scholarly journals Tolerance of upland rice genotypes to water deficit

2013 ◽  
Vol 17 (8) ◽  
pp. 805-810 ◽  
Author(s):  
Cleber M. Guimarães ◽  
Luís F. Stone ◽  
Paulo H. N. Rangel ◽  
Ana C. de L. Silva

Water deficit is one of the environmental factors that cause a great reduction in the upland rice grain yield. The objective of this study was to evaluate genotypes of upland rice with broad genetic diversity for tolerance to this stress and to identify secondary traits for evaluation of this tolerance. Sixty-four genotypes were evaluated during two years at the Experiment Station of EMATER, in Porangatu, GO, under well-watered and water deficit conditions. The genotypes showed differences in grain yield and were influenced differently by the water treatments, both under a mild water deficit in the first year and under a severe one in the second year. The genotype grain yield under water deficiency was significantly and positively correlated with tiller fertility, number of panicles m-2, 100-grain weight, and plant height, and negatively with spikelet sterility and the number of days for the occurrence of 50% panicle emergence. It was also observed that the most productive genotypes under water deficit conditions showed lower leaf temperature, indicating improved water status. Nine genotypes were productive in both water conditions and three were productive only when well-watered.

2015 ◽  
Vol 50 (7) ◽  
pp. 534-540 ◽  
Author(s):  
Cleber Morais Guimarães ◽  
Luís Fernando Stone ◽  
Adriano Pereira de Castro ◽  
Odilon Peixoto de Morais Júnior

Abstract: The objective of this work was to evaluate the feasibility of using physiological parameters for water deficit tolerance, as an auxiliary method for selection of upland rice genotypes. Two experiments - with or without water deficit - were carried out in Porangatu, in the state of Goiás, Brazil; the water deficit experiment received about half of irrigation that was applied to the well-watered experiment. Four genotypes with different tolerance levels to water stress were evaluated. The UPLRI 7, B6144F-MR-6-0-0, and IR80312-6-B-3-2-B genotypes, under water stress conditions, during the day, showed lower stomatal diffusive resistance, higher leaf water potential, and lower leaf temperature than the control. These genotypes showed the highest grain yields under water stress conditions, which were 534, 601, and 636 kg ha-1, respectively, and did not differ significantly among them. They also showed lower drought susceptibility index than the other genotypes. 'BRS Soberana' (susceptible control) was totally unproductive under drought conditions. Leaf temperature is a easy-read parameter correlated to plant-water status, viable for selecting rice genotypes for water deficit tolerance.


Author(s):  
Cleber M. Guimarães ◽  
Luís F. Stone ◽  
Ana C. de L. Silva

ABSTRACT To achieve an accurate phenotyping for drought tolerance, it is important to control water stress levels and timing. This study aimed to determine water use by upland rice plants during periods of irrigation withholding and its relationship with grain yield in order to increase the efficiency of this phenotyping. Two experiments were carried out in a randomized block design in which six water treatments (irrigation withholding for periods of 2, 4, 6, 8, 10 and 12 days) were compared, with four replicates. In the first experiment, treatments were applied at the R3 stage (panicle exsertion) and, in the second, at the R5 stage (beginning of grain filling). The amount of water evapotranspired was determined by the difference between the soil water storage at the beginning and at the end of irrigation withholding periods, from the surface to 80-cm depth. Evapotranspiration of upland rice from R3 stage was higher compared to that observed from R5 stage, when subjected to similar irrigation withholding periods in both growth stages. Rice grain yield is more sensitive to irrigation withholding imposed from R5 stage than from R3 stage.


2017 ◽  
Vol 47 (3) ◽  
pp. 185-194 ◽  
Author(s):  
Adriano Stephan NASCENTE ◽  
Ruby KROMOCARDI

ABSTRACT The upland rice farmers in Suriname use local varieties and low level technologies in the field. As a result, the upland rice grain yield is low, at about 1 000 kg ha-1. Our objective was to evaluate the use of upland rice cultivars from Suriname and Brazil, and the effect of nitrogen, N, phosphorus, P, and potassium, K, fertilizers on cultivation variables. We undertook four field trials in the Victoria Area, in the Brokopondo District, using a randomized block design each with four replications. The most productive rice varieties were BRS Esmeralda (grain yield 2 903 kg ha-1) and BRS Sertaneja (2 802 kg ha-1). The highest grain yield of 2 620 kg ha-1 was achieved with a top dressing application of 76.41 kg N ha-1 20 days after sowing. For P, the highest grain yield of 3 085 kg ha-1 was achieved with application of 98.06 kg ha-1 P2O5 applied at sowing. An application rate of 31.45 kg ha-1 of K2O at sowing achieved the highest grain yield of 2 952 kg ha-1. Together, these application rates of N, P and K resulted in rice grain yield of about 3 000 kg ha-1, which is three times greater than the national average for upland rice. We demonstrate that the use of improved rice varieties matched to the local conditions, and application of appropriate fertilizers, are management practices that can result in significant increases in rice grain yield in Suriname.


