scholarly journals Cultivar Difference in the Yield Response to Climatic Conditions after Heading Stage in High-Yielding Rice Cultivars

2016 ◽  
Vol 85 (4) ◽  
pp. 367-372 ◽  
Author(s):  
Kenji Nagata ◽  
Akihiro Ohsumi ◽  
Satoshi Yoshinaga ◽  
Hiroshi Nakano
2020 ◽  
Vol 13 (1) ◽  
pp. 86
Author(s):  
Yi Ma ◽  
Qi Jiang ◽  
Xianting Wu ◽  
Renshan Zhu ◽  
Yan Gong ◽  
...  

Accurate monitoring of hybrid rice phenology (RP) is crucial for breeding rice cultivars and controlling fertilizing amount. The aim of this study is to monitor the exact date of hybrid rice initial heading stage (IHSDAS) based on low-altitude remote sensing data and analyze the influence factors of RP. In this study, six field experiments were conducted in Ezhou city and Lingshui city from 2016 to 2019, which involved different rice cultivars and nitrogen rates. Three low-altitude remote sensing platforms were used to collect rice canopy reflectance. Firstly, we compared the performance of normalized difference vegetation index (NDVI) and red edge chlorophyll index (CIred edge) for monitoring RP. Secondly, double logistic function (DLF), asymmetric gauss function (AGF), and symmetric gauss function (SGF) were used to fit time-series CIred edge for acquiring phenological curves (PC), the feature: maximum curvature (MC) of PC was extracted to monitor IHSDAS. Finally, we analyzed the influence of rice cultivars, N rates, and air temperature on RP. The results indicated that CIred edge was more appropriate than NDVI for monitoring RP without saturation problem. Compared with DLF and AGF, SGF could fit CIred edge without over fitting problem. MC of SGF_CIred edge from all three platforms showed good performance in monitoring IHSDAS with good robustness, R2 varied between 0.82 and 0.95, RMSE ranged from 2.31 to 3.81. In addition, the results demonstrated that high air temperature might cause a decrease of IHSDAS, and the growth process of rice was delayed when more nitrogen fertilizer was applied before IHSDAS. This study illustrated that low-altitude remote sensing technology could be used for monitoring field-scale hybrid rice IHSDAS accurately.


2003 ◽  
Vol 4 (1) ◽  
pp. 90-92
Author(s):  
Yar Muhammad Memon ◽  
Haji Khan Keerio ◽  
Riaz Noor Panhwar ◽  
Babar Raza Qazi ◽  
Muhammad Aslam Rajp ◽  
...  

2018 ◽  
Vol 7 (2) ◽  
pp. 1-12 ◽  
Author(s):  
Tahmina Khanam ◽  
Nahid Akhtar ◽  
MA Halim ◽  
Feroza Hossain

The experiment was conducted to clarify the growth and yield response of two rice cultivars, BR55 and BR43 under salt stress. Six different concentrations of NaCl viz 50, 100, 150, 200, 250 and 300 mM and distilled water (control) were applied on the rice cultivars which were grown under pot culture condition. Growth parameters like plant height, tiller number, leaf number and leaf area were negatively affected by salinity in both cultivars. Salt stress caused a significant reduction in yield in both cultivars of rice. Growth reduction was higher in BR43 than in BR55.The reduction in yield and yield parameters were found to be lower in BR55 than those in BR43. The results obtained in the present study suggest that BR55 showed higher salt tolerance than in BR43. Jahangirnagar University J. Biol. Sci. 7(2): 1-12, 2018 (December)


1999 ◽  
Vol 79 (2) ◽  
pp. 231-238
Author(s):  
R. Drapeau

Orchardgrass (Dactylis glomerata L.) has good winter survival in the mid-north agricultural areas of eastern Canada. There is no information on the cutting management to use after the first harvest of orchardgrass under these climatic conditions. The objective of this study was to determine the required interval between harvests following a first harvest at heading stage to optimise the productivity and maintain the persistence of orchardgrass. An interval of 35 d between harvests was sufficient to obtain annual yields of 4 to 6 tonnes of dry matter per hectare. An interval of 28 d between harvests had no negative effects on orchardgrass persistence under our climatic conditions. A second harvest taken 42 d after the first one often had a negative effect on the dry matter yield of the third harvest. Each time this occurred, we observed that the second harvest had been taken after 20 July. Heading dates varied among years. In addition to the growth stage at the first harvest, the date of occurrence of the heading stage should be considered so that the second harvest will be taken before 20 July. Consequently, if heading is delayed in spring, the interval between the first and second harvest must be reduced to take the second harvest before 20 July. Delaying the third harvest had a negative effect on the dry matter yield of the first harvest of the following production year. These results indicate that it is possible to take three harvests before September under the climatic conditions of the mid-north of eastern Canada without affecting the persistence of orchardgrass. Key words: Dactylis glomerata L., orchardgrass, cutting stage, cutting intervals, cutting management, yield


