scholarly journals Evaluating RGB Imaging and Multispectral Active and Hyperspectral Passive Sensing for Assessing Early Plant Vigor in Winter Wheat

Sensors ◽  
2018 ◽  
Vol 18 (9) ◽  
pp. 2931 ◽  
Author(s):  
Lukas Prey ◽  
Malte von Bloh ◽  
Urs Schmidhalter

Plant vigor is an important trait of field crops at early growth stages, influencing weed suppression, nutrient and water use efficiency and plant growth. High-throughput techniques for its evaluation are required and are promising for nutrient management in early growth stages and for detecting promising breeding material in plant phenotyping. However, spectral sensing for assessing early plant vigor in crops is limited by the strong soil background reflection. Digital imaging may provide a low-cost, easy-to-use alternative. Therefore, image segmentation for retrieving canopy cover was applied in a trial with three cultivars of winter wheat (Triticum aestivum L.) grown under two nitrogen regimes and in three sowing densities during four early plant growth stages (Zadok’s stages 14–32) in 2017. Imaging-based canopy cover was tested in correlation analysis for estimating dry weight, nitrogen uptake and nitrogen content. An active Greenseeker sensor and various established and newly developed vegetation indices and spectral unmixing from a passive hyperspectral spectrometer were used as alternative approaches and additionally tested for retrieving canopy cover. Before tillering (until Zadok’s stage 20), correlation coefficients for dry weight and nitrogen uptake with canopy cover strongly exceeded all other methods and remained on higher levels (R² > 0.60***) than from the Greenseeker measurements until tillering. From early tillering on, red edge based indices such as the NDRE and a newly extracted normalized difference index (736 nm; ~794 nm) were identified as best spectral methods for both traits whereas the Greenseeker and spectral unmixing correlated best with canopy cover. RGB-segmentation could be used as simple low-cost approach for very early growth stages until early tillering whereas the application of multispectral sensors should consider red edge bands for subsequent stages.

1954 ◽  
Vol 5 (2) ◽  
pp. 198
Author(s):  
RF Williams

This paper reports a study in crop physiology in which an analysis of plant growth response and nutrient intake under irrigation in the field is used to interpret the effects of rice hulls as an organic manure. An exploratory experiment showed that relatively speaking the main effects of treatment took place quite early in the growth of the crop. For this reason the main experiment was virtually restricted to these early growth stages. The test plant in both experiments was the tomato. It was found that rice hulls can influence the growth of the crop in at least three ways. Seedling emergence may be delayed, early growth may be retarded by temporary shortage of available nitrogen, and growth may be stimulated by increase in available phosphorus. All three effects are modified by the addition of sulphate of ammonia, but in all cases the result is an increase in yield with rice-hull treatment. Mean seedling emergence for the six experimental treatments had a range of 2.8 days, and it is shown that the mean weights of 18-day-old seedlings could have been accounted for by these differences alone. The pattern of response at 18 days remains for at least five weeks and is not without its effect on the final yields. In spite of their low nitrogen content, rice hulls alone had only a transitory adverse effect on the nitrogen status of the soil. It is suggested that this may not have had any direct effect on the rate of dry-matter production, but that there was a temporary deflection of assimilates to favour root growth at the expense of shoot growth. Such an effect would, of course, have an adverse effect on fruit yield. Plant analyses suggest very considerable increases in available soil phosphorus due to rice-hull treatment. Much of this phosphorus appears to have been fixed during the course of the experiment, but Truog values obtained after the experiment indicated that significant effects of treatment were still present. The increases in Available phosphorus were less when sulphate of ammonia was added with the rice hulls.


2000 ◽  
Vol 125 (3) ◽  
pp. 282-287 ◽  
Author(s):  
Satoru Kondo ◽  
Akihiro Tomiyama ◽  
Hideharu Seto

Trans-jasmonic acid (JA), cis-JA, and trans-methyl jasmonate (MeJA) were quantified in pulp and seeds of `Tsugaru' apple [Malus sylvestris (L.) Mill. var. domestica (Borkh.) Mansf.] and `Satohnishiki' sweet cherry (Prunus avium L.). Trans-JA and cis-JA showed similar changes during development in both types of fruit. JA concentration was high in the early growth stages of apple pulp development, decreased with days after full bloom (DAFB), and then increased again during maturation. There was an initial decrease in concentration of MeJA in apple pulp, followed by a general increase towards harvest. Concentrations of JA and MeJA in the pulp of sweet cherry were high during early growth stages, then decreased towards harvest. PDJ treatment at 104 DAFB (preclimacteric stage) increased endogenous abscisic acid concentration and anthocyanin concentration at 122 and 131 DAFB (maturation stages) in apple. JA concentration in apple seeds was also high in the early growth stages, then decreased, and finally peaked at harvest. MeJA concentration in apple seeds increased towards harvest. In the seeds of sweet cherry, JA and MeJA concentrations generally increased until harvest. In both types of fruit, concentrations of JA and MeJA in the seeds were higher than those of pulp. On a dry weight basis, changes in concentration in the seeds preceded those in the pulp. These results demonstrate that relatively high amounts of JA and MeJA are associated with young developing fruit. These substances may have a role in regulation of fruit growth at early growth stages, though this has not been demonstrated. Chemical name used: n-propyl dihydrojasmonate (PDJ).


