scholarly journals Response of Rice Genotypes to Weed Competition in Dry Direct-Seeded Rice in India

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Gulshan Mahajan ◽  
Mugalodi S. Ramesha ◽  
Bhagirath S. Chauhan
Keyword(s):  
Grain Yield ◽  
Leaf Area Index ◽  
Leaf Area ◽  
Root Biomass ◽  
Early Stage ◽  
Weed Competition ◽  
Genotypic Differences ◽  
Area Index ◽  
Direct Seeded ◽  
Rice Genotypes

The differential weed-competitive abilities of eight rice genotypes and the traits that may confer such attributes were investigated under partial weedy and weed-free conditions in naturally occurring weed flora in dry direct-seeded rice during the rainy seasons of 2011 and 2012 at Ludhiana, Punjab, India. The results showed genotypic differences in competitiveness against weeds. In weed-free plots, grain yield varied from 6.6 to 8.9 t ha−1across different genotypes; it was lowest for PR-115 and highest for the hybrid H-97158. In partial weedy plots, grain yield and weed biomass at flowering varied from 3.6 to 6.7 t ha−1and from 174 to 419 g m−2, respectively. In partial weedy plots, grain yield was lowest for PR-115 and highest for PR-120. Average yield loss due to weed competition ranged from 21 to 46% in different rice genotypes. The study showed that early canopy closure, high leaf area index at early stage, and high root biomass and volume correlated positively with competitiveness. This study suggests that some traits (root biomass, leaf area index, and shoot biomass at the early stage) could play an important role in conferring weed competitiveness and these traits can be explored for dry-seeded rice.

Effects of Planting Density on Leaf Area and Productivity of Two Maize Cultivars in Nigeria

1982 ◽  
Vol 18 (1) ◽  
pp. 93-100 ◽  
Author(s):  
S. U. Remison ◽  
E. O. Lucas
Keyword(s):  
Grain Yield ◽  
Leaf Area Index ◽  
Leaf Area ◽  
Dry Matter ◽  
Plant Population ◽  
Planting Density ◽  
Dry Matter Yield ◽  
Area Index ◽  
Positive Correlation ◽  
Maize Cultivars

SUMMARYTwo maize cvs, FARZ 23 and FARZ 25, were grown at three densities (37,000, 53,000 and 80,000 plants/ha) in 1979 and 1980. Leaf area index (LAI) increased with increase in plant population and was at a maximum at mid-silk. Grain yield was highest at 53,000 plants/ha. There was no relation between LAI and grain yield but there was a positive correlation between LAI and total dry matter yield.

The effect of planting date and nitrogen management on yield and quality of aromatic rice (Oryza sativa)

2004 ◽  
Vol 142 (2) ◽  
pp. 183-191 ◽  
Author(s):  
M. GHOSH ◽  
B. K. MANDAL ◽  
B. B. MANDAL ◽  
S. B. LODH ◽  
A. K. DASH
Keyword(s):  
Oryza Sativa ◽  
Grain Yield ◽  
Leaf Area Index ◽  
Leaf Area ◽  
Amylose Content ◽  
Aromatic Rice ◽  
Area Index ◽  
Growth Environment ◽  
Yield And Quality

Growth environment and plant nutrition are two important factors influencing growth, yield and quality of aromatic rice (Oryza sativa L.). The present study was conducted at Kalyani, India to determine the effect of two planting dates and four fertilizer levels on different aromatic rice cultivars during the dry seasons of 1995/96 and 1996/97, while nine cultivars were evaluated during the wet seasons of 1996 and 1997. Thermal and photoperiodic conditions significantly influenced the vegetative (leaf area index and light extinction co-efficient) and reproductive (filled spikelets/panicle) growth of the crop. Delayed planting (23 February) significantly reduced the grain yield by 0·88 t/ha, amylose content by 0·5% and duration by 10 days; but increased the summed heliothermal units (17806 v. 18505). Thus, the cultivars became less efficient (27%) in heat use with delay in planting from 2 to 23 February. Relative availability of NH4+-N from urea and Azolla influenced the crop growth (leaf area index [LAI], tiller production and leaf chlorophyll content) and nutrient uptake. Supply of inorganic N either alone or in conjunction with Azolla significantly increased grain yield (18–41%) and protein content (0·1–0·7%) over 15 t/ha of Azolla alone. However, combined application of Azolla and urea lowered the amylose content below that achieved by application of either substance alone. Correlation studies among quality attributes indicated that long-grained varieties had lower head rice recovery (r=−0·69) due to more breakage during milling and greater test weight (r=0·93).

