scholarly journals Impact of plant density on the canopy area index and weed infestation depending on different cultivars of winter oilseed rape (Brassica napus L., ssp. oleifera Metzg.)

2014 ◽  
Vol 69 (2) ◽  
pp. 44-54
Author(s):  
KRZYSZTOF RÓŻYŁO ◽  
EDWARD PAŁYS

One way to increase the competitiveness of crop plants against weed infestation is to adjust crop density. Introduction of new (“semi-dwarf”) cultivars of winter oilseed rape triggers a need for research in this field. A two-factor experiment evaluated the effect of plant density and winter oilseed rape (WOSR) cultivars on the canopy architecture and weed infestation of a WOSR crop as well as on the correlation between these traits. During the 2010–2012 study period, the average plant density was 38.0; 29.4; and 22.9 plants m-2 (three row spacings were used: 33, 44, and 55 cm). The oilseed rape cultivars were as follows: conventional, hybrid and “semi-dwarf” hybrid. Experimental factors did not cause significant differences in the number of weeds and their mass. However, there was a clear trend of decreasing total number of weeds in the span of 33 cm spacing than in the 44 and 55 cm. Hybrid cultivar resulted in increasing of total number of weeds in comparison to the conventional one. The differences in the assimilation area of WOSR plants per unit of ground area were significant between row spacings until the end of the flowering stage and between cultivars until the flower bud development stage. During the growth stages from the beginning of flowering until the end of pod development significant negative correlations were found between the assimilation area and the number of weeds, while the correlations between the assimilation area and the weed weight were insignificant. Insignificant correlations also occurred between the number of oilseed rape plants per unit area and the mass of weeds. The results indicate the possibility of reducing the demand for seed sowing, without requiring additional costs for weed control.  

2016 ◽  
pp. 111-115
Author(s):  
Éva Vincze ◽  
Péter Pepó

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.


2019 ◽  
Vol 65 (No. 3) ◽  
pp. 125-130 ◽  
Author(s):  
Wacław Jarecki ◽  
Jan Buczek ◽  
Dorota Bobrecka-Jamro

In this experiment, the response of winter oilseed rape cv. SY Alister F1 to diverse foliar fertilization was evaluated. Foliar fertilization with the preparation Insol 5 was applied at the following dates: control (without a foliar fertilizer); autumn; autumn + spring; autumn + twice spring; spring and twice spring. Each variant in which autumn foliar fertilization was carried out contributed to a significant increase in plant density before harvest. In turn, each variant with spring foliar fertilization significantly increased the number of pods per plant compared to the control. Variants with autumn + spring, autumn + twice-spring, and twice-spring foliar fertilization influenced the increase in the soil-plant analysis development index (SPAD), thousand seed weight and protein and fat yield. The leaf area index was the highest after foliar fertilization applied in autumn + in spring or autumn + twice in spring. Foliar fertilization affected a significant increase in seed yield compared to the control. The content of protein and magnesium in seeds was the highest after the fertilizer application in autumn + twice in spring or twice in spring.


Agronomy ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 105
Author(s):  
Julien Louvieaux ◽  
Antoine Leclercq ◽  
Loïc Haelterman ◽  
Christian Hermans

Field trials were conducted with two nitrogen applications (0 or 240 kg N ha−1) and three modern cultivars of winter oilseed rape (Brassica napus L.) previously selected from a root morphology screen at a young developmental stage. The purpose is to examine the relationship between root morphology and Nitrogen Uptake Efficiency (NUpE) and to test the predictiveness of some canopy optical indices for seed quality and yield. A tube-rhizotron system was used to incorporate below-ground root growth information. Practically, clear tubes of one meter in length were installed in soil at an angle of 45°. The root development was followed with a camera at key growth stages in autumn (leaf development) and spring (stem elongation and flowering). Autumn was a critical time window to observe the root development, and exploration in deeper horizons (36–48 cm) was faster without any fertilization treatment. Analysis of the rhizotron images was challenging and it was not possible to clearly discriminate between cultivars. Canopy reflectance and leaf optical indices were measured with proximal sensors. The Normalized Difference Vegetation Index (NDVI) was a positive indicator of biomass and seed yield while the Nitrogen Balance Index (NBI) was a positive indicator of above-ground biomass N concentration at flowering and seed N concentration at harvest.


1999 ◽  
Vol 132 (2) ◽  
pp. 173-180 ◽  
Author(s):  
J. E. LEACH ◽  
H. J. STEVENSON ◽  
A. J. RAINBOW ◽  
L. A. MULLEN

The effects of plant density on the growth and yield of winter oilseed rape (Brassica napus) were examined in a series of five multifactorial experiments at Rothamsted Experimental Station between 1984 and 1989. Plant densities, manipulated by changing the seed rate and row spacing, or because of overwinter losses, ranged from 13·5 to 372 plants/m2. Normalized yields for the multifactorial plots increased with densities up to 50–60 plants/m2. In very high density plots in 1987/88, yield decreased as density increased >150 plants/m2. Plants grown at high density had fewer pod-bearing branches per plant but produced more branches/m2. Branch dry matter (DM) per plant was decreased by 42%, the number of fertile pods per plant and pod DM/plant by 37%. There was no effect of density on the number or DM of pods/m2. Over 74% of the fertile pods were carried on the terminal and uppermost branches of plants grown at high density in 1987/88 compared with only 34% in plants grown at low density in 1988/89. Seed DM/plant decreased with increase in density but seed size (1000-seed weight) increased. There was no effect of density on seed glucosinolate or oil contents.