HortScience ◽  
2006 ◽  
Vol 41 (2) ◽  
pp. 361-366 ◽  
Author(s):  
Laurie Hodges ◽  
Entin Daningsih ◽  
James R. Brandle

Field experiments were conducted over 4 years to evaluate the effects of antitranspirant (Folicote, Aquatrol Inc., Paulsboro, N.J.) and polyacrylamide gel (SuperSorb, Aquatrol Inc., Paulsboro, N.J.) on early growth of transplanted muskmelon grown either protected by tree windbreaks or exposed to seasonal winds. A randomized complete block design (RCBD) with split plot arrangement was used with wind protection (sheltered and exposed) areas as the main treatment and use of an antitranspirant spray or gel dip as subtreatments. Based on destructive harvests in the field, treatments and subtreatments did not affect dry weight or leaf area index in the first 2 years. Specific contrasts, however, showed that gel application significantly increased fresh weight, dry weight, and leaf area index over that of the untreated transplants whereas the spray application tended to reduce these factors during the first 3 weeks after transplanting. Significant differences between gel and spray subtreatments disappeared by 5 weeks after transplanting. Shelterbelts ameliorated crop microclimate thereby enhancing plant growth. Significantly, wind velocity at canopy height was reduced 40% on average and soil temperatures were about 4% warmer in the sheltered plots compared to the exposed plots during the first 5 weeks post-transplant. Muskmelon plants in the sheltered areas grew significantly faster than the plants in the exposed areas in 2 of the 3 years reported, with the 3-year average fresh weight increased by 168% due to wind protection. Overall transplanting success and early growth were enhanced the most by wind protection, followed by the polyacrylamide gel root dip, and least by the antitranspirant foliar spray. We conclude that microclimate modification by wind speed reduction can increase early muskmelon plant growth more consistently than the use of polyacrylamide gel as a root dip at transplanting or the use of an antitranspirant spray. A polyacrylamide gel root dip generally will provide more benefit during early muskmelon growth than the use of an antitranspirant spray.


2020 ◽  
Author(s):  
Lubna Lubna ◽  
Muhammad Aaqil Khan ◽  
Sajjad Asaf ◽  
Rehmatullah Jan ◽  
Muhammad Waqas ◽  
...  

Abstract Background Salinity stress is one of the most devastating environmental stress that inhibits plants growth and development. Many strategies including plant growth promoting fungi have been reported to mitigate salt stress. Results In this study, we adopted environmental friendly technique and screened different plant growth promoting fungi for different PGP traits and salinity stress. Among these isolate CSL1 were selected based on the basis of plant growth promoting characteristics producing IAA, GAs, organic acid and tolerance to NaCl stress. Furthermore, inoculation of fungal isolate CSL1 significantly increased shoot length (16%), root length (37%), shoot fresh and dry weight (19% and 25%), root fresh and dry weight (47 and 51%) and chlorophyll content (24%) under NaCl stress (200 mM). Endogenous ABA level (0.77 folds) were significantly decreased while SA contents (16%) were increase in CSL1 inoculated plants under NaCl stress. Similarly, higher level of antioxidants such as MDA (2 folds), SOA (29%), POD (8 folds) and PPO (3 folds) was observed in NaCl treated non-inoculated plants. ICP analysis showed an increase in Na+ (11 folds) and decrease in K+ content (15%). Furthermore, CSL-1 inoculation improved soybean adaptability against NaCl stress and a significant decrease in GmFDL19 expression (5 folds) GmNARK (4 folds) and GmSIN1 (3 folds) was observed. However, higher expression of GmAKT2 (15%) were observed in CSL-1 treated plants. Conclusion Fungal isolate CSL-1 have capability to mitigate salinity stress in soybean, increase plant growth and could be used as valuable ecofriendly microorganism resource, low cost based biotechnological approach for sustainable agriculture in salt affected areas.


2021 ◽  
Vol 12 ◽  
Author(s):  
Arianna Latini ◽  
Fabio Fiorani ◽  
Patrizia Galeffi ◽  
Cristina Cantale ◽  
Annamaria Bevivino ◽  
...  

