scholarly journals Perbandingan Model Regresi untuk Pengukuran Luas Daun Gandum di Daerah Tropis

2021 ◽  
Vol 9 (2) ◽  
pp. 150
Author(s):  
Fiky Yulianto Wicaksono ◽  
Muhamad Kadapi
Keyword(s):  
Leaf Area ◽  
Equation Model ◽  
Regression Equation ◽  
Plant Production ◽  
Coefficient Of Determination ◽  
Regression Equations ◽  
Linear Quadratic ◽  
Area Index ◽  
Net Assimilation ◽  
Materials Used

The growth of wheat plants can be determined by measuring leaf area index and net assimilation rate. Both measurements require leaf area data. Measurement of leaf area of wheat in Indonesia requires a method that is not only accurate, but also easier and cheaper. One of them is the regression method. The purpose of this study was to determine an accurate regression equation model in predicting wheat leaf area. This research was conducted from March to June 2021 at the Experimental Station and Plant Production Technology Laboratory, Faculty of Agriculture, UNPAD, Jatinangor, Sumedang. The materials used in this study were various leaf area printing papers from wheat plants aged 14 days after planting (DAP), 28 DAP, and 42 DAP. The regression equation was assembled from the relationship between leaf area with leaf width and length, then compared with the actual leaf area that measured by scanning. The results showed that the linear, quadratic, cubic, and logarithmic regression equations had a coefficient of determination of more than 90% to predict leaf area, at the age of 14, 28, and 42 DAP, as well as all plant ages. Quadratic regression had a limit of data that can be entered, so it needed circumspection in using the formula. Cubic regression tended to have better accuracy in predicting leaf area at 14, 28, and 42 DAP, but the accuracy was the same as other regression equations at all plant ages.

The growth of maize

1978 ◽  
Vol 90 (3) ◽  
pp. 569-577 ◽  
Author(s):  
G. O. Iremiren ◽  
G. M. Milbourn
Keyword(s):  
Leaf Area ◽  
Dry Matter ◽  
Matter Content ◽  
Net Assimilation Rate ◽  
Dry Matter Content ◽  
Dry Matter Yield ◽  
Assimilation Rate ◽  
Maize Silage ◽  
Area Index ◽  
Net Assimilation

SummaryTotal dry-matter yield of maize silage rose asymptotically as density was increased up to 17 plants/m2. Over the range 11–17 plants/m2, which is generally higher than is used in the U.K., the increase in yield was 1–1·6 t dry matter/ha which can justify the higher seed cost and although there was no adverse affect on time of maturity the risk of lodging increased at the highest density. During the harvest period whilst whole crop dry-matter percentage was rising from 23 to 28%, the ear dry-matter content rose steadily from 29 to 35%, whereas the leaf and stem dry-matter content remained essentially constant and only dried out at a later stage after a frost.Caldera 535 had a higher leaf area index and net assimilation rate than the earlier variety Julia which it outyielded by 15%. The additional yield was mainly stem tissue and the greater vegetative production caused an 11-day delay in reaching the silage stage of maturity (25% crop D.M.). NO differences occurred between density treatments and varieties in the forage quality components considered, namely percentage drymatter digestibility, modified acid-detergent fibre, crude protein and ash. Thus in U.K. conditions, total dry-matter yield exerts an overriding influence on the yields per unit area of these quality constituents. This contrasts with reports from the U.S.A. in which a reduced grain/stover ratio adversely influences silage quality.Removal of the whole ear (including husk and rachis) at an early stage in ear development resulted in a 50% reduction in the final dry-matter yield. In the earless plants, leaf area and net assimilation rate was lower, but the dry-matter content of the leaves and stem was considerably higher, and a marked purple coloration developed indicative of excess starch concentration. These results emphasize the need in maize silage not only for an adequate leaf canopy, best obtained early in the growing season by using high planting density and subsequently by using late maturing varieties, but also for sufficient sink capacity in the ear as well as in the stem fraction.

scholarly journals Estimation of Peanut Leaf Area Index from Unmanned Aerial Vehicle Multispectral Images

