scholarly journals CANOPY REFLECTANCE MEASUREMENTS USED TO ESTIMATE LATE BLIGHT (PHYTOPHTHORA INFESTANS) INFLUENCE ON POTATO YIELD CANOPY REFLECTANCE MEASUREMENTS USED TO ESTIMATE LATE BLIGHT (PHYTOPHTHORA INFESTANS) INFLUENCE ON POTATO YIELD

2020 ◽  
Vol 13 ◽  
pp. 21-27
Author(s):  
Manuela Hermeziu
Keyword(s):  
Late Blight ◽  
Phytophthora Infestans ◽  
Vegetation Index ◽  
Normalized Difference Vegetation Index ◽  
Field Experiments ◽  
Block Design ◽  
Potato Yield ◽  
Planting Density ◽  
Canopy Reflectance ◽  
Reflectance Measurements

"The present study was conducted to investigate potato late blight (Phytophtora infestans) influence on leaf chlorophyll level using datasets extracted from multispectral data captured at the canopy level. Field experiments were carried out to the National Institute of Research and Development for Potato and Sugar Beet Brasov, Romania in 2014-2016 period. It was used a complete randomized block design with four replicates, two planting distances between plants on row (25 and 30cm) and different fungicides, control technologies. Normalized Difference Vegetation Index (NDVI) was introduced to achieve a spectral vegetation index that can separate the vegetation from the uncovered ground. It is defined as the ratio between the infrared bands-red differences and sum them. Due to the different growth conditions, the effects of resulting variants from combinations of factors -varieties-planting density-late blight control technology-on the tubers yield have manifested with different intensity. In two of three years, the average NDVI value of plants grown at a density of 53.3 thousands hill/ha was significantly lower than the values determined at a density of 44.4 thousands hill/ha (NDVI 0.817 compared to 0.859 in 2014 and 0.905 compared to 0.895 in 2015). The correlation between the average values of NDVI yields and tubers were positive."

scholarly journals Late Leaf Spot Severity and Yield of New Peanut Breeding Lines and Cultivars Grown Without Fungicides

Plant Disease ◽  
2017 ◽  
Vol 101 (11) ◽  
pp. 1843-1850 ◽  
Author(s):  
Brian S. Jordan ◽  
Albert K. Culbreath ◽  
Timothy B. Brenneman ◽  
Robert C. Kemerait ◽  
William D. Branch
Keyword(s):  
Leaf Spot ◽  
Vegetation Index ◽  
Field Experiments ◽  
Organic Production ◽  
Canopy Reflectance ◽  
Cercospora Arachidicola ◽  
Early Season ◽  
Late Leaf Spot ◽  
Breeding Lines ◽  
Width Measurements

Peanut (Arachis hypogaea) cultivars with resistance or tolerance to Cercospora arachidicola and/or Cercosporidium personatum, the causes of early and late leaf spot, respectively, are needed for organic production in the southeastern U.S. To determine the potential of new breeding lines for use in such production systems, field experiments were conducted in Tifton, GA, in 2014 and 2015 in which nine breeding lines and two cultivars, Georgia-06G and Georgia-12Y, were grown without foliar fungicide applications. In one set of trials, cultivar Georgia-12Y and most of the breeding lines evaluated had early season vigor ratings, early-season canopy width measurements, final plant populations, and pod yield that were greater than those of standard cultivar Georgia-06G. In those trials, final late leaf spot Florida scale ratings were lower and canopy reflectance measured as the normalized difference vegetation index (NDVI), was higher all the breeding lines than those of Georgia-06G. In another set of trials, two of those same breeding lines had final late leaf spot ratings similar to those of Georgia-12Y in 2014, whereas in 2015, six of those breeding lines had final leaf spot ratings that were lower than those of Georgia-12Y. Yields were similar for Georgia-12Y and all the breeding lines in the Gibbs Farm trials. Across years and breeding lines at the Lang Farm, the relationship between visual estimates of defoliation and NDVI was described by a two sector piecewise regression with NDVI decreasing more rapidly with increasing defoliation above approximately 89%. The utility of NDVI for spot comparisons among breeding lines appears to be limited to situations where there are differences in defoliation. Georgia-12Y and multiple breeding lines evaluated show potential for use in situations such as organic production where acceptable fungicides available for seed treatment and leaf spot control are limited.

