scholarly journals SPINACH MANAGEMENT INFLUENCES WHITE RUST, CHLOROSIS, ROOT GROWTH AND YIELD

HortScience ◽  
1993 ◽  
Vol 28 (4) ◽  
pp. 267B-267
Author(s):  
Daniel I. Leskovar ◽  
Mark C. Black

Effects of spinach crop management strategies on white rust (Albugo occidentalis), leaf chlorosis, root growth and yield were evaluated in winter 1991/92. Irrigation main plots were low (I-low), medium (I-med) and high (I-high). Fungicide split-plots were none (F0), metalaxyl at planting (F1), and metalaxyl at planting plus experimental CGA 2014 foliar (F2). Genotype split-split-plots were ACX 5044 and ARK 88-354. The Gompertz model best described the white rust disease progress. At all irrigation levels, ACX 5044 had the higher rate of disease increase (rG) and earlier disease onset than ARK 88-354. Metalaxyl delayed disease onset and rG in ACX 5044 only at I-low and I-med, but not at I-high. ARK 88-354 was the least sensitive to fungicides. Yellowness and chlorosis, estimated by spectrophotometric measurements, were higher at I-med and I-high, and with F0, while ARK 88-354 had less chlorosis than ACX 5044. Root diameter was increased with F1 compared to F0. Lateral and tap root fresh and dry weights were higher for ARK 88-354. Yields for ARK 88-354 were significantly higher than ACX 5044. No treatments influenced the number of live or aphids parasitized by Pandora neoaphidis.

HortScience ◽  
2006 ◽  
Vol 41 (3) ◽  
pp. 492E-493
Author(s):  
Shengrui Yao ◽  
Ian A. Merwin ◽  
Michael G. Brown

Minirhizotrons were employed to study new root occurrence, turnover, and depth distribution of apple (Malus ×domestica Borkh.) rootstocks under four groundcover management systems (GMS): preemergence herbicide (Pre-H), postemergence herbicide (Post-H), mowed sod (Grass) and hardwood bark mulch (Mulch) that have been maintained since 1992 in an orchard near Ithaca, NY. Two root observation tubes were installed on both sides of one tree in three replicates for each GMS treatment. Root observations were taken at 2–3 week intervals during growing seasons of 2002 and 2003. Tree growth and yield data were collected annually since 1992. The Mulch and Post-H treatments had bigger trees and higher yields than other treatments; whereas the Grass treatment had the smallest trees and lowest yields. Higher number of new roots was observed in a light crop year (2002) than a heavy crop year (2003). Mulch trees had more shallow roots and Grass trees had fewer total roots than other treatments. Root diameter was positively correlated with overwintering root survival. The Pre-H GMS had higher root mortality during a hot and dry growing season (2002). GMS treatments affected root number and root depth distribution patterns. Hot and dry weather conditions and crop load reduced new root emergence, increased root mortality and reduced root median lifespan. GMS treatments together with environmental factors affected root growth, turnover and distribution.


2017 ◽  
pp. 31-43
Author(s):  
Berta Ratilla ◽  
Loreme Cagande ◽  
Othello Capuno

Organic farming is one of the management strategies that improve productivity of marginal uplands. The study aimed to: (1) evaluate effects of various organic-based fertilizers on the growth and yield of corn; (2) determine the appropriate combination for optimum yield; and (3) assess changes on the soil physical and chemical properties. Experiment was laid out in Randomized Complete Block Design, with 3 replications and 7 treatments, namely; T0=(0-0-0); T1=1t ha-1 Evans + 45-30-30kg N, P2O5, K2O ha-1; T2=t ha-1 Wellgrow + 45-30-30kg N, P2O5, K2O ha-1; T3=15t ha-1 chicken dung; T4=10t ha-1 chicken dung + 45-30-30kg N, P2O5, K2O ha-1; T5=15t ha-1 Vermicast; and T6=10t ha-1 Vermicast + 45-30-30kg N, P2O5, K2O ha-1. Application of organic-based fertilizers with or without inorganic fertilizers promoted growth of corn than the control. But due to high infestation of corn silk beetle(Monolepta bifasciata Horns), its grain yield was greatly affected. In the second cropping, except for Evans, any of these fertilizers applied alone or combined with 45-30-30kg N, P2O5, K2O ha-1 appeared appropriate in increasing corn earyield. Soil physical and chemical properties changed with addition of organic fertilizers. While bulk density decreased irrespective of treatments, pH, total N, available P and exchangeable K generally increased more with chicken dung application.


2020 ◽  
Vol 8 (5) ◽  
pp. 611-614
Author(s):  
Dr. SV Patil ◽  
Dr. Nagaraja G ◽  
Dr. GR Rajkumar ◽  
Dr. Lingaraju NN ◽  
Dr. Adiga JD

2020 ◽  
Vol 73 (9-10) ◽  
pp. 295-300
Author(s):  
Mirela Jukovic ◽  
Viktor Till

Introduction. Chronic subdural hematoma has become an important entity in radiological, neurological and neurosurgery practice. Classification. The classification of chronic subdural hematoma is most often done in relation to the time of the disease onset (acute, subacute and chronic), whereas the second classification is based on hematoma density using computed tomography. Clinical presentation. The clinical presentation may mimic a spectrum of various diseases and chronic subdural hematoma can be easily overlooked without radiological verification. Diagnosis. The diagnosis of chronic subdural hematoma is partly clinical and partly radiological. In most cases, computed tomography is the initial diagnostic method for detection of this disease. Many studies point to different management strategies in the diagnosis and treatment of the disease. Therapy. The therapy of chronic subdural hematoma depends on the patient?s neurological deficit, but generally it is divided into conservative and surgical treatment. Conclusion. The aim of this paper is to review chronic subdural hematomas with reference to their clinical and radiological characteristics for better understanding of these phenomena.


