Arbuscular Mycorrhiza and Its Influence on Crop Production

Mycorrhizal fungi can increase the effectiveness of a mineral fertilizer top dressing, positively affecting sweet pepper yield and quality. For this reason, an experiment was carried out between 2014 and 2016 to study the effect of top dressing doses and the inoculation of the root system with mycorrhizal fungi on the growth and yield of sweet pepper and the content of nutrients and macro- and microelements in the fruits. Root inoculation with Arbuscular Mycorrhizal Fungi (AMF) and mineral fertilizer doses were used as experimental factors with the following combinations: (1) mycorrhization: control (without AMF); AMF applied to the plant root zone during seedling production; AMF applied to the plant root zone after seedlings were transferred to pots; (2) top dressing doses: basic dose (100%); 50% of the basic dose; 25% of the basic dose. The sweet pepper fruits were harvested during physiological maturity. AMF inoculation of the root zone resulted in high sweet pepper yields of good quality. In particular, mycorrhizal fungi applied to the root system during seedling production positively affected the pepper yield and biometric characteristics, with fruits of the thickest pericarp and the largest mass. In the experimental units with AMF, the reduction in the top dressing fertilizer dose by 50% and 75% did not cause a statistically significant decrease in the yield of peppers and did not result in a deterioration of the biometric characteristics of the plants and fruits or a reduction in the biological value of the fruits. Despite the reduction in top dressing dose by 50% and 75%, AMF contributed to the accumulation of similar amounts of phosphorus in the sweet pepper fruits. The top dressing dose of 50% applied during seedling production to the experimental units with mycorrhizal fungi resulted in a significant increase in the content of potassium, calcium, and magnesium. A significant increase in the amount of sodium in the fruits was noted in the experimental units with mycorrhizal fungi applied to the roots when the seedlings were transferred to pots. To summarize, the application of mycorrhizal fungi to the pepper root zone during seedling production is recommended because it has a positive effect on the yield and its quality. In the unit with mycorrhiza, a lower dose of mineral fertilizers did not result in a significant decrease in the yield of pepper fruits. Full article

Barley (Hordeum vulgare, L.) is the fourth most important cereal crop in the world. Salinity decreases the productivity of plants grown under salinity conditions. It leads to deficiency and limited absorption of water and nutrients, ionic stress, oxidative stress, and osmotic imbalance. In saline soil, a field experiment was conducted to verify the effects of nine combinations among three levels of bio-fertilizers, i.e., control (without), arbuscular mycorrhizal fungi (AMF), and phosphate solubilizing bacteria (PSB), as well as three levels of phosphorus fertilizer recommended dose (RDP) on barley yield, its components and nutrients uptake, to evaluate the useful influences of these combinations to improve P management under salinity stress related to yield and its components as well as N, P, and K uptake in barley. Findings revealed that the combination AMF + 100% RDP improved plant height, length of spike, spikes weight, number of spikes plant⁻¹, weight of 1000-grain, straw yield, grain yield, uptake of nitrogen (N), phosphorus (P), potassium (K) in grain and uptake of nitrogen (N), phosphorus (P), potassium (K) in straw by 19.76, 33.21, 40.08, 33.76, 14.82, 24.95, 47.52, 104.54, 213.47, 168.24, 124.30, 183.59, and 160.84% in the first season, respectively. Meanwhile, the increase was 19.86, 29.73, 40.47, 39.94, 14.92, 24.95, 47.94, 104.73, 213.33, 168.64, 124.47, 183.86, and 161.09% in the second season, respectively. AMF showed greater efficiency and effectiveness compared to PSB in improving yield and its components for all studied traits. The results of principle component analysis indicated that all combinations except AMF + zero% RDP, PSB + zero% RDP, control + zero% RDP, and control + 66% RDP showed high scores on positive PC1, where all studied traits were high. Therefore, it is recommended to inoculate the soil with AMF or PSB with the addition of phosphate fertilizer at the recommended dose under salinity conditions, i.e., AMF + 100% RDP (T1) or AMF + 66% RDP (T2) or PSB + 100% RDP (T4). The use of bio-fertilizers has increased plant tolerance to salt stress, and this was evident from the increase in different traits with the use of treatments that include bio-fertilizers. Full article