scholarly journals Nitrogen management in wheat based on the normalized difference vegetation index (NDVI)

2018 ◽  
Vol 48 (9) ◽  
Author(s):  
André Luis Vian ◽  
Christian Bredemeier ◽  
Marcos Alexandre Turra ◽  
Cecília Paz da Silva Giordano ◽  
Elizandro Fochesatto ◽  
...  
Keyword(s):  
Technical Efficiency ◽  
Vegetation Index ◽  
Normalized Difference Vegetation Index ◽  
Field Experiments ◽  
Shoot Biomass ◽  
Sensor Field ◽  
N Dose ◽  
Plant Emergence ◽  
The Moment ◽  
The Relationship

ABSTRACT: Biomass production and nitrogen (N) accumulated in wheat shoots may be used for quantifying optimal topdressing nitrogen doses. The objective of this study was to develop and validate models for estimating the amount of biomass and nitrogen accumulated in shoots and the N topdressing dose of maximum technical efficiency in wheat using the normalized difference vegetation index (NDVI) measured by an active optical canopy sensor. Field experiments were carried out in two years and treatments consisted of N doses applied at plant emergence and as topdressing. NDVI, shoot biomass and N accumulated in shoots at the growth stage of six fully expanded leaves and grain yield were evaluated, being determined the topdressing N dose of maximum technical efficiency (DMTE). The NDVI was positively correlated to shoot biomass and N content in shoots and models for the relationship between these variables were developed and validated. The DMTE was negatively correlated with the NDVI value evaluated at the moment of N topdressing application. Thus, NDVI evaluation by an active optical canopy sensor can be used for nitrogen fertilization in variable rate, allowing the adjustment of applied N doses in different areas within a field.

scholarly journals Uji Ketahanan Klon Kentang Hasil Pesilangan Atlantic x Repita terhadap Penyakit Hawar Daun Phytophthora infestans

Agrikultura ◽  
2018 ◽  
Vol 29 (2) ◽  
pp. 100
Author(s):  
Helmi Kurniawan ◽  
Ineu Sulastrini ◽  
Tarkus Suganda
Keyword(s):  
Late Blight ◽  
Phytophthora Infestans ◽  
Field Test ◽  
Block Design ◽  
Environmentally Friendly ◽  
Statistical Test ◽  
The Other ◽  
Resistant Variety ◽  
Resistance Level ◽  
Randomized Block Design

ABSTRACTResistance Test of Potato Clones Derived from Crossing of Atlantic x Repita to Late Blight (Phytophthora infestans)Late blight, incited by Phytophthora infestans is the most destructive disease of potato. The management that is effective and environmentally-friendly is the use of resistant variety. The objective of this study was to test the resistance of the six potato clones (AR 04, AR 05, AR 06, AR 07, AR 08 and AR 09) derived from crossing var. Atlantic x var. Repita to late blight caused by P. infestans. Var. Atlantic, Repita and Granola were used as susceptible, resistant and susceptible but the most-grown variety, respectively. Field test was located in Ciwidey, one of the potato growing center where late blight is endemic since potatoes are continuously grown. The treatments were arranged in a randomized block design with 3 replicates. The result showed that clones AR 07 and AR 08 were more resistant than the other potato clones, but it still below the resistance level var. Repita. However, based on statistical test on the diseases development (AUDPC), clone AR 08 could be categorized as resistant, equal with of the resistance level of var. Repita.Keywords: Potato clones, Rsistance, P. infestansABSTRAKPenyakit hawar daun yang disebabkan Phytopthora infestans merupakan penyakit utama pada tanaman kentang. Pengendalian yang efektif dan ramah lingkungan adalah dengan penanaman varietas tahan. Penelitian ini bertujuan untuk menguji ketahanan 6 klon kentang (AR 4, AR5, AR6, AR7, AR 8, dan AR9) yang merupakan hasil persilangan antara var. Atlantic (produksi tinggi tetapi rentan) dengan var. Repita, sebagai tetua tahan terhadap penyakit hawar daun yang disebabkan oleh P. infestans. Varietas Atlantic, Repita dan Granola digunakan sebagai pembanding. Pengujian ketahanan dilakukan di Ciwidey, yang merupakan salah satu sentra produksi kentang di Jawa Barat dan endemik penyakit hawar daun. Perlakuan ditata menggunakan Rancangan Acak Kelompok dengan 3 ulangan. Hasil penelitian menunjukkan bahwa klon AR 07 dan Klon AR 08 memiliki ketahanan yang lebih baik dibanding klon-klon kentang lainnya, namun tingkat ketahanannya masih di bawah cv Repita. Namun, berdasarkan uji statistik terhadap nilai perkembangan penyakit (AUDPC) klon AR 08 dapat dikategorikan tahan, sama dengan derajat tahan var. Repita.Kata Kunci: Klon kentang, Ketahanan, P. infestans

