Effect of nitrogen supply on growth and photosynthesis of sunflower plants grown in the greenhouse

Abstract

The effects of nitrogen availability on growth and photosynthesis were followed in plants of sunflower (Helianthus annuus L., var. CATISSOL-01) grown in the greenhouse under natural photoperiod. The sunflower plants were grown in vermiculite under two contrasting nitrogen supply, with nitrogen supplied as ammonium nitrate. Higher nitrogen concentration resulted in higher shoot dry matter production per plant and the effect was apparent from 29 days after sowing (DAS). The difference in dry matter production was mainly attributed to the effect of nitrogen on leaf production and on individual leaf dry matter. The specific leaf weight (SLW) was not affected by the nitrogen supply. The photosynthetic CO 2 assimilation (A) of the target leaves was remarkably improved by high nitrogen nutrition. However, irrespective of nitrogen supply, the decline in photosynthetic CO 2 assimilation occurred before the end of leaf growth. Although nitrogen did not change significantly stomatal conductance (gs), high-N grown plants had lower intercellular CO 2 concentration (C i ) when compared with low-N grown plants. Transpiration rate (E) was increased in high-N grown plants only at the beginning of leaf growth. However, this not resulted in lower intrinsic water use efficiency (WUE).

Hastes florais de helicônia sob deficiência de macronutrientes

“…O nutriente que mais influenciou a produção da MSH foi o N (1,62 g), o que acarretou redução de 67% em comparação com as plantas cultivadas com solução completa. A redução da massa de matéria seca em razão da carência de N é relatada em diversas culturas ornamentais, como Spathiphyllum (Yeh et al, 2000) e Helianthus annus (Cechin & Fumis, 2004).…”

Effect of Nitrogen on Yield and Oil Quality of Sunflower (<i>Helianthus Annuus</i> L.) Hybrids under Sub Humid Conditions of Pakistan

“…Furthermore, maximum LAI reached to a value at 65 DAS in N 4 and minimum value for LAI was recorded in N 1 (Figure 4). The greater leaf expansion shown in sunflower hybrids could be attributed to higher rate of cell division and cell enlargement [11][12][13].…”

Effects of Corm Size, Organic Fertilizers, Fe-EDTA and Zn-EDTA Foliar Application on Nitrogen and Phosphorus Uptake of Saffron (<i>Crocus sativus</i> L.) in a Calcareous Soil under Greenhouse Conditions

“…Nitrogen is one of the main chemical elements required for plant growth and photosynthesis (Cechin and de Fatima Fumis, 2004;Salvagiotti et al, 2009), therefore plays a major role in achieving the maximum economic yield of saffron (Chaji et al, 2013;Kirmani et al, 2014;Koocheki and Seyyedi, 2015). In addition, by considering the particular role of phosphorous in cell division, ATP generation, chlorophyll synthesis (Schachtman et al, 1998) and plant reproductive growth (White and Veneklaas, 2012), as well as saffron yield improvement (Naghdi Badi et al, 2011), study on phosphorus and nitrogen uptake is essential to better understand the changes in corm yield of saffron.…”