scholarly journals Evaluation of Diagnostic Technologies for Assessing the N Nutritional Status of Lettuce

HortScience ◽  
1997 ◽  
Vol 32 (3) ◽  
pp. 519A-519
Author(s):  
C.A. Sanchez ◽  
M. Wilcox ◽  
J.L. Aguiar ◽  
K.S. Mayberry
Keyword(s):  
Nutritional Status ◽  
Field Experiments ◽  
Plant Biomass ◽  
Aerial Photographs ◽  
Growth Stages ◽  
Canopy Reflectance ◽  
N Nutrition ◽  
Iceberg Lettuce ◽  
Nitrate N ◽  
Diagnostic Technologies

Twenty field experiments were conducted to evaluate the response of iceberg lettuce (Lactuca sativa L.) to N and evaluate various diagnostic technologies as tools for assessing the N nutritional status of lettuce. Lettuce yields showed a curvilinear response to N in most experiments. Generally, the dry midrib nitrate-N test and the sap nitrate-N test appear to be sensitive indicators of the N nutritional status of lettuce after the folding stage of growth. The chlorophyll meter was not a sensitive indicator of the N nutritional status of lettuce. Preliminary data also show that canopy reflectance, including digital analysis of aerial photographs, is correlated to N nutritional status of lettuce. However, reflectance technologies do not readily distinguish between N deficiencies and other factors (insects, diseases, water stress, etc.) that affect plant biomass and color. Because plant tests do not appear to be sensitive indicators of N nutrition during early growth stages (before folding), a post-thinning (and pre-sidedress) soil nitrate-N test is currently being evaluated.

scholarly journals Assessment of the Effect of the Mineral Fertilization System on the Nutritional Status of Maize Plants and Grain Yield Prediction

Agriculture ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 404
Author(s):  
Renata Gaj ◽  
Piotr Szulc ◽  
Idzi Siatkowski ◽  
Hubert Waligóra
Keyword(s):  
Nutritional Status ◽  
Grain Yield ◽  
Field Experiments ◽  
Plant Biomass ◽  
Calcium Content ◽  
Development Stage ◽  
Mineral Fertilization ◽  
Stay Green ◽  
Maize Varieties ◽  
The Impact

A strict field experiment with maize was carried out in the years 2009–2011 at the Experimental Station of the Poznań University of Life Sciences. The impact of mineral fertilization levels on the nutritional status of plants at an early development stage 5–6 leaves (BBCH 15/16) was assessed, as well as the possibility of using biomass and the current state of nutrient supply to predict grain yield. The adopted assumptions were verified on the basis of field experiments with nine variants of mineral fertilization and two maize varieties (EURALIS Semences, Lescar, France) (ES Palazzo and ES Paroli SG—“stay-green” (SG)). Regardless of the variety tested, the plants were under-nutritioned with calcium and magnesium. Plant nutritional status and the accumulation of minerals at the BBCH 15/16 stage were the main factors determining the variability of maize grain yields. In addition, it was shown that maize biomass in the BBCH 15/16 stage, calcium content and the N:K ratio significantly determined grain yield of traditional variety. The yield of the “stay-green” hybrid was largely shaped by plant biomass in the BBCH 15/16 stage, potassium, calcium, magnesium contents and N:Mg ratio. Regression analysis showed that grain yield of the tested maize varieties was determined by plant biomass and its content from 59% to 69%.

scholarly journals In-Season Diagnosis of Rice Nitrogen Status Using Proximal Fluorescence Canopy Sensor at Different Growth Stages

2019 ◽  
Vol 11 (16) ◽  
pp. 1847 ◽  
Author(s):  
Shanyu Huang ◽  
Yuxin Miao ◽  
Fei Yuan ◽  
Qiang Cao ◽  
Huichun Ye ◽  
...  
Keyword(s):  
Field Experiments ◽  
Stem Elongation ◽  
N Uptake ◽  
Growth Stages ◽  
Cold Regions ◽  
N Nutrition ◽  
N Concentration ◽  
Field Samples ◽  
Different Growth Stages ◽  
N Status

