scholarly journals PHYSIOLOGICAL RESPONSES OF UPLAND RICE; WATER AND NITROGEN UPTAKES AND WATER USE EFFICIENCY UNDER WET AND PARTIAL DRYING SOIL CONDITIONS

2021 ◽  
Vol 9 (6) ◽  
pp. 405-417
Author(s):  
Mganga Joshua Fimbo Kitilu

Rice is an important cereal and staple food crop in Tanzania, the rice production has not met the demand, mainly due to water shortage. Dissemination of New Rice for Africa (NERICA) has been in progress to improve production in upland rice ecosystem. A pot experiment was conducted in a split plot design at university farm to elucidate water uptake, water use efficiency and nitrogen uptakes for two NERICA cultivars (NERICA1 and 2) and two Japanese rice cultivars ( and ). Amount of transpired water was recorded every day until maturity. Nitrogen uptake at booting and maturity growth stage were compared between these cultivars. The results indicated that amount of water transpired was greater for NERICA cultivars in the period from booting to maturity, in particular, under the dry soil condition. All the cultivars showed similar slope of regression lines between amount of transpired water and dry matter production (Water use efficiency), Nitrogen concentration per unit weight was higher in NERICA rice than in Japanese rice during grain filling stage. These results indicate that NERICA’s rice cultivars have high productivity due to higher water and Nitrogen uptake during grain filling stage compared with the Japanese rice cultivars tested.

Author(s):  
O. O. Bankole ◽  
A. Oluwaranti ◽  
F. E. Awosanmi

Aims: The objectives of this study were to evaluate maize genotypes of different maturity groups for seedling and grain filling water use efficiency and determine relationship that exist between the water use efficiency traits and yield of different maize maturity groups. Study Design:  Sixteen maize genotypes were planted in Randomized Complete Block Design in three replicates for emergence, vegetative, water use efficiency traits at the seedling and grain-filling growth stages and yield. Place and Duration of Study: The sixteen maize genotypes of different maturity groups were evaluated during the early and late cropping seasons of 2016 at the Obafemi Awolowo University Teaching and Research Farm, Ile-Ife, Nigeria Methodology: Data collected were subjected to Analysis of Variance (ANOVA), correlation analysis among water use efficiency traits and yield for each of the maturity groups. Results: There was no significant difference among the genotypes within each maturity groups for water use efficiency at seedling and grain filling growth stages. The late maturity group of maize used more water at the seedling growth stage than the other maturity groups in the early season of this study while in the late season, the early and extra-early maturity groups used more water than the other maturity groups. Increase in emergence percentage, reduction in speed of germination, and minimal days to complete germination increased water use efficiency at the seedling stage only during the early cropping season. Efficiency of water usage at the seedling growth stage was more among the late and intermediate maturing groups than the extra-early and early maturing groups in the early season while in the late season, the extra-early and early maturing groups used water more efficiently than the late and Intermediate maturing groups Conclusion: Maturity group played a significant role in the expression and manifestation of water use efficiency traits under different environmental conditions.


2021 ◽  
Vol 6 (3) ◽  
pp. 838-863
Author(s):  
Didi Darmadi ◽  
◽  
Ahmad Junaedi ◽  
Didy Sopandie ◽  
Supijatno ◽  
...  

<abstract> <p>The use of varieties that are able to adapt well to extreme environments is one strategy to overcome the challenges of decreasing production in sub-optimal land. Indonesian tropical rice varieties (Jatiluhur, IPB 9G, IPB 3S, Hipa 19, Mentik Wangi, Ciherang, Inpari 17, and Mekongga) have been tested and established as water-used-efficient varieties in an optimal environment. However, to date, these varieties have not been examined in the suboptimal area, in particular, drought stress conditions. Therefore, this study aimed to evaluate the adaptation response of production, morphological, and physiological character of several water-efficient rice varieties under drought stress in the field. The study was designed in a split-plot with two factors and 4 replications, where the first factor (main plot) was drought stress stages i.e. vegetative (Dv), reproductive (Dr), generative (Dg), and control (Dc). The second factor was rice varieties, consisting of eight varieties, i.e., Jatiluhur, IPB 3S, IPB 9G, Hipa 19, Mentik Wangi, Ciherang, Inpari 17, and Mekongga. The experiment was conducted from May to December 2018 in Muneng Kidul Village, Probolinggo Regency, East Java Province. The experimental variables were morphology, production, leaf scrolling score during drought stress, drought sensitivity index, water use efficiency, physiology and root anatomy. The result showed that upland rice varieties were more tolerant to drought stress and had a higher water use efficiency than lowland rice varieties. This shows that Jatiluhur and IPB 9G which are indicated to be adaptive to drought stress, and have the ability to regulate water use more efficiently when drought stress occurs. Therefore, water use efficiency could be used as selection characters under drought conditions in rice particularly tropical upland rice. Moreover, morphological characters, i.e., grain yiled per plot, weight of pithy grain, weight of shoot biomass and weight of roots could be the selection characters to predict drought tolerant tropical rice. According to physiological characters, photosynthesis rate, transpiration rate, proline content, malondialdehyde content, leaf water potential and leaf greenness could be used as a selection tool to predict water use efficient genotypes in rice. However, further studies are needed to understand the complex mechanisms of water use efficiency by combining various approaches.</p> </abstract>


2021 ◽  
Vol 12 ◽  
Author(s):  
Juan Carlos Suárez ◽  
Milan O. Urban ◽  
Amara Tatiana Contreras ◽  
Jhon Eduar Noriega ◽  
Chetan Deva ◽  
...  

