

Genotypic Variation ◽

Full Irrigation ◽

Corn Hybrids ◽

Area Index ◽

Leaf Chlorophyll ◽

Randomized Block Design

ABSTRACT The identification of genotypes that are tolerant to water deficit is crucial for the maintenance of the agricultural production. This study aimed to evaluate the genotypic variation for drought tolerance among corn genotypes by means of multivariate analysis, as well as to identify hybrids with high grain yield under conditions of water deficit and full irrigation. For this purpose, an experiment was conducted in a randomized block design, with 36 corn hybrids, being 34 experimental elite and two commercial (controls) hybrids, under water deficit and full irrigation, during the reproductive stage, with four replications. The irrigation levels, added to the rainfall, totaled 691.6 mm under full irrigation and 490.8 mm under water deficit. The evaluation encompassed the leaf area index, leaf chlorophyll content, interval between male and female flowering, number of rows per ear, number of grains per ear, ear length, 100-grain weight, ear yield, ear index, total number of grains, number of ears per m2, grain yield at 13 % of moisture and water-use efficiency. The evaluated hybrids showed useful genetic diversity for drought tolerance. Four experimental elite hybrids (3G7395, 3G7415, 1G7034 and 3G7335) stood out under water deficit, showing a high grain yield performance, if compared to the average of the control hybrids.

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Effect of Limited Irrigation on Water Consumption and Grain Yield of Spring Maize (Zea Mays)

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.404.415 ◽

2013 ◽

Vol 404 ◽

pp. 415-419

Author(s):

Heng Jia Zhang ◽

Jun Hui Li

Keyword(s):

Grain Yield ◽

Soil Water ◽

Leaf Area ◽

Water Use ◽

Water Consumption ◽

Irrigation Management ◽

Grain Filling ◽

Total Water ◽

Area Index ◽

Spring Maize

The soil water contents in spring maize field were monitored continuously using soil neutron probe combined with drying-weighing method. Meanwhile, the effect of limited irrigation on crop periodic water consumption and its percentage in total water use, leaf area index, and grain yield of spring maize were explored. The results indicated that both the periodic water consumption and its percentage in total water use varied from low to high then to low within maize growing season, with the maximum valued both at silking to middle grain filling. In addition, leaf area indexes were greatly improved by full irrigation before maize filling, and grain yield was not reduced by efficient limited irrigation management, contrarily, yield increase and 31.1% of significant irrigation water saving were achieved, which was beneficial to the optimization of soil water ecological processing and limited irrigation management.

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Improving photosynthesis to increase grain yield potential: an analysis of maize hybrids released in different years in China

Photosynthesis Research ◽

10.1007/s11120-021-00847-x ◽

2021 ◽

Author(s):

Yanyan Yan ◽

Peng Hou ◽

Fengying Duan ◽

Li Niu ◽

Tingbo Dai ◽

...

Keyword(s):

Grain Yield ◽

Leaf Area ◽

Chlorophyll Content ◽

Photosynthetic Rate ◽

Maize Yield ◽

Planting Density ◽

Yield Potential ◽

Photosynthetic Parameters ◽

Area Index ◽

Maize Cultivars

AbstractIn this work, we sought to understand how breeding has affected photosynthesis and to identify key photosynthetic indices that are important for increasing maize yield in the field. Our 2-year (2017–2018) field experiment used five high-yielding hybrid maize cultivars (generated in the 1970s, 2000s, and 2010s) and was conducted in the Xinjiang Autonomous Region of China. We investigated the effects of planting density on maize grain yield, photosynthetic parameters, respiration, and chlorophyll content, under three planting density regimens: 75,000, 105,000, and 135,000 plants ha−1. Our results showed that increasing planting density to the medium level (105,000 plants ha−1) significantly increased grain yield (Y) up to 20.32% compared to the low level (75,000 plants ha−1). However, further increasing planting density to 135,000 plants ha−1 did not lead to an additional increase in yield, with some cultivars actually exhibiting an opposite trend. Interestingly, no significant changes in photosynthetic rate, dark respiration, stomatal density, and aperture were observed upon increasing planting density. Moreover, our experiments revealed a positive correlation between grain yield and the net photosynthetic rate (Pn) upon the hybrid release year. Compared to other cultivars, the higher grain yield obtained in DH618 resulted from a higher 1000-kernel weight (TKW), which can be explained by a longer photosynthetic duration, a higher chlorophyll content, and a lower ratio of chlorophyll a/b. Moreover, we found that a higher leaf area per plant and the leaf area index (HI) do not necessarily result in an improvement in maize yield. Taken together, we demonstrated that higher photosynthetic capacity, longer photosynthetic duration, suitable LAI, and higher chlorophyll content with lower chlorophyll a/b ratio are important factors for obtaining high-yielding maize cultivars and can be used for the improvement of maize crop yield.

