Effect of seed rate and application of N fertilizer on grain yield and N uptake of rice under intermediate deepwater conditions (15–50 cm)

Abstract

In an intermediate deepwater (15-50 cm) situation, the number of tillers increased with increase of nitrogen fertilizer from 0 to 40 and 80 kg/ha and of seed rate from 100 to 200, 300 and 400 seeds/m 2 . The tiller mortality due to higher water depth was higher under no-N treatment and under higher seed rates. The number of panicles and grain yield increased significantly with increase in N. Similarly, an increase in the seed rate increased the number of panicles and decreased the number of grains per panicle and panicle weight. The grain yields of the different seed rates were similar. The interaction between N levels and seed rates was not significant. INTRODUCTIONIn low-lying, waterlogged areas, maintenance of an optimum plant population density for a desired crop yield is a major problem. Direct-sown rice crop in such a situation is often subjected to water stress, either deficit or excess, at the beginning of the crop growing season, and excess later resulting in suppression of tiller formation, death of tillers and

Physiological Basis of Improved Performance of Super Rice (Oryza sativa) to Deep Placed Fertilizer with Precision Hill-drilling Machine

“…Increased plant height in rice with the increasing levels of N fertilizer may be attributed to greater supply of nitrogen resulting in increased nitrogen metabolism (Singh and Sharma, 1987). This appeared to increase the length of internodes resulting in higher plant height in the F3 or F4 fertilizer levels as compared to F0 or lower levels of N fertilizer (Reddy et al, 1987;Milam and Sheppard, 1988).…”

Yield performance of rainfed lowland rice as affected by nursery fertilization under conditions of intermediate deepwater (15?50 cm) and flash floods

“…However, semi-dwarf rices having submergence tolerance developed in the recent years have been found to respond to N application and thus withstand excess water stress better (Jugsujinda et al, 1982;Rao et al, 1985;Reddy et al, 1986;Vergara, 1985). High initial vigor of the crop could be obtained by suitable management practices such as use of healthy, plump and treated seeds of a suitable variety and fertilizer application to nursery.…”

População de plantas, dose de nitrogênio e aplicação de fungicida na produção de arroz irrigado: I-características agronômicas

“…REDDY et al (1986) consideram o aumento do número de panículas por unidade de área como fator determinante do aumento da produtividade de arroz com incremento do nível de nitrogênio aplicado, compensando a influência negativa das doses de nitrogênio no número de grãos por panícula.…”

“…Trabalhos realizados associando diferentes populações de plantas e níveis de nitrogênio revelaram interação significativa entre esses fatores para produtividade (REDDY et al, 1986). Espera-se que, em populações de plantas mais baixas, ocorra compensação pela aplicação de doses mais elevadas de nitrogênio, tendo em vista seus efeitos sobre o perfilhamento e a produção de matéria seca.…”