Sensors ◽  
2020 ◽  
Vol 20 (23) ◽  
pp. 6732
Author(s):  
Haixia Qi ◽  
Bingyu Zhu ◽  
Zeyu Wu ◽  
Yu Liang ◽  
Jianwen Li ◽  
...  
Keyword(s):  
Leaf Area Index ◽  
Leaf Area ◽  
Vegetation Index ◽  
Field Experiments ◽  
Predictive Accuracy ◽  
Vegetation Indices ◽  
Planting Density ◽  
Coefficient Of Determination ◽  
Multispectral Images ◽  
Area Index

Leaf area index (LAI) is used to predict crop yield, and unmanned aerial vehicles (UAVs) provide new ways to monitor LAI. In this study, we used a fixed-wing UAV with multispectral cameras for remote sensing monitoring. We conducted field experiments with two peanut varieties at different planting densities to estimate LAI from multispectral images and establish a high-precision LAI prediction model. We used eight vegetation indices (VIs) and developed simple regression and artificial neural network (BPN) models for LAI and spectral VIs. The empirical model was calibrated to estimate peanut LAI, and the best model was selected from the coefficient of determination and root mean square error. The red (660 nm) and near-infrared (790 nm) bands effectively predicted peanut LAI, and LAI increased with planting density. The predictive accuracy of the multiple regression model was higher than that of the single linear regression models, and the correlations between Modified Red-Edge Simple Ratio Index (MSR), Ratio Vegetation Index (RVI), Normalized Difference Vegetation Index (NDVI), and LAI were higher than the other indices. The combined VI BPN model was more accurate than the single VI BPN model, and the BPN model accuracy was higher. Planting density affects peanut LAI, and reflectance-based vegetation indices can help predict LAI.

scholarly journals Effects of Gibberellic Acid (Ga3) on Growth and Yield Parameters of French Bean (Phaseolus Vulgaris L.)

2017 ◽  
Vol 43 (1) ◽  
pp. 49-60
Author(s):  
Ferdowsi Noor ◽  
Feroza Hossain ◽  
Umme Ara
Keyword(s):  
Growth Rate ◽  
Leaf Area ◽  
Dry Matter ◽  
Growth Parameters ◽  
French Bean ◽  
Research Field ◽  
Growth And Yield ◽  
Growth Stages ◽  
Area Index ◽  
Net Assimilation

A field study was conducted during the Rabi season of 2009-2010 in the research field of Bangladesh Council of Scientific and Industrial Research (BCSIR), Dhaka. Six levels of GA3, viz. 0, 30, 50, 70, 90 and 110 ppm were sprayed at 18 days after sowing (DAS). GA3 treatments significantly increased plant height than the control plants. GA3 with 30 to 90 ppm significantly increased number of branches and leaves, leaf area, leaf area index (LAI), leaf dry matter and total dry matter at different growth stages. GA3 at 30 to 70 ppm gradually increased crop growth rate (CGR), net assimilation rate (NAR) and relative growth rate (RGR) and declined advanced growth stages. Number of dry pods /plant, number of seeds /pod, 1000 seed weight, fresh fodder, fresh pod, dry seed yield and harvest index also significantly increased. Positive significant correlations were found among growth parameters and as well as yield contributing characters. Asiat. Soc. Bangladesh, Sci. 43(1): 49-60, June 2017

Relationship between tillering and leaf area index: quantifying critical leaf area index for tillering in rice

2002 ◽  
Vol 138 (3) ◽  
pp. 269-279 ◽  
Author(s):  
X. ZHONG ◽  
S. PENG ◽  
J. E. SHEEHY ◽  
R. M. VISPERAS ◽  
H. LIU
Keyword(s):  
Leaf Area Index ◽  
Leaf Area ◽  
Planting Density ◽  
Coefficient Of Determination ◽  
Area Index ◽  
N Input ◽  
Major Factors ◽  
The Relationship ◽  
Changing Light ◽  
Input Level

A field study was conducted at the International Rice Research Institute (IRRI), Philippines during the dry seasons of 1997 and 1998 under irrigated conditions. The objectives of this study were to quantify the critical leaf area index (LAIc) at which tillering stops based on the relationship between tillering rate and LAI, and to determine the effect of nitrogen (N) on LAIc in irrigated rice (Oryza sativa L.) crop. Results showed that the relative tillering rate (RTR) decreased exponentially as LAI increased at a given N input level. The coefficient of determination for the equation quantifying the RTR-LAI relationship ranged from 0·87 to 0·99. The relationship between RTR and LAI was affected by N input level, but not by planting density. The N input level had a significant effect on LAIc with a high N input level causing an increase in LAIc. Tillering stopped at LAI of 3·36 to 4·11 when N was not limiting. Under N limited conditions LAIc reduced to as low as 0·98. Transplanting spacing and number of seedlings per hill had little effect on LAIc. Results from this study suggest that LAI and plant N status are two major factors that influence tiller production in rice crops. The possibility that LAI influences tillering by changing light intensity and/or light quality at the base of the canopy where tiller buds and young tillers are located is discussed.