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Characteristics of the canopy, root system and grain yield of a crop of Lupinus angustifolius cv. Unicrop

Australian Journal of Agricultural Research ◽

10.1071/ar9750497 ◽

1975 ◽

Vol 26 (3) ◽

pp. 497 ◽

Cited By ~ 21

Author(s):

EAN Greenwood ◽

P Farrington ◽

JD Beresford

Keyword(s):

Carbon Dioxide ◽

Grain Yield ◽

Leaf Area ◽

Time Course ◽

Dry Weight ◽

Grain Filling ◽

Main Axis ◽

Carbon Dioxide Exchange ◽

Area Index ◽

Plant Parts

The time course of development of a lupin crop was studied at Bakers Hill, Western Australia. The aim was to gain insight into the crop factors influencing yield. Weekly measurements were made of numbers and weights of plant parts, and profiles of roots, leaf area and light interception. A profile of carbon dioxide in the crop atmosphere was taken at the time of maximum leaf area, and the net carbon dioxide exchange (NCE) of pods was estimated for three successive weeks. The crop took 10 weeks to attain a leaf area index (LAI) of 1 and a further 9 weeks to reach a maximum LAI of 3.75, at which time only 33% of daylight reached the pods on the main axis. Once the maximum LAI was attained at week 19, leaf fall accelerated and rapid grain filling commenced almost simultaneously on all of the three orders of axes which had formed pods. Measurements of NCE between pods on the main axis and the air suggest that the assimilation of external carbon dioxide by the pods contributed little to grain filling. Grain dry weight was 2100 kg ha-1 of which 30%, 60% and 10% came from the main axis, first and second order apical axes respectively. Only 23% of the flowers set pods and this constitutes an important physiological limitation to grain yield.

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Effects of Planting Density on Leaf Area and Productivity of Two Maize Cultivars in Nigeria

Experimental Agriculture ◽

10.1017/s0014479700013478 ◽

1982 ◽

Vol 18 (1) ◽

pp. 93-100 ◽

Cited By ~ 8

Author(s):

S. U. Remison ◽

E. O. Lucas

Keyword(s):

Grain Yield ◽

Leaf Area Index ◽

Leaf Area ◽

Dry Matter ◽

Plant Population ◽

Planting Density ◽

Dry Matter Yield ◽

Area Index ◽

Positive Correlation ◽

Maize Cultivars

SUMMARYTwo maize cvs, FARZ 23 and FARZ 25, were grown at three densities (37,000, 53,000 and 80,000 plants/ha) in 1979 and 1980. Leaf area index (LAI) increased with increase in plant population and was at a maximum at mid-silk. Grain yield was highest at 53,000 plants/ha. There was no relation between LAI and grain yield but there was a positive correlation between LAI and total dry matter yield.

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Measurement of grapevine canopy leaf area by using an ultrasonic-based method

OENO One ◽

10.20870/oeno-one.2013.47.3.1553 ◽

2013 ◽

Vol 47 (3) ◽

pp. 183 ◽

Cited By ~ 2

Author(s):

Marco Vitali ◽

Mario Tamagnone ◽

Tiziana La Iacona ◽

Claudio Lovisolo

Keyword(s):

