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The work was developed in the urban organic garden "Mercasa", Las Tunas; in the period from the first day to December 27, 2019, with the objective of evaluating the effect of different doses of VIUSID® Agro on the yield of lettuce crop, cv. Fomento-95, under urban organic garden conditions. A completely randomized design with four treatments (control without application and application of VIUSID® Agro at 0.15, 0.20 and 0.25 ml L-1 of water) was used. The following morphoagronomic variables were evaluated: plant height, leaf length and width, stem diameter, number of leaves, root length, mass per plant and yield. The data obtained were subjected to a simple analysis of variance using the Statgraphics statistical package. The best results obtained in most of the morphological and yield variables evaluated corresponded to the VIUSID® Agro dose of 0.15 ml L-1 of water, with greater economic feasibility. [ABSTRACT FROM AUTHOR]

The present work had as objective to know the effect of gamma rays of source 60Co in the agronomic and reproductive traits to obtain mutants of potato (Solanum tuberosum L.). Seed-tubers of the cultivar “Barna" imported from Holland with a weight (20 g), with six treatments: five irradiation doses 10, 20, 30, 40, 50 Gy and one non-irradiated control (0 Gy). In this study a strong reduction of plant emergence was observed, as the dose was progressively increased the emergency decreased. It is suggested not to apply doses higher than 50 Gy in seed-tubers, for works directed to the use of radiomutagenesis in the potato breeding of the potato, due to the negative effect in the emergency and in other important characters. Doses applied to potato seed tubers between 20 and 40 Gy could be evidence of induction of mutation, while at 10 Gy a stimulation of flowering was observed in the cultivar “Barna". [ABSTRACT FROM AUTHOR]

The common method to generate fertilizer recommendations is by fitting yield data for each crop separately through mathematical models. This work was carried out with the objective of comparing two response equation models to nitrogen rates in two economically important crops, corn and coffee, besides defining the most appropriate criteria to select the model that offers an adequate optimal fertilization rate. Thus, N doses from 0 to 200 kg ha-1 for corn (Zea mays) were studied along with different types of crop rotation: fallow followed by corn; fallow-corn inoculated with arbuscular mycorrhizal fungi (AMF); jackbean-corn and jackbean-corn inoculated with AMF, in experiments performed during 2003 and 2006. In the case of coffee crop, N doses from 0 to 400 kg ha-1 were studied depending on plant age, within the first two productive cycles of a Coffea canephora plantation, during 1996 and 2007. The rectilinear discontinuous model with lineal equations and the curvilinear continuous model with second degree equations were compared. Maximum yield, optimum economic rate and partial productivity factor were estimated by the equations obtained from each model. In both crops studied, the rectilinear discontinuous model offered lower fertilizer dose estimations than the one obtained by the curvilinear model, so that together with the partial productivity factor, they constitute effective methods to estimate the amount of nutriments to be applied, avoiding N overdoses. [ABSTRACT FROM AUTHOR]

In regions with high insolation is common to see sun damages on mandarins, especially in fruits located outside the canopy. The aim of this work was to assess kaolin particles application on Citrus unshiu Marc. cv. 'Okitsu', in several doses and moments, to control sunburn. Seven treatments with kaolin 95 %, combinations of doses (2 and 4 %) and frequencies (two, three and four applications), were tried. A randomized completed block design with four replications and three plants per plot was used. Before harvest, diameter (mm), juice (%), total soluble solids (°Brix), total acidity (mL) and maturity index (ratios) were measured on a sample of 15 fruits by experimental plot. At harvest, 40 fruits by plot were randomly selected and they were classified at three levels of sunburn: free of damage fruits (G.0); fruits with yellow spots up to 15 percent of the shell (G.1); fruits with yellow spots in more than 16 percent of the shell and dark necrotic tissue (G.2). Plots with kaolin application showed between 91,53 and 97,94 % of fruits G.0, whereas control plots showed only 73,97 %. Kaolin applications were effective to control sunburn on 'Okitsu' mandarin. Four applications per season at 2 % or three applications per season at 4 % of kaolin 95 %, allows reaching 97 % of fruits free of sunburn without affecting the internal quality. [ABSTRACT FROM AUTHOR]

In the Biofood Research Center carry up the investigation about agronomic biosolids effect, obtained from a wastewater treatment by anaerobic digestion of livestock waste, in bean (Phaseolus vulgaris L.) phenological indicators, var. «Milagro villaclareño», used a planting frame 0.90 x 0.07 m (14.3 plants.m-1), from December 4, 2009 in Red Ferralitic soil (Nitisol), pH:7.3 and containing P2 O5 and K2 O5 of 17.3 and 48.30 mg.100 g-1, respectively. Used a randomized block design with three treatments (dose: 0.0; 6.8 and 9 t.ha-1) and three replicates (nine experimental units), each plot had an area of 40 m², the biosolids are applied before planting in the final groove. The diameter of the stem after 40 days showed significant differences (p<0.01) in treatments with application of sewage sludge, similar behavior was achieved at the height of the plant from of 32 days after the establishment, reaching 65 cm in the fourth quarter. The number of pods per plant and grains per pod also showed statistical differences in the first case, the high application of sludge compared to other treatments and the second case the two applications compared to control. The treatment of 9 t.ha-1 gave the highest yield (2.40 t.ha-1) than the control in 0.80 t.ha-1. [ABSTRACT FROM AUTHOR]

This paper aims to evaluate the effect of differents rates of 60 Co gamma rays to stimulate germination in botanical potato seed (Solanum tuberosum L.) with very low germination rates. The progeny seeds Atzimba x TPS-13 from the International Potato Center (CIP) in Perú, were irradiated with doses of 10 to 100 Gray (Gy) at intervals of 10 Gy and unirradiated control. It was found that not all doses stimulate the germination of potato seed, a result that could be in agreement with those presented in radiosensitivity studies for both stimulating germination and to increase the genetic variability in crops. The dose 20 Gy showed the greatest stimulation of seed germination. [ABSTRACT FROM AUTHOR]

With the objective of producing biofertilizers using 3 Pseudomonas sp. strains, three experiments were carried out: first, to find appropriate culture means for bacteria multiplication, second to determine Pseudomonas sp. strain survival in the biofertilizer and third, to determine the efficient dose of biofertilizer application in beans (Phaseolus vulgaris L.), corns (Zea mays), potatoes (Solanum tuberosum L.) and tomatoes (Lycopersicon esculentum Mill) under greenhouse conditions. When evaluating the results, it was determined that the culture used for the Pseudomonas sp. multiplication, could be replaced by another lower cost culture. Pseudomonas sp. strain viability in the biofertilizer was similar during 3 months of conservation, so its use can be guaranteed until that date. Non significant differences were found between the biofertilizer applied doses to beans, corns, potatoes and tomatoes. Shoots and roots dry matter of beans and corn plants inoculated with Pseudomonas sp. strains differed significantly compared to control plants. Potato and tomato plants inoculated with Pseudomonas sp. did not differ significantly compared to non-inoculated control plants. [ABSTRACT FROM AUTHOR]