scholarly journals Morphophysiology of ornamental sunflower plant irrigated with saline water and application of silicon

2020 ◽  
pp. 1427-1432
Author(s):  
Lunara de Sousa Alves ◽  
Mário Leno Martins Véras ◽  
Nelto Almeida de Sousa ◽  
Fernanda Ferreira de Araújo ◽  
Edinete Nunes de Melo ◽  
...  

The use of saline water in agriculture is an alternative, especially in regions with water scarcity, such as the Brazilian Northeast semiarid. However, salt stress considerably reduces plant growth and development. In this sense, the objective was to evaluate the morphophysiological responses of the ornamental sunflower irrigated with saline water under application of silicon. The experimental design was entirely randomized conducted in a factorial 4 x 5 with 6 replicates, related to four electrical conductivity of the irrigation water (ECw): 0.5; 1.5; 2.5 and 3.5 dS m-1 five silicon rates: 0, 50, 100, 150 and 200 mg L-1, proceeding to the evaluation of: plant height, stem diameter, number of leaves, absolute and relative growth rates, initial fluorescence, maximum fluorescence, variable fluorescence, maximum efficiency of the photochemical process in FSII, potential quantum yield of photosystem II, stomatal conductance and instant efficiency in the use of water. The gradual increase of ECw reduces growth, chlorophyll fluorescence a and stomatal opening of the ornamental sunflower plants. The application of silicon above 100 mg L-1 promotes a decrease in ornamental sunflower stomatal conductance. It is recommended to irrigate ornamental sunflower plants with water of 0.5 dS m-1 associated with the application of 100 mg L-1 of silicon.

1958 ◽  
Vol 51 (3) ◽  
pp. 347-352 ◽  
Author(s):  
R. H. M. Langer

1. Swards of S. 48 timothy and S. 215 meadow fescue growing alone or together were sampled at intervals of 3 weeks throughout the season. The number and weight of leaves, stems and ears were determined, and leaf area was estimated.2. Despite high rainfall, the total number of tillers in both species declined from the beginning of the experiment until early July, but increased again from then onwards until the original complement had been approximately restored. The number of leaves failed to show a corresponding increase in the autumn because each tiller carried fewer leaves than earlier in the year.3. In the spring total dry weight increased more rapidly in meadow fescue than in timothy which in turn out-yielded meadow fescue later in the season. Both species attained their greatest dry weight soon after ear emergence, a period which was marked by considerable crop growth and relative growth rates.4. Leaf area index reached a maximum before total dry weight had increased to its highest level, but then declined in both species. Meadow fescue differed from timothy by producing a second crop of foliage after the summer with a leaf area index of about 7. This second rise appeared to be due mainly to increased leaf size in contrast to timothy whose leaves became progressively smaller towards the end of the season.5. The differences in growth between the species discussed with reference to their dates of ear emergence which in this experiment differed by about 6 weeks.


2018 ◽  
Vol 10 (5) ◽  
pp. 188 ◽  
Author(s):  
Jailton G. Ramos ◽  
Vera Lucia A. de Lima ◽  
Eliton S. G. Santos ◽  
Gibran O. de Medeiros ◽  
Mariana De O. Pereira ◽  
...  

The agricultural reuse of wastewater is already a reality in several countries of the world. The objective of this work was to evaluate the growth of hybrid corn AG 1051 grown in fertilized soil via the foundation and fertirrigation with the combination of human urine and treated cassava and NPK in protected environment.The experiment was conducted at the Federal University of Campina Grande, Campina Grande, Paraíba. The experimental design was the completely randomized one with 14 treatments and four replications, being two experiments, one fertilized via foundation and the other via fertigation. The treatments were as follows: T1 (NPK), T2 (470 mL), T3 (670 mL), T4 (870 mL), T5 (1070 mL), T6 (1270 mL), T7 (1470 mL) applied via fertilization of fertirrigado, and the same dosages applied via fertirrigation corresponding to T9 mineral fertilization, and T10, T11, T13 and T14 the different doses of organic fertilization. There was an average increase of 17.32% in the Index of Emergency Speed for the seeds that were cultivated in soil fertilized with T3 and T4 in relation to the one fertilized with NPK (T1), the soil fertilized with T3 was the one that presented the highest %E (Emergency Percentage) with 98, 81%. At 15 days after the emergency (DAE), the chemical fertilization through the foundation promoted greater leaf area gain differently than at 65 DAE. The organic fertilization via fertigation promoted the highest gains for absolute and relative growth rates of plant height stem diameter and number of leaves.


