Evaluation of manihot glaziovii scion-cassava understock grafting for cassava growth and root yield during rainy and dry seasons

2021 ◽  
pp. 1-14
Author(s):  
Pakornsiri Bangthong ◽  
Supachai Vuttipongchaikij ◽  
Pasajee Kongsil ◽  
Hernan Ceballos ◽  
Piya Kittipadakul
2018 ◽  
Vol 2 (2) ◽  
Author(s):  
Lansana Kamara ◽  
Fayia Kassoh ◽  
Ernest Kamara ◽  
Festus Masssaquoi ◽  
Keiwoma Yila ◽  
...  

2020 ◽  
Vol 57 (4) ◽  
pp. 302-309
Author(s):  
Sukanta Pal ◽  
Megha Sana ◽  
Hirak Banerjee ◽  
Lhingneikim Lhungdim

Effect of nitrogen and bio-fertilizer on growth and productivity of hybrid rice (cv. PHB 71) was assessed during dry seasons of 2017 and 2018 at Research Farm of BCKV under new alluvial zone of West Bengal. The experiment was laid out in factorial randomized block design with 12 treatment combinations having 4 levels of N and 3 types of bio-fertilizer replicated thrice. Application at 180 kg N/ha produced tallest plants at 90 DAT with maximum LAI (60 DAT), DMA (90 DAT), tillers/hill (90 DAT) and CGR (30-60 & 60-90 DAT). The same N rate resulted in highest panicles/m2, panicle length, panicle weight, filled grains/panicle and 1000-grain weight. A decrease in N dose from 180 to 150 kg/ha caused reduction in all those yield components; however, the variation was non-significant except for number of panicles/m2. Maximum grain yield, straw yield and harvest index was also achieved with 180 kg N/ha accounting 120.1, 34.9 and 32.8% more than the values obtained with zero-N; however, it was statistically at par with the yields and HI obtained with 150 kg N/ha. The Azospirillum application increased all the growth parameters, yield components and yield of hybrid rice over other tested bio-fertilizers (Azospirillum > PSB > K mobilizer), accounting 5.9 and 8.8% more than the yields obtained with PSB and K mobilizer. The interaction of N and bio-fertilizer exerted significant effect on growth attributes but failed to record any significant variations in yield components and yield of hybrid rice. The maximum economic benefit was achieved with combined application of 180 kg N/ha and Azospirillum.


2000 ◽  
Vol 31 (4-5) ◽  
pp. 317-338 ◽  
Author(s):  
Kathy L. Young ◽  
Ming-ko Woo

High Arctic patchy wetlands are ecological oases in a polar desert environment and are vulnerable to climatic warming. At present, understanding of their responses to external factors (climate and terrain) is limited. This study examines a wetland located in a topographic depression maintained by seasonal snowmelt, ground ice melt and lateral inflows. The wetland is located on Cornwallis Island, Nunavut, Canada. Hydrological, climatological and soil observations were made over several summers with different weather conditions. The summers of 1996 and 1997 were cool and wet but the summer of 1998 was warm and dry. The melt in 1996 was rapid due to rain on snow events and only lasted six days. Deeper snow in 1997 prolonged the melt season to 18 days. A shallow snow-cover in 1998 and early melt depleted the snow by early June. Surface, groundwater and storage fluctuations in the wetland were dictated by snowmelt, rainfall, evaporation loss from the wetland and lateral inputs which in turn were controlled by the melting of the late-lying snow storage in the catchment. Soil factors influence the spatial variations in ground thaw which affects the surface and subsurface flow. Streamflow response of the wetland reflects a nival regime and augmentation of streamflow thoughout the summer season in all three years is supported by multiple water sources: ground ice melt and suprapermafrost water from a large late-lying snowpack. Overall, this study suggests that the survival of some patchy wetlands depends on their interaction with the surrounding basin, with a dependency probably being more important during warm and dry seasons.


2015 ◽  
Vol 8 (1) ◽  
pp. 309-317 ◽  
Author(s):  
Xing Liting ◽  
Zhou Juan ◽  
Zhang Fengjuan ◽  
Wang Song ◽  
Dou Tongwen ◽  
...  

