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Rice varietal improvement process (Oryza sativa Lin.) implies genotype selection with appropriate resistance levels to Pyricularia grisea Sacc. causing the well-known disease Blast, which is the most important disease for the crop worldwide. Genotypes are sowed in "Infection Beds", where there are favorable conditions and a high incidence of the disease. A high barren seed percentage, which has not been studied yet, has been detected. The barren seed percentage in genotypes of short and middle cycle, and its relationship with the climatic variables: relative humidity, maximal, minimal and middle temperatures, precipitations and the incidence of biotic agents such as P. grisea, Rhizoctonia solani Khun, Sarocladium oryzae Sawada and the insect pest Diatraea saccharalis F. were studied. The results showed that barren seeds were high even in short cycle genotypes or for those of middle cycle, being the most frequent barren seed percentages from 35 to 45 %, In short cycle genotypes, the factor that most contributed to variability in barren seed was P. grisea (48,8%) while stem borer (68.8%) was that in the middle cycle genotypes. The flowering phase was present from April to May. The transition from one month to another was marked by an increment of the minimal temperature, highly correlated with the middle temperature, barren seed percentage, incidence of P. grisea, R. solani and D. saccharalis. These last three factors are correlated among them. [ABSTRACT FROM AUTHOR]

In «Los Palacios» Rice Research Station, belonging to the National Institute of Agricultural Sciences (INCA), the effect of some chitin derivatives (chitosan and its hydrolysate) and its copper combinations on in vitro growth and sporulation of Pyricularia grisea fungus was studied. This fungus is the causal agent of Blast, the most important disease of rice crop in the world, whose conidia are the initial inoculum of such disease. One 8-mm-diameter mycelial disk was submerged for 15 minutes in each treatment and three, five and seven days later, the colony diameter was measured. Afterwards, conidial number was counted by a counting chamber and the colony sporulation distribution was observed. Results showed no significative effect of chitosan and its hydrolysate at 100 mg.L-1 concentration nor their combination with copper on Pyricularia grisea mycelial growth; however, they inhibited pathogen sporulation between 70 and 85 %; the few sporulation of chitosans was dispersed to colony periphery, whereas in the control, it was grouped in the center. These results permit to lead the possibility of using chitosans at low concentrations in the initial disease inoculum reduction in the field. [ABSTRACT FROM AUTHOR]

The objective of this work is to present the new bean cultivar 'Odile', which was obtained from a selection of the SCR 15 line. This line was achieved through the conventional method of hybridization between SER 118xNCB 226 / -MC-4C-MC-14C -MC at the International Center for Tropical Agriculture (CIAT) and it was introduced in Cuba, in generation F8, in 2010. The selection in Cuba began in November 2010. 'Odile' has a reddish-brown color and presents very good culinary quality, it is medium cycle, resistant to yellow bean golden mosaic virus (BGYMV), common bean bacterium (Xanthomonas axonopodis pv phaseoli) and rust (Uromyces appendiculatus) and has shown a high and stable yield potential. [ABSTRACT FROM AUTHOR]

The effect of Q-63 chitosan active ingredient (100, 500 and 1000 mg/L) on the germination of Fusarium sp conidia, as well as its potentiality for protecting rice seeds inoculated with the pathogen was studied. The germination percentage of conidia treated with different concentrations of Q-63 was evaluated after 2, 5, 8, 11 and 14 hours, while the fungal infection percentage in seeds treated with Q-63 was determined after 6, 7, 8 and 9 days. The results showed that both 500 and 1000 mg/L concentrations inhibited conidia germination completely until 14 hours. However, the best protective effect on seeds (93.3 %) was obtained with the higher concentration at 9 days. [ABSTRACT FROM AUTHOR]

A genetic breeding program was carried out in "Los Palacios" Rice Research Station, belonging to the National Institute of Agricultural Sciences (INCA), with the main objective of diversifying the varietal composition of rice crop. INCA LP-11 and INCA LP-15 are two new short and medium-cycle varieties, respectively, obtained by hybridizations and further field selections. Their best characteristics are excellent agricultural and industrial yields as well as tolerance to the main pests and diseases. Their behaviour has been validated in different locations of the country. [ABSTRACT FROM AUTHOR]