Effect of water management treatments on rice characteristics and cooking behaviour

Rice (Oryza sativa L.) is adapted to grow both in submerged and aerobic soils. Changes in the agro-environmental conditions and socio-cultural needs of rice farmers, as well as the reduction in the availability of irrigation water in some rice-growing areas, have led to the introduction of new cultivation practices. The different irrigation conditions, however, may influence rice composition and its cooking quality. The work aims at investigating the effect of different water management on rice milling yield, grains biometric characteristics, nitrogen and amylose content, pasting properties and cooking behaviour. Baldo, Gladio, Loto and Selenio varieties were grown in 3 different agricultural systems, characterised by a progressively more intense use of water: dry seeding and delayed flooding (A); dry seeding and rotational irrigation (B); water seeded and continuous flooding (C). The various agricultural systems did not affect the milling yield of Baldo, Gladio, and Selenio, while a significant (P<0.05) decrease was observed only for Loto when cultivated in system A. A significant (P<0.05) increase of the nitrogen content for Gladio, and a decrease for Selenio, were observed when conditions A and B were used in comparison with the conventional irrigation. As regards the amylose, practice A determined a significant (P<0.05) reduction for Gladio and Baldo. The three irrigation practices also slightly affected the pasting properties of the samples, but with different trends depending on the variety. Loto cultivated in condition B showed a greater resistance to gelatinization and a higher consistency than the corresponding sample cultivated in water. Considering the overall dataset, it is not possible up to now to highlight an univocal influence of the water-soil regime on rice quality, since the investigated characteristics seem to be mainly influenced by the variety.