Effects of Different Water Conditions on Rice Growth at the Seedling Stage

Abstract

Water scarcity has led to the adoption of water-saving irrigation technology around the world. Drip-irrigation has been used for rice (Oryza sativa L.) cultivation in Xinjiang, China. Researchers reported 12.0 t/ha yield; however, drip-irrigated rice produces around 6-8 t/ha in practice, and it is clear that water deficiency explains this gap. Therefore, the objective of this experiment was to compare the growth, photosynthetic characteristics, and antioxidant activity of rice grown in nutrient solutions with water potentials of 0.00, -0.02, -0.05, and -0.09 MPa [0, 2.5, 5.0, and 7.5% polyethylene glycol (PEG), respectively], to determine the optimal water conditions for drip-irrigated rice. There was no significant difference between the 0, 2.5, and 5.0% PEG treatments for relative growth rate and relative water content after 10 and 20 days. However, 2.5 and 5.0% PEG treatments substantially affected the photosynthetic capacity and antioxidant enzyme activity after 10 and 20 days. Treatment with 7.5% PEG inhibited shoot growth. There was a significant reduction in antioxidant enzyme activity. Water-saving rice cultivation, such as drip-irrigated rice, suffered mild drought stress at -0.02 to -0.05 Mpa, but this did not inhibit growth. The amount of irrigation should be increased to obtain higher rice yields under drip-irrigation conditions. EFEITOS DE DIFERENTES CONDIÇÕES DE ÁGUA SOBRE O CRESCIMENTO DE ARROZ NA FASE DE MUDASRESUMO -A escassez de água levou à adoção de tecnologia de irrigação que economiza água em todo o mundo. A irrigação por gotejamento tem sido usada para o cultivo de arroz em Xinjiang, China. Pesquisadores relataram 12,0 t/ha de rendimento; no entanto, o arroz irrigado por gotejamento produz cerca de 6-8 t/ha na prática, e está claro que a deficiência de água explica essa lacuna. Portanto, o objetivo deste experimento foi comparar o crescimento, as características fotossintéticas e a atividade antioxidante do arroz cultivado em solução nutritiva com potencial hídrico de 0,00, -0,02, -0,05 e -0,09 MPa [0, 2,5, 5,0 e 7,5 % polietilenoglicol (PEG), respectivamente], para determinar as condições ótimas da água para o arroz irrigado por gotejamento. Não houve diferença significativa entre os tratamentos 0, 2,5 e 5,0% de PEG para a taxa de crescimento relativo e o conteúdo relativo de água após 10 e 20 dias. No entanto, os tratamentos de 2,5 e 5,0% de PEG afetaram substancialmente a capacidade fotossintética e a atividade das enzimas antioxidantes após 10 e 20 dias. O tratamento com 7,5% de PEG inibiu o crescimento das brotações. Houve uma redução significativa na atividade das enzimas antioxidantes. O cultivo de arroz que economiza água, como o arroz irrigado por gotejamento, sofreu um leve estresse hídrico de -0,02 a -0,05 Mpa, mas isso não inibiu o crescimento. A quantidade de irrigação deve ser aumentada para obter maiores rendimentos de arroz sob condições de irrigação por gotejamento.Palavras-chave: Condição aeróbica. Atividade enzimática. Capacidade fotossintética.

Model Pemantau Kelembaban dan Irigasi Sawah Otomatis Berbasiskan Internet of Things

“…Nilai pertumbuhan dari tanaman di sawah menurun sesuai dengan jumlah air yang tersedia. Selain dari sisi pertumbuhan, nilai protein larut air yang terkandung di dalamnya ikut terpengaruh [3]. Gambar 1 menunjukkan ilustrasi kandungan air dalam tanah.…”

A critical review on the improvement of drought stress tolerance in rice (Oryza sativa L.)

“…Traits influencing drought stress in rice are presented in Table 2. (Yang et al, 2019) Water use efficiency 39% (Yang et al, 2019) Plant height 49.31% (Singh et al, 2018) Shoot length mild (Zhang et al, 2018) 1000 grain weight 13.71% (Moonmoon and Islam, 2017) Photosynthesis Decreased (Fahad et al, 2017) Panicle development Reduced (Wei et al, 2017) Leaf area and biomass Reduced (Upadhyaya et al, 2017) Reproductive (mild) 53 to 92% (Lafitte et al, 2007) Reproductive (severe) 48 to 94% (Lafitte et al, 2007) Stage of reproduction 24 to 84% (Venuprasad et al, 2007) Grain filling (mild) 30 to 55% (Basnayake et al, 2006) Grain filling (severe) 60% (Basnayake et al, 2006) Traits Function Reference Proline contents Highly accumulated under drought (Dien et al, 2019) Sugar contents Increased under drought (Dien et al, 2019) Starch contents Increases and protect the plant (Dien et al, 2019) Leaf strach regulation Improved osmotic stress tolerance Spikelets fertility Improved under drought stress (Moonmoon and Islam, 2017)…”

“…The plant's ability to survive under lower water content in tissue is called DT (Fleury et al, 2010;Zhang et al, 2018). DT is a complex process in rice controlled by several genetic factors and complicated morphophysiological mechanisms (Li and Xu, 2007), including retention of turgor pressure via osmotic regulation, improved cell elasticity, reduced cell size as well as DT via protoplasmic resistance.…”

Phenology, gas exchange, biomass accumulation, and irrigated rice yield under alternative irrigation managements

“…It is advisable to encourage the adoption of intermittent flood irrigation systems, provided they can maintain soil moisture levels near 90% of field capacity. This moisture level is considered optimal, as the resulting water stress during rice cultivation is mild and does not adversely affect key parameters such as growth rate, stomatal conductance, transpiration, net photosynthesis, or defensive metabolic responses (proline content and antioxidant enzyme activity) (Zhang et al., 2019).…”