A quantitative comparison of the growth, development and yield of different varieties of oilseed rape

1975 ◽  
Vol 85 (1) ◽  
pp. 159-174 ◽  
Author(s):  
E. J. Allen ◽  
D. G. Morgan
Keyword(s):  
Field Experiment ◽  
Leaf Area Index ◽  
Leaf Area ◽  
Oilseed Rape ◽  
Quantitative Comparison ◽  
Area Index ◽  
The Mean ◽  
Growth Development ◽  
The Individual ◽  
Pod Growth

SUMMARYA field experiment to compare the growth, development and yields of four varieties of oilseed rape, Cresus, Guile, Rigo and Nilla, is described and the results discussed. Cressus was the highest-yielding variety largely because it produced more pods and more seeds per pod. The numbers of pods and seeds per pod were positively correlated with the leaf area index at the onset of flowering. This suggests that the rate of supply of carbon assimilates to the inflorescences around the time of anthesis is an important yield-determining character. The mean weight of the individual seeds was greater in Cresus than Guile and this difference, which developed late on in pod growth, also contributed to the higher yields in Cresus.

scholarly journals Remote Sensing to Study Mangrove Fragmentation and Its Impacts on Leaf Area Index and Gross Primary Productivity in the South of Peninsular Malaysia

2021 ◽  
Vol 13 (8) ◽  
pp. 1427
Author(s):  
Kasturi Devi Kanniah ◽  
Chuen Siang Kang ◽  
Sahadev Sharma ◽  
A. Aldrie Amir
Keyword(s):  
Remote Sensing ◽  
Leaf Area Index ◽  
Leaf Area ◽  
Primary Productivity ◽  
Peninsular Malaysia ◽  
Area Index ◽  
Mangrove Area ◽  
The Mean ◽  
Shape Complexity ◽  
The Impact

Mangrove is classified as an important ecosystem along the shorelines of tropical and subtropical landmasses, which are being degraded at an alarming rate despite numerous international treaties having been agreed. Iskandar Malaysia (IM) is a fast-growing economic region in southern Peninsular Malaysia, where three Ramsar Sites are located. Since the beginning of the 21st century (2000–2019), a total loss of 2907.29 ha of mangrove area has been estimated based on medium-high resolution remote sensing data. This corresponds to an annual loss rate of 1.12%, which is higher than the world mangrove depletion rate. The causes of mangrove loss were identified as land conversion to urban, plantations, and aquaculture activities, where large mangrove areas were shattered into many smaller patches. Fragmentation analysis over the mangrove area shows a reduction in the mean patch size (from 105 ha to 27 ha) and an increase in the number of mangrove patches (130 to 402), edge, and shape complexity, where smaller and isolated mangrove patches were found to be related to the rapid development of IM region. The Moderate Resolution Imaging Spectro-radiometer (MODIS) Leaf Area Index (LAI) and Gross Primary Productivity (GPP) products were used to inspect the impact of fragmentation on the mangrove ecosystem process. The mean LAI and GPP of mangrove areas that had not undergone any land cover changes over the years showed an increase from 3.03 to 3.55 (LAI) and 5.81 g C m−2 to 6.73 g C m−2 (GPP), highlighting the ability of the mangrove forest to assimilate CO2 when it is not disturbed. Similarly, GPP also increased over the gained areas (from 1.88 g C m−2 to 2.78 g C m−2). Meanwhile, areas that lost mangroves, but replaced them with oil palm, had decreased mean LAI from 2.99 to 2.62. In fragmented mangrove patches an increase in GPP was recorded, and this could be due to the smaller patches (<9 ha) and their edge effects where abundance of solar radiation along the edges of the patches may increase productivity. The impact on GPP due to fragmentation is found to rely on the type of land transformation and patch characteristics (size, edge, and shape complexity). The preservation of mangrove forests in a rapidly developing region such as IM is vital to ensure ecosystem, ecology, environment, and biodiversity conservation, in addition to providing economical revenue and supporting human activities.