scholarly journals Relationship between Flag Leaf Characteristics and Main Yield Components in Oat (Avena sativa L.)

2019 ◽  
Vol 76 (1) ◽  
pp. 71
Author(s):  
Ionuṭ RACZ ◽  
Rozalia KADAR ◽  
Sorin VȂTCĂ ◽  
Ioana Virginia BERINDEAN ◽  
Adrian CECLAN ◽  
...  
Keyword(s):  
Grain Yield ◽  
Leaf Area Index ◽  
Leaf Area ◽  
Avena Sativa ◽  
Yield Components ◽  
Flag Leaf ◽  
Chlorophyll Concentration ◽  
Area Index ◽  
Leaf Chlorophyll ◽  
Leaf Chlorophyll Concentration

The objective of this study was to investigate relationships between leaf area index, leaf chlorophyll concentration, yield components and grain yield in oat (Avena sativa L.). Ten oat varieties were analyzed in field conditions regarding those traits. Flag leaf chlorophyll concentration range between 451.51 and 747.79 units of μmol of chlorophyll per m2. Also, leaf area index range between 13.68 to 32.84 cm2. Significant correlation indices were highlighted between yield components and leaf area index, yield/yield components and chlorophyll concentration of flag leaf.

scholarly journals Assessment of Climate Change Impact on Crop yield and Evaluation of Coping Strategy using Crop Growth Simulation Model

2020 ◽  
Vol 15 (1) ◽  
pp. 106-122
Author(s):  
J. Alam ◽  
R. K. Panda
Keyword(s):  
Climate Change ◽  
Grain Yield ◽  
Simulation Model ◽  
Leaf Area Index ◽  
Leaf Area ◽  
Co2 Concentration ◽  
Maize Yield ◽  
Crop Growth ◽  
Climate Change Scenarios ◽  
Area Index

 Any change in climate will have implications for climate-sensitive systems such as agriculture, forestry and some other natural resources. Changes in solar radiation, temperature and precipitation will produce changes in crop yields and hence economics of agriculture. It is possible to understand the phenomenon of climate change on crop production and to develop adaptation strategies for sustainability in food production, using a suitable crop simulation model. CERES-Maize model of DSSAT v4.0 was used to simulate the maize yield of the region under climate change scenarios using the historical weather data at Kharagpur (1977-2007), Damdam (1974-2003) and Purulia (1986-2000), West Bengal, India. The model was calibrated using the crop experimental data, climate data and soil data for two years (1996-1997) and was validated by using the data of the year 1998 at Kharagpur. The change in values of weather parameters due to climate change and its effects on the maize crop growth and yield was studied. It was observed that increase in mean temperature and leaf area index have negative impacts on maize yield. When the maximum leaf area index increased, the grain yield was found to be decreased. Increase in CO2 concentration with each degree incremental temperature decreased the grain yield but increase in CO2 concentration with fixed temperature increased the maize yield. Adjustments were made in the date of sowing to investigate suitable option for adaptation under the future climate change scenarios. Highest yield was obtained when the sowing date was advanced by a week at Kharagpur and Damdam whereas for Purulia, the experimental date of sowing was found to be beneficial.

scholarly journals Effect of Spacing and Nitrogen Level on Growth and Yield of Maize (Zea mays L.) in Mid hill of Nepal

