scholarly journals Yield and Metabolite Production of Pelargonium sidoides DC. in Response to Irrigation and Nitrogen Management

Metabolites ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 219 ◽  
Author(s):  
Motiki Mofokeng ◽  
Gerhard Prinsloo ◽  
Hintsa Araya ◽  
Christian du Plooy ◽  
Ntshakga Sathekge ◽  
...  

Competition for water between agricultural and non-agricultural economic sectors hampers agricultural production, especially in water-scarce regions. Understanding crop responses in terms of yield and quality to irrigation is an important factor in designing appropriate irrigation management for optimal crop production and quality. Pelargonium sidoides DC., often harvested from the wild, is in high demand in the informal market and for commercial formulations. Agricultural production of high-quality materials through cultivation can help reduce pressure on its wild populations. This study aimed at determining the effects of water and nitrogen on P. sidoides yield and metabolite production. The irrigation treatments applied were 30%, 50%, and 70% of an allowable depletion level (ADL), while the nitrogen (N) levels were 0 (control), 50, 100, and 150 kg ha−1. The 30% ADL resulted in a significantly higher biomass and root yield. Nitrogen at 50 and 100 kg ha−1 resulted in a significantly higher biomass yield, compared to the N control. An increase in sugars and citrate cycle components was observed for the well-watered 30% ADL treatment, whereas water-stressed (50% and 70% ADL) treatments increased alanine, aspartate, and glutamate metabolism, increasing levels of asparagine, 4-aminobutyrate, and arginine. The treatments had no significant effect on the root content of esculin, scopoletin, and umckalin. Water stress induced metabolite synthesis to mitigate the stress condition, whereas under no water stress primary metabolites were synthesized. Moreover, cultivation of P. sidoides as a conservation strategy can increase yield without affecting its bioactivity, while providing sustenance for the rural communities.

Agronomy ◽  
2019 ◽  
Vol 9 (9) ◽  
pp. 559 ◽  
Author(s):  
Lin ◽  
Lin ◽  
Wu ◽  
Chang

Water deficits during the growing season are a major factor limiting crop production. Therefore, reducing water use during crop production by the application of regulated deficit irrigation (RDI) is crucially important in water resources. There are few reports on the biostimulants used for growth and water use efficiency (WUE) in maize (Zea mays Linn.) under RDI. Therefore, the influence of betaine and chitin treatments, alone and in combination, on maize cultivar ‘White Pearl’ was assessed by observing changes in the physiology and morphology of plants exposed to RDI. Plants were grown in plastic pots in greenhouses and maintained under full irrigation (FI) for 1 week until imposing RDI and biostimulants. Plants were then subjected to FI (no water deficiency treatment, field capacity >70%) and RDI (field capacity <50%) conditions until the end of each experiment. Plant agronomic performance, photosynthesis parameters, and WUE values were recorded weekly for 8 weeks and three individual experiments were carried out to assess the efficacy of biostimulants and irrigation treatments. Betaine (0, 50, and 100 mM/plant) was foliage-treated every 2 weeks during Experiment 1, but chitin (0, 2, and 4 g/kg) was applied to the soil at the beginning of Experiment 2. The optimal concentration of each chemical alone or in combination was then applied to the plants as Experiment 3. A factorial experiment design of two factors with different levels under a completely randomized arrangement was used in this investigation. Betaine (50 mM) or chitin (2 g/kg) treatments alone significantly elevated total fresh weight (63.03 or 124.07 g/plant), dry weight (18.00 or 22.34 g/plant), and cob weight (3.15 or 6.04 g/plant) and boosted the water-stress tolerance of the maize under RDI compared to controls. However, a combination treatment of 50 mM betaine and 2 g/kg chitin did not increase plant height, fresh shoot and root weights, dry cob weight, and total dry weight under RDI compared to controls. Soil-plant analysis development (SPAD) values (>30) were effective in detecting plant growth performance and WUE values under RDI. These findings may have greater significance for farming in dry lands and offer information for further physiological studies on maize WUE and water stress tolerance


EDIS ◽  
2017 ◽  
Vol 2017 (5) ◽  
Author(s):  
Davie Mayeso Kadyampakeni ◽  
Kelly T. Morgan ◽  
Mongi Zekri ◽  
Rhuanito Ferrarezi ◽  
Arnold Schumann ◽  
...  

Water is a limiting factor in Florida citrus production during the majority of the year because of the low water holding capacity of sandy soils resulting from low clay and the non-uniform distribution of the rainfall. In Florida, the major portion of rainfall comes in June through September. However, rainfall is scarce during the dry period from February through May, which coincides with the critical stages of bloom, leaf expansion, fruit set, and fruit enlargement. Irrigation is practiced to provide water when rainfall is not sufficient or timely to meet water needs. Proper irrigation scheduling is the application of water to crops only when needed and only in the amounts needed; that is, determining when to irrigate and how much water to apply. With proper irrigation scheduling, yield will not be limited by water stress. With citrus greening (HLB), irrigation scheduling is becoming more important and critical and growers cannot afford water stress or water excess. Any degree of water stress or imbalance can produce a deleterious change in physiological activity of growth and production of citrus trees.  The number of fruit, fruit size, and tree canopy are reduced and premature fruit drop is increased with water stress.  Extension growth in shoots and roots and leaf expansion are all negatively impacted by water stress. Other benefits of proper irrigation scheduling include reduced loss of nutrients from leaching as a result of excess water applications and reduced pollution of groundwater or surface waters from the leaching of nutrients. Recent studies have shown that for HLB-affected trees, irrigation frequency should increase and irrigation amounts should decrease to minimize water stress from drought stress or water excess, while ensuring optimal water availability in the rootzone at all times.


