scholarly journals Role of Chitosan in Disease Suppression, Growth and Yield of Carrot

2021 ◽  
Vol 3 (3) ◽  
pp. 34-40
Author(s):  
M. A. Rahman ◽  
R. Jannat ◽  
A. M. Akanda ◽  
M. A. R. Khan ◽  
M. T. Rubayet

An attempt was made for controlling of Rhizoctonia canker caused by Rhizoctonia solani and southern blight caused by Sclerotium rolfsii in pot and field experiments under inoculated condition and also to increase the growth promoting factors and yield of carrot through the application of chitosan. Before setting the experiments in the field, laboratory experiments were carried out to select virulent isolates of R. solani and S. rolfsii and effective dose of chitosan on mycelial growth inhibition of virulent isolates of test pathogens. In the pathogenicity test, R. solani isolate R-1 and S. rolfsii isolate S-1 were found to be the most virulent against carrot seedlings. In vitro application of 1.0% chitosan was found to inhibit 100% mycelial growth of both tested pathogens. The field experiment was laid out following randomized complete block design with four treatments, where no treatment was done in T1, pathogen was inoculated in T2 and seed treatment and soil amendment with 1.0% chitosan was done in T3 and T4, respectively, in pathogen inoculated condition. Application of 1.0% chitosan as seed treatment or soil amendment significantly reduced post-emergence seedling mortality, incidence of diseases and enhanced seedling growth and also yields of carrot. On the contrary, post-emergence seedling mortality, incidence of Rhizoctonia canker and southern blight of carrot were highest in treatment T2 where soil was inoculated with pathogens. Chitosan could be used as an alternative of fungicide to suppress Rhizoctonia canker and southern blight in sustainable agriculture and improvement the yield of carrot.

2021 ◽  
Vol 2 (2) ◽  
pp. 124-137
Author(s):  
S. Chaterjee ◽  
Rayhanur Jannat ◽  
M. M. Hossain ◽  
M. R. Amin ◽  
M. T. Rubayet

Chitosan is a biodegradable natural compound that has a great potentiality in agriculture for controlling plant diseases. An attempt was made to control Fusarium wilt caused by Fusarium oxysporum f. sp. melongenae under inoculated field condition and increase the growth and yield of brinjal by chitosan. Before setting the experiments in the field, preliminary laboratory experiments were carried out to select virulent isolate and effective dose of chitosan against the mycelial growth of the selected pathogen. F. oxysporum f. sp. melongenae isolate F-1 was found to be the most virulent on brinjal in pathogenicity test. Chitosan @ 1.0% concentration was appeared to be the highest inhibitory to the test pathogen at in vitro condition. Additionally, seed treatment with 1.0% chitosan for 12 hrs resulted in the highest increased in germination and seedling growth of brinjal. The field experiment was conducted following Randomized Complete Block Design (RCBD) with four treatments. No treatment was given in T1, the pathogen was inoculated in T2 and seed treatment and soil amendment with 1.0% chitosan was done in T3 and T4, respectively, in test pathogen inoculated condition. Application of 1.0% chitosan as a seed treatment (T3) or soil amendment (T4) significantly reduced pre- and post-emergence seedling mortality, incidence and severity of Fusarium wilt as well as enhanced germination percentage, plant growth and yield of brinjal. On the contrary, pre-emergence and post-emergence seedling mortality, disease incidence and severity of Fusarium wilt were highest in treatment T2 where the soil was inoculated with pathogen without chitosan. Therefore, chitosan could be used against this vascular disease as an alternative to inorganic fungicides and augment yield.


2002 ◽  
Vol 37 (4) ◽  
pp. 308-316 ◽  
Author(s):  
J. C. Faircloth ◽  
J. R. Bradley ◽  
J. W. Van Duyn

Field experiments were conducted in 1997–1999 in Washington Co., NC, to examine how cotton, Gossypium hirsutum, is affected by thrips species composition and abundance, environmental factors, and insecticide applications. Populations of adult and juvenile thrips were monitored in seedling cotton treated with insecticide applications of either imidacloprid as a seed treatment, acephate as a foliar spray, or aldicarb applied in-furrow. The number of plants per 3.05 row-m, location of the first fruiting branch, number of open bolls per 1.52 row-m, yields, accumulated degree-d 60′s (DD60′s), and accumulated rainfall were recorded each year the studies were conducted. Aldicarb and acephate provided better thrips control than did imidacloprid in all 3 yrs. Thrips species ratios differed among years. In 1997, the aldicarb treatment resulted in a better “earliness profile” (lower fruit set and more early opening bolls) than either acephate or imidacloprid, while in 1998 and 1999 there were few differences in these plant parameters. In 1997, all insecticide treatments resulted in statistically higher yields compared with the untreated check. Accumulated DD60′s were consistently higher in 1998 and 1999 than in 1997 after the first thrips sampling date. Cumulative rainfall appeared to be inversely associated with juvenile thrips populations.