This study aims to highlight the major effects of biochar incorporation into potting soil substrate on plant growth and performance in early growth stages of five elite Italian varieties of durum wheat (Triticum durum). The biochars used were obtained from two contrasting feedstocks, namely wood chips and wheat straw, by gasification under high temperature conditions, and were applied in a greenhouse experiment either as pure or as nutrient-activated biochar obtained by incubation with digestate. The results of the experiment showed that specific genotypes as well as different treatments with biochar have significant effects on plant response when looking at shoot traits related to growth. The evaluated genotypes could be clustered in two main distinct groups presenting, respectively, significantly increasing (Duilio, Iride, and Saragolla varieties) and decreasing (Marco Aurelio and Grecale varieties) values of projected shoot system area (PSSA), fresh weight (FW), dry weight (DW), and plant water loss by evapotranspiration (ET). All these traits were correlated with Pearson correlation coefficients ranging from 0.74 to 0.98. Concerning the treatment effect, a significant alteration of the mentioned plant traits was observed when applying biochar from wheat straw, characterized by very high electrical conductivity (EC), resulting in a reduction of 34.6% PSSA, 43.2% FW, 66.9% DW, and 36.0% ET, when compared to the control. Interestingly, the application of the same biochar after nutrient spiking with digestate determined about a 15–30% relief from the abovementioned reduction induced by the application of the sole pure wheat straw biochar. Our results reinforce the current basic knowledge available on biological soil amendments as biochar and digestate.


Weed Science ◽  
1987 ◽  
Vol 35 (2) ◽  
pp. 247-252 ◽  
Author(s):  
Thai K. Van ◽  
Kerry K. Steward ◽  
Richard D. Conant

Control of monoecious and dioecious hydrilla [Hydrilla verticillata(L.f.) Royle # HYLLI] biotypes required a minimum 2 days of exposure to diquat (6,7-dihydrodipyrido [1,2-α:2′,1′-c] pyrazinediium ion) at a concentration of 0.25 mg/L under laboratory conditions. When treatment concentration was increased to 2.0 mg/L diquat, the minimum required contact time was reduced to 6 or 12 h depending on plant growth stage. Early growth emerging from sprouting tubers appeared to be more susceptible to diquat treatments. Herbicide uptake was linear during a 4-day exposure to14C-diquat up to 1.0 mg/L, and the amounts of radioactivity in plant tissue varied proportionally with ambient levels of14C-diquat in water. The lethal concentration of diquat in hydrilla tissue was estimated to be 81 μg/g plant dry weight when hydrilla was exposed to diquat at 0.25 mg/L for 2 days.


2003 ◽  
Vol 93 (3) ◽  
pp. 256-261 ◽  
Author(s):  
Fabrício Á. Rodrigues ◽  
Francisco X. R. Vale ◽  
Lawrence E. Datnoff ◽  
Anne S. Prabhu ◽  
Gaspar H. Korndörfer

The objective of this study was to determine the effect of silicon (Si) and rice growth stages on tissue susceptibility to sheath blight (Rhizoctonia solani Kühn) under controlled conditions. Rice plants (cv. Rio Formoso) were grown in pots containing low-Si soil amended with Si at 0, 0.48, 0.96, 1.44, and 1.92 g pot-1 and inoculated with R. solani at the following days after emergence: 45 (four-leaf stage), 65 (eight-leaf stage), 85 (tillering), 117 (booting), and 130 (panicle exsertion). For plants inoculated with R. solani at all growth stages, Si concentration in straw increased as rate of Si increased from 0 to 1.92 g pot-1. Concentration of calcium in the straw did not differ among plant growth stages. Although incubation period was not affected by the amount of Si added to the soil, this variable was shorter at booting and panicle exsertion stages. As the rates of Si increased in the soil, the total number of sheath blight lesions on sheaths and total area under the relative lesion extension curve decreased at all plant growth stages. The severity of sheath blight was lower at booting and panicle exsertion stages as the rates of Si increased in the soil. In general, plants grown in Si-nonamended pots and inoculated with R. solani were more vulnerable to infection at all growth stages, but especially at 45 days after emergence. Plant dry weights for inoculated plants increased as the Si rates increased from 0 to 1.92 g pot-1. The greatest dry weight increases occurred for plants inoculated at booting and panicle exsertion stages. Si fertilization is a promising method for controlling sheath blight in areas where soil is Si deficient and when cultivars that exhibit an acceptable level of resistance to sheath blight are not available for commercial use.


