scholarly journals Effects of Potassium Management on Physiological Traiats, Enzyme Activity and Cotton Fiber Cellulose Content

2021 ◽  
Author(s):  
Fábio Echer ◽  
Vinicius José Souza Perez ◽  
Giuliano Oliveira Carnevalli Baltazar ◽  
Gustavo Ricardo Aguiar Silva ◽  
Adriana Lima Moro ◽  
...  
Keyword(s):  
Enzyme Activity ◽  
Stomatal Conductance ◽  
Leaf Area Index ◽  
Leaf Area ◽  
Cover Crops ◽  
Cotton Fiber ◽  
Cover Crop ◽  
Nutrient Use Efficiency ◽  
Cellulose Content ◽  
Area Index

Abstract AimsPotassium (K) is prone to be washed out of plant tissues independent of mineralization since it is not strongly bound to organic structures in the plant. Therefore, cover crops can enhance K cycling in cropping systems increasing the nutrient use efficiency by taking it up deep in the soil profile and releasing it on the soil surface. However, it is not clear if this cycling would have an effect on cotton morphophysiology, enzyme activity, and eventually on fiber quality. MethodsPotassium was applied to two cotton cultivars, either to the cover crop ruzigrass (Urochloa ruzisiensis), or to cotton grown after the grass or not, and split between the cover crop and cotton. ResultsCotton leaf area index was increased late in the season by K, with small differences between fertilized treatments, but was highest at full bloom when at least part of the K was applied to cotton. Stomatal conductance was improved, mainly late in the season and when cotton was grown after ruzigrass. Consequently, the enzymatic activity and accumulation of cellulose in the cotton fiber were also increased. ConclusionPotassium fertilization improves cotton physiological parameters such as leaf area index and stomatal conductance, but the effect on enzyme activity depends on the enzyme and on the cotton cultivar. Early cellulose accumulation in the fiber is favored by potassium fertilization and cotton rotation with ruzigrass.

scholarly journals (12) Influence of Single and Biculture Cover Crops with or without Synthetic Nitrogen on Leaf Area Index and Above Ground Biomass Yields of Sweet Corn

HortScience ◽  
2006 ◽  
Vol 41 (4) ◽  
pp. 1063B-1063
Author(s):  
Wayne F. Whitehead ◽  
Bharat P. Singh
Keyword(s):  
Leaf Area Index ◽  
Leaf Area ◽  
Cover Crops ◽  
Cover Crop ◽  
Sweet Corn ◽  
Dry Weight ◽  
Above Ground Biomass ◽  
Hairy Vetch ◽  
Area Index ◽  
Ground Biomass

During the 2004–05 growing season, a study was conducted to determine effect of cover crop, their mixture and fertilizer N rates on above ground biomass (AGB) yields, and Leaf Area Index (LAI) of Bt sweet corn. The following cover crop nitrogen fertility treatments were applied using randomized complete-block design with three replications: 1) fall-0 N, fallow; spring-0 N, 2) fall-0 N, abruzzi rye; spring-0 N, 3) fall-0 N, hairy vetch; spring-0 N, 4) fall-0 N, abruzzi rye+hairy vetch; spring-0 N, 5) fall-0 N, fallow; spring-101 kg N/ha, 6) fall-0 N, abruzzi rye; spring-101 kg N/ha, 7) fall-0 N, hairy vetch; spring-101 kg N/ha, 8) fall-0 N, abruzzi rye+hairy vetch; spring-101 kg N/ha, 9) fall-0 N, fallow; spring-202 kg N/ha, 10) fall-0 N, abruzzi rye; spring-202 kg N/ha, 11) fall-0 N, hairy vetch; spring-202 kg N/ha, and 12) fall-0 N, abruzzi rye+hairy vetch; spring-202 kg N/ha. In Spring 2005, `Attribute BSS0977' bi-color (BC) supersweet (sh2) corn seeds were field planted. AGB yields were collected during harvest week while LAI was recorded at tasseling (6/27), silking (7/8) and one week after harvest (7/25). Hairy vetch; spring-101 kg N/ha produced highest LAI at tasseling (2.18), silking (2.73), and one week after harvest (2.57). Lowest LAI at tasseling (1.12) and silking(1.60) were produced by abruzzi rye; spring-0 N with fallow; spring-0 N producing lowest LAI (1.40) one week after harvest. Maximum AGB fresh (40.5 Mg/ha) and dry weight (12.1 Mg/ha) yields were produced by hairy vetch; spring-101kg N/ha, while minimum AGB fresh (9.6 Mg/ha) and dry weight (3.6 Mg/ha) yields were produced by abruzzi rye; spring-0 N. Results imply LAI at each growth stage and AGB yields of this BCsh2 corn variety are best supported by hairy vetch supplemented with N at 101 kg/ha.