How forests change transit times of transpiration, evaporation and streamflow – a modeling approach

2021 ◽  
Author(s):  
Ingo Heidbüchel ◽  
Jie Yang ◽  
Jan H. Fleckenstein
Keyword(s):  
Leaf Area Index ◽  
Leaf Area ◽  
Water Cycle ◽  
Rooting Depth ◽  
Water Fluxes ◽  
Area Index ◽  
Transit Times ◽  
Physically Based ◽  
Forested Areas ◽  
The Individual

&lt;p&gt;In a recent paper we investigated how different catchment and climate properties influence transit time distributions. This was done by employing a physically-based spatially explicit 3D model in a virtual catchment running many different scenarios with different combinations of catchment and climate properties. We found that the velocity distribution of water fluxes through a catchment is more sensitive to certain properties while other factors appear less relevant. Now we expanded the approach by adding vegetation to the model and thus introducing new hydrologic processes (transpiration and evaporation) to the simulated water cycle. On the one hand we wanted to know how these new processes would influence transit times of the water fluxes to the stream, on the other hand we were interested in how exactly differences in the vegetation itself (e.g. rooting depth and leaf area index) would alter the various flux velocities (including transit times of transpiration and evaporation). It was very interesting to observe that streamflow in forested areas appeared to become older on average. We also found that transpiration was generally younger if the vegetation had shallower roots and/or a larger leaf area index. The biggest difference in the age of evaporation was detected for different amounts of subsequent precipitation (evaporation was generally younger in a wetter climate). In conclusion, we found that forests influence the age of the different water fluxes within a catchment. According to our results the overall hydrologic cycle is decelerated when adding vegetation to a model that otherwise only simulates evaporation.&lt;/p&gt;&lt;p&gt;Still, in order to make meaningful predictions on the age of hydrologic fluxes, it is not constructive to single out specific catchment and climate properties. The multitude of influences from different parameters makes it very challenging to find rules and underlying principles in the integrated catchment response. Therefore it is necessary to look at the individual parameters and their potential interactions and interdependencies in a bottom-up approach.&lt;/p&gt;

scholarly journals Management of Anthracnose in Common Bean by Foliar Sprays of Potassium Silicate, Sodium Molybdate, and Fungicide

Plant Disease ◽  
2014 ◽  
Vol 98 (1) ◽  
pp. 84-89 ◽  
Author(s):  
L. R. Polanco ◽  
F. A. Rodrigues ◽  
E. N. Moreira ◽  
H. S. S. Duarte ◽  
I. S. Cacique ◽  
...  
Keyword(s):  
Leaf Area Index ◽  
Leaf Area ◽  
Sodium Molybdate ◽  
Potassium Silicate ◽  
Colletotrichum Lindemuthianum ◽  
Area Index ◽  
Healthy Leaf ◽  
Foliar Sprays ◽  
The Mean ◽  
Spray Treatment