Physalis peruviana L. is one of the most favorable tropical fruit due to its fast growth and nutritional properties. The current research outlined the response to drought stress of golden berry plants inoculated with arbuscular mycorrhizal fungi Claroideoglomus claroideum and propagated in vitro as well as from seeds. The implementation of mycorrhizal symbiosis was determined by root colonization, glomalin content, and alkaline and acid phosphatases in roots and soil. The plant protection was assured by enzyme and non-enzyme antioxidants. The adapted in vitro propagated plants demonstrated higher resistance to drought than plants developed from seeds indicated by increased growth parameters (shoot, root biomass, fruit number), plastid pigment content, antioxidant activity, and less enhance mentofoxidative markers levels in water-deficient conditions. The findings in the present research are relevant to obtain the optimal mycorrhizal association and type of propagation in an adverse environment for golden berry development and will lead to the establishment of a database and model of varied plant responses to stressful conditions such as drought. Full article

One filed experiment was carried out to study the effect of Arbuscular Mycorrhiza fungi and three preceding winter crops, i.e., Meskawy cultivar of Egyptian clover berseem (Trifolium alexandrinum L.), Careem cultivar of sugar beet (Beta vulgaris) and Sakha 94 cultivar of wheat (Triticum aestivum) and five fertilizer combinations as treatments of NPK mineral and bio fertilizer which included 100% NPK (T1), 75% NPK + arbuscular mycorrhiza fungi (AMFs) (T2), 50% NPK + arbuscular mycorrhiza fungi (AMFs) (T3), 75% NPK + mycrobein (T4) and 50% NPK + mycrobein (T5) on maize intercropping with cowpea. The results showed that berseem was the best as a preceding crop and gave the highest values of maize and cowpea, followed by sugar beet as a preceding crop. While wheat recorded the lowest values. Fertilizer treatments had significant effect on all maize and cowpea traits. The treatment 75% NPK + arbuscular mycorrhiza fungi (AMFs) (T2) gave the highest values. Meanwhile, no significant differences were found between fertilizer treatments T1 (100% NPK mineral) and T2 (75% NPK + arbuscular mycorrhiza fungi (AMFs)) combination on all studied characters of maize. The interaction had a significant effect on most studied characters of maize and cowpea in the two growing seasons. The cultivation of the two components of intercropping after berseem with T2 fertilizer recorded the highest values. Mixing the third cut of cowpea with maize straw increased significantly the quality and digestibility of forge in both seasons. Planting after berseem and T2 fertilizer gave the highest values as yield advantageous for land equivalent ratio (LER) and relative crowding coefficient (K) which recorded 1.51 and 1.6 and 9.45 and 15.35 in the first and second seasons, respectively. The increases in net return were 3955.67 and 5062.50 L.E., which equates to a percentage of 34.25 and 44.71%, by cultivation intercropping component after berseem and T2 fertilizer treatment (75% NPK + arbuscular mycorrhiza fungi (AMFs)) compared with maize pure stand in first and second seasons, respectively. Full article