scholarly journals A Canopy Transpiration Model Based on Scaling Up Stomatal Conductance and Radiation Interception as Affected by Leaf Area Index

Water ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 252
Author(s):  
Muhammad Shahinur Alam ◽  
David William Lamb ◽  
Nigel W. M. Warwick
Keyword(s):  
Stomatal Conductance ◽  
Leaf Area Index ◽  
Leaf Area ◽  
Festuca Arundinacea ◽  
Radiation Energy ◽  
Scaling Up ◽  
Controlled Environment ◽  
Canopy Conductance ◽  
Individual Layer ◽  
Area Index

Estimating transpiration as an individual component of canopy evapotranspiration using a theoretical approach is extremely useful as it eliminates the complexity involved in partitioning evapotranspiration. A model to predict transpiration based on radiation intercepted at various levels of canopy leaf area index (LAI) was developed in a controlled environment using a pasture species, tall fescue (Festuca arundinacea var. Demeter). The canopy was assumed to be a composite of two indistinct layers defined as sunlit and shaded; the proportion of which was calculated by utilizing a weighted model (W model). The radiation energy utilized by each layer was calculated from the PAR at the top of the canopy and the fraction of absorbed photosynthetically active radiation (fAPAR) corresponding to the LAI of the sunlit and shaded layers. A relationship between LAI and fAPAR was also established for this specific canopy to aid the calculation of energy interception. Canopy conductance was estimated from scaling up of stomatal conductance measured at the individual leaf level. Other environmental factors that drive transpiration were monitored accordingly for each individual layer. The Penman–Monteith and Jarvis evapotranspiration models were used as the basis to construct a modified transpiration model suitable for controlled environment conditions. Specially, constructed self-watering tubs were used to measure actual transpiration to validate the model output. The model provided good agreement of measured transpiration (actual transpiration = 0.96 × calculated transpiration, R2 = 0.98; p < 0.001) with the predicted values. This was particularly so at lower LAIs. Probable reasons for the discrepancy at higher LAI are explained. Both the predicted and experimental transpiration varied from 0.21 to 0.56 mm h−1 for the range of available LAIs. The physical proportion of the shaded layer exceeded that of the sunlit layer near LAI of 3.0, however, the contribution of the sunlit layer to the total transpiration remains higher throughout the entire growing season.

scholarly journals WOOD-DERIVED BIOCHAR INFLUENCES NUTRIENT USE EFFICIENCY OF HEAVY METALS IN SPINACH (SPINACIA OLERACEA) UNDER GROUNDWATER AND WASTEWATER IRRIGATION

2019 ◽  
Vol 27 (3) ◽  
pp. 144-152 ◽  
Author(s):  
Sadaf Aslam Ghori ◽  
Shamim Gul ◽  
Saniya Tahir ◽  
Meenah Sohail ◽  
Saira Batool ◽  
...  
Keyword(s):  
Leaf Area Index ◽  
Leaf Area ◽  
Plant Biomass ◽  
Nutrient Use Efficiency ◽  
Wastewater Irrigation ◽  
Area Index ◽  
Nutrient Use ◽  
Groundwater Irrigation ◽  
Use Efficiency ◽  
Biochar Amendment

Present study analysed the influence of slow-pyrolyzed wood-derived biochar on growth performance and heavy metal accumulation in the leaves of spinach grown under groundwater and wastewater irrigation. Biochar was applied in soil as 5% (~30 t·ha−1) and 10% (~60 t·ha−1) amendment. According to results, plant biomass was significantly higher under wastewater than groundwater irrigation. Biochar amendment increased significantly the aboveground plant biomass and root biomass and promoted water use efficiency (WUE). Under groundwater irrigation, biochar amendment at 10% application rate, increased the leaf area index (P < 0.05), while amendment of biochar at all application rates significantly reduced leaf area index under wastewater irrigation (P < 0.05). Application of biochar also reduced accumulation of rhizosphere soil around roots under wastewater irrigation, indicating less exudate production in the rhizosphere of plants. Biochar significantly reduced the concentration of copper (Cu) in under wastewater irrigation. Biochar increased the nutrient use efficiency (NUE) of plants for zinc (Zn) and Cu under wastewater irrigation.