2008 ◽  
Vol 24 (1) ◽  
pp. 19-26 ◽  
Author(s):  
Joseph B. Yavitt ◽  
S. Joseph Wright

Abstract:We irrigated and fertilized (with nutrients) seedlings of Doliocarpus olivaceus (Dilleniaceae, a shade-tolerant liana), Faramea occidentalis (Rubiaceae, a shade-tolerant understorey tree) and Tetragastris panamensis (Burseraceae, a shade-tolerant canopy tree) growing in the understorey of an old-growth tropical moist forest in Panama to assess the impact of seasonal water availability and nutrient-poor soils on seedling growth rates. In control plots, height growth rates were greater in the dry season than in the wet season for Doliocarpus (21%) and for Faramea (89%), whereas Tetragastris had similar seasonal rates. For numbers of leaves, Faramea had 3.5-fold greater relative growth rates in the dry season than in the wet season, while Doliocarpus and Tetragastris lost leaves (semi-deciduous) during the same period. Irrigation and nutrient augmentation increased height growth rates for all three species (45% to 272%). For Doliocarpus, irrigation and nutrient augmentation prevented leaf fall during the dry season. For Faramea in the dry season, irrigation and nutrient augmentation when applied independently reduced the growth of new leaves by 65% to 87%, but relative growth rates for number of leaves were the same as the control rates in the combined irrigation and nutrient augmentation treatment. The growth of new leaves for Tetragastris responded to dry-season irrigation but not nutrient augmentation. Although all measurements occurred beneath the forest canopy, during the dry season, Tetragastris had a negative relationship between canopy openness and relative growth rate for number of leaves, whereas the other two species had a positive relationship. Our results show that soil resources influence growth rates even in the deep shade of the forest understorey, and demonstrate different responses to soil resources among species that might contribute to niche differentiation and species coexistence.


1961 ◽  
Vol 1 (2) ◽  
pp. 49-54
Author(s):  
S. U. Khan

It is sometimes said that "national planning will simply have no meaning if it completely ignores the economic disparities between the two wings and fails to evolve a sensible pattern of regional planning"2. The lack of much essential data on a regional basis, however, renders any precise estimate of the relative growth rates almost impossible. Data either are not available or are inadequate on such important variables as production, income, consumption and trade, so that even a correct evaluation of past development efforts is not possible. The implications of such a situation for future planning are not difficult to understand. In this article an attempt is made to estimate the absorption of specified commodities in East and West Pakistan separately3. This will indicate the pattern of consumption and also give a rough idea about the growth rate of the two wings. With this purpose in view, quantity indices of absorption are prepared for each wing separately, taking data on availability of goods and prices from the Institute's monograph on Inflation. The quantity indi¬ces, however, are not of course strictly comparable with national income estimates because of the difference in coverage of the two series. National income data include government, services, trade, etc., while the quantity indices cover only specified goods available for each region.


HortScience ◽  
1990 ◽  
Vol 25 (9) ◽  
pp. 1091G-1091
Author(s):  
Anne K. Hurley ◽  
B. Greg Cobb