Leaf Area ◽

Large Scale ◽

Irrigation Management ◽

Management Training ◽

Ultrasonic Sensors ◽

Leaf Sample ◽

Area Index ◽

Canopy Area ◽

Point Quadrat ◽

Leaf Canopy

Aim: Measurement of leaf area in grapevine has always been a critical point in researches focused on irrigation management, training systems, source-sink interrelationships and efficiency of spray application to canopies. In this work, we propose the use of ultrasonic sensors as a fast and accurate tool for the estimation of large portions of leaf canopy area.Methods and results: Through outputs of ultrasonic sensors installed on a tractor moving along vineyard rows, we calculated an ultrasonic-based leaf density index that we correlated with three measurements or estimates of canopy area: I) direct measurement of the area of a canopy portion (LAØ), assessed by summing the areas of all the leaves, where each single-leaf area was assessed by regressing the leaf diameter (the maximum width perpendicular to the main rip) against the related leaf area calculated on the basis of a relation between the leaf diameter and the leaf area, previously assessed through an area meter on a 20-leaf sample; II) the point quadrat output (LApq); and III) the canopy leaf area index (LAI) obtained through LAI-2000 (Li-Cor) technology. The measurements were assessed on six cultivars in three replicate rows (8-12 plants per cultivar per row) in a vineyard trained to a vertical trellis system.Conclusion: When we correlated the three independent control parameters with each other, we obtained highly significant correlations between LApq and LAØ, but less significant correlations between these two and LAI-2000 outputs. Also, the correlations between ultrasonic outputsoutputs and LAØ and LApq were significant, with R2 ranging between 0.84 and 0.85. On the contrary, no significant correlation was found between ultrasonic outputs and LAI-2000 outputs. These results were obtained by averaging all the values belonging to each replicated cultivar (10.5 m along the row, i.e., twelve contiguous vines); on the contrary, when the analysis was done over a shorter distance (3.5 m, i.e., four contiguous vines), the reliability of the ultrasonic-based method decreased.Significance and impact of the study: These results point to the ultrasonic technology as a powerful tool to estimate large-scale leaf canopy area, with potential applications in precision farming. At the moment, however, the limitation of this approach is the requirement of reference values for leaf area (e.g., assessed by point quadrat) to obtain absolute and not only relative outputs. With this application we can quantify, in a few hours, the canopy of a whole vineyard, in order to analyze different vegetation zones or to follow canopy development.

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The Morphological Change in Sunflower Plant under Hardening Conditions to Drought Tolerance. II. Leaf Number and Leaf Area

Baghdad Science Journal ◽

10.21123/bsj.6.3.470-479 ◽

2009 ◽

Vol 6 (3) ◽

pp. 470-479

Author(s):

Baghdad Science Journal

Keyword(s):

Drought Tolerance ◽

Plant Growth ◽

Leaf Area ◽

Room Temperature ◽

Agricultural Practices ◽

Growth Stages ◽

Full Irrigation ◽

Original Weight ◽

Leaf Formation ◽

Neutron Moisture

The study was conducted during the spring season of 2000 and2001. The objective was to study the changes in leaves number of sunflower plants and its leaf area during growth stages under hardening conditions to drought tolerance. Agricultural practices were made according to recommendations.Asplit-split plots design was used with three replications.The main plots included irrigation treatments:irrigation to100%(full irrigation),75and50%of available water.The sub plots were the cultivars Euroflor and Flame.The sub-sub plots represented four seed soaking treatments:Control(unsoaking), soaking in water ,Paclobutrazol solution(250ppm),and Pix solution(500ppm). The soaking continued for 24 hours then seeds were dried at room temperature until they regained their original weight. Amount of water for each irrigation were calculated to satisfy water depletion in soil using a neutron moisture meter. Results indicated that stress 800Kp reduced leaves number after 72 days from Planting by 5.29% compared with full irrigation as a mean of seasons.Increased stress to 600 and 800 Kp caused decreasing in leaf area at physiological maturation by 36.10 and 44.32% than full irrigation as a mean of seasons. Flame was superior over Euroflor after 58 days from planting in leaves number by 12.30 % in the season of 2001, while Euroflor was superior by 4.87% after58 days from planting in the season of 2000 ,and in leaf area by 58.25% after 44 days from planting in the season of 2001, and by 34.72% as a mean of seasons.Soaking the seeds presowing in paclobutrazol and pix solutions enhanced leaf formation , the percentage of increase reached to 5.57 and 7.49% after 86 days from planting as a mean of seasons, and leaf area by 35.9 and 36.95% respectively, compared with unsoaked as a mean of seasons. This study suggest that it could improve plant growth and kept sutable leaf area during seeds filling and drought tolerance by soaking the seeds presowing in water or plant growth regulators.