Author(s):  
Adriano S. Nascente ◽  
Luís F. Stone ◽  
Cleber M. Guimarães

An important point in no-tillage system is the time between cover crop glyphosate desiccation and rice sowing. This study aimed to verify the effect of Brachiaria ruziziensis management time before rice sowing on rice yield and its components. The experiment was conducted under greenhouse conditions and consisted of four types of B. ruziziensis management: with Brachiaria and with herbicide (WBWH), without Brachiaria shoots and with herbicide (NBWH), without Brachiaria shoots and without herbicide (NBNH), and with Brachiaria and without herbicide (WBNH), at four times: 30, 20, 10, and 0 days, preceding the rice sowing. The amount of B. ruziziensis dry matter increased as the management was done closer to the rice sowing date. The WBWH and WBNH managements (this one causes the lowest rice grain yield) must be done 30 days before rice sowing; while NBWH management must be done ten or more days before rice sowing. On the other hand, NBNH management (this one favors the best rice grain yield) can be done until rice sowing day. Despite some reduction in rice yield caused by the B. ruziziensis management, when it was done at the proper time the rice grain yield was similar to the control (without Brachiaria sowing and without herbicide application).


2019 ◽  
Vol 37 (2) ◽  
pp. 166-172
Author(s):  
Eduardo Pradi Vendruscolo ◽  
Aliny Heloísa Alcântara Rodrigues ◽  
Sávio Rosa Correa ◽  
Alexander Seleguini ◽  
Sebastião Ferreira de Lima

Rice is an important source of energy for a large part of the world’s population. The development and application of technologies that contribute to the improvement of production forthis grain have great importance. The objective of this study was to evaluate the influence of rice seed immersion in a niacin solution on plant development, physiology and production. Thetreatments were defined by a combination of two immersion times for the seeds (12 h and 24 h) in four niacin concentrations (0.00, 100, 200 and 300 mg L-1) distributed in five replicates. Characteristics relating to seedling emergence, plant vegetativedevelopment, relative indices of chlorophyll and grain yield were evaluated. We verified that the immersion of the seeds for 12 h gave higher relative indices of chlorophyll, whereas immersion for 24 h increased the speed of emergence and the number of tillers and panicles. The doses of niacin positively affected the relative chlorophyll indices and the production characteristics, up to a maximum concentration of 172.57 mg L-1. We concluded that the immersion of rice seeds for 24 h increased the speed of seedling emergence, leaf number, and panicles per area. However, the relative indices of chlorophyll in leaves decreased. The use of niacin promoted the numbers of spikelets per panicle, fertility of the spikelets and the weight of 1000 grains, besides increasing the relative index of chlorophyll in the leaves of rice plants.


2018 ◽  
Vol 10 (2) ◽  
pp. 220-227 ◽  
Author(s):  
Mamadou FOFANA ◽  
Lekan Suleiman SAKARIYAWO ◽  
Mauton O. POPOGBE ◽  
Akeem A. OYEKANMI ◽  
Jamiu O. AZEEZ ◽  
...  

The present investigation tested the hypothesis that there would be variation in physiological responses to water deficit among rice varieties from different production ecologies, with contrasting tolerance to water deficit under repeated cycle of soil moisture deficit, at reproductive growth stage. A screen house and a field trial were conducted at International Institute of Tropical Agriculture, Ibadan and Ikenne (Latitude 6° 52' N, Longitude 3° 43' E) respectively. Both experiments had rice varieties (‘IR 64’, ‘WAB 56-104’, ‘IR 77298-1-2-B-10’ and ‘NERICA 4’) and stress status (stress and control) as treatment factor’s, arranged in a randomised complete block design with three replicates. In both trials, the physiological mechanism that underpins varietal differences with repeated cycles of water deficit at the reproductive growth stage was more balanced water status, improved foliar characters, efficient photosynthetic capacity and higher grain yield in comparatively drought tolerant upland rice varieties (‘NERICA 4’ and ‘WAB 56-104’), as opposed with the results for the drought susceptible cultivar ‘IR 64’. A converse pattern was observed on water stressed rice, despite fewer cycles of water deficit on the field. The results could have suggested that the initiation of water deficit is the rate limiting step rather than its intensity at the reproductive growth stage.    