In karst regions, due to the heterogeneous features of karst medium, the characteristics of the groundwater flow turn to be of high complexity. Researchers have been seeking proper forecasting methods for karst water dynamic for many years. This paper, taking the spring in Jinan as an example, using regression analysis, analyzed the factors influencing spring water dynamic, and quantitatively evaluated the influencing coefficients of spring water level concerning rainfall, exploitation and recharge as well as the natural decay coefficient of spring water in dry seasons. The prediction model coupling multiple factors was built by investigating natural and anthropogenic factors influencing groundwater level, which could be used for forecasting dynamic of spring water in Jinan. The calculated value of model was highly coincided with the observed value. In consideration of the characteristics of uneven precipitation in Jinan, the suitable zones and volume of artificial recharge were investigated finally, which could help to sustain the spewing of Jinan springs significantly.


2018 ◽  
Vol 48 (4) ◽  
pp. 420-428
Author(s):  
Johana Juliet Caballero Vanegas ◽  
Karen Bibiana Mejía Zambrano ◽  
Lizeth Manuela Avellaneda-Torres

ABSTRACT Understanding the impacts of agricultural practices on soil quality indicators, such as enzymatic activities, is of great importance, in order to advance in their diagnosis and sustainable management. This study aimed to evaluate the effect of ecological and conventional agricultural managements on enzymatic activities of a soil under coffee agroecosystems. The enzymatic activities were associated with the biogeochemical cycles of nitrogen (urease and protease), phosphorus (acid and alkaline phosphatase) and carbon (β-glucosidase), during the rainy and dry seasons. Physical-chemical soil proprieties were also assessed and related to resilience scores linked to the climatic variability reported for the areas under study. The activities of urease, alkaline and acid phosphatase and ß-glucosidase were statistically higher in ecological agroecosystems than in conventional ones. This may be attributed to the greater application of organic waste in the ecological environment, as well as to the absence of pesticides and synthetic fertilizers, which allow better conditions for the microbial activity. The resilience scores to the climate variability that showed the highest correlations with the assessed enzymatic activities were: the farmers' knowledge on soil microorganisms, non-use of pesticides and synthetic fertilizers and non-dependence on external supplies. It was concluded that the enzymatic activities are modified by the management systems, being specifically favored by the ecological management. This agroecosystem, in the long term, ensures an efficient use of the soil resources, with a lower degradation and contamination.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Melinda Boyers ◽  
Francesca Parrini ◽  
Norman Owen-Smith ◽  
Barend F. N. Erasmus ◽  
Robyn S. Hetem

AbstractSouthern Africa is expected to experience increased frequency and intensity of droughts through climate change, which will adversely affect mammalian herbivores. Using bio-loggers, we tested the expectation that wildebeest (Connochaetes taurinus), a grazer with high water-dependence, would be more sensitive to drought conditions than the arid-adapted gemsbok (Oryx gazella gazella). The study, conducted in the Kalahari, encompassed two hot-dry seasons with similar ambient temperatures but differing rainfall patterns during the preceding wet season. In the drier year both ungulates selected similar cooler microclimates, but wildebeest travelled larger distances than gemsbok, presumably in search of water. Body temperatures in both species reached lower daily minimums and higher daily maximums in the drier season but daily fluctuations were wider in wildebeest than in gemsbok. Lower daily minimum body temperatures displayed by wildebeest suggest that wildebeest were under greater nutritional stress than gemsbok. Moving large distances when water is scarce may have compromised the energy balance of the water dependent wildebeest, a trade-off likely to be exacerbated with future climate change.


2021 ◽  
Vol 9 (4) ◽  
pp. 410
Author(s):  
Fan Zhang ◽  
Xin Peng ◽  
Liang Huang ◽  
Man Zhu ◽  
Yuanqiao Wen ◽  
...  

In this study, a method for dynamically establishing ship domain in inland waters is proposed to help make decisions about ship collision avoidance. The surrounding waters of the target ship are divided to grids and then calculating the grid densities of ships in each moment to determine the shape and size of ship domain of different types of ships. At last, based on the spatiotemporal statistical method, the characteristics of ship domains of different types of ship in different navigational environments were analyzed. The proposed method is applied to establish ship domains of different types of ship in Wuhan section of the Yangtze River in January, February, July, and August in 2014. The results show that the size of ship domain increases as the ship size increases in each month. The domain size is significantly influenced by the water level, and the ship domain size in dry seasons is larger than in the wet seasons of inland waters.