HortScience ◽  
2020 ◽  
Vol 55 (8) ◽  
pp. 1280-1287
Author(s):  
Bernadine C. Strik ◽  
Amanda J. Davis ◽  
David R. Bryla ◽  
Scott T. Orr

A 2-year trial was established in Oct. 2016 in western Oregon to evaluate the effects of various in-row mulch treatments on the establishment of northern highbush blueberry (Vaccinium corymbosum L. ‘Duke’). The treatments included douglas fir [Pseudotsuga menziesii (Mirb.) Franco] sawdust, black weed mat (woven polypropylene groundcover), green weed mat, and sawdust covered with black or green weed mat. Soil temperature was unaffected by the color of the weed mat, but it was often higher during the day in beds with weed mat mulch than in those with sawdust alone or sawdust covered with weed mat. Black or green weed mat also resulted in higher canopy temperatures, particularly when sawdust was underneath the weed mat. Plant growth was mainly unaffected by the color of the weed mat, and the maximum depth of the root system was similar among the mulch treatments. However, plants grown with sawdust mulch, with or without weed mat, had a greater canopy width and volume in year 2, a wider root system in both years, and more dry weight (DW) in the crown in year 1 and in the whips in year 2 than those with weed mat alone. Furthermore, plants with weed mat over sawdust were taller in year 1 and had greater canopy cover and more DW in new wood in year 2 than those with sawdust alone, and they had a larger canopy, more root development, and greater DW in the crown, new and old wood, fruit, and pruning wood in one or both years than those with weed mat alone. Over the course of the 2 years of the study, the net gain in total plant DW was lowest when the plants were grown with black weed mat and highest when they were grown with black weed mat over sawdust. Although it was more expensive initially, the use of weed mat over sawdust resulted in more plant growth than weed mat alone due to the insulating properties of the sawdust, and it was more effective for weed control than using sawdust alone.


2019 ◽  
pp. 36-40
Author(s):  
M. M. Abdelkader ◽  
M. Yu. Puchkov

Relevance. Tomato considered a significant vegetable crop that plays a prominent role in the field of human health. At present, there are large numbers of tomato cultivars with a wide range of morphological and sensorial characteristics which determine their use. Farmers often use some chemical substances which have similar structure and activity with endogenous plant hormone called (exogenous) as a low-cost alternative to regulate plant growth and increase yield. Thus, the use of Plant Growth Regulators (PGRs) has become an important component of the agro-technical procedures for most cultivated species.Methods. This study aims to evaluate the effect of four growth regulators (Krezacin, Chitosan, Zircon and Energene) on growth, productivity and quality of two Russian tomato varieties (Moriana and Superjol) under delta Volga conditions. Each type applied three times on both cultivars (Soaking tomato seeds before sowing, spraying on plants at vegetative phase, spraying on plants at flowering phase with three replications.Results. The results showed that; combination between Energene and cultivar Moriana enhanced the most of studied characters (Germination – 83.1%, fresh weight of Arial parts – 241.9 g, dry weight – 74.4 g, Number of № flowers/plant – 51.0, № fruits /plant – 35.6, fruit set – 69.8%, plant yield – 2.44 kg, TSS – 5.1°Brix, Content of Ascorbic Acid – 25.6 mg/100 g); Interaction between “Energene x Superjol” gave the maximum value for Plant height (85.6 cm), Fruit weight (72.6 g); while “Krezacin x Moriana” registered the highest fruit dry matter (6.77%) and Acidity (0.53%); Applying Zircon on Cultivar Moriana increased number of leaves/plant (56.8) and nitrate contents (27.6 mg/kg); the maximum LAI (150.1 cm2 ) obtained from interaction between Chitosan and cultivar Superjol whereas, “Chitosan x Moriana” treatment gave the highest level of Carotenoids (4.12%). 


HortScience ◽  
1995 ◽  
Vol 30 (4) ◽  
pp. 912A-912
Author(s):  
Matt Welch ◽  
D.L. Creech

The poultry industry is a $1 billion industry in Texas, with most production centered in eastern Texas. The nursery industry is a $600 million industry, with 25% of the producers located in eastern Texas. With hundreds of millions of birds produced each year, and each bird producing ≈2 lb of manure, waste disposal is a growing problem. Composted poultry litter was mixed with composted pine bark to create five media with varying percentages of poultry litter as a component: 0%, 5%, 10%, 20%, and 40%. A randomized complete-block design was used with poultry litter rates as main plots and plant species tested as subplots. Five species included: tomato, marigold, Cortaderia selloana, Asian jasmine, and Salvia leucantha. Prior to planting, all 1-gal containers were leached with 1000 ml of water, the leachate collected, and tested for conductivity. Plant growth measurements to be presented include plant height and dry weight. The results of media and leaf tissue nutrient analysis will be presented.


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