Predicting time trend of dry matter accumulation and leaf area index of winter cereals under nitrogen limitation by non-linear models

Author(s):  
Ali Rahemi-Karizaki ◽  
Nabi Khaliliaghdam ◽  
Abbas Biabani
2017 ◽  
Vol 5 (4) ◽  
pp. 423-429 ◽  
Author(s):  
Mohan Mahato ◽  
Bishnu Bilas Adhikari

A field experiment was conducted under humid subtropical agro-climatic condition of Nepal during rainy season of 2014. The experiment was laid out in to two factor Randomized Complete Block Design with  three replications consisting three drought tolerant rice varieties (Sukhadhan-4, Sukhadhan-5 and Radha-4) and four planting geometry (15 cm × 10 cm, 15 cm × 15 cm, 20 cm × 15 cm and 20 cm × 20 cm). The results revealed that the highest plant height and maximum leaf area index was recorded in planting geometry 15 cm × 10 cm in all growth stages. Whereas, planting geometry 20 cm × 15 cm produced the maximum number of tiller m-2 in all growth stage.  While planting geometry 20 cm × 15 cm and 20 cm × 20 cm produced statistically similar crop growth rate and dry matter accumulation in all stage of growth. Regarding the varieties, Sukhadhan- 4 showed highest plant height up to 75 DAT and plant height was statistically similar to Radha - 4 in 60 and 75 DAT. But maximum number of tiller m-2, leaf area index, crop growth rate and dry matter accumulation were recorded in Sukhadhan – 5 varieties. Int. J. Appl. Sci. Biotechnol. Vol 5(4): 423-429


Author(s):  
Rupinder Kaur Jassal ◽  
Harmeet Singh

An experiment was conducted at Punjab Agricultural University, Ludhiana during 2015 and 2016 to study the effect of priming, different seed rate on growth and seed yield of soybean planted under bed and flat method. The study was planned in factorial split plot design, keeping two planting techniques (flat sowing and bed sowing) and two seed priming treatments ( non primed seeds and 100 ppm GA3 primed seeds) in main plot and three seed levels ( 50, 62.5 and 75 kg ha-1) in sub plot. The objective of the study was to evaluate the effect of seed priming on growth and productivity under different planting techniques with the use of varying seed rates. The results revealed that growth attributes viz. emergence count, plant height, dry matter accumulation, leaf area index and photosynthetic active radiation interception (%) was significantly higher under bed planting technique as compared to flat sowing method. The pooled seed yield was increased by 15.6 % in bed planted soybean crop as compared to flat planted crop. Soybean seeds primed with 100 ppm GA3 recorded significant results in all the growth parameters. Primed seed recorded increase in yield 15.3 % than non primed seeds. Seed rate of 62.5 kg ha-1 recorded significantly higher emergence count, plant height, dry matter accumulation, leaf area index and photosynthetic active radiation interception (%) which was statistically similar in results with 75 kg ha-1 seed rate in both the two years. Pooled seed yield of 62.5 kg ha-1seed rate was 4.61 % higher than 75 kg ha-1 and 12.6 % than 50 kg ha-1 seed rate.


1981 ◽  
Vol 96 (1) ◽  
pp. 167-186 ◽  
Author(s):  
D. W. Lawlor ◽  
W. Day ◽  
A. E. Johnston ◽  
B. J. Legg ◽  
K. J. Parkinson