2019 ◽  
Vol 5 (5) ◽  
pp. 550-562

Drawn upon field research in two peri-urban villages of Hanoi in 2014 and short re-visits recently, the research examines the widespread of gambling and other social issues in Hanoi’s urbanizing peri-urban communities which happened concurrently with the phenomenon of “land fever,” and at the time local villagers received compensation from land appropriation. The article aims to understand the impact of urbanization on these communities and the interface between urbanization and the increase of social problems. It argues that gambling, drug use, and other social problems have been existing in Vietnamese rural communities long before; however, when urbanization came, some people have higher chances to engage in these activities. Those are villagers who want to transform quickly into entrepreneurs or bosses by joining the “black credit” market and gambling. Together with middle-aged and old farmers who greatly relied on agricultural production and face difficulties in transforming their occupation, they formed the group of losers in the urbanization process. Received 6th January 2019; Revised 26th April 2019; Accepted 15th May 2019


2018 ◽  
pp. 1128-1136
Author(s):  
Olga V. Bershadskaya ◽  

The article studies features of socio-economic and socio-political development of the Black Sea village in 1920s. Documents from the fond of the Black Sea District Committee (Obkom) of the RCP (b) -VKP (b) stored in the Center for Documentation of the Modern History of the Krasnodar Krai allow not only to reconstruct the developments in the Black Sea village in the NEP days, but also to understand the nature of its evolution. Uniqueness of the Black Sea village was greatly determined by its geographical environment. There had formed a sectoral makeup of agricultural production: fruit-farming, viticulture, tobacco growing. Rugged relief forced peasants to form holdings or farms; therefore rural communities were rare. Its another distinctive feature was its motley national composition. Over 50 ethnic groups inhabited the district, among most numerous were the Russians, the Ukrainians, the Armenians, and the Greeks. In the first years of the NEP, the main tasks facing district authorities were to develop ‘high-intensity’ industries and to shape local peasant farms into food base for cities and resorts. While tackling these tasks, they had to deal with shortages of land and poor communications and to bring lease relations and work-hands employment up to scratch. The situation was complicated by socio-political inertia of rural population of the district that came from the absence of community tradition. Study of the documents from the fond of the Black Sea party obkom shows that local authorities were well aware of the peculiarity of their region, but in most cases had to follow guidelines set ‘from above’ to introduce all-Russian standards.


Author(s):  
Eckart Woertz

West Asia is one of the most water-scarce regions of the world and one of its foremost importers of virtual water despite sustained efforts at self-sufficiency, especially in cereal production. Technology-oriented policy solutions eye a reorientation of agriculture towards fruit and vegetables that are less water-intensive than cereals and provide more value added per water unit consumed. Turkey is a role model here; the country has an agricultural trade surplus and ranks among the top ten agricultural economies globally in value terms. Yet technology-oriented policy prescriptions overlook the sociopolitical ‘problemsheds’ that emerge (along with new agro-lobbies) and agriculture as the main water consumer has to compete with other economic sectors and sprawling urbanization. This article looks at the different categories of countries and their specific challenges.


2021 ◽  
Author(s):  
Lynette Morgan

Abstract Crop production in many regions has been reliant on irrigation for almost as long as man has been cultivating plant life. For 6000 years, irrigation has ranked among the most powerful tools of human advancement (Postel, 1999), and by the start of the 21st century no less than 75% of the world's fresh water was in use for agricultural production (Levy and Coleman, 2014). In 2012, twenty percent of total cultivated land was under irrigation, contributing forty percent of the total food production worldwide, this represented 275 million hectares under actual irrigation with a total of 324 million hectares equipped for irrigation (FAO, 2016). Irrigation, which can be defined as 'the artificial application of water to land, soil or other growing medium for the purposes of crop growth', has become a global issue in more recent times as the increasing demand for fresh water has seen problems develop with water scarcity, quality issues and conflict over usage.