scholarly journals Weed Suppression by Cover Plants in the Amazonian

2019 ◽  
Vol 11 (7) ◽  
pp. 148
Author(s):  
Leandro Amorim Damasceno ◽  
José Eduardo Borges Carvalho ◽  
Francisco Alisson Xavier ◽  
Ansselmo Ferreira dos Santos ◽  
Gerlândio Suassuna Gonçalves ◽  
...  
Keyword(s):  
Leaf Area Index ◽  
Leaf Area ◽  
Cover Crops ◽  
Dry Matter ◽  
Block Design ◽  
Area Ratio ◽  
Weed Suppression ◽  
Leaf Area Ratio ◽  
Area Index ◽  
Jack Bean

The productivity of citrus plants has not reached its maximum potential due to the action of several factors that directly affect agricultural profitability. Among these factors, weed interference has a great importance since it causes a reduction in crop productivity. The aim of this study was to assess the effect of different cover crops on suppression of weeds in an orange orchard. The research was conducted in a commercial orange production area located in Rio Preto da Eva, AM, Brazil. The experimental design was a randomized block design with six treatments and four replications. Treatments were control, millet, jack bean, forage turnip, brachiaria, millet + jack bean. The evaluated characteristics were weed density, soil cover percentage, total weed dry matter, total cover plant dry matter and growth indices (leaf area index, leaf area ratio, and specific leaf area). Cover plants provided a good dry matter production and had a suppressive effect on weed growth, except for forage turnip. Brachiaria and jack bean presented the highest values of leaf area index and leaf area ratio.

Improving Seed Potato Leaf Area Index, Stomatal Conductance and Chlorophyll Accumulation Efficiency through Irrigation Water, Nitrogen and Phosphorus Nutrient Management

2016 ◽  
Vol 4 (1) ◽  
pp. 127 ◽  
Author(s):  
Gathungu Geofrey Kingori ◽  
Aguyoh Joseph Nyamori ◽  
Isutsa Dorcas Khasungu
Keyword(s):  
Stomatal Conductance ◽  
Leaf Area Index ◽  
Leaf Area ◽  
Chlorophyll Content ◽  
Seed Potato ◽  
Irrigation Water ◽  
Potato Leaf ◽  
Area Index ◽  
Water Rate ◽  
P Application

A study was conducted in a Rainshelter (RTrial) at Horticultural Research and Teaching Farm, Egerton University to determine the effect of integration of irrigation water, nitrogen (N) and phosphorus (P) application on seed potato leaf area index (LAI), stomatal conductance and chlorophyll content. The treatments arranged in a split-split plot layout in a completely randomised block design, consisted of three irrigation water rates (40%, 65% and 100% field capacity), four N rates (0, 75, 112.5 and 150 kg N/ha) supplied as urea (46% N), and four P rates (0, 50.6, 75.9, 101.2 kg P/ha) supplied as triple superphosphate, replicated three times and repeated once. During the growth leaf area, stomatal conductance, and chlorophyll content were measured. Data collected were subjected to analysis of variance and significantly different means separated using Tukey’s Studentized Range Test at P≤0.05. Leaf area index was greater with high irrigation water at 100%, N at 150 kg N/ha and P at 101.2 kg P/ha, which was 2.6 and 1.3 at 51 days after planting (DAP) and 3.5 and 3.1 at 64 DAP. Furthermore, low irrigation water rate at 40% together with low N and P rates of 0 kg N/ha and 0 kg P/ha had the least LAI, which was 0.28 and 0.19 at 51 DAP and 0.28 and 0.24 at 64 DAP both in RTrials I and II, respectively. Subjecting potato to 100% compared to 40% irrigation rate increased stomatal conductance at 87 days after planting (DAP) by 32.82 and 31.99 mmolm⁻²s⁻¹, leaf chlorophyll content index by 16.2 and 16.5, 19.8 and 19.6, and 15 and 20.3, when integrated with high compared with low N and P application rates at 59, 73 and 87 DAP, in RTrials I and II respectively. Irrespective of N and P rates LAI, stomatal conductance and chlorophyll content were significantly greater with high irrigation water at 100% followed by 65% and was lowest with 40% irrigation water rate.

scholarly journals Grafting effect on photosynthetic activity and yield of tomato under a plastic house in Colombia

