Effect of Time after Incorporation of Lablab Green Manure on Root Rot Pathogens and Establishment of Common Bean ( Phaseolus vulgaris L.) (original) (raw)
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2018
Green manure incorporation is important for restoration of soil quality, particularly buildup of organic matter and supply of nutrients to plants. However, undecomposed plant residues reduce crop establishment and plant stand. Therefore, there is need to determine suitable time for green manure incorporation before planting. The effect of time after incorporation of lablab green manure on soilborne pathogens and bean crop establishment was evaluated by incorporating 12t/ha of lablab green manure at planting and at 7, 14, and 28 days before planting. Soil samples were collected before and after incorporation of green manure at planting, and at two, four and six weeks after planting. Data was collected on crop emergence, plant stand, yield, incidence and severity of root rot, and population of root rot pathogens. Incorporation of lablab residues 28 days before planting resulted in 21% improvement in germination, with corresponding reduction in root rot incidence and severity of 8% and 36%, respectively, compared to plots incorporated with green manure at planting. Plots incorporated with lablab green manure earlier before planting had reduced population of root rot pathogens, while those incorporation at planting excited the population of root rot pathogens and also had up to 71% reduction in grain yield compared to plots where lablab residue was incorporated 28 days before planting. The results of the study showed that a period of 28 days between Lablab green manure incorporation and planting is necessary to allow for proper decomposition, resulting in a reduction in root rot incidence and an increase in grain yield.
2018
Green manures improve soil health and fertility but application of undecomposed lablab residues lead to low crop establishment. The study was carried out to determine the effect of green manure on microbial population and establishment of bean crop. Bean varieties were planted on plots each treated with lablab green manure at one ton ha-1 over whole plots and in rows, DAP fertilizer was applied at 75 kg/ha. Data was collected on microbial population, crop emergence, root rot incidence and severity, and yield. Green manure incorporation increased soil organic carbon, nitrogen, phosphorus and potassium but reduced germination percentage by about 35% and increased incidences of root rot by 30% compared to plots without green manure. The population of root rot pathogens was significantly higher in plots treated with green manure two weeks after emergence while the population of saprophytic fungi was low. Plots treated with lablab green manure reduced grain and biomass yields by 25%. Green manure increases soil nutrients directly and improves crop establishment after decomposition. Results of the study revealed a considerable increase in the population of root rot pathogens with corresponding decrease in the population of antagonistic fungi thus the poor emergence and crop establishment can be associated with increase in population of root rot pathogens and stress experienced by seeds during decomposition
African Journal of Biological Sciences, 2021
Common bean production is constrained by root rot complexes resulting to as much as 70% losses in Kenya. This study sought to establish the effect of soil amendments biochar and vermicompost on root rot fungal pathogens of common bean in Western Kenya. Application of biochar, vermicompost and fertilizer were done in farmer fields in four agro ecological zones of Western Kenya prior to planting during the long rains of 2013 and 2014. No applications were done in the shot rains seasons of 2013 and 2014. Plant emergence and disease incidence was recorded in the field and disease severity determined in the laboratory. Isolation and identification of pathogens was done from treatment plots following a two weeks and six weeks sampling after planting. Pathogens isolated were identified using morphological characteristics. Soil amendments positively influenced plant emergence. Root rot disease incidence and severity was greatly reduced up to 40% and 60% every season respectively. Biochar and vermicompost treatments reduced the population of fungal pathogens and also influenced the populations of beneficial microorganisms such as Trichoderma and Paecilomyces lilacinus. Application of soil amendments increased yield by 46% and also soil pH and nutrients were increased. In conclusion treatment application of vermicompost and biochar reduce root rot disease and improve bean productivity. which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made.
International Journal of AgriScience, 2014
Root rot is a major constraint to bean production in western Kenya causing poor crop stand and high yield losses. The disease is caused by a complex different pathogens which together exhibit synergistic effects. The pathogens survive in soils as resting spores and options of managing the disease are limited This study evaluated the effectiveness of incorporating lablab biomass in managing root rot of beans in maize intercrop system. The experimental treatments evaluated were incorporation of lablab biomass over the whole plot, biomass placed between rows of beans, biomass removed from the plot plus application of inorganic fertilizer and biomass removed from the plot without fertilizer application. In each experimental treatment, four bean varieties KK8, KK15, KK072 (tolerant to root rot) and GLP2 (susceptible to root rot) were planted intercropped with maize. The experiment was carried out at two agro-ecologically and soil fertility diverse sites. Incidence of root rot and chafer ...
2013
A field experiment was conducted to evaluate the manual potential of two organic manure :- Farmyard manure (FYM), Poultry manure (PM) vis-a-vis, 0% to100% recommended dose of fertilizer – NPK and to find out the most productive cropping system at various combination of organic manure and chemical fertilizer. Field experiment was carried out for the period of six months January to June 2010, to determine the affect of organic and chemical fertilizer application on the growth parameters of French bean (Phaseolus vulgaris). During the study it was noticed that the organic manure enhanced the function of chemical fertilizer. The capital used for making organic manure is cheaper than that of chemical fertilizers and maintain the soil fertility.
High occurrence of root rots is attributed to continuous and inappropriate cropping systems, low soil fertility levels, low moisture in soil, use of farm saved seeds and use of root rot susceptible bean (Phaseolus vulgaris L.) varieties. This study evaluated the effect of soil fertility and intercropping on the incidence and severity of root rot diseases of common bean. Soil samples were collected at the start of the 2016 short rain cropping season to determine the soil nutrients status, and the incidence and population of soil borne fungal pathogens. The soil samples were analyzed for total nutrient status and pH levels. Soil borne fungal pathogens were isolated from the soil and stem bases by pour plate technique. Farm saved seeds of bean varieties KK8 and GLP2 were planted in field experiments at three sites in pure stand, intercropped with maize, applied with and without fertilizer. Data collected included seedling emergence, stand count, bean fly incidence, root rot distribution, incidence and severity, and yield. The pathogens isolated from soil and stem bases included F. oxysporum, F. solani, Pythium spp, Macrophomina and Rhizoctonia spp, with Fusarium spp. being the most predominant at 40% incidence and mean population of 3000 CFU/g of soil. Bean intercropped with maize had 22% lower intensity of root rot compared to the sole crop. The findings of this study demonstrate that low soil fertility, use of farm saved seeds and high inoculum levels of soil borne pathogens in the soil contributed to the high incidence of root rots in the study sites. In addition bean varieties intercropped with maize had a 17% lower incidence of root rot pathogens compared to bean varieties from sole crop. It was observed that intercropping system reduces pests and diseases. However, root rot pathogens isolated from bean intercropped with maize had a significantly lower incidence than the sole crops.
2015
having 5.3 to 5.5 to study the effect of organic sources of nutrients viz., vermicompost, FYM and along with inorganic fertilizers in French bean under irrigated condition with an objective to study growth and yield without degrading soil quality by using various nutrient compositions. In this investigation, vermicompost treatment (T2) recorded the highest in all observations except biomass of whole plant (above and ground biomass) which was recorded highest in N:P:K (T1) treatment this may be due to high composition of Nitrogen in inorganic fertilizers which supplement to the plant’s vegetative phase. Thus it may be concluded that vermicompost was found useful than any other type of treatments under irrigated condition of Srinagar valley. [Nature and Science. 2009;7(5):52-54]. (ISSN: 1545-0740).