Author(s):  
Roshan Kumar Mehta ◽  
Shree Chandra Shah

The increase in the concentration of greenhouse gases (GHGs) in the atmosphere is widely believed to be causing climate change. It affects agriculture, forestry, human health, biodiversity, and snow cover and aquatic life. Changes in climatic factors like temperature, solar radiation and precipitation have potential to influence agrobiodiversity and its production. An average of 0.04°C/ year and 0.82 mm/year rise in annual average maximum temperature and precipitation respectively from 1975 to 2006 has been recorded in Nepal. Frequent droughts, rise in temperature, shortening of the monsoon season with high intensity rainfall, severe floods, landslides and mixed effects on agricultural biodiversity have been experienced in Nepal due to climatic changes. A survey done in the Chitwan District reveals that lowering of the groundwater table decreases production and that farmers are attracted to grow less water consuming crops during water scarce season. The groundwater table in the study area has lowered nearly one meter from that of 15 years ago as experienced by the farmers. Traditional varieties of rice have been replaced in the last 10 years by modern varieties, and by agricultural crops which demand more water for cultivation. The application of groundwater for irrigation has increased the cost of production and caused severe negative impacts on marginal crop production and agro-biodiversity. It is timely that suitable adaptive measures are identified in order to make Nepalese agriculture more resistant to the adverse impacts of climate change, especially those caused by erratic weather patterns such as the ones experienced recently.DOI: http://dx.doi.org/10.3126/hn.v11i1.7206 Hydro Nepal Special Issue: Conference Proceedings 2012 pp.59-63


2016 ◽  
Vol 38 (3) ◽  
pp. 363 ◽  
Author(s):  
Frank Akiyoshi Kuwahara ◽  
Gustavo Maia Souza ◽  
Kezia Aparecida Guidorizi ◽  
Ciniro Costa ◽  
Paulo Roberto de Lima Meirelles

Water deficiency during the dry seasons influences the relationship between water and gas exchange in tropical grasses, reducing their productive potential. In addition, the phosphorus (P) deficiency Brazilian soils adds to the set of factors limiting crop production. In this context, the objective of this study was to evaluate the responses of different tropical forage species to phosphorus supplementation as mitigating the damage caused by water stress. Seeds of Urochloa brizantha cv. MG-4, Urochloa decumbens cv. Basilisk, Panicum maximum cv. Áries, Panicum maximum cv. Tanzânia and Paspalum atratum cv. Pojuca were germinated in pots containing 10 liters of red-yellow Acrisol type soil. Experiments were conducted by combining levels of phosphorus, 8,0 and 100,0 mg of P dm-3, with two irrigation regimes, 100 and 40% replacement of transpired water. The biometric parameters, photosynthetic capacity, leaf water potential and soil chemical characteristics were evaluated, and the data was submitted to analysis of variance (ANOVA, p < 0.05), and subsequently the means were compared using a Tukey test (p < 0.05). The results showed for tropical grasses grown under water stress, there is a clear mitigating effect of phosphorus supplementation, especially on the maintenance of biomass growth. 


2020 ◽  
Vol 27 (5) ◽  
pp. 36-47
Author(s):  
D. S. Ternovsky ◽  
V. Ya. Uzun

The article presents the results of a study aimed at proving the existence of systematic error in traditional calculations of long-term growth rates of agricultural production based on chain indices of agricultural production. According to the authors, the article also introduces a more accurate assessment of its dynamics with the account to the structure of the relationship between prices and the volume of agricultural production. The paper describes a theoretical model that is a methodological basis for the study and explains the discrepancy in assessing the dynamics of agricultural production using chain indices and indexes at constant prices. It allows establishing differences in the ratios of the Laspeyres, Paasche, and Lowe indices for crop and livestock production, due to factors in the formation of demand and the complex structure of the relationship between the price level and the volume of production. The adequacy of the constructed theoretical model is proved based on aggregated data that eliminated the influence of incompleteness of the initial information. As a result, it was established that livestock production is characterized by time-distributed changes in prices and quantity of products, which makes it possible to assess its dynamics using both chain indices and symmetric indices. It is proved that the dynamics of crop production cannot be adequately described using chain indices, since a positive correlation of prices of the previous period and production volumes of the current period causes an overstatement of the index in comparable prices of the previous year. Based on calculations within the proposed aggregated model, it is proved that the use of constant prices as the Lowe index weights, updated every five years, is an acceptable approximation of the Fisher symmetric index. Application of the indicated methodology for calculating the index to the data on Russian agricultural production by main types of products in 1990-2018 allowed to establish an overstatement of dynamics by 11.9%. The main difference falls on crop production (+ 19.6%), while for livestock - the differences are insignificant (-0.7%).


2021 ◽  
Vol 36 ◽  
pp. 08004
Author(s):  
M.G. Manucharyan

One of the most important components of national security is food security. The country's food security is mainly ensured through the development of agriculture, food production and food import systems. The main problems of the development of the agri-food system of the republic were the increase of the level of provision of the population with food, the increase of the level of economic protection of the country, which, first of all, requires an increase of agricultural production to provide the population with locally produced food products, raw materials to the processing industry as much as possible, as well as to increase export volumes. The main goal of the research is to develop and outline the ways of further development of the RA food self-sufficiency based on the development of agricultural production. Based on the analysis of the current situation in the agricultural market, to propose a set of economic development measures, which will contribute to the increase of the food security level, the development of the agri-food system, the reduction of the poverty level of the rural communities. The research substantiated the preconditions for further growth of agricultural production, as a result of comprehensive studies and analyzes, the main directions of improving food production and increasing efficiency were outlined, which conditioned the scientific novelty.


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