Banana plant growth. 2. Dry matter production, leaf area and growth analysis

1972 ◽  
Vol 12 (55) ◽  
pp. 216 ◽  
Author(s):  
DW Turner
Keyword(s):  
Plant Growth ◽  
Leaf Area ◽  
Dry Matter ◽  
Early Summer ◽  
Growth Stages ◽  
Assimilation Rate ◽  
Banana Plant ◽  
Area Index ◽  
Net Assimilation ◽  
Plant Crop

The quantitative aspects of banana plant growth (omitting roots) at Alstonville, New South Wales, are described. Dry matter distribution, leaf area index (L), net assimilation rate (E), leaf area ratio (F) and relative growth rates (R), were measured. For a spring planting, only 1695 kg ha-l dry matter were produced in the first twelve months but 6780 kg were produced in the first half of the second year as the bunch and first ratoon crop developed. The plant crop was characterized by early leaf growth (high F) whereas in the ratoon crops, corm growth was a feature of early growth stages. Leaf area index was less than 1 for the first twelve months but reached 5 after 18 months. Plants were 3.1 m X 1.9 m apart. Net assimilation rate was affected by internal and external factors. The main internal control was the growth of suckers, which tended to increase E. Removal of the suckers in autumn or winter caused a sudden drop i i ~ E and absolute growth rate but when they were removed in early summer E was increased. The external controls affecting E were solar radiation, temperature and soil moisture, although the amount of variation explained in correlations was low. - R appeared to be constant in the plant crop within morphologically defined growth stages. This was not so in moon crops and R was probably a resultant of ontogenetic and climatic drifts. Desuckering in autumn and winter decreased R. Early summer desuckering increased R.

scholarly journals A new method for estimating the leaf area index of cucumber and tomato plants

2003 ◽  
Vol 21 (4) ◽  
pp. 666-669 ◽  
Author(s):  
Flávio Favaro Blanco ◽  
Marcos Vinícius Folegatti
Keyword(s):  
Leaf Area Index ◽  
Leaf Area ◽  
Area Measurement ◽  
Quadratic Model ◽  
Regression Equations ◽  
Area Index ◽  
Tomato Plants ◽  
Potted Plants ◽  
Growing Period ◽  
Area Distribution

Non-destructive methods of leaf area measurement are useful for small plant populations, such as experiments with potted plants, and allow the measurement of the same plant several times during the growing period. A methodology was developed to estimate the leaf area index (LAI) of cucumber and tomato plants through the evaluation of the leaf area distribution pattern (LADP) of the plants and the relative height of the leaves in the plants. Plant and leaf height, as well as the length and width of all leaves were measured and the area of some leaves was determined by a digital area meter. The obtained regression equations were used to estimate the leaf area for all relative heights along the plant. The LADP adjusted to a quadratic model for both crops and LAI were estimated by measuring the length and width of the leaves located at the relative heights representing the mean leaf area of the plants. The LAI estimations presented high precision and accuracy when the proposed methodology was used resulting in time and effort savings and being useful for both crops.

scholarly journals Weed Management in Wheat by Cuscuta Alone and in Combination with Commercial Weedicides Allymax and Axial

2020 ◽  
Vol 38 ◽  
Author(s):  
Y. ABDULLAH ◽  
M.S. BALOCH ◽  
A.N. SHAH ◽  
M.M. HASHIM ◽  
M.A. NADIM ◽  
...  
Keyword(s):  
Leaf Area ◽  
Aqueous Extract ◽  
Weed Management ◽  
Block Design ◽  
Wheat Yield ◽  
Wheat Crop ◽  
Limiting Factor ◽  
Area Index ◽  
Net Assimilation ◽  
Hand Weeding