Cucumis sativus, L., `Poinsett' seedlings were grown under artificial light in 40% modified Hoagland's solution until an average plant plastochron index of 4.73 was reached. Plants were then placed in solutions of (1) 0 mM NaCl, (2) 80 mM NaCl (salt-shock), or (3) placed in a dropwise gradient solution of NaCl and Hoagland's until the final concentration of 80 mM NaCl was reached at 41 hours. Leaves of the 80 mM shock treatment wilted immediately, but recovered turgor within 6 hours. Leaves of 80 mM gradient did not wilt at anytime. The control and gradient treatments had relative growth rates which were similar to each other, but RGR decreased in the shock treatment. Invertase activity was measured in the roots at 24, 41, and 48 hours after initial treatment. Invertase activity of shock treatment increased significantly over the controls at 24 hours. The 80mM gradient was not significantly different than either treatment. Four isozymes of α– galactosidase were detected. The relative intensities of the bands varied with time and treatment. One invertase band was resolved in roots on 8% native acrylamide gels. SDS gels indicated increases in proteins in the gradient treatment compared to the control and the 80 mM shock treatment.


1979 ◽  
Vol 69 (1) ◽  
pp. 141-148 ◽  
Author(s):  
A. Mudd ◽  
G. L. Bateman

AbstractGrowth of the food fungus of the leaf-cutting ant Atta cephalotes (L.) on extracts of plants selected by the ants was shown to be affected by the plant species, the pH of the extract, the concentration of the sap or plant extract and pretreatment of the substrate by the ants. It was not possible to establish an unambiguous relationship between the rate of growth of the fungus on leaf extracts and the foraging preferences of the ants for the leaves. There were indications, however, that the fungus grows most rapidly on extracts of plant material preferred by A. cephalotes. Relative growth rates of the fungus on different substrates may be related to the presence of growth inhibitors rather than to nutrient availability.


1996 ◽  
Vol 26 (9) ◽  
pp. 1556-1568 ◽  
Author(s):  
Thimmappa S. Anekonda ◽  
Richard S. Criddle ◽  
Lee D. Hansen ◽  
Mike Bacca

Seventeen Eucalyptus species and 30 rapid-growing Eucalyptuscamaldulensis trees (referred to as plus trees), growing in a plantation were studied to examine relationships among measured plant growth and respiratory parameters, geographical origins, and growth climate. The respiratory parameters measured at two different temperatures by isothermal calorimetry were metabolic heat rate, rate of CO2 production, and the ratio of heat rate to CO2 rate. Metabolic heat rate was also measured as a continuous function of temperature by differential scanning calorimetry in the range of 10 to 40 °C. Tree growth was measured as rates of height and stem volume growth. The values of respiratory and growth variables of Eucalyptus species are significantly correlated with latitude and altitude of origin of their seed sources. The maximum metabolic heat rate, the temperature of the maximum heat rate, the temperature coefficients of metabolic rate, and the temperatures at which the slopes of Arrhenius plots change are all genetically determined parameters that vary both within and among species. Measurement of growth rate–respiration rate–temperature relationships guide understanding of why relative growth rates of Eucalyptus species and individual genotypes differ with climate, making it possible to identify genotypes best suited for rapid growth in different climates. The temperature dependence of respiration rates is an important factor determining relative growth rates of eucalypts in different climates. To achieve optimum biomass production the temperature dependence of individual plants must be matched to growth climate.


1967 ◽  
Vol 69 (3) ◽  
pp. 305-315 ◽  
Author(s):  
J. E. Jackson

Growth analysis of cotton crops sown in the Sudan Gezira at monthly intervals between August and May revealed a marked seasonal pattern of growth. Irrespective of plant age and fruiting state growth of non-senescent plants was slowest during the cool winter months. Relative growth rates of young plants were highest in August, September and early October due to the high specific leaf areas and fairly high net assimilation rates found then. They were lowest when minimum temperatures were lowest. Net assimilation rates were also lowest in the coolest months, probably as a result of restricted growth. High temperatures in the spring reduced fruiting. It is concluded that low minimum temperatures and high evaporation rates are both associated with slow growth, and play a large part in determining the characteristic decline of growth rates of cotton sown at the usual date in August.I wish to thank the Chief of the Research Division, Ministry of Agriculture, Sudan, for permission to publish this paper and to record my gratitude to the team of field and laboratory assistants, especially Salih Saad and Hassan Osman, who helped in the work.


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