Efeito do calcário e do fósforo na produtividade de grãos e seus componentes nos cultivares de trigo

Abstract

The knowledge of the interactions among wheat genotypes (Triticum aestivum L.) and factors that affect grain yield (lime, fertilizer, water) is important for an adequate choice of cultivars and definition of a proper fertilization. The objective of this work is to study the variability of grain yield and yield components among wheat materials in response to lime and phosphorus application. The experiments were carried out annually, from 1987 to 1995, at the Itararé Experimental Station, Instituto Agronômico, Campinas, State of São Paulo, Brazil under dryland condition. A complete randomized block design in a split-split plot arrangement with 4 replications was used. The main plots contained three rates of lime (0; 6.5, and 13 t.ha -1 ), the split plots three rates of phosphorus (0, 30, and 90 kg.ha -1 of P 2 O 5 ), and the split split plots four wheat genotypes ('IAC-5', 'IAC-24', 'IAC-60', and 'Anahuac'). The results showed that in acid and low-fertility conditions, the IAC-60 and IAC-5 genotypes surpassed the other materials in relation to grain yield, ear length, components of the grain yield and harvest index. The genotype IAC-60 was more responsive to lime and phosphorus. Grain yield, ear length, grain yield components and harvest index were more affected by P than by lime application. Grain yield correlated better with number of grains by ear than with other evaluated features. Considering grain yield, the genotype IAC-60 was more productive and more responsive, IAC-5 more productive but less responsive and IAC-24 and Anahuac less productive. The use of genotypes tolerant to soil acidity and adapted to low fertility but responsive to lime and fertilizer can make feasible wheat cultivation in lowfertility soils with less investment.

Influência de calcário e fósforo no desenvolvimento e produção de variedades de maracujazeiro-amarelo

“…Além desse aspecto, estudos envolvendo a interação da aplicação de calcário com a adubação fosfatada na cultura do maracujazeiro praticamente inexistem, embora essa prática de manejo da fertilidade do solo se mostre relevante para a elevação do rendimento de outras culturas, como: trigo (FREITAS et al, 1999), goiabeira (NATALE et al, 2000) e soja (PIAIA et al 2004).…”

Low-P tolerance mechanisms and differential gene expression in contrasting wheat genotypes

“…Wheat (Triticum aestivum L.) cultivars Anahuac, sensitive to low-P and aluminum, and Toropi, used as source for tolerance in breeding programs (Ben & Dechen, 1998;Freitas et al, 1999;Abichequer et al, 2003;Camargo et al, 2006;Silva et al, 2008), were the plant materials used in this study.…”