2021 ◽  
Vol 74 (3) ◽  
pp. 9621-9629
Author(s):  
Jamer Alexis Ramirez Jimenez ◽  
Paulo Eduardo Ribeiro Marchiori ◽  
Oscar de Jesús Córdoba-Gaona
Keyword(s):  
Stomatal Conductance ◽  
Quantum Yield ◽  
Leaf Area Index ◽  
Leaf Area ◽  
Dry Matter ◽  
Phenological Stages ◽  
Area Index ◽  
Tomato Yield ◽  
Use Efficiency ◽  
Radiation Use

Grafting is an effective approach to improve tomato yield and for tolerance to various abiotic and biotic stresses. This technique consists of using a vigorous or resistant plant (rootstock) to replace the root system of a genotype of economic interest (scion) but susceptible to one or more stress factors. The present work aimed to evaluate the physiological and productive response of a commercial tomato scion grafted on different rootstocks in Colombia’s high-Andean region. For this purpose, a tomato cv. Libertador was grafted on two commercial (“Olimpo” and “Armada”) tomato rootstocks in a randomized complete block experimental design. Four scion×rootstock combinations were evaluated by vigor rootstock, resistant rootstock, self-grafting, and non-grafted plants. Net photosynthesis, transpiration rate, stomatal conductance, water use efficiency, and radiation use efficiency were evaluated during six phenological stages (701, 704, 706, 708, 710, and 712), according to the BBCH scale; while the leaf area index and quantum yield were analyzed in five phenological stages (except 706). The highest values of photosynthesis, stomatal conductance, water and radiation use efficiency were registered in the initial phase of the production stage (701), which tended to decline at the end of the life cycle (712). Transpiration rate was similar throughout the growth cycle. Nevertheless, vigor rootstock presented the lowest photosynthesis rate; it was superior in terms of leaf area index, leaves dry matter, and tomato yield. The quantum yield values of the photosystem II did not indicate photochemical injuries in any of the scion×rootstock combinations. The higher tomato yield was reached in vigor rootstock and was associated with a more significant accumulation of dry matter in the leaf and higher leaf area index.

RESPONSE OF CASSAVA TO PROLONGED WATER STRESS IMPOSED AT DIFFERENT STAGES OF GROWTH

2002 ◽  
Vol 38 (3) ◽  
pp. 333-350 ◽  
Author(s):  
M. A. El-Sharkawy ◽  
L. F. Cadavid
Keyword(s):  
Leaf Area Index ◽  
Leaf Area ◽  
Root Biomass ◽  
Nitrogen Concentration ◽  
Nutrient Use Efficiency ◽  
Root Production ◽  
Shoot Biomass ◽  
Area Index ◽  
Nutrient Use ◽  
Use Efficiency

A two-year field trial was conducted to study the effects of prolonged water stress on cassava (Manihot esculenta) productivity, and on nutrient uptake and use efficiency. Four contrasting cultivars were supplied with adequate fertilization and watering, except when water was excluded by covering the soil with plastic sheets for different periods, depending on treatment: from two to six months, four to eight months, or from six to twelve months after planting (early, mid-season and terminal stress respectively). Sequential harvests were made at 2, 4, 6, 8 and 12 months after planting to determine leaf area index and shoot and root biomass. At final harvest, nitrogen, phosphorus, potassium, calcium and magnesium concentrations in shoots and storage roots were determined.During both early and mid-season stress, leaf area index and shoot and root biomass were significantly smaller than those in the controls across all cultivars. After recovery from stress, leaf area index was greatly enhanced with less dry matter allocated to stems, and root yields approached those in the controls. One cultivar, CMC 40, had greater final root yield under stress treatments. Nutrient concentration in roots and shoots was less in all cultivars with early stress and resulted in higher nutrient use efficiency in all elements for root production. The same trend was observed under mid-season stress, except for nitrogen concentration, which remained unchanged.Terminal stress did not affect leaf area index, but reduced the shoot biomass in all cultivars. Final root yields were smaller than those in the controls except for CMC 40 whose final root yield was greater under stress. Nitrogen concentration was greater in root biomass but less in shoot biomass of all cultivars, resulting in lower nitrogen–use efficiency for root production. Across cultivars, only potassium- and magnesium-use efficiencies were greater than in the controls. CMC 40 was the only cultivar with consistently greater use efficiency of nitrogen, phosphorus, potassium, calcium and magnesium for root production under terminal stress. This higher nutrient use efficiency was due, mainly, to a greater root production rather than to smaller nutrient concentration. This cultivar is suitable as a gene source for improving cassava in order to maximize root production per unit nutrient extracted under stressful environmental conditions.

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