scholarly journals Effects of Oxygen Deprivation and Pythium Root Rot on Sugarcane Red Rot

Plant Disease ◽  
1998 ◽  
Vol 82 (11) ◽  
pp. 1237-1241 ◽  
Author(s):  
Zhi Yin ◽  
J. W. Hoy

The effects of oxygen deprivation or poor drainage and Pythium root rot on development of red rot, caused by Colletotrichum falcatum, and spring shoot population of sugarcane were evaluated under controlled and field conditions. Detached stalks of five cultivars were exposed to low atmospheric oxygen (0.5 to 2.7%), created by enclosing stalks in sealed chambers through which humidified nitrogen gas was passed for 0, 1, or 2 weeks. Stalks were then inoculated with C. falcatum and maintained for 6 weeks with humidified air flow. Red rot severity, assessed as four disease traits, was not increased by previous oxygen deprivation. In field experiments, inoculation of stalks of three cultivars with C. falcatum before planting resulted in a reduction in shoot populations the following spring. Poor drainage resulted in an additional reduction in shoot populations developing from inoculated stalks. Soil atmospheric oxygen was reduced in the root zone below planted stalks under poor drainage conditions. However, only minor reductions in oxygen were detected in the zone of elevated rows in which planted stalks were located. The detrimental effect of poor drainage on shoot populations from inoculated stalks was alleviated by metalaxyl application. Pythium root rot, caused by Pythium arrhenomanes, reduced the initial root system and growth of shoots in greenhouse experiments. The combination of P. arrhenomanes and C. falcatum inoculation increased dead bud percentage in one of two cultivars and red rot severity for both. The results suggest that spring shoot populations developing from red rot-affected stalks exposed to poor drainage can be reduced by the combined effects of red rot and Pythium root rot.

Plant Disease ◽  
1997 ◽  
Vol 81 (10) ◽  
pp. 1132-1138 ◽  
Author(s):  
C.-T. Lo ◽  
E. B. Nelson ◽  
G. E. Harman

Trichoderma harzianum strain 1295-22 is an effective biocontrol agent for several fungal diseases. The efficacy of granule and spray applications of strain 1295-22 for control of Pythium root rot, brown patch, and dollar spot of creeping bentgrass was investigated. Spray applications of conidial suspensions (SA) of strain 1295-22 significantly reduced all three diseases of creeping bentgrass turf in both greenhouse and field experiments. Control was greatest when Triton X-100 at 0.1% was added to aqueous spray suspensions. When SA were applied weekly, the biocontrol treatments were equivalent to standard fungicides. Broadcast granule applications (GA) also significantly reduced foliar symptoms of Pythium root rot, dollar spot, and brown patch; turf quality also was enhanced. The populations of Trichoderma spp. in the root zone of a bentgrass putting green treated with SA or GA of strain 1295-22 increased 10- to 100-fold after treatment compared with untreated plots. However, strain 1295-22 was present at high levels on bentgrass leaves only following SA. Collectively, the results suggest that strain 1295-22 possesses both rhizosphere and phylloplane competence. The combination of broadcast applications of granules followed by spray applications of conidia reduced damage from both root and foliar diseases.


2007 ◽  
Vol 53 (2) ◽  
pp. 196-206 ◽  
Author(s):  
V. Jayakumar ◽  
R. Bhaskaran ◽  
S. Tsushima

Plant extracts and antifungal microorganisms were tested singly and in combination for biocontrol of sugarcane red rot disease ( Colletotrichum falcatum ) using two sugarcane ( Saccharum officinarum L.) cultivars, CoC671 and CoC92061, in pot and field experiments. Leaf extracts of Abrus precatorius and Bassia latifolia and the rhizome extract of Curcuma longa reduced Colletotrichum falcatum mycelial growth by 80%, 58%, and 57%, respectively. Although sugarcane- planting materials (setts) treated individually with either Pseudomonas fluorescens Md1 or A. precatorius in pot experiments had the lowest incidences of red rot, 20.1% and 24.2%, respectively, none of the plant extracts were effective in the field. In contrast, when the two varieties were tested separately in two field locations, the setts treated with A. precatorius in combination with a spray or soil application of P. fluorescens Md1 had the lowest incidence of red rot in both locations, e.g., 3.1% and 3.4% incidence for CoC92061 in one location, and had a similar response to the chemical control. The results suggest the applicability of plant-based extracts for the suppression of sugarcane red rot disease in the field as an environment-friendly tool in combination with antagonists.