2020 ◽  
Vol 3 (2) ◽  
pp. 50-55
Author(s):  
Ramhari Gaire ◽  
Chudamani Pant ◽  
Nischal Sapkota ◽  
Rajan Dhamaniya ◽  
Tej Narayan Bhusal
Keyword(s):  
Grain Yield ◽  
Leaf Area Index ◽  
Leaf Area ◽  
Plant Height ◽  
Block Design ◽  
Organic Matter Content ◽  
Growth And Yield ◽  
Nitrogen Level ◽  
Area Index ◽  
Close Spacing

AbstractA field experiment was carried out to study the effect of spacing and nitrogen level on growth and yield of maize in Parbat from February to July, 2019. The experiment was laid out in two Factorial Randomized complete Block Design (RCBD) comprising of spacing: 60×15 cm and 60×25 cm and nitrogen: 30, 60, 90 and 120 kg/ha level as treatment with three replications. “Arun-2” variety of maize was planted on clay loam and acidic soil (pH 5.3) having medium in total nitrogen (0.15%), medium in soil available phosphorus (48.1 kg/ha), medium in soil available potassium (218.8 kg/ha) and medium in organic matter content (2.92%). Result shows that yield was significantly increased with increment in N-level up to 90 kg N/ha. The grain yield (5.18 mt/ha) was significantly higher at 90 kg N/ha than at 30 and 60 kg N/ha but at par with 120 kg N/ha. Significant effect on grain yield due to spacing was observed. The grain yield (4.11 mt/ha) obtained at spacing 60×15 cm. Moreover, the highest grain yield showed that highest grain yield (4.33 mt/ha) was obtained under 90 kg N/ha plus 60×15 cm spacing. The result revealed that different spacing and nitrogen level significantly affect the plant height and leaf area index. The plant height and leaf area index were significantly high at close spacing (60×15 cm) and at 120 kg N/ha. Likewise, yield attributing characteristics like cob length, cob diameter, number of kernel/rows, number of kernel row, thousand gran weight were the highest at 90 kg/ha but as par with 120 kg/ha at close spacing (60×15 cm). This study suggested that maize production can be maximized by cultivating “Arun-2” maize fertilizing with 90 kg N/ha and maintaining 60×15 cm spacing.

scholarly journals Influence of seed priming and water stress on selected physiological traits of borage

2015 ◽  
Vol 27 (2) ◽  
pp. 151-159 ◽  
Author(s):  
Soheila Dastborhan ◽  
Kazem Ghassemi-Golezani
Keyword(s):  
Medicinal Plant ◽  
Grain Yield ◽  
Leaf Area Index ◽  
Leaf Area ◽  
Field Experiments ◽  
Seedling Emergence ◽  
Field Performance ◽  
Stability Index ◽  
Seed Priming ◽  
Area Index

Abstract Borage is a valuable medicinal plant with various constituents in leaves, flowers and seeds. Hence, it is important to improve the performance of this medicinal plant under different environmental conditions. Thus, two field experiments were arranged as split-plots based on a RCB design with three replications in 2012 and 2013, to evaluate the effects of seed priming and different irrigation intervals on selected physiological properties of borage leaves. Irrigation intervals (irrigation after 60, 90, 120, 150 mm evaporation from Class A pans, respectively) and priming treatments (control, water, KNO3 and KH2PO4) were allocated to the main and sub plots, respectively. The chlorophyll content index was enhanced under limited irrigation treatments, mainly due to a decrease in leaf area index and intercepting more radiation. However, the membrane stability index was stable under different irrigation intervals. Decreased relative water content and leaf area index and increased leaf temperature under lower water availability led to some reductions in the grain yield of borage. All of the priming techniques, particularly hydro-priming, enhanced the seedling emergence rate, leaf area index and consequently grain yield per unit area. Therefore, seed hydro-priming can be used to improve the field performance of borage, particularly when sufficient water is available.

