Arid Conditions
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Sheila D. P. da Silva ◽  
Gracielle P. de Souza ◽  
Agnaldo R. de M. Chaves ◽  
Marcelle A. da Silva ◽  
Rafaela R. de Souza ◽  

ABSTRACT Knowledge of how climatic conditions affect plant morphophysiology is essential for understanding how to manage the growth cycles of different crops. The aim of this study was to evaluate the effects of the growing seasons in a semi-arid area on the morphophysiological variables of ornamental sunflower plants. The experiment was carried out in a randomized block design in a split-plot arrangement with four replicates. Six cultivars (‘Bonito de Outono Sortido’, ‘Sol Noturno’, ‘Sol Vermelho’, ‘Jardim Amarelo Alto’, ‘Girassol F1 Sunbright Supreme’ and ‘Girassol F1 Vincents Choice’) were evaluated in the main plots and two different growing seasons (GS) in the subplots (GS1 - warm climate and GS2 - mild climate). Evaluations of gas exchange, chlorophyll indices, and leaf surface area were carried out at the reproductive stage (R5.5). The cultivation of ornamental sunflowers in semi-arid regions was significantly affected by the growing season. Changes in gas exchange variables and the morphophysiology of ornamental sunflower plants in the two growing seasons reflected the high phenotypic plasticity characteristic of this species. The cultivation of ornamental sunflowers under semi-arid conditions in the growing season, when air temperature and solar radiation are high, could be limited due to elevated transpiration rates. Therefore, it is recommended that they are grown mainly during the moderate climatic season in semi-arid regions.

2022 ◽  
Vol 260 ◽  
pp. 107278
Darley de Araújo Nascimento ◽  
Alexsandro dos Santos Brito ◽  
Luiz Mariano Neves da Silva ◽  
Leandro Santos Peixouto ◽  
Vanessa Fernandes Cotrim

2022 ◽  
Vol 12 (1) ◽  
Michael Spate ◽  
Mumtaz A. Yatoo ◽  
Dan Penny ◽  
Mohammad Ajmal Shah ◽  
Alison Betts

AbstractA growing body of archaeological research on agro-pastoralist populations of the Inner Asian mountains indicates that these groups adapted various systems of mobile herding and cultivation to ecotopes across the region from as early as 5000 BP. It has been argued that these adaptations allowed the development of flexible social-ecological systems well suited to the long-term management of these mountain landscapes. At present, less attention has been paid to examining the long-term ecological legacy of these adaptations within the sedimentary or palaeoenvironmental record. Here we present sediment, palynomorph and charcoal data that we interpret as indicating agro-pastoralist environmental perturbations, taken from three cores at middle and high altitudes in the Kashmir Valley at the southern end of the Inner Asian mountains. Our data indicate spatially and temporally discontinuous patterns of agro-pastoralist land use beginning close to 4000 BP. Periods of intensification of upland herding are often coincident with phases of regional social or environmental change, in particular we find the strongest signals for agro-pastoralism in the environmental record contemporary with regionally arid conditions. These patterns support previous arguments that specialised agro-pastoralist ecologies across the region are well placed to respond to past and future climate deteriorations. Our data indicating long-term co-evolution of humans and landscape in the study area also have implications for the ongoing management of environments generally perceived as “pristine” or “wilderness”.

2022 ◽  
Vol 16 (4) ◽  
pp. 19-23
Natal'ya Kudryashova ◽  
Galina Bulahtina ◽  
Aleksandr Kudryashov ◽  
Andrey Hyupinin