Phosphorus is the second most significant macro nutrient in rice productivity. Phosphorus fixation in Egyptian soil makes it unavailable for rice to absorb. The goal of this study was to examine the effects of microbial and chemical sources of phosphorus fertilizers on the Egyptian Sakha 106 rice cultivar by applying different sources of phosphorus to increase the bioavailability of soil phosphorus for plants and to allow it to be fixed biologically to change it from an insoluble form to a soluble and available form for rice to absorb. So, in the 2019 and 2020 seasons, a field experiment was conducted at the experimental farm of Sakha Agricultural Research Station, Sakha, Kafr El-Sheikh, Egypt. The experiment was carried out using a Randomized Complete Block Design with four replications to determine the best phosphorus source for rice and soil among various treatments, which included 100% single super phosphate (SSP) basal application (P1), 75% single super phosphate (SSP) basal application (P2), P2 + phosphate-solubilizing bacteria (PSBs) top-dressing, P2 + arbuscular mycorrhizal fungi (AMFs) top-dressing P2 + phosphorus nanoparticles (PNPs) foliar spraying, P2 + phosphoric acid (PA) foliar spraying, P2 + (PSBs + AMFs) foliar spraying, P2 + (PSBs + PNPs) foliar spraying, P2 + (PSBs + PA) foliar spraying, P2 + (PNPs + PA) foliar spraying, P2 + (PSBs + PNPs + PA) foliar spraying and zero-phosphorus fertilizer. The results showed that the highest values were mostly obtained using the combination of 75% SSP basal application with the foliar spraying of PSBs, PNPs and PA, with substantial beneficial impacts on the leaf area index (3.706 and 3.527), dry matter accumulation (464.3 and 462.8 g m²), plant height (96.33 and 95.00 cm), phosphorus uptake in grain (24.3 and 24.49 Kg ha⁻¹), phosphorus uptake in straw (17.7 and 17.0 Kg ha⁻¹) and available phosphorus in the soil at harvest (21.75 and 21.70 ppm) in the 2019 and 2020 seasons, respectively; moreover, 75% SSP basal application with the foliar spraying of PSBs, PNPs and PA or 100% SSP basal application alone improved the number of panicles (506.3 or 521.1 and 521.9 or 547.1 m⁻²), filled grain weight (3.549 or 3.534 and 3.627 or 3.767 g panicle⁻¹), the percentage of filled grain (96.19 or 96.47 and 95.43 or 96.24%), grain yield (9.353 or 9.221 and 9.311 or 9.148 t ha⁻¹) and straw yield (11.51 or 11.46 and 11.82 or 11.69 t ha⁻¹) in the 2019 and 2020 seasons, respectively. Chemical P fertilizers combined with the foliar spraying of PSBs, PNPs and PA obtained the highest crop productivity and improved most of the examined characteristics without any significant changes with respect to chemical P application alone in some other characteristics, followed by 75% SSP + top-dressing with PSBs + AMFs. The treatment that included the combination of 75% SSP basal application and the foliar spraying of PSBs +PNPs +PA is recommended, as it might be utilized to boost rice yield by solubilizing P in soil and increasing the absorption efficiency. In addition, it reduces chemical P fertilizers by 25%, which would guarantee a cleaner environment and soil conservation. Full article

Many terrestrial plants form reciprocal symbioses with beneficial fungi in roots; however, it is not clear whether Vicia villosa, an important forage and green manure crop, can co-exist with these fungi and how such symbiosis affects plant growth and soil properties. The aim of this study is to analyze the effects of inoculation with three arbuscular mycorrhizal fungi (AMF) such as Diversisporaspurca, Funneliformismosseae, and Rhizophagusintraradices and an endophytic fungus Serendipitaindica on plant growth, root morphology, chlorophyll and sugar levels, soil nutrients, and aggregate size distribution and stability in V. villosa plants. After 63 days of inoculation, the beneficial fungi colonized the roots with colonization rates of 12% to 92%, and also improved plant growth performance and root morphology to varying degrees, accompanied by the most significant promoted effects after R.intraradices inoculation. All AMF significantly raised chlorophylls a and b, carotenoids and total chlorophyll concentrations, along with a significant increase in leaf sucrose, which consequently formed a significantly higher accumulation of glucose and fructose in roots providing carbon sources for the symbionts. Root fungal colonization was significantly (p < 0.01) positively correlated with chlorophyll compositions, leaf sucrose, and root glucose. In addition, inoculation with symbiotic fungi appeared to trigger a significant decrease in soil Olsen-P and available K and a significant increase in NH₄-N, NO₃-N, and glomalin-related soil protein levels, plus a significant increase in the proportion of water-stable aggregates at the size of 0.5–4 mm as well as aggregate stability. This improvement in soil aggregates was significantly (p < 0.01) positively correlated with root fungal colonization rate and glomalin-related soil protein concentrations. The study concludes that symbiotic fungi, especially R. intraradices, improve the growth of V. villosa, which is associated with fungal modulation of sugars, soil fertility and root structural improvement. Full article