Precision nitrogen (N) management requires an accurate and timely in-season assessment of crop N status. The proximal fluorescence sensor Multiplex®3 is a promising tool for monitoring crop N status. It performs a non-destructive estimation of plant chlorophyll, flavonol, and anthocyanin contents, which are related to plant N status. The objective of this study was to evaluate the potential of proximal fluorescence sensing for N status estimation at different growth stages for rice in cold regions. In 2012 and 2013, paddy rice field experiments with five N supply rates and two varieties were conducted in northeast China. Field samples and fluorescence data were collected in the leaf scale (LS), on-the-go (OG), and above the canopy (AC) modes using Multiplex®3 at the panicle initiation (PI), stem elongation (SE), and heading (HE) stages. The relationships between the Multiplex indices or normalized N sufficient indices (NSI) and five N status indicators (above-ground biomass (AGB), leaf N concentration (LNC), plant N concentration (PNC), plant N uptake (PNU), and N nutrition index (NNI)) were evaluated. Results showed that Multiplex measurements taken using the OG mode were more sensitive to rice N status than those made in the other two modes in this study. Most of the measured fluorescence indices, especially the N balance index (NBI), simple fluorescence ratios (SFR), blue–green to far-red fluorescence ratio (BRR_FRF), and flavonol (FLAV) were highly sensitive to N status. Strong relationships between these fluorescence indices and N indicators, especially the LNC, PNC, and NNI were revealed, with coefficients of determination (R2) ranging from 0.40 to 0.78. The N diagnostic results indicated that the normalized N sufficiency index based on NBI under red illumination (NBI_RNSI) and FLAV achieved the highest diagnostic accuracy rate (90%) at the SE and HE stages, respectively, while NBI_RNSI showed the highest diagnostic consistency across growth stages. The study concluded that the Multiplex sensor could be used to reliably estimate N nutritional status for rice in cold regions, especially for the estimation of LNC, PNC, and NNI. The normalized N sufficiency indices based on the Multiplex indices could further improve the accuracy of N nutrition diagnosis by reducing the influences of inter-annual variations and different varieties, as compared with the original Multiplex indices.

scholarly journals A New Curve of Critical Leaf Potassium Concentration Based on the Maximum Root Dry Matter for Diagnosing Potassium Nutritional Status of Sweet Potato

2021 ◽  
Vol 12 ◽  
Author(s):  
Zunfu Lv ◽  
Guoquan Lu
Keyword(s):  
Nutritional Status ◽  
Sweet Potato ◽  
Dry Matter ◽  
Field Experiments ◽  
Growth Period ◽  
Nutrient Concentrations ◽  
Growth Stages ◽  
Application Rates ◽  
Maximum Root ◽  
K Concentration

Critical leaf nutrient concentrations have often been used to diagnose the nutritional status of crops. Determining critical leaf potassium (K) concentrations for the maximum root dry matter (RDM) will provide a reliable means of linking leaf K nutrient concentrations to the yield of sweet potato. Three field experiments, using varying K application rates (0–300 kg K ha−1) and two sweet potato cultivars, were performed in the Zhejiang Province of China. A new critical leaf K curve (Kleaf) based on the maximum RDM was determined to assess K nutrition in sweet potato and described by the equation Kleaf=4.55×RDMmax-0.075. A critical root K curve (Kroot) based on the maximum RDM was also determined to assess K nutrition and described by the equation Kroot=2.36×RDMmax-0.087. The K nutrition index (KNI) was constructed to identify the situations of K-limiting and non-K-limiting treatments. The leaf KNI (KNIleaf) ranged from 0.56 to 1.17, and the root K KNI (KNIroot) ranged from 0.52 to 1.35 during the growth period of sweet potato. The results showed that the critical leaf K concentration curve can be used as an accurate leaf K status diagnostic tool at critical growth stages that connected leaf nutrient concentration and sweet potato tuber yield. This K curve will contribute to K management of sweet potato during its growth period in China.

scholarly journals The Nitrogen-Fixing Bacteria—Effective Enhancers of Growth and Chemical Composition of Egyptian Henbane under Varied Mineral N Nutrition

Agronomy ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 921
Author(s):  
Rania M. A. Nassar ◽  
Engy A. Seleem ◽  
Gianluca Caruso ◽  
Agnieszka Sekara ◽  
Magdi T. Abdelhamid
Keyword(s):  
Seed Yield ◽  
Field Experiments ◽  
Tropane Alkaloids ◽  
Pharmaceutical Products ◽  
N Fertilizer ◽  
Recommended Dose ◽  
Mineral N ◽  
N Nutrition ◽  
N Dose ◽  
Egyptian Henbane

