Effects of Mycorrhiza Inoculation and Grafting for Sweet Pepper (Capsicum annuum L.) Crop Under Low-Tech Greenhouse Conditions

Abstract

In low-cost, unheated greenhouses and tunnels the use of arbuscular mycorrhizal fungi (AMF) and/or grafting can be a less expensive and sustainable solution to combat the adverse effects of monoculture, instead of costly soilless culture. The aim of the present study was to investigate the effects of a commercially available AMF inoculant and grafting on sweet pepper, under circumstances of modelling commercial low-tech greenhouse production. ‘SV9702PP F1’ sweet pepper hybrid was cultivated for seven months in an unheated greenhouse. Beside the control, three treatments were applied: ungrafted AMF treated plants, plants grafted on ‘Bagi F1’ hybrid and AMF treated plus grafted plants. AMF was applied into the planting holes just before transplanting. AMF treatment had positive effects on relative chlorophyll content of leaves (expressed in SPAD value), on plant stand, on plant mass production, on yield and on root colonization rate, despite the high presence of indigenous populations of AMF in the greenhouse soil. With the applied rootstock/scion combination, grafting did not significantly affect the aforementioned parameters. SPAD values were increased by the AMF treatment during periods when smaller doses of nitrogen (less than 0.8 g N per m-2 week-1) were applied. Significant positive correlation was found between root colonization rate and marketable yield. AMF treatment increased the yield by 18% (from 12.43 to 14.74 kg m-2), mostly due to higher number of fruits. Yield increase was mainly realised during the last third of the harvest period, when the applied nutrient doses were low and temperature conditions were suboptimal.
 
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 In press - Online First. Article has been peer reviewed, accepted for publication and published online without pagination. It will receive pagination when the issue will be ready for publishing as a complete number (Volume 47, Issue 4, 2019). The article is searchable and citable by Digital Object Identifier (DOI). DOI link will become active after the article will be included in the complete issue.
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A Microbial-Based Biostimulant Enhances Sweet Pepper Performance by Metabolic Reprogramming of Phytohormone Profile and Secondary Metabolism

“…Moreover, similarly to the trial reported by Ombódi et al (2019), we observed a better yield response of pepper to mycorrhizal inoculation (+66% in the second fruit harvest made on 9 January-174 DAT) when the microclimate conditions for plant growth were suboptimal (low light and temperature occurring during January). Finally, in the current experiment the total yield increases induced by inoculation with AMF and Trichoderma koningii were due to both higher fruit number and mean fruit weight whereas in the trial of Ombódi et al (2019) the yield increases were mostly due to higher number of fruits. The above findings indicate a reduced activity of indigenous arbuscular mycorrhizal fungi and Trichoderma spp.…”

“…Similarly, in two field experiments, Ortas (2019) reported that mycorrhizal inoculation increased yield of the tomatoes, green peppers and eggplants and P and Zn uptake in comparison with uninoculated plants. In the current experiment the total yield increase resulting from inoculation of sweet pepper plants with AMF and Trichoderma koningi was higher (24%) than the value (18%) reported by Ombódi et al (2019) using an inoculum containing six different arbuscular mycorrhizal species under unheated greenhouse conditions and the value (12.7%) recorded by Almaca et al (2013) using an inoculum containing Glomus mosseae and G. etunicatum under field conditions. The above differences in pepper yield response could be attributed to the different mycorrhizal species used in the trials and the addition of Trichoderma koningi in the current experiment.…”

“…in enhancing crop productivity in comparison with exogenous selected arbuscular mycorrhizal fungi and Trichoderma species under field conditions. Similarly, Ombódi et al (2019) reported that inoculation of pepper plants at transplanting with a commercial product containing six different arbuscular mycorrhizal species was able to enhance mycorrhizal root colonization, leaf chlorophyll content (SPAD index) and fruit yield in comparison with naturally occurring mycorrhizal fungi in untreated control. The above findings may be explained by the depression of native mycorrhizal fungi in horticultural production systems caused by the frequent soil tillage and the overuse of chemical inputs.…”

Degradation of soil arbuscular mycorrhizal fungal diversity and functionality accompanied by the aggravation of pepper Phytophthora blight in a facility shed in Southwest China

“…Disease‐suppressive soil is a promising tool in sustainable agriculture, which relies on the effective activation of indigenous microbial community to protect host plants against pathogens. Colonization by soil AM fungi is an important indicator for appraising plant nutrient acquisition, photosynthetic performance, and defense ability (Douds et al, 2012; Mathur et al, 2018; Ombodi et al, 2019). This study showed both decrease of root AM fungal colonization and increase of soil P. capsici population along with increasing severities of pepper Phytophthora blight (Table 2).…”

Performance of the root system of tomato plants inoculated with arbuscular mycorrhizal fungi and submitted to the grafting technique

“…The grafting technique is commonly used in horticultural crops of fruits, including solanaceous crops Chiomento et al (2020) Performance of the root system of tomato... (Ombódi et al, 2019), with the objective of improving plant tolerance to biotic (Lee, 2007) and abiotic stresses (Rouphael et al, 2017). The introduced plant (graft)…”