ABSTRACT: The present study was to assess the additive effects of cuscuta (akasbel) aqueous extract alone and in combination with full and reduced doses of commercially available weedicides against weeds in wheat crop during the year 2016-2017. The study was conducted in a randomized complete block design (RCBD) with 3 replications. The results showed that hand weeding and use of weedicides Allymax and Axial (full and half recommended doses) significantly controlled all prevailing weeds and increased yield and yield contributing parameters over the weedy check/control and sole application of cuscuta aqueous extract. Hand weeding and Allymax (full dose) showed minimum weed population, relative density, fresh and dry weed biomass and higher leaf area index (LAI), leaf area duration (LAD), crop growth rate (CGR), plant height, 1000 grain weight and grain yield while net assimilation rate (NAR), chlorophyll content, number of tillers, spike length, grains spike-1 and biological yield were maximum only in hand weeding. These findings suggest that in order to attain highest wheat yield, the field should be kept free from weeds by hand weeding (if labour is not a limiting factor) or use recommended dose of weedicide Allymax for efficient weed management in wheat.

scholarly journals Shading, Growth, and Dry-matter Partitioning of Cocoyam [Xanthosoma sagittifolium (L.) Schott]

1991 ◽  
Vol 116 (6) ◽  
pp. 1117-1121 ◽  
Author(s):  
Hector R. Valenzuela ◽  
Stephen K. O'Hair ◽  
Bruce Schaffer
Keyword(s):  
Leaf Area ◽  
Linear Equations ◽  
Dry Weight ◽  
Leaf Lamina ◽  
Dry Matter Partitioning ◽  
Area Index ◽  
Xanthosoma Sagittifolium ◽  
Leaf Density ◽  
Net Assimilation ◽  
Effect Of Light

Cocoyam was grown in 100%, 50%, or 30% daylight to determine the effect of light intensity on growth characteristics at various stages of plant development. Beginning ≈ 2 months after planting, growth was monitored at three or four monthly intervals. Plants grown in shade had more petiole and leaf lamina growth and extension, as well as increased top: corm plus cormel ratio (dry-weight basis), than plants grown in 100% daylight. Shade-grown plants had a higher leaf area index and specific leaf area than sun-grown plants. Sun-grown plants had a higher net assimilation rate and specific leaf density than shade-grown plants. Linear equations were developed to predict lamina area through measurements of leaf lamina width and length, petiole length, and lamina dry weight.

scholarly journals Growth of Jatropha curcas L. fertilized with nitrogen and potassium under conditions of dry tropical forest of Colombia

2017 ◽  
Vol 35 (2) ◽  
pp. 223-231
Author(s):  
Omar Montenegro R. ◽  
Stanislav Magnitskiy ◽  
Liz Patricia Moreno ◽  
Aquiles Enrique Darghan
Keyword(s):  
Growth Rate ◽  
Tropical Forest ◽  
Leaf Area ◽  
Jatropha Curcas ◽  
Fertilizer Application ◽  
Area Index ◽  
Dry Tropical Forest ◽  
Jatropha Curcas L ◽  
Reproductive Phase ◽  
Net Assimilation

Due to the demand in biofuel, the plant species that are not eatable and do not compete with traditional crops in Colombia, such as Jatropha curcas L., have become an important option. To produce more knowledge on the growth of this species, the research was carried out with different amounts of N and K fertilizers applied during the first 435 days after sowing (das) under dry tropical forest conditions. With the highest N dose (150 kg ha-1), the largest leaf area index was obtained in all evaluation period. The highest net assimilation rate (NAR) values were seen in the treatment with 150 kg ha-1 of N at 75 das, 1.852 g m-2 d-1, with no differences presented among the treatments with fertilizer application. The highest absolute growth rate (AGR) was observed when 150 kg ha-1 of N+180 kg ha-1of K2O were applied at the start of the reproductive phase (345 das), 24.5 g d-1. The specific leaf area (SLA) did not present a response to the treatments. The relative growth rate (RGR) reached zero value at 402 das for the plants without fertilizers. The accumulation of biomass in J. curcas was influenced by the fertilizers with N and K, presenting rapid initial vegetative growth (first 165 das) which decreased with the starting of the reproductive phase.

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