Egyptian henbane (Hyoscyamus muticus L.) plants are rich sources of alkaloids used in pharmaceutical products. Recently, rising efforts have been devoted to reducing mineral fertilizer supply, production cost, and environmental pollution via decreasing the doses of nitrogenous fertilizers and adopting biofertilizer farming systems. Two field experiments were conducted to examine the potential role of N fixing bacteria Azotobacter spp. and Azospirillum spp. on the growth, mineral status, tropane alkaloids, leaf anatomy, and seed yield of Egyptian henbane grown with different levels of mineral nitrogen fertilizer, i.e., 25%, 50%, and 100% of the recommended dose, equal to 30, 60, and 120 kg N ha−1. N fertilizer improved growth, mineral elements, tropane alkaloids, seed yield, and yield components of Egyptian henbane, which showed a gradually rising trend as the rate of N fertilizer increased. High doses of N fertilizer presumably elicited favorable changes in the anatomical structure of Egyptian henbane leaves. The application of 50% N dose plus N fixing bacteria affected Egyptian henbane trials similarly to 100% of recommended N dose. In conclusion, the N fixing bacteria proved to be a sustainable tool for a two-fold reduction in the recommended dose of mineral N fertilizer and the sustainable management of Egyptian henbane nutrition.

Acrolein Reduces Biomass and Seed Production of Potamogeton pectinatus in Irrigation Channels

2004 ◽  
Vol 18 (3) ◽  
pp. 605-610 ◽  
Author(s):  
Diego J. Bentivegna ◽  
Osvaldo A. Fernández ◽  
María A. Burgos
Keyword(s):  
Plant Growth ◽  
Field Experiments ◽  
Plant Biomass ◽  
Treatment Plant ◽  
Irrigation District ◽  
Potamogeton Pectinatus ◽  
Individual Plant ◽  
Plant Weight ◽  
The Third ◽  
Irrigation Channels

Chemical weed control with acrolein has been shown to be a lower cost method for reducing submerged plant biomass of sago pondweed in the irrigation district of the Lower Valley of Rio Colorado, Argentina (39°10′S–62°05′W). However, no experimental data exist on the effects of the herbicide on plant growth and its survival structures. Field experiments were conducted during 3 yr to evaluate the effect of acrolein on growth and biomass of sago pondweed and on the source of underground propagules (i.e., rhizomes, tubers, and seeds). Plant biomass samples were collected in irrigation channels before and after several herbicide treatments. The underground propagule bank was evaluated at the end of the third year. Within each treatment, plant biomass was significantly reduced by 40 to 60% in all three study years. Rapid new plant growth occurred after each application; however, it was less vigorous after repeated treatments. At the end of the third year at 3,000 m downstream from the application point, plant biomass at both channels ranged from 34 to 3% of control values. Individual plant weight and height were affected by acrolein treatments, flowering was poor, and seeds did not reach maturity. After 3 yr, acrolein did not reduce the number of tubers. However, they were significantly smaller and lighter. Rhizomes fresh weight decreased by 92%, and seed numbers decreased by 79%. After 3 yr of applications, operational functioning of the channels could be maintained with fewer treatments and lower concentrations of acrolein.

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.

Inoculant formulation and fertilizer nitrogen effects on field pea: Nodulation, N2 fixation and nitrogen partitioning

2004 ◽  
Vol 84 (1) ◽  
pp. 79-88 ◽  
Author(s):  
G. W. Clayton ◽  
W. A. Rice ◽  
N. Z. Lupwayi ◽  
A. M. Johnston ◽  
G. P. Lafond ◽  
...  
Keyword(s):  
Pisum Sativum ◽  
Field Experiments ◽  
Field Pea ◽  
Nitrogen Partitioning ◽  
Residual Soil ◽  
N Accumulation ◽  
N Nutrition ◽  
Application Rates ◽  
River Region ◽  
Inoculant Formulation