2012 ◽  
Vol 26 (2) ◽  
pp. 364-370 ◽  
Author(s):  
Sanjeev K. Bangarwa ◽  
Jason K. Norsworthy ◽  
Edward E. Gbur

Yellow nutsedge is a problematic weed in polyethylene-mulched tomato production. Soil fumigation with methyl bromide is the most effective method of controlling nutsedges, but because of ozone depletion, the phase-out of methyl bromide has complicated nutsedge control in polyethylene-mulched tomato and other vegetable crops. Plants belonging to the Brassicaceae family produce glucosinolates, which upon tissue decomposition generate biocidal isothiocyanates and therefore can be used as a biological alternative for yellow nutsedge control. Field experiments were conducted in 2007 and 2009 to study the influence of soil amendment with ‘Seventop’ turnip cover crop on the interference of yellow nutsedge planted at 0, 50, and 100 tubers m−2in raised-bed polyethylene-mulched tomato production. There was no advantage of soil amendment with Seventop on reducing yellow nutsedge interference in polyethylene-mulched tomato. Regardless of soil amendment, increasing initial tuber density from 50 to 100 tubers m−2increased yellow nutsedge shoot density, shoot dry weight, and tuber production at least 1.7, 1.6, and 1.6 times, respectively. As a result, tomato canopy width, shoot dry weight, and marketable yield decreased with increasing initial tuber densities. However, increased tuber density had minimal impact on tomato height. Relative to weed-free plots, interference of yellow nutsedge at 50 and 100 tubers m−2reduced marketable yield of tomato up to 32 and 49%, respectively. Shading of the middle and lower portion of tomato plants by yellow nutsedge shoots could be the major factor for reducing tomato growth and yield in weedy plots. It is concluded that soil amendment with Seventop turnip is not a viable option for reducing yellow nutsedge interference at 50 and 100 tuber m−2in polyethylene-mulched tomato.


2019 ◽  
Vol 44 (3) ◽  
pp. 553-567 ◽  
Author(s):  
VO Dania ◽  
JA Omidiora

Damping-off (Pythium aphanidermatum) is a soil-borne disease which accounts for seedling mortality and significant yield losses in tomato production. Laboratory and screenhouse experiments were conducted in 2017, with a repeated field trial in 2018 to evaluate the efficacy of combining three biological control agents (BCAs), Trichodermaviride, T. harzianumand Bacillus subtilis with Allium sativumextract for the integrated management of the disease in tomato crop. Treatments were laid out in a completely randomized design and randomized complete block design in the screenhouse and field experiments, respectively with eighteen treatments and three replications. The BCAs and extract were formulated and applied using seed treatment and soil sprinkling methods. Treatment combinations of BCAs with A. sativumwere more effective in the reduction of mycelial growth of the pathogen with inhibitory values that ranged between 77.6-91.2% than single inoculation. Seed treatment before planting was more effective than soil sprinkle method, reducing pre-emergence and damping-off incidence to between 6.8-18.3% and 9.7-26.3% under screenhouse and field conditions, respectively than the sprinkling method. Soil sprinkle with T. harzianumin combination with A. sativumextract had the highest cumulative tomato fruit yield of 902 kg/ha-1under field conditions. This study showed that combined application of BCAs and A. sativumextract reduced damping-off disease and thereby improved the fruit yield of tomato. Bangladesh J. Agril. Res. 44(3): 553-567, September 2019


1987 ◽  
Vol 108 (3) ◽  
pp. 627-634 ◽  
Author(s):  
M. Syed Anwarulla ◽  
K. Shivashankar

SummaryIn two separate field experiments with green gram (Vigna radiata L. Wilczek) and black gram (Vigna mungo L. Wilczek), the effect of seed treatment of molybdenum at 4, 8 and 12 g of sodium molybdate/kg seeds as well as foliar nutrition of sodium molybdate at 0·4, 0·8 and 1·2 kg/ha was evaluated on the nodulation characteristics and leghaemoglobin content of nodules and growth and yield of crops. Both seed treatment and foliar application of sodium molybdate were found to be superior to controls in respect of the number of nodules per plant and dry weight of nodules. The leghaemoglobin content of nodules in both crops was maximal in the treatments with the highest dose of seed treatment followed by the highest dose of molybdenum for foliar sprays. Molybdenum favourably influenced the growth of green gram and black gram by increasing the number of branches and leaves and by nearly doubling the leaf area index. This resulted in increased D.M. and yield of pods.