In recent years, livestock farms in the Astrakhan region have mainly used grasses from natural hayfields and pastures for fodder. But, due to the sharp aridization of the climate, and, as a consequence, the more frequent droughts, as well as the unregulated growth of the number of animals on farms, the reserves of natural herbage are often insufficient. Therefore, the region began to increase the area of sown hayfields for irrigation. The aim of the work is to study the effect of various irrigation methods on the productivity of cereal-leguminous mixtures with multi-cut use in the conditions of light chestnut soils of the Northern Caspian region. The studies were carried out in 2017-2020 in the Astrakhan region. All studied irrigation methods (sprinkler irrigation, drip irrigation with a belt laying depth of 0.0, 0.15, 0.25, 0.35 and 0.45 m, periodic flooding), with the exception of subsoil irrigation, with an ordinary method of sowing contributed to the development of both cereals and legumes. In these variants of the experiment, cereals occupied a significant part in the total herbage - from 40.0 to 61.0%. When using the spread sowing method, only in one variant, the share of cereal grasses was 54.0% (periodic flooding). In all others with this method of sowing, the amount of cereals in the total mass was insignificant, or they were completely absent. The widespread method of sowing was also the most productive in all the years of research. The maximum yield in the experiment was noted in all variants of the experiment in the third year of the life of grasses in 2019.The highest productivity with the spread method of sowing was noted in 2019 in the variants of the experiment with a belt laying depth of 0.25, 0.35 and 0.45 m and amounted to 98.1, 104.4 and 111.0 t/ha, respectively. In the variants with the row-sowing method, the yield was lower than with the wide-spread one. The highest yield with this method of sowing was also noted in 2019 in variants with subsurface drip irrigation with a belt laying depth of 0.35 and 0.45 m and amounted to 105.5 and 104.8 t/ha, respectively

2022 ◽  
Ha Nguyen ◽  
Cornelius Gropp ◽  
Anna Möckel ◽  
Nikita Hanikel ◽  
Alicia Lund ◽  

We report a retrosynthetic strategy and its implementation to making covalent organic frameworks (COFs) with irreversible hydrazide and diazole (oxadiazole and thiadiozole) linkages. This involved the synthesis of a series of 2D and 3D hydrazine-linked frameworks, followed by their oxidation and dehydrative cyclization. Each linkage synthesis and functional group transformation—hydrazine, hydrazide, oxadiazole, and thiadia-zole—was evidenced by 15N multi-CP-MAS NMR. In addition, the isothermal water uptake profiles of these frameworks were studied, leading to the discovery that one hydrazide-linked COF is suitable for water harvest-ing from air in arid conditions. These COFs displayed characteristic S-shaped water sorption profiles, a steep pore-filling step below 18% relative humidity at 25 °C, and a total uptake capacity of 0.45 g g–1 at P/Psat = 0.95. In addition, a total of ten 2D and 3D structures with various such linkages were studies for their affinity to water. We found that even small changes made on the molecular level can lead to major differences in the water isotherm profiles and therefore pointing to the utility of water sorption analysis as a complementary analytical tool to study linkage transformations.

2021 ◽  
Vol 12 (6) ◽  
pp. 725-730
Guendouz Ali ◽  
Hannachi Abderrahmane ◽  
Fellahi Zine El Abidine ◽  
Benalia Frih ◽  

Breeders are permanently looking for an efficient method of developing genotypes with improved yield. The aim of this study was to evaluate the performance of some durum wheat genotypes, the study of the correlations between traits and the direct effect of each trait on final grain yield. Twenty genotypes of durum wheat (Triticum durum Desf.) were planted in the experimental fields of INRAA, Setif, Algeria in (2016 –2017) crop season. The genotypes tested were grown in a randomized block design with three replications. The analyses of variance (ANOVA) demonstrate the existence of genetic diversity between genotypes tested. In addition, significant and positive correlations were registered between grain yield (GY) and days to heading (DH), number of spikes per square meter (NSM) and number of kernels per spike (NKS). The path analysis (PA) demonstrates positive and significant direct effects of the number of spikes per square meter (NSM), thousand kernels weight (TKW) and number of kernels per spike (NKS) on grain yield. Overall, the results proved that the genotypes Rezzak, Ofanto and BIDI 17 have the best ranking with the highest grain yield, and these can be recommended as the best genotypes for some in this area. In addition, the Principal Component Analysis (PCA) proved that the genotypes Rezzak, Bidi17, Ofanto, Kebir and Adnan 2 are very suitable genotypes for growing under semi-arid conditions.