Field pea (Pisum sativum L.) acreage has expanded rapidly in the past 10 yr in the Peace River Region of Alberta as well as western Canada. Understanding nitrogen dynamics of Rhizobium inoculants and applied N will provide farmers opportunities to improve N nutrition of field pea. Field experiments were conducted (a) to compare the effects of soil inoculation using granular inoculant, and seed inoculation using peat powder and liquid inoculants with an uninoculated check, on field pea nodulation and N2 fixation, and (b) to determine whether starter N is required by field pea to enhance N2 fixation. The effects of inoculant formulation on nodule number, N accumulation and N2 fixation were in the order: granular > peat powder > liquid = uninoculated. Field pea, from soil-applied inoculant, accumulated more N prior to and during podfilling than field pea with seed-applied inoculant. Fertilizer N application rates < 40 kg N ha-1 had no significant effects on biomass N at flatpod, indicating that starter N was not necessary. Application rates greater than 40 kg N ha-1 reduced nodulation, but the total amounts of N accumulated by plants did not vary. The close proximity of a highly concentrated band of N fertilizer had a greater impact on nodulation and subsequent N2 fixation than the residual soil N level. Under field conditions, soil-applied inoculant improved N nutrition of field pea compared to seed-applied inoculation, with or without applied urea-N. Key words: Granular inoculant, Pisum sativum, Rhizobium, inoculation, field pea, nodulation, N2 fixation

scholarly journals An Analytical View on Water Use Efficiency of Some Main Crops Grown in the Non-costal Parts of Thrace Region

2020 ◽  
pp. 47-57
Author(s):  
Recep Cakir
Keyword(s):  
Water Use Efficiency ◽  
Water Use ◽  
Irrigation Water ◽  
Field Experiments ◽  
Soil Depth ◽  
Growth Stages ◽  
Irrigation Water Use ◽  
Rainfed Farming ◽  
Use Efficiency ◽  
Thrace Region

The article contains data obtained from evaluations related to irrigation water use efficiency (IWUE) and water use efficiency (WUE), for the main crops, irrigated at different stages of growth, on the basis of some findings obtained in the Research Institute in Kırklareli. Each of the experimental crops was sown and farmed following procedures applied by the farmers in the region, except of the irrigation applications which were based on the sensitivity of a certain crop to water shortage in the soil, during the specific growth stages. Similar procedures were applied and all the experimental treatments were irrigated at growth stages, as predicted in the research methodology, and water amounts required to fill the 0-90 cm soil depth to field capacity were implied. Evaluation data obtained from the field experiments with three major crops, grown on the non-coastal lands of Thrace Region showed, that the productivity of irrigation water, as well as water use efficiencies of all analysed crops, are growth stage controlled. The highest IWUE and WUE efficiencies of 0.87 and 0.92 kg da-1 m-3; and 1.08 kg da-1 m-3 and 0.81 kg da-1 m-3; were determined for wheat and sunflower crops, irrigated at booting and flowering stages, respectively. Each m3 of irrigation water, applied during the most sensitive fruit formation stage (Ff) of pumpkin crop, provided additionally 8.47 kg da-1 fruit yield, 8.09 fruit numbers and 0.28 kg da-1 seed yields, more than those of rainfed farming (R).

scholarly journals Influence of meteorological parameters on wheat yield under different sowing conditions

MAUSAM ◽  
2022 ◽  
Vol 73 (1) ◽  
pp. 161-172
Author(s):  
ANANTA VASHISTH ◽  
DEBASISH ROY ◽  
AVINASH GOYAL ◽  
P. KRISHNAN
Keyword(s):  
Relative Humidity ◽  
Soil Temperature ◽  
Air Temperature ◽  
Field Experiments ◽  
Wheat Yield ◽  
Weather Condition ◽  
Grain Filling ◽  
Crop Growth ◽  
Leaf Water ◽  
Growth Stages

Field experiments were conducted on the research farm of IARI, New Delhi during Rabi 2016-17 and 2017-18. Three varieties of wheat (PBW-723, HD-2967 and HD-3086) were sown on three different dates for generating different weather condition during various phenological stages of crop. Results showed that during early crop growth stages soil moisture had higher value and soil temperature had lower value and with progress of crop growth stage, the moisture in the upper layer decreased and soil temperature increased significantly as compared to the bottom layers. During tillering and jointing stage, air temperature within canopy was more and relative humidity was less while during flowering and grain filling stage, air temperature within canopy was less and relative humidity was more in timely sown crop as compared to late and very late sown crop. Radiation use efficiency and relative leaf water content had significantly higher value while leaf water potential had lower value in timely sown crop followed by late and very late sown crop. Yield had higher value in HD-3086 followed by HD-2967 and PBW-723 in all weather conditions. Canopy air temperature difference had positive value in very late sown crop particularly during flowering and grain-filling stages. This reflects in the yield. Yield was more in timely sown crop as compared to late and very late sown crop.  

Sign in / Sign up

Export Citation Format

Share Document