2011 ◽  
Vol 25 (3) ◽  
pp. 466-472 ◽  
Author(s):  
Sanjeev K. Bangarwa ◽  
Jason K. Norsworthy ◽  
John D. Mattice ◽  
Edward E. Gbur

Methyl bromide has been widely used as a broad-spectrum fumigant for weed control in polyethylene-mulched bell pepper. However, because of environmental hazards, the phase-out of methyl bromide requires development of alternative weed management strategies. Brassicaceae plants produce glucosinolates which are hydrolyzed to toxic isothiocyanates following tissue decomposition, and therefore can be used as a cultural strategy. Field experiments were conducted in 2007 and 2009 to study the influence of soil amendment (‘Seventop’ turnip cover crop vs. fallow) and the effect of initially planted yellow nutsedge tuber density (0, 50, and 100 tubers m−2) on the interference of yellow nutsedge in raised-bed polyethylene-mulched bell pepper. Total glucosinolate production by the turnip cover crop was 12,635 and 22,845 µmol m−2in 2007 and 2009, respectively, and was mainly contributed by shoots. In general, soil amendment with the turnip cover crop was neither effective in reducing yellow nutsedge growth and tuber production nor in improving bell pepper growth and yield compared to fallow plots at any initial tuber density. Averaged over cover crops, increasing initial tuber density from 50 to 100 tubers m−2increased yellow nutsedge shoot density, shoot dry weight, and tuber production ≥ 1.4 times. However, increased tuber density had minimal impact on yellow nutsedge height and canopy width. Compared to weed-free plots, interference of yellow nutsedge reduced bell pepper dry weight and marketable yield ≥ 42 and ≥ 47%, respectively. However, bell pepper dry weight and yield reduction from 50 and 100 tubers m−2were not different. Light was the major resource for which yellow nutsedge competed with bell pepper. Yellow nutsedge shoots grown from initially planted 50 and 100 tubers m−2caused up to 48 and 67% light interception in bell pepper, respectively. It is concluded that yellow nutsedge interference from initial densities of 50 and 100 tubers m−2are equally effective in reducing bell pepper yield and that soil biofumigation with turnip is not a viable management option for yellow nutsedge at these densities.


Author(s):  
V. Govardhan Rao ◽  
D. N. Dhutraj ◽  
K. D. Navgire ◽  
K. T. Apet

Trichoderma harzianum is commonly used as effective biological control agent against phytopathogens especially the soil-borne fungi while some isolates are able to ameliorate plant growth. In the present study, Trichoderma fortified with different organic amendments were evaluated to reduce the pre-emergence and post-emergence seedling mortality, diseases of stem and root of eggplant caused by Fusarium oxysporum f. sp. melongenae, a soil-borne fungal pathogen. Two experiments were set up, one at pot culture and second in the field under natural epiphytotic conditions. Among the nine Trichoderm harzianum fortified amendments tested, neem seed cake recorded significant and superior effect as pre-sowing soil application against Fusarium wilt with respect to seed germination (92.33%), pre-emergence seed rot (7.66%) and post-emergence seedling mortality (15.33%) in pot culture. However, cotton cake recorded least efficacy in all respect. Similar trend observed in wilt incidence under field experiments during autumn 2018 (17.47%) and 2019 (18.60%) with T. harzianum fortified neem cake soil application against Fusarium wilt with mean inhibition of disease incidence (58.43%) and also observed excellent enhancement of mean yield (54.63%). It is observed that organic amendment at higher concentrations further increase the microbial populations and stimulate the microbial activity in soil against Fusarium oxysporum resulted to decrease the pathogen populations. Moreover, yield and yield related attributes increased remarkably due to fortified amendments providing adequate nutrient reservoir to the bioagents thereby enhancing its survival in a hostile environment.


2020 ◽  
Vol 4 (41) ◽  
pp. 35-43
Author(s):  
ALEKSEY A. VASIL’EV ◽  
◽  
ALEKSEY N. VASIL’EV ◽  
DMITRIY BUDNIKOV ◽  
ANTON SHARKO

The use of electrophysical influences for pre-sowing treatment of seeds is an effective way to increase their sowing quality. The use of these methods is limited by the fact that their implementation requires new technological equipment in grain processing lines. This problem is solved more easily when pre-sowing processing is performed using installations for active ventilation and grain drying. (Research purpose) The research purpose is in determining the possibility of using active ventilation units and ultra-high-frequency convective grain dryers for pre-sowing grain processing and to evaluating the effectiveness of such processing using computer modeling. (Materials and methods) It is necessary to ensure the uniformity of processing with external influence the seeds placed in a dense layer. Authors carried out pre-sowing treatment of seeds on real installations. Treated seeds were sown in experimental plots and the results of treatment were evaluated. (Results and discussion) The article presents graphs of changes in grain temperature and humidity during processing. To check the feasibility of pre-sowing treatment, authors performed modeling of air-heat and ultra-high-frequency convective seed treatment processes. Based on the results of field experiments, air-heat treatment stimulates the development of secondary plant roots, contributes to an intensive increase in the green mass of plants; ultra-high-frequency convective seed treatment allows increasing the number of productive stems in plants, the number of ears in one plant. (Conclusions) Technological equipment designed for drying and active ventilation of grain can be effectively used for pre-sowing seed processing. In the course of field experiments, it was revealed the possibility of controlling the structure of the crop using different types of external influence on seeds during their pre-sowing processing.


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