SUMMARYThe effects of water deficit on growth of spring barley were analysed under five irrigation treatments. One crop was irrigated at weekly intervals from emergence throughout the growing season, and one was not irrigated at all after emergence. Soil water deficits in the other treatments were allowed to develop early, intermediate or late in the crop's development.Weekly irrigation produced a crop with a large leaf area index (maximum value 4) and maintained green leaf and awns throughout the grain-filling period. Early drought decreased leaf area index (maximum value 2) by slowing expansion of main-stem leaves and decreasing the number and growth of tiller leaves. Leaf senescence was also increased with drought. Drought late in the development of ears and leaves and during the grain-filling period caused leaves and awns to senesce so that the total photosynthetic areas decreased faster than with irrigation. Photosynthetic rate per unit leaf area was little affected by drought so total dry-matter production was most affected by differences in leaf area.Early drought gave fewer tillers (550/m2) and fewer grains per ear (18) than did irrigation (760 tillers/m2 and 21 grains per ear). Late irrigation after drought increased the number of grains per ear slightly but not the number of ears/m2. Thus at the start of the grain-filling period crops which had suffered drought early had fewer grains than irrigated (9·5 and 18·8 × 103/m2 respectively) or crops which suffered drought later in development (14 × 103/m2).During the first 2 weeks of filling, grains grew at almost the same rate in all treatments. Current assimilate supply was probably insufficient to provide this growth in crops which had suffered drought, and stem reserves were mobilized, as shown by the decrease in stem mass during the period. Grains filled for 8 days longer with irrigation and were heavier (36–38 mg) than without irrigation (29–30 mg). Drought throughout the grainfilling period after irrigation earlier in the season resulted in the smallest grains (29 mg).Grain yield depended on the number of ears, the number of grains per ear and mass per grain. Early drought decreased tillering and tiller ear production and the number of grains that filled in each ear. Late drought affected grain size via the effects on photosynthetic surface area.Drought decreased the concentrations of phosphorus, potassium and magnesium in the dry matter of crops, and irrigation after drought increased them. Concentration of nitrogen was little affected by treatment. Possible mechanisms by which water deficits and nutrient supply affect crop growth and yield are discussed.


1986 ◽  
Vol 78 (1) ◽  
pp. 47-53 ◽  
Author(s):  
S. C. Mason ◽  
D. E. Leihner ◽  
J. J. Vorst ◽  
E. Salazar

2020 ◽  
Vol 203 ◽  
pp. 02008
Author(s):  
Baifeng Cang ◽  
Hao Jiang ◽  
Rong Ma ◽  
Yunzhe Li ◽  
Jingjing Cui ◽  
...  

In order to study the application of light and simplified cultivation mode in straw returning field. In the experiment, two treatments of straw returning and non-straw returning were used under the light simplified cultivation mode, and the differences of tiller number, dry matter accumulation, leaf area index, chlorophyll and yield were studied. Field cultivation experiments were carried out with Jihong 9 and Jinongda 138. The results showed that the yields of Jihong 9 and Jinongda138 straw returning to the field under the light and simplified cultivation mode were 2.00% and 3.63% higher than those under the non-straw returning mode. The total grain number in the yield components increased by 3.35% and 11.60% respectively. Dry matter increased by 19.70% and 7.66% in mature period. The leaf area index (LAI) and SPAD value in the later period of straw returning were higher than those in the non-straw returning, and the number of effective tillers was lower. Light and simplified cultivation can be used as a new mode of rice high-yield cultivation under straw returning, which improves the total grain number, leaf area index, SPAD value and dry matter in the later stage, and increases rice yield. The yield advantage of Jinongda 138 under straw returning (SJ138) is more significant.


Biologija ◽  
2016 ◽  
Vol 62 (1) ◽  
Author(s):  
Raouf Seyed Sharifi ◽  
Ali Namvar

Crop phenology is one of the most important aspects of crop yield determination and it is essential to predicting physiological responses under varying field conditions. In order to evaluate plant density and intra-row spacing effects on phenology, dry matter accumulation, and leaf area index of maize in second cropping, a factorial experiment based on randomized complete block design was conducted at the research farm of the University of Mohaghegh Ardabili. Experimental factors were: plant population at three levels (7, 9, and 11 plants m–2) with three levels of intra-row spacing (45, 60, and 75 cm). The results showed that the maximum plant height (179.07  cm), total dry matter (592  g  m–2) in 83–91 days after sowing, days to 50% anthesis (45 days), days to 50% silking (50 days), LAI (4.07) in 63–70 days after sowing were observed in the plots with 11 plants m–2 and intra-row spacing of 45 cm. Based on the results, it was concluded that application of 11 plants m–2 with row spacing of 45 cm can be recommended for profitable maize production.


1995 ◽  
Vol 31 (1) ◽  
pp. 65-73 ◽  
Author(s):  
S. S. Prihar ◽  
V. K. Arora ◽  
G. Singh ◽  
R. Singh

SummaryDry matter and tuber yields of potato grown in a sub-tropical environment were estimated employing simple radiation-based models which require meteorological information on air temperature and solar radiation. Two versions of the MacKerron and Waister (1985) model, in which estimation of dry matter accumulation relies on a single composite parameter, radiation use efficiency (RUE), were compared with the Versteeg and Van Keulen (1986) model, which explicitly accounts for temperature and radiation effects on dry matter accumulation. In the original version of the MacKerron and Waister model, a linear change in the radiation interception factor with leaf area index is assumed; in the modified version an exponential change in the interception factor with leaf area index is considered. The accumulation of dry matter estimated from all three models was close to the measured values throughout the growing season, but estimates of tuber yield differed widely. Our analysis showed that the best agreement with measured values was obtained using the MacKerron and Waister linear model with RUE values adjusted according to the incident radiation level.Estimatión del rendimiento del tubérculo de la patata