This study aimed to determine whether foliar sprays of potassium silicate (KSi), sodium molybdate (NaMo), or a combination of both (KSi + NaMo), with or without the fungicide azoxystrobin (Azox), could reduce anthracnose symptoms and, consequently increase yield. Two two-by-four factorial experiments, consisting of untreated or fungicide treated, as well as sprays of KSi, NaMo, KSi + NaMo, and no spray (control), were arranged in a randomized block design with three replications. Treatments were as follows: treatment 1, KSi spray; treatment 2, NaMo spray; treatment 3, KSi + NaMo spray; treatment 4, Azox spray; treatment 5, Azox + KSi spray; treatment 6, Azox + NaMo spray, treatment 7, Azox + KSi + NaMo spray; and treatment 8, control (no KSi, NaMo, or Azox). The KSi, NaMo, and Azox treatments were sprayed at the rates of 35 g/liter, 90 g/ha, and 120 g a.i./ha, respectively. The KSi was applied at 20, 27, 40, and 55 days after sowing (das). The NaMo was sprayed only at 27 das whereas the fungicide was sprayed at 27, 40, and 55 das. Plants were inoculated with Colletotrichum lindemuthianum at 23 das. Azox reduced the mean area under disease progress curve (AUDPC) by 63% and mean yield was increased by 150%. Similarly, the mean AUDPC was reduced by 29, 14, and 41% with KSi, NaMo, and KSi + NaMo sprays, respectively, while mean yield increased by 13, 20, and 47%, with KSi, NaMo, or KSi + NaMo sprays, respectively. The variables leaf area index (LAI), leaf area index duration (LAD), healthy leaf area duration (HAD), and radiation intercepted (RI) were not affected by KSi spray. The values for the variables LAI, healthy leaf area index (HLAI), LAD, HAD, RI, intercepted radiation of the healthy leaf area, and healthy leaf area absorption were significantly increased as a result of NaMo spray. The results of the present study support the novel possibility of using a foliar spray of KSi in association with NaMo to decrease anthracnose symptoms in bean plants and, consequently, achieve greater yield.

scholarly journals The effect of different crops and slopes on runoff and soil erosion

2020 ◽  
Vol 15 (3) ◽  
pp. 773-780
Author(s):  
Jinhua Gao ◽  
Yu Bai ◽  
Haifeng Cui ◽  
Yu Zhang
Keyword(s):  
Soil Erosion ◽  
Field Experiment ◽  
Leaf Area Index ◽  
Leaf Area ◽  
Environmental Issues ◽  
Area Index ◽  
The Impact

Abstract Runoff and soil erosion are serious environmental issues in farmland management. In a field experiment in Xingmu, China, data from nine plots with different slopes and crops were collected, and the crops' leaf area index (LAI) used to represent the impact of vegetation on runoff and soil erosion. The results show that slope and crop both have significant effects on runoff and soil erosion, and that the LAI can indicate the effects of different crops.

scholarly journals EVALUATION OF SIMPLE HAND-HELD MECHANICAL SYSTEMS FOR HARVESTING TEA (CAMELLIA SINENSIS)

2006 ◽  
Vol 42 (2) ◽  
pp. 165-187 ◽  
Author(s):  
P. J. BURGESS ◽  
M. K. V. CARR ◽  
F. C. S. MIZAMBWA ◽  
D. J. NIXON ◽  
J. LUGUSI ◽  
...  
Keyword(s):  
Leaf Area Index ◽  
Leaf Area ◽  
Camellia Sinensis ◽  
Step Height ◽  
Area Index ◽  
Yield Increase ◽  
Coarse Material ◽  
Terminal Bud ◽  
The Mean

Over an eight-year period, harvesting methods based on simple mechanical aids (blade and shear) were evaluated against hand harvesting on mature morphologically contrasting tea clones in Southern Tanzania. The effects of shear step height (5–32 mm) and the harvest interval (1.8–4.2 phyllochrons) were also examined. Except in the year following pruning, large annual yields (5.7–7.9 t dry tea ha−1) were obtained by hand harvesting at intervals of two phyllochrons. For clones K35 (large shoots) and T207 (small shoots), the mean harvested shoot weights were equivalent to three unfurled leaves and a terminal bud. The proportions of broken shoots (40–48 %) and coarse material (4–6 %) were both relatively high. Using a blade resulted in similar yields to hand harvesting from K35 but larger yields from T207 (+13 %). The yield increase from clone T207 was associated with the harvest of more shoots and heavier shoots, smaller increases in canopy height, and a higher proportion (7–9 %) of coarse material compared to hand harvesting. On bushes, which had been harvested by hand for two years following pruning, using flat shears (no step) supported on the tea canopy resulted, over a three year period, in yields 8–14 % less than those obtained by hand harvesting and, for clone K35, a reduction in the leaf area index to below 5. The development of a larger leaf area index is made possible by adding a step to the shear. However, since annual yields were reduced by 40–50 kg ha−1 per mm increase in step height, the step should be the minimum necessary to maintain long-term bush productivity. As mean shoot weights following shear harvesting were about 13 % below those obtained by hand harvesting, there is scope, when using shears, to extend the harvest interval from 2 to 2.5 phyllochrons.