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 Effect of Seed Distribution and Population on Maize (Zea maysL.) Grain Yield

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Bee Khim Chim ◽  
Peter Omara ◽  
Natasha Macnack ◽  
Jeremiah Mullock ◽  
Sulochana Dhital ◽  
...  
Keyword(s):  
Grain Yield ◽  
Vegetation Index ◽  
Normalized Difference Vegetation Index ◽  
Block Design ◽  
N Uptake ◽  
Plant Spacing ◽  
Randomized Complete Block Design ◽  
Seed Distribution ◽  
Treatment Structure ◽  
Number Of Seeds

Maize planting is normally accomplished by hand in the developing world where two or more seeds are placed per hill with a heterogeneous plant spacing and density. To understand the interaction between seed distribution and distance between hills, experiments were established in 2012 and 2013 at Lake Carl Blackwell (LCB) and Efaw Agronomy Research Stations, near Stillwater, OK. A randomized complete block design was used with three replications and 9 treatments and a factorial treatment structure of 1, 2, and 3 seeds per hill using interrow spacing of 0.16, 0.32, and 0.48 m. Data for normalized difference vegetation index (NDVI), intercepted photosynthetically active radiation (IPAR), grain yield, and grain N uptake were collected. Results showed that, on average, NDVI and IPAR increased with number of seeds per hill and decreased with increasing plant spacing. In three of four site-years, planting 1 or 2 seeds per hill, 0.16 m apart, increased grain yield and N uptake. Over sites, planting 1 seed, every 0.16 m, increased yields by an average of 1.15 Mg ha−1(range: 0.33 to 2.46 Mg ha−1) when compared to the farmer practice of placing 2 to 3 seeds per hill, every 0.48 m.

scholarly journals Developing Active Canopy Sensor-Based Precision Nitrogen Management Strategies for Maize in Northeast China

2019 ◽  
Vol 11 (3) ◽  
pp. 706 ◽  
Author(s):  
Xinbing Wang ◽  
Yuxin Miao ◽  
Rui Dong ◽  
Zhichao Chen ◽  
Yanjie Guan ◽  
...  
Keyword(s):  
Optimization Algorithm ◽  
Northeast China ◽  
Vegetation Index ◽  
Normalized Difference Vegetation Index ◽  
Field Experiments ◽  
Management Strategies ◽  
N Fertilizer ◽  
Yield Potential ◽  
Maize Production ◽  
N Management