2021 ◽  
Vol 11 (3) ◽  
pp. 295-301
Leslie Velarde-Apaza ◽  
Issaak Vásquez-Romero ◽  
Joao De Souza-Pacheco ◽  
Richard Solórzano-Acosta ◽  
Guido Sarmiento-Sarmiento

Я.П. Татьяна

Целью исследований являлась оценка коллекционного материала рыжика озимого по урожайности и основным параметрам адаптивности. Исследования проводили в лесостепной зоне Пензенской области в 2018–2020 гг. Объектом исследований являлись образцы рыжика озимого, различного эколого-географического происхождения. В качестве стандарта использовали сорт Барон, селекции Пензенского НИИСХ. Вегетационный период озимого рыжика в 2018 году протекал в острозасушливых условиях при ГТК=0,40. Условия вегетации в 2019 году характеризовались как засушливые, ГТК составил 0,63 единицы, сумма осадков за период составила 98,1 мм. Вегетация рыжика в 2020 году проходила при более благоприятных условиях (ГТК=1,03), сумма осадков составила 147,4 мм при температуре 19,4°С. Урожайность сортообразцов озимого рыжика, за годы исследований, варьировала в широких пределах от 130,9 до 157,2 г/м2 . Наиболее высокая продуктивность отмечена у номеров к-4164 (153,0 г/м2 ), к-4169 (153,1 г/м2 ) и к-3290 (157,2 г/м2 ), которая существенно превышала сорт Барон (на 8,7-12,9 г/м). Наибольшей экологической адаптивностью отличались образцы к-3290 (Алтайский край), к-1553 (Армения), к-4169 (Чехословакия) и сорт Барон, значения которого составили bi=0,96-1,02 и S2 d1 = 0,08-0,11. Номера к-4155, к-2224 и к-3290 отличались наибольшей стабильностью и пластичностью, показатели индекса стабильности (ИС) и индекса экологической пластичности (ИЭП) которых составили 17,4-18,8% и 1,04- 1,08. Наибольшим значением уровня стабильности сорта (ПУСС) отличались образцы к-4169, к-4164 и к-1553, значения которых составили 1,40, 1,41 и 1,46 соответственно. Число стручков на растении у сортообразцов варьировало от 151 до 287 штук, при 251 штуке на растении у сорта Барон. Количество семян в стручке варьировало в пределах 13-18 штук, масса 1000 семян в пределах 1,05-1,42 г. Наиболее крупные семена были у номеров к-4165 и к-3290, масса 1000 семян которых составила 1,40 и 1,42 г соответственно. The aim of the research was to assess the collection material of winter camelina in terms of yield and main parameters of adaptability. The studies were carried out in the forest-steppe zone of the Penza region in 2018 - 2020.The object of research was samples of winter camelina of various ecological and geographical origin. Variety Baron, selection of the Penza Research Institute of Agriculture, was used as a standard. The growing season of winter camelina in 2018 proceeded in severely arid conditions with GTC=0.40. The growing conditions in 2019 were characterized as arid, the GTC was 0.63 units, the amount of precipitation for the period was 98.1 mm. Camelina vegetation in 2020 took place under more favorable conditions (GTC=1.03), the amount of precipitation was 147.4 mm at a temperature of 19.4°C. The yield of varieties of winter camelina, over the years of research, varied widely from 130.9 to 157.2 g/m2 .The highest productivity was noted for numbers k-4164 (153.0 g/m2 ), k-4169 (153.1 g/m2 ) and k-3290 (157.2 g/m2 ), which significantly exceeded the Baron variety by (8,7-12.9 g/m)2 . Samples k-3290 (Altai Territory), k-1553 (Armenia), k-4169 (Czechoslovakia) and variety Baron were characterized by the highest ecological adaptability, the values of which were bi=0.96- 1.02 and S2 d1 =0,08-0.11.The numbers k-4155, k-2224 and k-3290 were distinguished by the greatest stability and plasticity, the indicators of the stability index (IS) and the environmental plasticity index (IEP) of which were 17.4-18.8% and 1.04-1.08%. Samples k-4169, k-4164 and k-1553 were distinguished by the highest value of the level of stability of the variety (PUSS), the value of which was 1.40, 1.41 and 1.46, respectively. The number of pods per plant in the accessions varied from 151 to 287 pods, with 251 pods per plant in the Baron variety. The number of seeds in a pod varied within 13-18 pieces, the weight of 1000 seeds was within 1.05-1.42 g. The largest seeds were for numbers k-4165 and k-3290, the weight of 1000 seeds of which was 1.40 and 1.42 g, respectively.

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