Relationship between yield, growth and spike weight in wheat under phosphorus deficiency and shading

Abstract

SU MMARYThe effect of phosphorus deficiency on yield formation in spring wheat (Triticum aestivum cv. Prointa Oasis) was investigated, focusing on crop growth and dry matter partitioning during the spike growth period (SGP), which is critical for grain number determination. Two experiments combining shading and P deficiency were performed at Balcarce, Argentina (37x45kS). The main treatments were two levels of soil P-availability : low P, a naturally low P fertility soil (7 . 0 and 5 . 5 mg Bray extractable P/kg soil, in the first and second experiments respectively) and high P, a P dose that does not limit growth. The sub-treatments were two levels of radiation (shaded and control). Phosphorus deficiency affected yield mainly through the number of grains/unit surface (m 2 ). Differences in grain number/m 2 were related to differences in dry weight of spikes/m 2 , measured 7 days after anthesis, excluding grain weight. The duration of the SGP did not change much as result of P deficiency : 27 days with high P and only 3 days more with low P. Therefore, changes in spike dry weight were mainly due to differences in spike growth rate. In turn, the spike growth rate of all treatments was linearly related to crop growth rate, with little effect of dry matter partitioning to spikes. Finally, differences in crop growth rate between P treatments were mainly determined by the amount of intercepted radiation. It was concluded that P deficiency resulted in a reduction in intercepted radiation during the SGP, thus causing a reduction in grain number and crop yield.

Ecophysiological determinants of tuber yield as affected by potato genotype and phosphorus availability

“…However, according to the genotype × P rate interaction in Experiment 1, RUE was decreased by P deficiency in six genotypes, where yield reduction was on average 53% (in contrast to the 33% in Experiment 2). This is in line with the RUE reduction reported in other crops, where yield reduction was greater than 40% under P deficiency (Plénet et al, 2000;Rodríguez et al, 2000;Lázaro et al, 2010). Therefore, RUE reductions in potato in response to P deficiency could be expected when P availability is so deficient for growth that causes high yield reductions.…”

“…Nevertheless, there is much less information about how the RUE of potato responds to P availability. Leaf photosynthesis rates of other species have been shown to decrease with P deficiency (Plesnicar et al, 1994;Halsted and Lynch, 1996;Rodríguez et al, 1998a,b); however, contrasting results have been found regarding RUE responses to P deficiency (Plénet et al, 2000;Rodríguez et al, 2000;Fletcher et al, 2008b;Lázaro et al, 2010;Sandaña and Pinochet, 2011;Sandaña et al, 2012). In the study of Jenkins and Ali (1999), the RUE of potato crops was not affected by the P supply.…”

“…It has been observed in different cereal crops that nutrient deficiencies decrease RI during the crop cycle through reductions in LAI. (N deficiency: Hall et al, 1995;Salvagiotti and Miralles, 2008;Massignam et al, 2009;P deficiency: Pellerin et al, 2000;Colomb et al, 2000;Plénet et al, 2000;Fletcher et al, 2008a;Rodríguez et al, 1998aRodríguez et al, , 2000Lázaro et al, 2010;Sandaña and Pinochet, 2011;Sandaña et al, 2012). However, for potato crops there is much less information about the effects of soil constraints, particularly P deficiency, on RI and its impact on total biomass and tuber yield (Harris, 1992;Jenkins and Ali, 1999).…”

Optimizing Phosphorus Fertilization Promotes Dry Matter Accumulation and P Remobilization in Oilseed Flax

“…Studies have shown that P has a profound effect on plant growth and development, with increased P fertilization often increasing the grain yield of oilseed crops (Gao et al, 2006;Grant et al, 2010). Some of these observations of P effects on oilseed crops are similar to those found in other crops, such as spring wheat (Triticum aestivum L.; Lázaro et al, 2010) and soybean (Glycine max; Lauer and Blevins, 1989). Some of these observations of P effects on oilseed crops are similar to those found in other crops, such as spring wheat (Triticum aestivum L.; Lázaro et al, 2010) and soybean (Glycine max; Lauer and Blevins, 1989).…”

Utilization of molecular markers for improving the phosphorus efficiency in crop plants

“…The Pi uptake rates are higher between pH 5.0 and 6.0 where HPO À2 4 dominates (Furihata, Suzuki, & Sakurai, 1992;Ullrich Eberius, Novacky, & Van Bel, 1984). P deficiency affects the growth and yield in several crop plants including rice (Oryza sativa) (Wissuwa & Ae, 2001a), maize (Zea mays) (Plenet, Etchebest, Mollier, & Pellerin, 2000), wheat (Triticum aestivum) (Lazaro, Abbate, Cogliatti, & Andrade, 2010), sorghum (Sorghum bicolor) (Camacho, Malavolta, Guerrero Alves, & Camacho, 2002), common bean (Phaseolus vulgaris) (Bonser, Lynch, & Snapp, 1996), soybean (Glycine max) (Mahamood, Abayomi, & Aduloju, 2009) and foxtail millet (Setaria italica) (Ceasar et al, 2014). About 5.7 billion hectares of agricultural land around the world lack Pi (Batjes, 1997; Heuer et al, 2009).…”