IMPLANTATION SYSTEMS AND SURFACE IRRIGATION FOR MAIZE CROP IN LOWLAND AREAS

2020 ◽  
Vol 19 ◽  
pp. 10
Author(s):  
ELISA DE ALMEIDA GOLLO ◽  
ADROALDO DIAS ROBAINA ◽  
MARCIA XAVIER PEITER ◽  
ENIO MARCHESAN ◽  
ROBSON GIACOMELI ◽  
...  
Keyword(s):  
Grain Yield ◽  
Leaf Area Index ◽  
Leaf Area ◽  
Dry Mass ◽  
Surface Irrigation ◽  
Maize Crop ◽  
Area Index ◽  
Productive Potential ◽  
Lowland Area ◽  
Santa Maria

The raised seedbed implantation system and the use of surfaceirrigation can be important practices to enable rotation with rice and ensure theexpression of the productive potential of maize in lowland areas. The purpose ofthis work was to evaluate the use of implantation systems and surface irrigationon agronomic characteristics and grain yield of maize crop in lowland areas.Two experiments were conducted in the experimental lowland area of theFederal University of Santa Maria – UFSM, during the 2014/15 crop season.The experiments consisted in the use of implantation systems with and withoutraised seedbeds and surface irrigation. The evaluated characteristics were plantheight, shoot dry mass, leaf area index, yield components and grain yield. Plantheight, leaf area index and shoot dry mass are higher when maize is grown inraised seedbeds in lowland areas. The raised seedbed system can be consideredan efficient way to improve drainage in the cultivation area, resulting in a highergrain yield. The use of irrigation during periods of water deficit, in the criticalperiod of crop growth, increases the grain yield of maize grown in lowland areas.

Photosynthesis of wheat under field conditions. III. Seasonal trends in carbon dioxide uptake of crop communities

1971 ◽  
Vol 22 (1) ◽  
pp. 1 ◽  
Author(s):  
DW Puckridge
Keyword(s):  
Carbon Dioxide ◽  
Grain Yield ◽  
Leaf Area Index ◽  
Leaf Area ◽  
Dry Weight ◽  
Field Conditions ◽  
Wheat Cultivars ◽  
Area Index ◽  
Carbon Dioxide Uptake ◽  
Assimilation Chamber

Photosynthesis of two wheat cultivars grown in the field was examined during three seasons by use of a portable field assimilation chamber. There were large differences in dry weight, leaf area, and carbon dioxide uptake between seasons. Variations in carbon dioxide uptake by the community were related mainly to changes in leaf area index (LAI). There were changes in carbon dioxide uptake per unit LAI with time, and between the two cultivars in the first season, but the effects of these changes were small compared with the effects of LAI. Differences in grain yield were correlated with LAI and carbon dioxide uptake in the period after anthesis.

Early regeneration conifer identification and competition cover assessment using airborne digital camera imagery

2000 ◽  
Vol 76 (6) ◽  
pp. 915-928 ◽  
Author(s):  
K. A. Haddow ◽  
D. J. King ◽  
D. A. Pouliot ◽  
D. G. Pitt ◽  
F. W. Bell
Keyword(s):  
Leaf Area Index ◽  
Leaf Area ◽  
Vegetation Cover ◽  
Early Stage ◽  
Digital Camera ◽  
Vegetation Management ◽  
Forest Vegetation ◽  
Crop Species ◽  
Area Index ◽  
Forest Vegetation Management

The potential of low cost, high-resolution airborne digital camera imagery for use in early stage forest regeneration assessment was investigated. Airborne imagery with 2.5-cm pixel size was acquired near Sault Ste. Marie, Ontario, over a forest vegetation management research site to: i) evaluate capabilities for identification and stem counting of two-year old conifer crop species under leaf-off and leaf-on conditions using classification of spectral and textural image information, and ii) develop models relating vegetation cover parameters to image spectral and texture information. Results indicate strong potential for identification and counting of conifer trees when competing vegetation cover is low or in leaf-off condition. However, systematic decreases in class separability and conifer count accuracy were observed with increasing competition. In image modelling of competition Leaf Area Index and Cover, statistically significant relations were found using primarily spectral measures. Stratification by competition species improved model fits and included texture measures in some models. Key words: airborne remote sensing, forest vegetation management, regeneration, digital cameras, leaf area index, cover, tree classification

Sign in / Sign up

Export Citation Format

Share Document