scholarly journals Dry Matter Production and Root System Development of Rice Cultivars under Fluctuating Soil Moisture

2000 ◽  
Vol 3 (2) ◽  
pp. 197-207 ◽  
Author(s):  
Dionisio M. Bañoc ◽  
Akira Yamauchi ◽  
Akihiko Kamoshita ◽  
Len J. Wade ◽  
Jose R. Pardales
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.


2002 ◽  
Vol 71 (1) ◽  
pp. 28-35 ◽  
Author(s):  
Yoshiharu WADA ◽  
San-Iku YUN ◽  
Hiroki SASAKI ◽  
Tadanobu MAEDA ◽  
Kunio MIURA ◽  
...  

Author(s):  
G.V. Venkataravana Nayaka ◽  
G. Prabhakara Reddy ◽  
R. Mahender Kumar

Background: Growth and yield characteristics of genotypes depend on genetic and environmental factors. Among the different production factors, varietal selection at any location plays an important role. Proper crop management depends on the growth characteristics of various varieties to get maximum benefit from new genetic material. Among the different water- saving irrigation methods in rice, the most widely adopted is alternate wetting and drying (AWD). Many of the rice cultivars vary in their performance under different systems of cultivation.Methods: A field experiment was conducted on a clay loam soil at Indian Institute of Rice Research (IIRR) Rajendranagar, Hyderabad, Telangana during the kharif seasons of 2017 and 2018. to study the “productivity and water use efficiency of rice cultivars under different irrigation regimes and systems of cultivation” The treatments consisted of two irrigation regimes Alternate wetting and drying and Saturation as main plot treatments, three establishment methods System of Rice Intensification (SRI), Drum Seeding (DS) and Normal transplanting (NTP) as sub plot treatments and four Cultivars namely DRR Dhan 42, DRR Dhan 43, MTU-1010 and NLR-34449 as sub-sub plot treatments summing up to 24 treatment combinations laid out in split-split plot design with three replications.Result: At 60, 90 DAS/DAT and harvest significantly dry matter production (DMP) was recorded with DRR Dhan 43 cultivar (607, 4320 and 11548 kg ha-1 respectively in pooled means of both 2017 and 2018) than other cultivars. Whereas MTU-1010 and NLR-34449 recorded on par dry matter production values at all the crop growth stages during both the years of study. However, DRR Dhan 42 produced the lowest dry matter production compared to other genotypes. DRR Dhan 43 recorded higher dry matter accumulation (g m-2) in root, stem and leaves at all the crop growth stages, during both the years of the study over other cultivars. Alternative wetting and drying method of irrigation recorded significantly higher DMP at all the growth stages of rice (60, 90 DAS/DAT and at harvest) except at 30 DAS/DAT during both 2017 and 2018 as compared to saturation. SRI recorded significantly higher DMP as compared to normal transplanting; however, it was comparably at par with drum seeding at all the growth stages.


2020 ◽  
Vol 38 (2) ◽  
pp. 280-286
Author(s):  
Anna Bárbara De Souza Cruz ◽  
José de Anchieta Alves de Albuquerque ◽  
Paulo Roberto Ribeiro Rocha ◽  
Leandro Torres de Souza ◽  
Diego Lima de Souza Cruz ◽  
...  

As a control measure against weeds, the use of herbicides is an effective and inexpensive alternative. However, there are no products recommended for the cultivation of cowpea in Brazil, making it necessary to search for alternative solutions. The objective of this study was to evaluate the effect of herbicides applied in the pre- and post-emergence on cowpea nodulation and production under conditions of the Amazonian savannah. Two experiments were carried out in a randomized block design with four replicates, using the cowpea cultivar BRS Aracê subjected to the pre-emergence herbicides: Metribuzin, Sulfentrazone, Smetolachlor, Pendimethalin, Oxadiazon, Alachlor, Metribuzin + Pendimethalin, Metribuzin + Alachlor and Quizalofop-p-ethyl, Bentazon, Fomesafen, Imazethapyr, Imazamox + Bentazon, Quizalofop-p-ethyl + Imazethapyr, Quizalofop-p-ethyl + Imazamox and Quizalofop-p-ethyl + Bentazon, and post-emergence herbicides: Quizalofop-p-ethyl, Bentazon, Fomesafen, Imazethapyr, Imazamox + Bentazon, Quizalofop-p-ethyl + Imazethapyr, Quizalofop-p-ethyl + Imazamox, and Quizalofop-p-ethyl + Bentazon. The number of nodules in each plant, the dry matter of nodules, dry matter of roots and the grain yield were evaluated. According to the results obtained, the management of weeds in pre- or post-emergence according to the herbicide used affects the nodulation and productivity of cowpea under the conditions of the Amazonian savannah. The herbicides Metribuzin in preemergence,and Fomesafen and the mixture of Quizalofop-pethyl + Imazethapyr in post-emergence are not recommended for weed control in cowpea. The application of Oxadiazon, Alachlor, and Pendimethalin in pre-emergence can be considered interesting because they do not inhibit the development of the root system or the nodulation of cowpea which provides agreater grain yield. Regarding weed control strategies at postemergence, the application of the herbicide Imazethapyr and the combination of the herbicides quizalofop-p-ethyl + imazamox, Quizalofop-p-ethyl + Bentazon and Imazamox + Bentazon allow satisfactory levels of grain yield, root system development and nodulation of cowpea.


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