José Salvador Simoneti Foloni

Soil fertility, nutrition and yield of maize and barley with gypsum application on soil surface in no-till

Annual crop yield and nutrition have shown differentiated responses to modifications in soil chemical properties brought about by gypsum application. The aim of this study was to evaluate the effect of gypsum application rates on the chemical properties of a Latossolo Bruno (Clayey Oxisol), as well as on the nutrition and yield of a maize-barley succession under no-till. The experiment was set up in November 2009 in Guarapuava, Parana, Brazil, applying gypsum rates of 0.0, 1.5, 3.0, 4.5, and 6.0 Mg ha-1 to the soil surface upon sowing maize, with crop succession of barley. Gypsum application decreased the levels of Al3+ and Mg2+ in the 0.0-0.1 m layer and increased soil pH in the layers from 0.2-0.6 m depth. Gypsum application has increased the levels of Ca2+ in all soil layers up to 0.6 m, and the levels of S-SO42- up to 0.8 m. In both crops, the leaf concentrations of Ca and S were increased while Mg concentrations have decreased as a function of gypsum rates. There was also an effect of gypsum rates on grain yield, with a quadratic response of maize and a linear increase for barley. Yield increases were up to 11 and 12 % in relation to control for the maximum technical efficiency (MTE) rates of 3.8 and 6.0 Mg ha-1 of gypsum, respectively. Gypsum application improved soil fertility in the profile, especially in the subsurface, as well as plant nutrition, increasing the yields of maize and barley.

Dessecação química em pré-colheita da mamona

The castor bean has indeterminate growth habit and non-uniformity of grain maturation at harvest. However, pre-harvest desiccant application can increase the efficiency of mechanized harvesting. The objective of this work was to evaluate effects of the herbicides glyphosate alone or mixed with 2,4-D, and paraquat alone, in pre-harvest desiccation of castor bean. The field experiments were arranged in a completely randomized design, with four replications, in Rancharia, Sao Paulo State, from March to September 2005. The experiment one evaluated the application of two doses of 2,4-D associated with four doses of glyphosate at 10, 20 and 30 days after application (DAA). The experiment two evaluated four doses of paraquat at 30 DAA. The pre-harvest desiccation of castor bean with 2,4-D + glyphosate showed effect only from 20 DAA. The 2,4-D applied alone provided significant dehydration of the plant, however, the effect was lower than the mixture 2,4-D + glyphosate. The best pre-harvest desiccation in castor bean was obtained with 1.34 kg 2,4-D ha-1 plus 1.42 kg glyphosate ha-1. The dose 1.2 kg paraquat ha-1 significantly reduced moisture in castor bean, however, it was less efficiently than the mixture 2,4-D + glyphosate.

Genótipos de trigo em diferentes densidades de semeadura

The wheat tillering capacity defines yield and yield components, being affected by seeding rate. This study aimed at evaluating wheat genotypes under different seeding rates, in Londrina and Ponta Grossa, Parana State, Brazil, in 2009 and 2010. A completely randomized blocks design, in a factorial scheme, with four replications, was used. The agronomic traits of three wheat genotypes (PF 014384, BRS Tangara and BRS Pardela) were evaluated under the seeding rates of 150 pl m -2 , 250 pl m -2 , 350 pl m -2 and 450 pl m -2 . In Londrina, the maximum yield was observed at densities close to 270 pl m -2 , while in Ponta Grossa (2009) there was a linear fit. There was no adjustment for plant height, concerning seeding rate. The number of ears per area (ears m -2 ) was higher in Ponta Grossa (2009) and did not differ between the locations, in 2010. In Ponta Grossa (2010), the highest one thousand seeds weight was estimated at the density of 341 pl m -2 , while in Londrina (2010) it was estimated at 150 pl m -2 and 450 pl m -2 . The seeding rate affected grain yield, depending on place and year. In Londrina, there was a limit for yield, concerning seeding rate. The one thousand seeds weight was influenced by seeding rate, depending on year and location. Plant height was affected by genotype and growing area.