2006 ◽  
Vol 32 (4) ◽  
pp. 307-321 ◽  
Author(s):  
John Clifford Sutton ◽  
Coralie Rachelle Sopher ◽  
Tony Nathaniel Owen-Going ◽  
Weizhong Liu ◽  
Bernard Grodzinski ◽  
...  

The etiology and epidemiology of Pythium root rot in hydroponically-grown crops are reviewed with emphasis on knowledge and concepts considered important for managing the disease in commercial greenhouses. Pythium root rot continually threatens the productivity of numerous kinds of crops in hydroponic systems around the world including cucumber, tomato, sweet pepper, spinach, lettuce, nasturtium, arugula, rose, and chrysanthemum. Principal causal agents include Pythium aphanidermatum, Pythium dissotocum, members of Pythium group F, and Pythium ultimum var. ultimum. Perspectives are given of sources of initial inoculum of Pythium spp. in hydroponic systems, of infection and colonization of roots by the pathogens, symptom development and inoculum production in host roots, and inoculum dispersal in nutrient solutions. Recent findings that a specific elicitor produced by P. aphanidermatum may trigger necrosis (browning) of the roots and the transition from biotrophic to necrotrophic infection are considered. Effects on root rot epidemics of host factors (disease susceptibility, phenological growth stage, root exudates and phenolic substances), the root environment (rooting media, concentrations of dissolved oxygen and phenolic substances in the nutrient solution, microbial communities and temperature) and human interferences (cropping practices and control measures) are reviewed. Recent findings on predisposition of roots to Pythium attack by environmental stress factors are highlighted. The commonly minor impact on epidemics of measures to disinfest nutrient solution as it recirculates outside the crop is contrasted with the impact of treatments that suppress Pythium in the roots and root zone of the crop. New discoveries that infection of roots by P. aphanidermatum markedly slows the increase in leaf area and whole-plant carbon gain without significant effect on the efficiency of photosynthesis per unit area of leaf are noted. The platform of knowledge and understanding of the etiology and epidemiology of root rot, and its effects on the physiology of the whole plant, are discussed in relation to new research directions and development of better practices to manage the disease in hydroponic crops. Focus is on methods and technologies for tracking Pythium and root rot, and on developing, integrating, and optimizing treatments to suppress the pathogen in the root zone and progress of root rot.


Plant Disease ◽  
1997 ◽  
Vol 81 (11) ◽  
pp. 1247-1250 ◽  
Author(s):  
Zhi Yin ◽  
J. W. Hoy

The effect of drought conditions at planting time on sugarcane red rot, caused by Colletotrichum falcatum, was evaluated in experiments conducted under controlled conditions and in the field. For experiments under controlled conditions, detached and topped mature stalks of five cultivars were inoculated with conidia of C. falcatum, then exposed to a 3-week desiccation treatment, followed by 3 weeks without desiccation, or maintained for 6 weeks without desiccation. Disease severity, assessed as the number of nodes beyond which rot symptoms extended, number of nodes rotted, internode rot severity, and a rot severity index, was increased in five cultivars by exposure to desiccation. However, response of individual cultivars varied for some disease traits assessed. In field experiments, C. falcatum inoculation alone did not reduce spring shoot populations for seven cultivars. The lowest shoot populations occurred in plantings of inoculated stalks exposed to desiccation. Some cultivars were adversely affected by desiccation alone. These results demonstrate that red rot severity can be increased by the occurrence of drought conditions during the initial growth processes of vegetatively propagated sugarcane stalks.


2013 ◽  
Vol 171 (2) ◽  
pp. 488-503 ◽  
Author(s):  
P. T. Prathima ◽  
M. Raveendran ◽  
K. K. Kumar ◽  
P. R. Rahul ◽  
V. Ganesh Kumar ◽  
...  