2018 ◽  
Vol 131 (8) ◽  
pp. 1741-1759 ◽  
Author(s):  
Junli Zhang ◽  
Shiferaw Abate Gizaw ◽  
Eligio Bossolini ◽  
Joshua Hegarty ◽  
Tyson Howell ◽  
...  

2011 ◽  
Vol 39 (1) ◽  
pp. 183
Author(s):  
Aise DELIBORAN ◽  
Erdal SAKIN ◽  
Hasan ASLAN ◽  
Ahmet MERMUT

This field experiment examined the effects of magnesium (Mg) and phosphorus (P) fertilizers, which were given in different doses to soybean grown in different water levels, on plant water consumption, water-yield relations and grain yield factors. The experiment used a random blocks designed with three consecutive and was conducted over two years 2006 and 2007. Four different P doses (0-4-8-12 kg P da-1) and three different Mg doses (0-4-8 kg Mg da-1) were applied with three different water levels (I1, I2, I3). Cumulative pan values obtained from Class A Pan evaporation pool were applied as irrigation (I) 33% for I1, 67% for I2, 100% for I3. At the end of experiment were determined plant water consumption, water-yield relations and grain yield. At the start of irrigation, 548.00 mm, 786.00 mm and 1 017.00 mm of water were given to I1, I2 and I3 plots, respectively in the first year, and 457.98 mm, 698.02 mm and 931.00 mm irrigation water was given in the second year. Plant water consumption values (ETa) were determined as 648.00 mm, 903.00 mm and 1164.00 mm for I1, I2 and I3 parts in the first year, and 567.00 mm, 825.00 mm and 1070.00 mm in the second year. Moreover, according to experiment plots, irrigation water treatment efficiency (IWTE) varied between 0.14 and 0.53 kg m-3 in the first year and between 0.16 and 0.59 kg m-3 in the second year.


2017 ◽  
Vol 4 (4) ◽  
pp. 489-497
Author(s):  
N. Rawal ◽  
D. Chalise ◽  
N. Khatri

Field experiments were conducted during winter seasons of 2013 and 2014 on the alkaline and silty loam soils of NWRP, Bhairahawa to study the interaction of the most promising wheat genotypes with different nitrogen levels under different agro-ecological zones and recommend the appropriate dose of nitrogen for newly released varieties. The experiment was laid out in split plot design: four nitrogen levels (0, 50, 100 and 150 kg/ha) as a whole plot and six wheat genotypes (BL 3623, BL 3629, BL 3872, NL 1008, NL 1055 and Vijay) as a sub-plot which were replicated three times. There was significant effect of varieties and nitrogen levels on plant height, number of spikes, thousand grain weight and grain yield in both the years. In first year, the highest grain yield of 3.35 t/ha was obtained from the application of nitrogen @ 150 kg/ha with the genotype BL 3872 which is followed by the genotypes BL 3623 (3.15 ton/ha) and NL 1055 (3.05 ton/ha). Similarly in second year, the genotype NL 1055 gave the highest grain yield of 4.01 ton/ha followed by genotypes BL 3629 (3.83 ton/ha) and BL 3623 (3.81 ton/ha) from the application of nitrogen @ 150 kg/ha. Based on two years results, it can be concluded that N was a limiting factor in the productivity of wheat. Nitrogen @ 150 kg per ha produced higher yield and yield attributing characters. Similarly, the wheat genotypes NL 1055, BL 3629, BL 3623 and BL 3872 were superior among the genotypes.


Author(s):  
Bekir Atar ◽  
Burhan Kara

In spite of the low grain yield they produce, the hulled wheat have become even more important in recent years because of their resistance to negative environmental conditions and healthy nutritional content. The research was carry out in order to comparison the yield and yield characteristics of durum (Kiziltan-91 and C-1252), hulled (Einkorn and Emmer) and bread wheat (Tir) varieties in Isparta ecological conditions in 2013-14 and 2014-15 vegetation periods. In both years, the highest grain yield was obtained in Kiziltan-91 variety (3992 and 3758 kg ha-1 respectively). The grain yield of hulled wheats in the first year (Einkorn 1269 kg ha-1, Emmer 2125 kg ha-1) was around Turkey averages. However, grain yield decreased of commercial wheat varieties due to the negative effect of high amount of rainfall in June in the second year, but considerably increased in (Einkorn 2150 kg ha-1, Emmer 2533 kg ha-1). N uptake was found to be lower in the than durum wheats. In terms of grain protein content, the highest values were obtained in Emmer variety (16.4%-15.3%).


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