ECOLOGICAL AND THERAPEUTICAL STUDIES ON THE DWARF DISEASE OF RICE PLANTS (5) EFFECT OF GIBBERELLIN ON THE GROWTH AND YIELD OF DWARF DISEASED AND HEALTHY RICE PLANTS

Many benefits ofTrichodermainoculation for improving crop production have been documented, including growth and yield enhancement and the alleviation of biotic and abiotic stresses. However, because rice is usually cultivated under continuous flooding that creates anaerobic soil conditions, this limits the benefits of these beneficial fungi. Cultivating rice with the methods of the System of Rice Intensification (SRI) provides rice plants with a more favorable environment for their colonization by beneficial microbes in the soil because the soil is more aerobic under SRI management and contains more organic matter. This study evaluated the effects ofTrichodermainoculation of rice plants under SRI management compared with transplanted and flooded rice plants, considering also the effects of different means of fertilization and different varieties in rice. Experiments were conducted in 2015 and 2016 under the tropical climate of Nepal’s western terai (plains) during both the rainy season (July to November) and the dry season (March to July). The results indicated significantly better performance (P = 0.01) associated withTrichodermainoculation for both seasons and for both systems of crop management in terms of grain yield and other growth-contributing factors, compared to non-inoculated rice cropping. Relatively higher effects on grain yield were recorded also with organic compared to inorganic fertilization; for unimproved (heirloom) varieties compared with improved varieties; and from SRI vs. conventional flooded crop management. The yield increase withTrichodermatreatments across all trials was 31% higher than in untreated plots (4.9 vs 4.5 mt ha−1). WithTrichodermatreatment, yields compared with non-treated plots were 24% higher with organic SRI (6.38 vs 5.13 mt ha−1) and 52% higher with non-organic SRI (6.38 vs 3.53 mt ha−1). With regard to varietal differences, under SRI managementTrichodermainoculation of the improved variety Sukhadhan-3 led to 26% higher yield (6.35 vs 5.04 mt ha−1), and with the heirloom variety Tilkidhan, yield was 41% higher (6.29 vs 4.45 mt ha−1). Economic analysis indicated that expanding the organic cultivation of local landraces under SRI management should be profitable for farmers where such rice has a good market price due to its premium quality and high demand and when SRI enhances yield. These varieties’ present low yields can be significantly increased by integratingTrichodermabio-inoculation with SRI cultural methods. Other recent research has shown that such inoculation can be managed profitably by farmers themselves.

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Growth and yield responses of rice to carbon dioxide concentration

The Journal of Agricultural Science ◽

10.1017/s0021859600075729 ◽

1990 ◽

Vol 115 (3) ◽

pp. 313-320 ◽

Cited By ~ 132

Author(s):

J. T. Baker ◽

L. H. Allen ◽

K. J. Boote

Keyword(s):

Grain Yield ◽

Carbon Dioxide Concentration ◽

Co2 Concentration ◽

Growing Season ◽

Growth And Yield ◽

Shoot Biomass ◽

Controlled Environment ◽

Rice Plants ◽

Net Assimilation ◽

Yield Responses

SUMMARYRice plants (Oryza salivaL., cv. IR30) were grown in paddy culture in outdoor, naturally sunlit, controlled-environment, plant growth chambers at Gainesville, Florida, USA, in 1987. The rice plants were exposed throughout the season to subambient (160 and 250), ambient (330) or superambient (500, 660, 900 μmol CO2/mol air) CO2concentrations. Total shoot biomass, root biomass, tillering, and final grain yield increased with increasing CO2concentration, thegreatest increase occurring between the 160 and 500 μmol CO2/mol air treatments. Early in the growing season, root:shoot biomass ratio increased with increasing CO2concentration; although the ratio decreased during the growing season, net assimilation rate increased with increasingCO2concentration and decreased during the growing season. Differences in biomass and lamina area among CO2treatments were largely due to corresponding differences in tillering response. The number of panicles/plant was almost entirely responsible for differences in final grain yield among CO2treatments. Doubling the CO2 concentration from 330 to 660 μmol CO2/mol air resulted in a 32 % increase in grain yield. These results suggest that important changes in the growth and yield of rice may be expected in the future as the CO2concentration of the earth's atmosphere continues to rise.