2018 ◽  
Vol 45 (7) ◽  
pp. 696 ◽  
Author(s):  
Jingjing Wu ◽  
Herbert J. Kronzucker ◽  
Weiming Shi

Elevated CO2 concentrations ([CO2]) in the atmosphere often increase photosynthetic rates and crop yields. However, the degree of the CO2 enhancement varies substantially among cultivars and with growth stage. Here, we examined the responses of two rice cultivars, Wuyunjing23 (WYJ) and IIyou084 (IIY), to two [CO2] (~400 vs ~600) and two nitrogen (N) provision conditions at five growth stages. In general, both seed yield and aboveground biomass were more responsive to elevated [CO2] in IIY than WYJ. However, the responses significantly changed at different N levels and growth stages. At the low N input, yield response to elevated [CO2] was negligible in both cultivars while, at the normal input, yield in IIY was 18.8% higher under elevated [CO2] than ambient [CO2]. Also, responses to elevated [CO2] significantly differed among various growth stages. Elevated [CO2] tended to increase aboveground plant biomass in both cultivars at the panicle initiation (PI) and the heading stages, but this effect was significant only in IIY by the mid-ripening and the grain maturity stages. In contrast, CO2 enhancement of root biomass only occurred in IIY. Elevated [CO2] increased both total N uptake and seed N in IIY but only increased seed N in WYJ, indicating that it enhanced N translocation to seeds in both cultivars but promoted plant N acquisition only in IIY. Root C accumulation and N uptake also exhibited stronger responses in IIY than in WYJ, particularly at the heading stage, which may play a pivotal role in seed filling and seed yield. Our results showed that the more effective use of CO2 in IIY compared with WYJ results in a strong response in root growth, nitrogen uptake, and in yield. These findings suggest that selection of [CO2]-responsive rice cultivars may help optimise the rice yield under future [CO2] scenarios.


Genetika ◽  
2016 ◽  
Vol 48 (2) ◽  
pp. 463-472
Author(s):  
Borivoj Pejic ◽  
Ksenija Mackic ◽  
Dragisa Milosev ◽  
Erkut Peksen ◽  
Srdjan Seremesic ◽  
...  

Mitigation of global climate change impact on the agricultural production is the major priorities in future research. Cowpea as a drought tolerant plant is interesting for growing in semi-arid climate of the Vojvodina region. The effect of water stress on yield of cultivated plants can be obtained by calculating the yield response factor (Ky) which represents the ratio between the relative evapotranspiration deficit (1-ETa/ETm) and the relative decline in yield (1-Ya/Ym). The values of Ky ranged from 0.91 to 1.17 for genotype G1 and G2 respectively. Genotype G1, with a value lower than 1 of Ky, shows a good tolerance to water deficit, on the contrary, genotype G2, with a greater Ky than 1, expresses some sensitivity to water stress. Obtained results will be used in breeding programs to develop cowpea cultivars tolerant to stressful conditions, primarily to water stress, as well as more productive in water use.


1970 ◽  
Vol 10 (45) ◽  
pp. 426 ◽  
Author(s):  
RE White ◽  
KP Haydock

Siratro (Phaseolus atropurpureus) was grown under a range of soil and climatic conditions in sub-tropical Queensland, over the years 1964 to 1967. Phosphate concentration in the tops, sampled immediately prior to flowering, was poorly correlated with either the relative yield response to applied phosphorus, or the amount of phosphorus required to lift yield to a maximum. Fifty per cent of the variation in P required could be accounted for by regression on great soil group, which crudely reflected differences in phosphate buffering capacity between soils. The critical value of phosphorus in the plant, corresponding to a yield of 90 per cent of the maximum, varied from 0.16 to 0.29 per cent. Twenty-five per cent of this variation was due to differences in the rain falling in the 28 days prior to sampling : the lower the rainfall, the lower the critical value. Rain falling 28 days prior to sampling and great soil group together accounted for 41 per cent of the variation in critical value. The effect of moisture stress on the critical value was more likely plant physiological, than one of a diminished phosphate supply from the soil.


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