Precision nitrogen (N) management (PNM) strategies are urgently needed for the sustainability of rain-fed maize (Zea mays L.) production in Northeast China. The objective of this study was to develop an active canopy sensor (ACS)-based PNM strategy for rain-fed maize through improving in-season prediction of yield potential (YP0), response index to side-dress N based on harvested yield (RIHarvest), and side-dress N agronomic efficiency (AENS). Field experiments involving six N rate treatments and three planting densities were conducted in three growing seasons (2015–2017) in two different soil types. A hand-held GreenSeeker sensor was used at V8-9 growth stage to collect normalized difference vegetation index (NDVI) and ratio vegetation index (RVI). The results indicated that NDVI or RVI combined with relative plant height (NDVI*RH or RVI*RH) were more strongly related to YP0 (R2 = 0.44–0.78) than only using NDVI or RVI (R2 = 0.26–0.68). The improved N fertilizer optimization algorithm (INFOA) using in-season predicted AENS optimized N rates better than the N fertilizer optimization algorithm (NFOA) using average constant AENS. The INFOA-based PNM strategies could increase marginal returns by 212 $ ha−1 and 70 $ ha−1, reduce N surplus by 65% and 62%, and improve N use efficiency (NUE) by 4%–40% and 11%–65% compared with farmer’s typical N management in the black and aeolian sandy soils, respectively. It is concluded that the ACS-based PNM strategies have the potential to significantly improve profitability and sustainability of maize production in Northeast China. More studies are needed to further improve N management strategies using more advanced sensing technologies and incorporating weather and soil information.

scholarly journals Sprinkling Irrigation Enhances Production of Oospores of Phytophthora Infestans in Field-Grown Crops of Potato

2000 ◽  
Vol 90 (10) ◽  
pp. 1105-1111 ◽  
Author(s):  
Yigal Cohen ◽  
Sonja Farkash ◽  
Alexander Baider ◽  
David S. Shaw
Keyword(s):  
Late Blight ◽  
Phytophthora Infestans ◽  
Mating Type ◽  
Field Experiments ◽  
Soil Surface ◽  
Field Trials ◽  
Detached Leaves ◽  
Oospore Formation ◽  
Potato Crops ◽  
Host Tissues

Two field experiments were conducted to study the effect of overhead sprinkling irrigation on oospore formation by the late blight fungus Phytophthora infestans in potato. Total rain (natural + sprinkling) accumulated in treatments of experiment 1 (winter 1997 to 1998) were 765, 287, and 219 mm and treatments of experiment 2 (winter 1999 to 2000) were 641, 193, and 129 mm. Sporangia from 11 isolates of P. infestans were combined in eight pairs, seven of A1 and A2 and one of A2 and A2 mating type, and were sprayed on field-grown potato crops (42 plants per plot at 7 m2 each) and examined for their ability to form oospores in the host tissues. In experiment 1, oospores were recorded in a total of 132 of 1,680 leaflets (7.9%), 24 of 105 stems, and 2 of 90 tubers. In experiment 2, oospores were recorded in 40 of 519 leaflets (7.7%), but not in any of the 90 stems or the 45 tubers examined. Both the proportion of leaflets containing oospores and the number of oospores per leaflet increased with time after inoculation and were dependent on the rain regime, the position of leaves on the plant, and the isolate pair combination. In both field trials, increasing the rainfall significantly enhanced oospore production in leaves. Leaf samples collected from the soil surface had significantly more oospores than those collected from the midcanopy. Two pairs in experiment 1 were more fertile than the others, whereas the pair used in experiment 2 was the least fertile. The total number of oospores per leaflet usually ranged from 10 to 100 in experiment 1, but only from 2 to 10 in experiment 2. Maximal oospore counts in the field were 200 and 50 in experiments 1 and 2, respectively, but ranged from ≈2,000 to 12,000 oospores per leaflet in detached leaves in the laboratory. We concluded that P. infestans can produce oospores in the foliage of field-grown potato crops, especially when kept wet by regular overhead sprinkling irrigation, but production was far below that in the laboratory.

scholarly journals Identification of the QTL-allele System Underlying Two High-Throughput Physiological Traits in the Chinese Soybean Germplasm Population