In our study, we analyzed 30years of climatological data revealing the bean production risks for Western Amazonia. Climatological profiling showed high daytime and nighttime temperatures combined with high relative humidity and low vapor pressure deficit. Our understanding of the target environment allows us to select trait combinations for reaching higher yields in Amazonian acid soils. Our research was conducted using 64 bean lines with different genetic backgrounds. In high temperatures, we identified three water use efficiency typologies in beans based on detailed data analysis on gasometric exchange. Profligate water spenders and not water conservative accessions showed leaf cooling, and effective photosynthate partitioning to seeds, and these attributes were found to be related to higher photosynthetic efficiency. Thus, water spenders and not savers were recognized as heat resistant in acid soil conditions in Western Amazonia. Genotypes such as BFS 10, SEN 52, SER 323, different SEFs (SEF 73, SEF 10, SEF 40, SEF 70), SCR 56, SMR 173, and SMN 99 presented less negative effects of heat stress on yield. These genotypes could be suitable as parental lines for improving dry seed production. The improved knowledge on water-use efficiency typologies can be used for bean crop improvement efforts as well as further studies aimed at a better understanding of the intrinsic mechanisms of heat resistance in legumes.


Agronomy ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 465
Author(s):  
Wenming Wu ◽  
Shiji Wang ◽  
Lin Zhang ◽  
Jincai Li ◽  
Youhong Song ◽  
...  

In the southern Huang-Huai-Hai (HHH) region, China, maize production is frequently threatened by waterlogging at the seedling stage and by drought at the big flare stage. A two-year field experiment was performed to explore whether subsoiling (SS) in the winter wheat season could improve the photosynthetic capacity and increase the water use efficiency (WUE) of summer maize using the variety, Luyu9105. A split design was adopted in the experiment. The main plots used tillage practices, including SS and rotary tillage (RT). The subplots consisted of two irrigation methods, i.e., applied supplemental irrigation at the big flare stage (I) and no irrigation at the big flare stage (NI). The results showed that the SS treatment significantly increased soil water content (SWC) in the 40–60 cm soil layer. The SS treatment improved green leaf area index (gLAI) by 15.1%–30.2%, and enhanced the ear-leaf net photosynthetic rate (Pn), stomatal conductance (gs), intercellular CO2 concentration (ci) and transpiration rate (Tr), and was accompanied by an increase in the grain-filling duration (T) by 5 days and the mean grain-filling rate (Va). The SS treatment decreased the stomatal limitation (Ls), indicating that RT treatment, which was under lower SWC, led to a decrease in Pn. Applied supplemental irrigation under RT treatment was able to compensate for the growth of leaves, but could not reverse the decreasing trend in the gLAI. Ultimately, the SS treatment improved WUE by 9.1%–9.9%, and increased grain yields by 10.0%–29.3%. Therefore, this study showed that in the southern Huang-Huai-Hai Plain, which has a yellow cinnamon soil type, the practice of SS can improve the photosynthetic characteristics of leaves and WUE of rainfed summer maize.


1997 ◽  
Vol 48 (5) ◽  
pp. 595 ◽  
Author(s):  
K. L. Regan ◽  
K. H. M. Siddique ◽  
D. Tennant ◽  
D. G. Abrecht

Wheat cultivars with very early maturities appropriate for late sowings in low-rainfall (<325 mm) short-season environments are currently unavailable to wheat growers in the eastern margin of the cropping region of Western Australia. A demonstration that very early-maturing genotypes can out-perform current commercial cultivars would open new opportunities for breeding programs to select very early-maturing, high- and stable-yielding cultivars for these environments. Six field experiments were conducted over 4 seasons at 2 low-rainfall sites in Western Australia to investigate crop growth, grain yield, and water use efficiency of very early-maturing genotypes compared with current commercial cultivars when sown after 1 June. Very early-maturing genotypes reached anthesis up to 24 days (328 degree-days) earlier than the current cultivars, produced less leaves, had similar yields and dry matter, and maintained high water use efficiencies. On average across seasons and locations the very early-maturing genotypes (W87–022–511, W87–114–549, W87–410–509) yielded more than the later maturing cultivars Gamenya and Spear (190 v. 160 g/m2) but they were similar to the early-maturing commercial cultivars Kulin and Wilgoyne (191 g/m2). Very early-maturing genotypes generally had a higher harvest index and produced fewer spikelets, but heavier and more grains, than Kulin and Wilgoyne. There were only small differences in total water use between very early-maturing genotypes and commercial cultivars; however, very early-maturing genotypes used less water in the pre-anthesis period and more water in the post-anthesis period than the later maturing genotypes, and hence, experienced less water deficit during the grain-filling period. This study indicates that there is a role for very early-maturing genotypes in low-rainfall short-season environments, when the first autumn rains arrive late (after 1 June).


Sign in / Sign up

Export Citation Format

Share Document