Search

An experiment was carried out under semi-controlled conditions to evaluate the effect of biofertilization with Gluconacetobacter diazotrophicus and Funneliformis mosseae on Guinea grass (Megathyrsus maximus cv. Likoni). Five treatments (simple and combined inoculation with G. diazotrophicus and F. mosseae, fertilization with 25 mg N kg-1 of soil and a control without biofertilizers or nitrogenous fertilizer) were studied in a completely random design with five repetitions. Biofertilization with G. diazotrophicus and F. mosseae separately produced higher effects than the control without biofertilizers. However, with the combined application of both, the highest frequency of mycorrhizal colonization was reached (52.4 %), as well as concentrations of N in aerial biomass (18.5 g kg-1) and aerial biomass yields (7.45 g pot-1) and radical (7.38 g pot-1), similar to those obtained with nitrogen fertilization. It is concluded that the co-inoculation with G. diazotrophicus and F. mosseae is effective in improving nitrogenous nutrition and biomass yields of Megathyrsus maximus cv. Likoni. [ABSTRACT FROM AUTHOR]

Rice husk is a by-product of the milling process of ripe rice grains. It provides important nutrients such as phosphorus and potassium and when mixed with soil and fertilizers, it delays soil compaction and hardening, favoring root and plant development. In this study, for the first time in Cuba, the application effect of rice husks as mulch in a three-year-old avocado plantation was evaluated. A notable increase in the number of mycorrhizal fungi spores was obtained, as well as a significant increase in yield, soil moisture retention and a control in the proliferation of unwanted plants. [ABSTRACT FROM AUTHOR]

An experiment was carried out to evaluate the contribution of biofertilization to the reduction of nitrogen fertilization in Urochloa hybrid cv. Mulato II with the use of rhizobacterium Azospirillum brasilense and the arbuscular mycorrhizal fungus (AMF) Rhizoglomus irregulare. A total of three doses of nitrogen (0, 70 and 100 kg ha-1) were evaluated, alone and combined with the application of both biofertilizers, in a random block design, with factorial arrangement and four replications. For biofertilization, inocula containing A. brasilense with a concentration of 109 CFU mL-1, and R. irregulare, with a concentration of 30 spores g-1 were used. Both were applied by the seeds coating method at the time of sowing. In the case of A. brasilense, a second application was made, at a rate of 20 L ha-1 after the first cut. The grass significantly responded (P <0.01) to nitrogen fertilization. The highest yields (14.5 t ha-1), concentrations of nitrogen in biomass (16.1 g kg-1) and organic matter digestibility (64.7 %), as well as the lowest content of neutral detergent fiber (68.1 %) were obtained with the dose of 100 kg N ha-1. With the biofertilization, without the application of nitrogen, these indicators reached similar values to those registered with the addition of 100 kg N ha-1. The effect of biofertilizers was maintained for a year. It is concluded that biofertilization with A. brasilense and R. irregulare constitutes an effective alternative to reduce the use of nitrogen fertilizer in B. hybrid cv. Mulato II. [ABSTRACT FROM AUTHOR]

The physiological studies related to the mycorrhizal symbiosis have made difficult due to the condition of the symbionts that are characterized by the fungi that intervene in the association, which, up to now, can't grow in axenic conditions. However, in vitro root cultivation techniques, as a simplified system for the establishment of the arbuscular mycorrhizal symbiosis, have been widely used and they are very important in several investigations. The aim of this study was to obtain disinfected spores of Rhizoglomus sp. (INCAM-11) from soil, which express high percentages of germination and low levels of contamination on in vitro conditions and determine the growth period of the germination hyphae. INCAM-11 propagules were disinfected and their percentages of germination and contamination, as well as the germinative tube length were evaluated. Results show that the immersion time of spores in antibiotic solution during 24 hours, before its inoculation in the Modified Strulla and Romand (MSR) medium, can reduces the contamination percentage and the moment of germination. In the other hand, the hyphae germination spreads in the culture medium during 30 days approximately, before stopping their growth, contributing to the later establishment of the association in the transformed roots. [ABSTRACT FROM AUTHOR]

The presence of arbuscular mycorrhizae and communities of arbuscular mycorrhizal fungi (AMF) associated to four grasses established in areas of livestock basin “El Tablón”, belonging to the Estación Experimental "Escambray", Cumanayagua municipality, Cienfuegos province, was determined. Megathyrsus maximusscv. Likoni, Pennisetum purpureum cv. king grass, Brachiaria decumbens cv. CIAT-606 and Cynodon nlemfuensis vc. Jamaicano grasses were evaluated. A random block design was applied, with four treatments and 15 repetitions. All species showed arbuscular mycorrhizal colonization. The highest value was obtained in Brachiaria decumbens vc. CIAT-606, with 66.27%, while the rootlets of Pennisetum purpureum vc. king grass showed the lowest levels of this variable, with 48.80%. Eight species and five morphotypes of AMF, belonging to eight genera, were observed. The highest density of mycorrhizal fungi spores was associated with Pennisetum purpureum cv. king grass, with 3399 spores/100 g of soil, while the lowest corresponded to Brachiaria decumbens cv. CIAT-606, with only 195 spores/100 g. Arbuscular mycorrhizal fungi communities were more populated by species belonging to Glomus genus in the four studied pastures. [ABSTRACT FROM AUTHOR]

The presence of arbuscular mycorrhizae and communities of arbuscular mycorrhizal fungi (AMF) associated to four grasses established in areas of livestock basin "El Tablón", belonging to the Estación Experimental "Escambray", Cumanayagua municipality, Cienfuegos province, was determined. Megathyrsus maximuss cv. Likoni, Pennisetum purpureum cv. king grass, Brachiaria decumbens cv. CIAT-606 and Cynodon nlemfuensis vc. Jamaicano grasses were evaluated. A random block design was applied, with four treatments and 15 repetitions. All species showed arbuscular mycorrhizal colonization. The highest value was obtained in Brachiaria decumbens vc. CIAT-606, with 66.27%, while the rootlets of Pennisetum purpureum vc. king grass showed the lowest levels of this variable, with 48.80%. Eight species and five morphotypes of AMF, belonging to eight genera, were observed. The highest density of mycorrhizal fungi spores was associated with Pennisetum purpureum cv. king grass, with 3399 spores/100 g of soil, while the lowest corresponded to Brachiaria decumbens cv. CIAT-606, with only 195 spores/100 g. Arbuscular mycorrhizal fungi communities were more populated by species belonging to Glomus genus in the four studied pastures. [ABSTRACT FROM AUTHOR]