Agronomy ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 806
Author(s):  
Ali A. A. Mekdad ◽  
Mostafa M. Rady ◽  
Esmat F. Ali ◽  
Fahmy A. S. Hassan

Field trials for two seasons (2018/2019 and 2019/2020) were conducted to investigate the influence of the addition of three levels of potassium (K) (K1 = 60, K2 = 120, and K3 = 180 kg K2O ha−1) and/or sulfur (S) (S1 = 175, S2 = 350, and S3 = 525 kg CaSO4 ha−1) to the soil, as well as the sowing date (the 1st of September, D1; or the 1st of October, D2) on the potential improvement of physiology, growth, and yield, as well as the quality characteristics of sugar beet yield under soil salinity conditions. With three replicates specified for each treatment, each trial was planned according to a split-split plot in a randomized complete block design. The results revealed that early sowing (D1) led to significant improvements in all traits of plant physiology and growth, in addition to root, top, and biological yields and their quality, gross and pure sugar, and K- and S-use efficiencies based on root yield (R-KUE and R-SUE). The K3 level (180 kg K2O ha−1) positively affected the traits of plant physiology, growth, yield and quality, and R-SUE, and reduced the attributes of impurities, impurity index, and R-KUE. Additionally, the S3 level (525 kg CaSO4 ha−1) affirmatively affected plant physiology, growth, yield and quality traits, and R-KUE, and decreased impurity traits, impurity index, and R-SUE. The interaction of D1 × K3 × S3 maximized the yield of roots (104–105 ton ha−1) and pure sugar (21–22 ton ha−1). Path coefficient analysis showed that root yield and pure sugar content had positive direct effects with 0.62 and 0.65, and 0.38 and 0.38 in both studied seasons, respectively, on pure sugar yield. Significant (p ≤ 0.01) positive correlations were found between pure sugar yield and root yield (r = 0.966 ** and 0.958 **). The study results recommend the use of the integrative D1 × K3 × S3 treatment for sugar beet to obtain maximum yields and qualities under salt stress (e.g., 8.96 dS m−1) in dry environments.


2021 ◽  
Vol 22 (9) ◽  
pp. 4826
Author(s):  
Yang Gao ◽  
Zhonghou Tang ◽  
Houqiang Xia ◽  
Minfei Sheng ◽  
Ming Liu ◽  
...  

A field experiment was established to study sweet potato growth, starch dynamic accumulation, key enzymes and gene transcription in the sucrose-to-starch conversion and their relationships under six K2O rates using Ningzishu 1 (sensitive to low-K) and Xushu 32 (tolerant to low-K). The results indicated that K application significantly improved the biomass accumulation of plant and storage root, although treatments at high levels of K, i.e., 300–375 kg K2O ha−1, significantly decreased plant biomass and storage root yield. Compared with the no-K treatment, K application enhanced the biomass accumulation of plant and storage root by 3–47% and 13–45%, respectively, through promoting the biomass accumulation rate. Additionally, K application also enhanced the photosynthetic capacity of sweet potato. In this study, low stomatal conductance and net photosynthetic rate (Pn) accompanied with decreased intercellular CO2 concentration were observed in the no-K treatment at 35 DAT, indicating that Pn was reduced mainly due to stomatal limitation; at 55 DAT, reduced Pn in the no-K treatment was caused by non-stomatal factors. Compared with the no-K treatment, the content of sucrose, amylose and amylopectin decreased by 9–34%, 9–23% and 6–19%, respectively, but starch accumulation increased by 11–21% under K supply. The activities of sucrose synthetase (SuSy), adenosine-diphosphate-glucose pyrophosphorylase (AGPase), starch synthase (SSS) and the transcription of Susy, AGP, SSS34 and SSS67 were enhanced by K application and had positive relationships with starch accumulation. Therefore, K application promoted starch accumulation and storage root yield through regulating the activities and genes transcription of SuSy, AGPase and SSS in the sucrose-to-starch conversion.


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