Scientifica ◽  
2015 ◽  
Vol 2015 ◽  
pp. 1-6 ◽  
Author(s):  
Shamim Gul ◽  
M. H. Khan ◽  
B. A. Khanday ◽  
Sabeena Nabi

To investigate the response of rainfed maize to sowing methods and NPK levels, an experiment was undertaken during kharif of 2011 and 2012 at Dryland (Kerawa) Agriculture Research Station, Sher-e-Kashmir University of Agricultural Sciences and Technology of Kashmir, Budgam. The experiment was laid out in a randomized block design with combination of 2 sowing methods (flat sowing, 75 cm apart rows, and ridge sowing, 75 cm apart ridges) and 3 fertility levels (60 : 40 : 20, 75 : 50 : 30, and 90 : 60 : 40 N : P2O5 : K2O kg ha−1) with three replications. Various growth characters, namely, plant height, leaf area index, dry matter accumulation, number of days to different phenological stages, and yield, and yield contributing characters namely, cob length, number of grains cob−1, cob diameter (cm), and 100-seed weight (g), were significantly higher with S2over S1during both the years of experimentation. Fertilizer levels F3(90 : 60 : 40) and F2(75 : 50 : 30) at par with one another produced significant increase in growth and yield characters, namely, plant height, leaf area index, dry matter production at different growth stages, cob length, number of cobs plant−1, number of grains cob−1, and 100-seed weight over F1(60 : 40 : 20). Significantly higher grain yield was recorded with fertilizer level F3(90 : 60 : 40) being at par with F2(75 : 50 : 30) and showed significant increase over F1(60 : 40 : 20) with superiority of 5.4 and 5.7 per cent during 2011 and 2012, respectively. The findings of the study concluded that ridge method of sowing of maize with NPK levels of 75 : 50 : 30 kg ha−1showed better performance of crop in terms of growth, yield, and yield attributes.


Agronomy ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1033
Author(s):  
Cailong Xu ◽  
Ruidong Li ◽  
Wenwen Song ◽  
Tingting Wu ◽  
Shi Sun ◽  
...  

Multiple cropping systems boost grain yields and have an immense potential to increase land productivity. In such cropping systems in China, soybean is directly seeded after the wheat harvest in early June. After the wheat harvest, the farmland has low amounts of soil moisture and contains large amounts of wheat straw, which negatively affect soybean growth and yields. To address these challenges, an integrated management practice (IMP) than can achieve precise direct seeding and straw mulching return, was developed. In this study, differences in the soil temperature and moisture, seedling quality, dry matter accumulation, soybean yield, and greenhouse gas emissions were investigated between IMP and the farmers’ practices (FP). Compared with the FP treatment, IMP significantly increased the soil moisture and decreased the soil temperature in the topsoil layer. In addition, under the IMP treatment, the rate of emergence and developmental uniformity of soybean plants significantly increased by 21.7% and 99.5%, respectively, thus increasing the leaf area index by 30.0% and dry matter accumulation by 12.0% and, in turn, increasing soybean yields by 24.7%. A principal component analysis showed that the dry matter weight, relative water content, leaf area index, and developmental uniformity were strong sensitivity indices for the IMP treatment. In addition, the intensity of emission of N2O and greenhouse gases under IMP both decreased significantly by 25.1% and 28.9% compared with the FP, respectively. Thus, it was concluded that IMP is a suitable farming practice for sustainable agricultural production, and it has broad prospects for application in wheat–soybean double cropping systems in China and other similar areas globally.


1983 ◽  
Vol 100 (2) ◽  
pp. 351-358 ◽  
Author(s):  
C. F. Green ◽  
L. V. Vaidyanathan ◽  
M. N. Hough

SUMMARYSequential dry-matter measurements for winter wheat crops grown at different sites during different seasons were plotted against accumulated potential evaporation. A relation consisting of two intersecting straight lines represented the observations. Early crop growth had a gentle slope due to an incomplete leaf canopy. Later growth occurred at a rate which depended upon the amount of applied nitrogen, the amount of radiation and the availability of water. The intersection occurred consistently at a leaf area index of 1·25.


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