scholarly journals Monitoring leaf area index at watershed level through NDVI from Landsat-7/ETM+ data

2004 ◽  
Vol 61 (3) ◽  
pp. 243-252 ◽  
Author(s):  
Alexandre Cândido Xavier ◽  
Carlos Alberto Vettorazzi
Keyword(s):  
Leaf Area Index ◽  
Leaf Area ◽  
Vegetation Index ◽  
Hydrological Cycle ◽  
Riparian Forest ◽  
Empirical Relationships ◽  
Area Index ◽  
Landsat 7 ◽  
The Mean ◽  
The Relationship

Leaf area index (LAI) is an important parameter of the vegetation canopy, and is used, for instance, to estimate evapotranspiration, an important component of the hydrological cycle. This work analyzed the relationship between LAI, measured in field, and NDVI from four dates (derived from Landsat-7/ETM+ data), and with such vegetation index, to generate and analyze LAI maps of the study area for the diverse dates. LAI data were collected monthly in the field with LAI-2000 equipment in stands of sugar cane, pasture, corn, eucalypt, and riparian forest. The relationships between LAI and NDVI were adjusted by a potential model; 57% to 72% of the NDVI variance were explained by the LAI. LAI maps generated by empirical relationships between LAI and NDVI showed reasonable precision (standard error of LAI estimate ranged from 0.42 to 0.87 m² m-2). The mean LAI value of each monthly LAI map was shown to be related to the total precipitation in the three previous months.

Yielding of Asparagus Depending on Harvest Ending Date

2010 ◽  
Vol 73 (1) ◽  
pp. 67-75
Author(s):  
Mikołaj Knaflewski ◽  
Włodzimierz Krzesiński ◽  
Monika Gąsecka ◽  
Jerzy Stachowiak
Keyword(s):  
Field Experiment ◽  
Leaf Area Index ◽  
Leaf Area ◽  
Cross Section ◽  
Significant Influence ◽  
Light Absorption ◽  
Harvest Time ◽  
Storage Roots ◽  
Area Index

Yielding of Asparagus Depending on Harvest Ending DateThe field experiment focused on the determination of yielding of asparagus cv. ‘Thielim’ in relation to harvest duration: traditional (until June 20th), shortened (June 10th) and prolonged (30thJune) harvests. The variation in harvest ending dates did not have a significant influence on the total, marketable and non-marketable yields as well as on the crown weight and the number of storage roots. However, the extension of harvest time until June 30thresulted in an increase in the number of spears in the total and marketable yields, accompanied by a decrease in their diameter. Also prolonging harvest affected negatively the summer stalk size. During harvest until June 10thasparagus plants probably did not use their full yielding potential, because of too short harvest time. It resulted in increased height, weight, light absorption of summer stalks, leaf area index (LAI) and the total of cross-section areas of summer stalks (PPPA) with no significant differences in yield.

scholarly journals Study of plant physiological parameters in winter oilseed rape (Brassica napus var. napus f. biennis L.) production on chernozem soil

2016 ◽  
pp. 111-115
Author(s):  
Éva Vincze ◽  
Péter Pepó
Keyword(s):  
Leaf Area Index ◽  
Leaf Area ◽  
Chlorophyll Content ◽  
Oilseed Rape ◽  
Plant Density ◽  
Sowing Date ◽  
Winter Oilseed Rape ◽  
Sowing Time ◽  
Area Index ◽  
Relative Chlorophyll Content