2021 ◽  
Vol 12 ◽  
Author(s):  
Lei Wang ◽  
Fangdong Liu ◽  
Xiaoshuai Hao ◽  
Wubin Wang ◽  
Guangnan Xing ◽  
...  
Keyword(s):  
High Throughput ◽  
Vegetation Index ◽  
Normalized Difference Vegetation Index ◽  
Genome Wide Association Study ◽  
Agronomic Traits ◽  
Block Design ◽  
Physiological Traits ◽  
Growth And Yield ◽  
Genetic Changes ◽  
Soybean Germplasm

The QTL-allele system underlying two spectral reflectance physiological traits, NDVI (normalized difference vegetation index) and CHL (chlorophyll index), related to plant growth and yield was studied in the Chinese soybean germplasm population (CSGP), which consisted of 341 wild accessions (WA), farmer landraces (LR), and released cultivars (RC). Samples were evaluated in the Photosynthetic System II imaging platform at Nanjing Agricultural University. The NDVI and CHL data were obtained from hyperspectral reflectance images in a randomized incomplete block design experiment with two replicates. The NDVI and CHL ranged from 0.05–0.18 and 1.20–4.78, had averages of 0.11 and 3.57, and had heritabilities of 78.3% and 69.2%, respectively; the values of NDVI and CHL were both significantly higher in LR and RC than in WA. Using the RTM-GWAS (restricted two-stage multi-locus genome-wide association study) method, 38 and 32 QTLs with 89 and 82 alleles and 2–4 and 2–6 alleles per locus were identified for NDVI and CHL, respectively, which explained 48.36% and 51.35% of the phenotypic variation for NDVI and CHL, respectively. The QTL-allele matrices were established and separated into WA, LR, and RC submatrices. From WA to LR + RC, 4 alleles and 2 new loci emerged, and 1 allele was excluded for NDVI, whereas 6 alleles emerged, and no alleles were excluded, in LR + RC for CHL. Recombination was the major motivation of evolutionary differences. For NDVI and CHL, 39 and 32 candidate genes were annotated and assigned to GO groups, respectively, indicating a complex gene network. The NDVI and CHL were upstream traits that were relatively conservative in their genetic changes compared with those of downstream agronomic traits. High-throughput phenotyping integrated with RTM-GWAS provides an efficient procedure for studying the population genetics of traits.

scholarly journals UJI KETAHANAN GALUR-GALUR KENTANG TRANSGENIK HASIL TRANSFORMASI DENGAN GEN RB TERHADAP PENYAKIT HAWAR DAUN (PHYTOPHTHORA INFESTANS) DI KP PASIRSARONGGE, CIANJUR

2013 ◽  
Vol 13 (2) ◽  
pp. 141-150
Author(s):  
Edy Listanto ◽  
M. Herman ◽  
Eri Sofiari
Keyword(s):  
Late Blight ◽  
Phytophthora Infestans ◽  
First Generation ◽  
Block Design ◽  
Transgenic Potato ◽  
Resistant Plant ◽  
Randomized Complete Block Design ◽  
Transgenic Lines ◽  
Transgenic Potatoes ◽  
Rb Gene

Resistance test strains of transgenic potatoes transformed with RB gene to late blight (Phytophthora infestan) in KP Pasirsarongge, Cianjur.  Potato late blight caused by Phytophthora infestans (P. infestans) (Mönt.) de Barry continues to be one of the most important crop diseases of all time. Genetic engineering of potato using RB gene for resistant plant to this disease is the most effective and environmental friendly to prevent widespread of late blight. This research aims to perform resistance of transgenic potato lines containing RB gene to lateblight (P. infestans) in Pasirsarongge, Cianjur field trial station. The first generation of transgenic lines were planted on polybag containing soil:manures using randomized complete block design. Tested plant inoculation was done naturaly from inoculum source from border row (Granola) that has been planted at one month before. The symptom was observed at one month after planting and damage scoring was done every three days for five times. Twenty two transgenic lines of tested plant showed various resistance respond to late blight (P. infestans) attack. Three transgenic lines showed highly resistance to late blight (P. infestans) were lines 11, 24, and 25, one transgenic line has resistant level was line 6.

Sign in / Sign up

Export Citation Format

Share Document