2020 ◽  
Vol 21 (3) ◽  
pp. 179-193
Author(s):  
Chatterjee Anupriya ◽  
Nirwan Shradha ◽  
Bandyopadhyay Prasun ◽  
Agnihotri Abha ◽  
Sharma Pankaj ◽  
...  

: Oilseed brassicas stand as the second most valuable source of vegetable oil and the third most traded one across the globe. However, the yield can be severely affected by infections caused by phytopathogens. White rust is a major oomycete disease of oilseed brassicas resulting in up to 60% yield loss globally. So far, success in the development of oomycete resistant Brassicas through conventional breeding has been limited. Hence, there is an imperative need to blend conventional and frontier biotechnological means to breed for improved crop protection and yield. : This review provides a deep insight into the white rust disease and explains the oomycete-plant molecular events with special reference to Albugo candida describing the role of effector molecules, A. candida secretome, and disease response mechanism along with nucleotide-binding leucine-rich repeat receptor (NLR) signaling. Based on these facts, we further discussed the recent progress and future scopes of genomic approaches to transfer white rust resistance in the susceptible varieties of oilseed brassicas, while elucidating the role of resistance and susceptibility genes. Novel genomic technologies have been widely used in crop sustainability by deploying resistance in the host. Enrichment of NLR repertoire, over-expression of R genes, silencing of avirulent and disease susceptibility genes through RNA interference and CRSPR-Cas are technologies which have been successfully applied against pathogen-resistance mechanism. The article provides new insight into Albugo and Brassica genomics which could be useful for producing high yielding and WR resistant oilseed cultivars across the globe.


2020 ◽  
Author(s):  
Rui Zhang ◽  
Yi Wang ◽  
Zhichun Zhou

Abstract Background: Both NH4+ and NO3– are capable of greatly influencing plants’ growth and biomass. However, the belowground responses of subtropical trees to either NH4+ or NO3– deposition remain poorly understood. Here, we discuss how these two forms of N deposition can affect root development, and experimentally analyzed how they could impact nitrogen and phosphorus absorption in two types (broadleaved with a fibrous root system vs. conifer with a tap root system) of subtropical tree species. Results: In a greenhouse in southern China, 1-year-old S. superba and P. massoniana seedlings grown on P-limited and P-normal soil were treated with NaNO3 and NH4Cl solutions of 0, 80, and 200 kg N ha–1 year–1, corresponding to the control, N80, and N200 groups, respectively. Root phenotype characteristics and metabolism ability were measured after 8 months of growth. The results showed that the root morphology and physiology variables differed significantly between the two species under different N and P treatments. Although S. superba had a larger quantity of roots than P. massoniana, both its root growth rate and root absorption were respectively lower and weaker. N addition differentially affected root growth and activity as follows: (1) NO3–-N80 and NH4+-N80 increased root growth and activity of the two species, but NH4+-N80 led to thicker roots in S. superba; (2) NO3–-N200 and NH4+-N200 had inhibitory effects on the roots of P. massoniana, for which NH4+-N200 led to thinner and longer roots and even the death of some roots; and (3) NH4+-N could promote metabolic activity in thicker roots (> 1.5 mm) and the NO3–-N was found to stimulate activity in thinner roots (0.5–1.5 mm) in the fibrous root system having a larger quantity of roots, namely S. superba. By contrast, NO3–-N and NH4+-N had an opposite influence upon functioning in the tap root system with a slender root, namely P. massoniana. Conclusion: We conclude P. massoniana has a much higher root absorption efficiency; however, nitrogen deposition is more beneficial to the root growth of S. superba.


Weed Science ◽  
1972 ◽  
Vol 20 (1) ◽  
pp. 1-3 ◽  
Author(s):  
C. S. Hoveland ◽  
G. A. Buchanan

Fall panicum (Panicum dichotomiflorum Michx.) and Texas panicum (Panicum texanum Buckl.) were grown in the greenhouse under flooding treatments of 0, 6, and 9 days in 10 for 1 month. Fall panicum was more tolerant of flooded soil than was Texas panicum. Root development of Texas panicum was reduced by 50% under all flooding treatments. Herbage and root growth of fall panicum with flooding was similar to that on well-drained soil. Fall panicum root diameter was greater than that of Texas panicum, but both species increased under flooding. Tolerance of fall panicum to flooding may partially explain why it competes so well with crop plants during wet periods.


2019 ◽  
Vol 256 ◽  
pp. 108567 ◽  
Author(s):  
Catherine R. Simpson ◽  
Juan Carlos Melgar ◽  
Shad D. Nelson ◽  
Mamoudou Sétamou

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