We made plant physiology examinations in Arkaso winter oilseed rape hybrid substance: relative chlorophyll content (SPAD) and leaf area index (LAI) measurements. The experiment was set in University of Debrecen Agricultural Sciences Center at Látóképi Experimental Station in four replications, in two different sowing times (I. sowing date on 08/22/2014 and II. sowing date on 09/09/2014 sowing againhappened because of the incomplete germination in the second subtance 01/10/2014) Three different plant density 200, 350 and 500 thousand ha-1, under the same nutrient supply, 45 cm row spacing. The experiment was green crop of winter wheat. The relative chlorophyll content (SPAD) and leaf area index (LAI) measurements were made in seven different times. We measured the maximum value of chlorophyll content in the first sowing time at 500, and the second sowing time at 350 thousand ha-1 plant density. The measurement results proved that there was a linear relationship between the number of plants and the LAI. The maximum leaf area index values we measured in both the sowing time at 500 thousand ha-1 reached.

COMPARISON OF INBRED AND HYBRID CORN GRAIN YIELD MEASURED AT EQUAL LEAF AREA INDEX

1972 ◽  
Vol 52 (3) ◽  
pp. 315-319 ◽  
Author(s):  
D. J. MAJOR ◽  
R. B. HUNTER ◽  
L. W. KANNENBERG ◽  
T. B. DAYNARD ◽  
J. W. TANNER
Keyword(s):  
Grain Yield ◽  
Leaf Area Index ◽  
Leaf Area ◽  
Plant Density ◽  
Area Index ◽  
Wide Range ◽  
The Mean ◽  
Common Plant ◽  
Single Cross Hybrids ◽  
Corn Grain

Grain yield of 44 single crosses and their component inbreds of corn (Zea mays L.) was determined over a wide range of plant populations. Yield was determined for inbreds and single cross hybrids at unit intervals of leaf area index (LAI) of 1–4. Mean inbred yield was no greater than 60% of the mean hybrid yield, regardless of whether yields were compared at a common plant density or LAI. Optimum LAI (LAI where grain yield was at its maximum) was higher for the hybrids than for the inbreds.

scholarly journals Leaf area index and radiation extinction coefficient of a coffee canopy under variable drip irrigation levels

2019 ◽  
Vol 41 ◽  
pp. e42703 ◽  
Author(s):  
Jéfferson de Oliveira Costa ◽  
Rubens Duarte Coelho ◽  
Timóteo Herculino da Silva Barros ◽  
Eusímio Felisbino Fraga Júnior ◽  
André Luís Teixeira Fernandes
Keyword(s):  
Leaf Area Index ◽  
Leaf Area ◽  
Extinction Coefficient ◽  
Drip Irrigation ◽  
Deficit Irrigation ◽  
Area Index ◽  
Irrigation Level ◽  
Mean Error ◽  
The Mean ◽  
Irrigation Levels

The leaf area index (LAI) is relevant in studies of phenomena at different scales, such as for the leaf to canopy scale and the calculation of the extinction coefficient of photosynthetically active radiation (kPAR), providing input for the parameterization of physiological basis models. The objective of this work was to verify the variation of the LAI and the coffee kPAR subjected to different drip irrigation levels (130, 100, 70, and 40%) and to compare the data obtained from radiation bar linear sensors (SunScan) in the plants that received full irrigation with the values found by other LAI estimation methodologies. The study was conducted in Piracicaba, São Paulo State, Brazil, using the species Coffea arabica cv. Red Catuaí IAC 144; a drip irrigation system was adopted, with the irrigation controlled by tensiometry. The mean LAI values were higher in the L130 (irrigation level of 130%) and L100 (irrigation level of 100%) treatments than those with deficit irrigation depths. The mean kPAR values were lower for the L130 and L100 treatments than the values found in the deficit irrigation depth treatments. When comparing SunScan to other methodologies, the mean error (ME) and absolute mean error (AME) were high.

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