2013 ◽  
Vol 53 (1) ◽  
pp. 79-88 ◽  
Author(s):  
Kinga Matysiak ◽  
Sylwia Kaczmarek

Abstract Winter oilseed rape is strongly responsive to changes in the plant density. Any change in plant density significantly affects the morphological characteristics and yield of the crop. In addition, plant growth habit can be modified by the use of plant growth regulators. Apart from plant growth regulators like eg. chlorocholine chloride some triazoles have dual properties (fungicide and plant growth regulator) eg. tebuconazole. The trials were carried out in the years 2006-2008 at the Institute of Plant Protection - National Research Institute in Poznan (Poland). The treatments consisted of chlorocholine chloride, tebuconazole and flusilazole applied in spring at the growth stage BBCH 30 and BBCH 50 of winter oilseed rape. The field trials were conducted with two sowing densities of winter oilseed rape: 60 seeds/ m2 and 120 seeds/m2. The vegetation seasons varied according to the weather conditions, and the second testing year was characterised by drought in May and June. In the experiments plant height, SPAD units, number of siliques per plant, seed number per silique, weight of thousand seeds, yield, protein and fat content in the seeds were estimated. The increase of silique numbers per plant appeared only at the lower sowing density as a result of the application of tebuconazole or a mixture of tebuconazole with CCC. Flusilazole had a positive impact on seed number per silique. At both sowing densities, changes in the weight of a thousand seeds under the influence of the test preparations, were observed only in that year which had wet weather conditions. A more favourable effect of the test substances on the weight of a thousand seeds was obtained at the lower sowing density. All the tested substances positively affected SPAD unit values at the lower sowing density. At the higher sowing density, SPAD unit values increased after the application of flusilazole, and after a mixture of CCC + tebuconazole. The tested substances had a positive impact on plant yield but they did not affect the protein and fat content in oilseed rape seeds.


Weed Research ◽  
2006 ◽  
Vol 46 (1) ◽  
pp. 22-33 ◽  
Author(s):  
S PRIMOT ◽  
M VALANTIN-MORISON ◽  
D MAKOWSKI

Author(s):  
Oskars Balodis ◽  
Zinta Gaile

Abstract Crop yield per area is the product of plant density and productivity of an individual plant. Plant density and the time of winter oilseed rape sowing influences yield components (parameters of individual plant productivity), such as pod number per plant, seed number per pod, plant productivity, seed weight, and plant branching. The aim of this three-year (2008–2010) study was to investigate winter oilseed rape yield components depending on sowing date (five sowing dates) and sowing rate (four sowing rates for each variety) as initial cause of plant density at harvest for two type winter oilseed rape varieties (open pollinated ‘Californium’ and hybrid ‘Excalibur’). Field trials were carried out at the Research and Study Farm “Vecauce” of the Latvia University of Agriculture. Winter oilseed rape yield components (pod number per plant and seed number per pod, plant productivity (seed number per plant and plant productivity in g) as well as the number of primary branches per plant) were affected (p < 0.05) by sowing date and rate for both varieties. In general, no significant effect of sowing rate on 1000-seed weight was observed (p > 0.05), but sowing date influenced this component significantly (p < 0.05). A yield compensation mechanism was demonstrated by significant (p < 0.05) negative correlations between plant density at harvest and parameters of individual plant productivity.


Plant Disease ◽  
2019 ◽  
Vol 103 (8) ◽  
pp. 2090-2099 ◽  
Author(s):  
Xiaorong Zheng ◽  
Annette Pfordt ◽  
Laxman Khatri ◽  
Alice Bisola Eseola ◽  
Antonia Wilch ◽  
...  

Oilseed rape, an important source of vegetable plant oil, is threatened by Verticillium longisporum, a soil-borne vascular fungal pathogen so far occurring in oilseed rape growing regions in Europe and Canada. Despite intensive research into V. longisporum in the last decades in controlled conditions, basic knowledge is still lacking about the time course of infection, temporal pattern of colonization, and disease development on field-grown plants. In this study, colonization of roots, stem bases, and stems with V. longisporum was followed by real-time PCR from the seedling until mature plant stages in 2-year field experiments with microsclerotia-infested plots and either spring-type or autumn-sown (winter-type) oilseed rape cultivars. The temporal pattern of plant colonization differed between greenhouse and field-grown oilseed rape and between spring- and winter-type plants in the field. Within 28 to 35 days, a continuous systemic colonization with V. longisporum was detected in roots and shoots of young plants in the greenhouse associated with significant stunting. In contrast, real-time PCR analysis of V. longisporum in field-grown winter oilseed rape plants displayed a strongly discontinuous colonization pattern with low fungal growth in roots during juvenile growth stages until flowering, whereas in spring oilseed rape, no root colonization was observed until early flowering stages. Hence, stem colonization with the pathogen required 6 months in winter oilseed rape and 1 month in spring oilseed rape from the time of initial root infection. The different patterns of stem colonization were related to soil temperature. Average soil temperatures in 5-cm depth during 7 days before sampling time points from 2 years of field experiments displayed a significant relationship with fungal colonization in the root. A climate chamber inoculation trial with soil temperature levels that varied from 6 to 18°C revealed a threshold temperature of >12°C in the soil to enable root invasion. This soil condition is reached in winter-type oilseed rape in the field in Germany either until the eight-leaf stage in early autumn or after pod stage in spring, whereas in spring-sown oilseed rape early root infection is delayed owing to the cool conditions during juvenile growth stages. The delay of stem colonization in field-grown oilseed rape may explain the lack of stunting as observed in the greenhouse and the previously reported inconsistent effects of V. longisporum on yield levels and seed quality, which were confirmed in this study.


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