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Maize hybrids contrasting for drought tolerance differ during the vegetative stage

Semina Ciências Agrárias ◽

10.5433/1679-0359.2020v41n4p1093 ◽

2020 ◽

Vol 41 (4) ◽

pp. 1093

Author(s):

Suerlani Aparecida Ferreira Moreira ◽

Pablo Fernando Santos Alves ◽

Carlos Eduardo Corsato ◽

Alcinei Mistico Azevedo

Keyword(s):

Water Stress ◽

Drought Tolerance ◽

Chlorophyll Content ◽

Water Deficit ◽

Leaf Temperature ◽

Vegetative Stage ◽

Maize Hybrids ◽

Water Regimes ◽

Dry Biomass ◽

Relative Chlorophyll Content

Maize hybrids contrasting for drought tolerance differ during the vegetative stage. Drought is the main constraint on maize production in developing nations. Differences during development between genetic materials of maize grown under water restriction suggest that the plant can be improved with a view to its adaptation. In maize, sensitivity to water stress can occur at any stage of its phenological development. However, few studies report its effects on the vegetative phase of the cycle. On this basis, this study was conducted to examine how shoot and root-system indices are expressed in cultivation under water deficit as well as determine which indicators best explain the difference between hybrids in the evaluated water regimes. Commercial seeds of hybrids BR1055 and DKB-390 (drought-tolerant) and BRS1010 (drought-sensitive) were germinated in PVC tubes (1.0 m × 0.1 m) in a randomized complete block design, in a 3 × 2 factorial arrangement. The experiment was developed in a greenhouse where two water regimes were tested: no water stress and with water stress from the VE stage. The soil consisted of quartz sand mixed with a commercial fertilizer. Stem and root traits were evaluated up to the V5 growth stage. Relative chlorophyll content, leaf temperature, stem length, phenology, shoot dry biomass, root length, root dry biomass, root surface area, root volume and D95 were responsive to water deficit. The parameters that allowed the distinction between the hybrids in water the regimes were relative chlorophyll content, leaf temperature, phenology and average root diameter.

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TOLERANCE OF F 2 POPULATIONS OF COWPEA TO WATER DEFICIT

Revista Caatinga ◽

10.1590/1983-21252018v31n106rc ◽

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.

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Combining Ability for Agromorphological and Physiological Traits in Different Gene Pools of Common Bean Subjected to Water Deficit

Agronomy ◽

10.3390/agronomy9070371 ◽

2019 ◽

Vol 9 (7) ◽

pp. 371 ◽

Cited By ~ 2

Author(s):

Isabella Mendonça Arruda ◽

Vânia Moda-Cirino ◽

Alessandra Koltun ◽

Douglas Mariani Zeffa ◽

Getúlio Takashi Nagashima ◽

...

Keyword(s):

Water Stress ◽

Drought Tolerance ◽

Grain Yield ◽

Common Bean ◽

Water Deficit ◽

Seed Quality ◽

Plant Performance ◽

Physiological Traits ◽

Gene Pools ◽

Group I

Water stress is one of the main limiting factors for common bean crops, negatively affecting grain yield and seed quality. Thus, the objective of this study was to evaluate the inheritance of agromorphological and physiological traits related to drought tolerance in order to identify promising combinations. The experiment was carried out in a greenhouse with a partial diallel scheme between three drought-tolerant genotypes (IAPAR 81, BAT 477. and SEA 5), and nine cultivars widely grown in Brazil (BRS Estilo, IAC Alvorada, IPR Campos Gerais, IPR Uirapuru, IPR Nhambu, BRS Esteio, IPR Garça, BRS Radiante, and DRK 18), in a randomized block design with four replicates. The plants were grown in pots with substrate under 80% of pot capacity until they reached the stage R5, when water supply was restricted to 30% for 20 days in the pots under stress treatment. A wide variability for the agromorphological and physiological traits was observed. Water deficit reduced plant performance for most agromorphological traits and altered their physiological metabolism. Additive and non-additive effects are involved in the genetic control of the majority of agromorphological and physiological traits both under water stress and control (well-watered) conditions. The parental genotypes BAT 477 (group I) and IAC Alvorada, IPR Uirapuru, and BRS Esteio (group II) may be included in breeding programs aiming at improving drought tolerance in common bean since they present high positive general combining abilities for agromorphological traits. The crosses IAPAR 81 × IPR Campos Gerais, and SEA 5 × BRS Radiante resulted in the best combinations considering grain yield per plant and total dry biomass, when cultivated under water deficit.

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