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BIOLEACHING UNTUK MENINGKATKAN PRODUKTIVITAS LAHAN SULFAT MASAM AKTUAL UNTUK TANAMAN PADI

BERITA BIOLOGI ◽

10.14203/beritabiologi.v17i3.2922 ◽

2018 ◽

Vol 17 (3) ◽

Author(s):

Eni Maftu’ah ◽

Ani Susilawati

Keyword(s):

Crop Yields ◽

Rice Variety ◽

Growth And Yield ◽

Acid Sulfate Soil ◽

Acid Sulfate ◽

Rice Plants ◽

Microbial Utilization ◽

Tidal Swamp ◽

Two Factors ◽

Main Plot

Technology of microbial utilization to accelerate the oxidation of pyrite followed by leaching (bioleaching) has the potential to resolve problems in land management of actual acid sulphate soil. The research aims to obtain a bioleaching technology package that can improve the productivity of the actual acid sulfate soil. The experiment was conducted on tidal swamp land that has soil type of actual acid sulfate at Wana Raya sub-district, district Batola, South Kalimantan, in July - November, 2014. The study was designed by using strip plot with three replications. The treatment consisted of two factors, namely application of an oxidizing microbial pyrite and leaching amount (intensity). The main plot consisted of (P0) without leacing (naturally), (P1) six times leaching , (P2) eight times leaching, and (P3) 12 times leaching. Subplot consisted of (M0) without oxidizing microbial pyrite, (M1) with oxidizing microbial plant used in this study is Inpara 3 of rice variety. Observations were made on soil pH, oxidizing bacteria pyrite, growth of rice plants (plant height and number of tillers) and rice yield. The results showed that the main problem of actual acid sulfate land studied is a high soil acidity (pH of 3.44). Influ-ence of leaching was greater than microbial application on crop yields. Application of the pyrite oxidizing bacterial and leaching eight times gave the best influence on the growth and yield of rice plants.

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Tolerance Mechanisms and Irrigation Management to Reduce Iron Stress in Irrigated Rice

10.21203/rs.3.rs-473723/v1 ◽

2021 ◽

Author(s):

Felipe de Campos Carmona ◽

Janete Mariza Adamski ◽

Andriele Wairich ◽

Joseane Biso de Carvalho ◽

Gustavo Gomes Lima ◽

...

Keyword(s):

Grain Yield ◽

Soil Solution ◽

Irrigation Management ◽

Iron Toxicity ◽

Growth And Yield ◽

Water Suppression ◽

Continuous Irrigation ◽

Rice Plants ◽

Fe Toxicity ◽

The Impact

Abstract Iron toxicity is a major nutritional disorder in rice plants, especially in flooded areas. The use of alternative crop management practices, such as soil drainage, may mitigate negative impacts of iron toxicity, since soil aeration that follows drainage can oxidize and precipitate potentially toxic Fe+2 into Fe3+. This study aimed to evaluate the impact of alternative water management on agronomical and physiological parameters in rice plants grown in a field location with iron toxicity history. Rice cultivars BR-IRGA 409 (sensitive) and IRGA 425 (resistant to iron toxicity) were tested. Irrigation management comprised three treatments: Continuous Irrigation (CI), one cycle of water Suppression (1S) and two cycles of water Suppression (2S). Evaluations included the ionic composition of soil solution and leaf tissues, grain yield, antioxidant responses and gene expression. Permanent soil flooding resulted in higher grain yield in plants from the resistant than from the sensitive genotype, which had higher malondialdehyde (MDA) concentrations in leaves. In contrast, two cycles of alternate soil drying resulted in equivalent grain yield and MDA concentrations in both genotypes. Resistance to iron toxicity in IRGA 425 plants seems related to limited Fe translocation to shoots, increased tolerance to oxidative stress in leaves and higher expression of Ferritin, OsGAP1, OsWRKY80 and Oryzain-α genes. Plants from the BR-IRGA 409 cultivar (sensitive to Fe toxicity) improved growth and yield under the interrupted irrigation treatments, probably due to lower Fe availability in the soil solution. Management of water irrigation successfully alleviated Fe toxicity in rice plants cultivated in field conditions.

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