2013 ◽  
Vol 93 (4) ◽  
pp. 619-625 ◽  
Author(s):  
K. F. Chang ◽  
S. F. Hwang ◽  
H. U. Ahmed ◽  
B. D. Gossen ◽  
G. D. Turnbull ◽  
...  

Chang, K. F., Hwang, S. F., Ahmed, H. U., Gossen, B. D., Turnbull, G. D. and Strelkov, S. E. 2013. Management strategies to reduce losses caused by fusarium seedling blight of field pea. Can. J. Plant Sci. 93: 619–625. Fusarium seedling blight can cause substantial reductions in the stand density of field pea in western Canada. In greenhouse experiments, emergence decreased and root rot severity rose with increasing inoculum density. In field trials in 2007 and 2008 near Edmonton, AB, seeding at different depths and seeding dates did not consistently affect emergence or yield in Fusarium-infested soils. In field experiments, emergence declined significantly with each increase in inoculum level. Also, seed yield were reduced at high levels of disease pressure. Treatment of seed with Apron Maxx improved emergence, nodulation and yield of treatments challenged with inoculum of F. avenaceum in both greenhouse and field experiments. This research demonstrates the need to prevent seedling blight and root rot through proper seed treatment.


2021 ◽  
Vol 58 (2) ◽  
pp. 224-231
Author(s):  
Anuradha ◽  
Lenika Kashyap ◽  
Rajinder Kumar ◽  
Paramjit Singh

Author(s):  
Bareen Sidqi Shareef Al-Tovi ◽  
Raed Abduljabbar Haleem

This study was conducted to test the pathogenicity of Fusarium species, the causes of crown and root rot disease of wheat crop, under three different conditions (Laboratory, Greenhouse and Field) and to show the best method for pathogenicity among different conditions. Pathogenicity test of six isolates of Fusarium species (F. graminearum, F. oxysporum, F. avenaceum, F. nivale, F. solani and F. udum) was tested on durum (Simeto) cultivar of wheat by test tube method in the laboratory, the tested fungi had substantial effect on seed germination. F. oxysporum showed the highest germination failure (44.44%) which significantly differed with other species. In the greenhouse, seedlings were inoculated by spore suspension at the base of each plant stem. The most virulent fungus after 35 days of inoculation was F. oxysporum (0.78) followed by F. solani (0.70) and F. graminearum (0.66), while the lowest disease severity was recorded by F. udum (0.16). Also in the field pathogenicity experiments of three Fusarium species (F. graminearum, F. oxysporum and F. solani) were performed on a durum (Simeto) and soft (Cham6) cultivars. Spore suspension was applied at the 2- to 3-leaf Zadoks’s growth stage. Disease severity was calculated at two stages of wheat growth (Booting and Ripening).The most virulent fungus was F. graminearum (0.42) that was significantly different from  other fungi. This work indicated that F. graminearum, F. oxysporum and F. solani showed higher infection than remaining tested species under threeconditions. Pathogenicity test in laboratory by test tube method (In-vitro) appeared more effective than greenhouse and field experiments


2013 ◽  
Vol 726-731 ◽  
pp. 3035-3039 ◽  
Author(s):  
Xue Bin Qi ◽  
Zong Dong Huang ◽  
Dong Mei Qiao ◽  
Ping Li ◽  
Zhi Juan Zhao ◽  
...  

Agriculture is a big consumer of fresh water in competition with other sectors of the society. The agricultural sector continues to have a negative impact on the ecological status of the environment. The worlds interest in high quality food is increasing. Field experiments were conducted to investigate the effect of subsurface drip irrigation on physiological responses, yield and water use efficiency, Soil nitrogen, Root weight density of potato in the semi-humid region of middle China using subsurface drip irrigation. The experiment used second-stage treated wastewater with and without addition of chloride, and both subsurface drip and furrow irrigations were investigated. Results indicated that the alternate partial root-zone irrigation is a practicable water-saving strategy for potato. The drip with chlorinated and non-chlorinated water improved water use efficiency by 21.48% and 39.1%, respectively, and 44.1% in the furrow irrigation. Partial root zone drying irrigation stimulates potato root growth and enhances root density. The content of the heavy metal in the potato tubers is no more than the National Food Requirements, and it is consistent with National Food Hygiene Stands.


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