Lucio Zabot

Tamanho ótimo de parcela e número de repetições em soja (Glycine max (L.) Merril)

With the objective of verifying if different cultivars of soybean modify the estimates of the optimum plot size and of the numbers of replications, an experiment was conduced in the agriculturist year of 2000/01 in area pertaining to the Department of Crop Science in Santa Maria University Campus. Two cultivars of soybean were used (BRS 137 and Fepagro-RS10), conducted in a randomized block design with three replications. The size of plot was evaluated through the method of maximum modified bending. The test of parallelism of SEBER (1976), was used to verify the heterogeneousness of reply among tested cultivars. The number of replications was estimated through the described methodology for HATHEWAY (1961). It can be concluded that to cultivars studied the number of replications that confers an adequate accuracy is equal to seven and the optimum plot size is 3.96m2.

Metodologia experimental para rendimento de grãos de soja em condições de restrição de espaço

The aim of this research was to optimize experimental planning for soybean crop in experiments with restrictions for grain yield, in order to reduce experimental plot size. The experiment was carried out at Santa Maria Federal University, in the agricultural year of 2000/2001, using a randomized block design, with three replicates, and two soybean cultivars (BRS137 and Fepagro RS10) used as treatments. Each replication was constituted by 18 rows of 8-m long and 44 cm of spacing between rows. Harvest was performed in basic units (ub) of 1 m of row (0.44 m2), totaling 144 ub. Plot size and true difference between treatment means were estimated by Hatheway method, with three different numbers of replications (4, 8 and 16) to verify, in the grain yield variable, which combination would minimize experimental area for soybean crop. The same plot size can be used for different soybean cultivars, keeping constant precision degree and number of replicates. Experiments can be optimized using larger number of replications and reducing plot size.

Comportamento da cultivar BR-IPAGRO 44-guapo brilhante de feijoeiro em quatro populaçções de plantas na safrinha em Santa Maria-RS

The common bean cultivar Guapo Brilhante, type II, was grown during the latter season of 2001 in Santa Maria-RS, Brazil, in four plant populations (200, 300, 400, and 500 thousand plants ha-1). The experiment design was randomized blocks with four replications. The grain yield, yield components and some morphological traits were evaluated. The highest estimated yield was 2684kg ha-1 with 337 thousand plants ha-1, demonstrating that, with proper cultural practices, in the latter season, it is possible to produce almost three times more than the best production average of the State of Rio Grande do Sul, Brazil in the 90 decade. The increase in plant population increases the first pod height, first pod base height, and the number of internodes. With 400 thousand plants ha-1 the first pod height and the first pod base height are enough to mechanic harvesting, but with potential losses.

Efeitos da população de plantas e de tratamento fitossanitário no rendimento de grãos do feijoeiro comum, cultivar "TPS Nobre"

Three experiments were conducted in Santa Maria and Constantina - Rio Grande do Sul State - Brazil, to determine the effect of plant population on disease occurrence in common bean (type II grown) in the first and second growing season and to determine the most appropriate plant population. The experiment was established as a split-plot randomized block design with five replications. The results showed that there was no effect of plant population in disease incidence. The high plant populations provided higher or similar grain yield compared with the grain yield of the low plant populations.