Effect of Sowing Density on the Growth, Yield and Nutrient Uptake of Hybrid Sunflower (Helianthus annuus L.) in Rabi Season

Impact of Plant Density and Humic Acid Application on Yield, Yield Components and Nutrient Uptakes of Sunflower (Helianthus annuus L.) Grown in a Newly Reclaimed Soil

“…On the other side, plant density (D 3 ) gave the highest values of leaf uptakes of N, K, Mg, Mn and Zn in both seasons. Similar results have been reported by Ravichandran and Srinivasan (2017) who found that plant density (30x30 cm 2 ) single seedling with applying 200% recommended dose of NPK fertilizers (RDF) showed significantly higher uptakes of the N, P and K during 2015 and 2016 seasons (66.7 and 71.5 kg ha -1 , 21.3 and 24.5 kg ha -1 , as well as 145.3 and 169.2 kg ha -1 , respectively) compared to that of 60x30 cm with single seedling with adding, 100% of the RDF (34.5 and 38.2 kg ha -1 , 11 and 12.3 kg ha -1 , as well as 76.9 and 86.2 kg ha -1 , respectively, during 2015 and 2016 seasons). It was noticed that the higher nutrient uptake, with using the higher plant population level is attributed to more below and aboveground competition for nutrients and all the applied resources are effectively utilized.…”

“…Therefore increase in the plant population increases seed oil and protein yields per unit area (Ibrahim, 2012;Awais et al, 2013;Ali et al, 2014;and Hatami 2017). On the contrary, the opposite trend was observed by (Radwan et al, 2013, Baghdadi et al, 2014, and Ravichandran and Srinivasan (2017). Moreover, Al-Thabet (2006), Rauf et al (2012), Awais et al, (2013) and Yasin et al, (2013) mentioned that the plant density showed no significant effect either on oil or protein percentage.…”

“…It is often manipulated in order to ensure optimum plant populations to reduce the yield losses due to overcrowdings that influence sunflower yield and seed oil percentage (Basha, 2000 andAllam et al, 2003). Increasing the plant scourge per unit area incrementally increased sunflower plant height and biological yield per unit area (Ali et al (2012b); Ibrahim (2012); Awais et al (2013); Radwan et al (2013;Ali et al, (2014), Baghdadi et al, (2014) and Ravichandran and Srinivasan (2017). On the other hand, increasing the plant score significantly decreased the stem and head diameter, head dry weight and seed yield plant -1 (Ibrahim, 2012;Awais et al, 2013 andRadwan et al, 2013).…”

“…Plant populations were reported to influence the nutrient uptake by sunflower. A high nutrient uptake caused by high plant population level was recorded by Ravichandran and Srinivasan (2017) Humic acid (HA) is formed through the chemical and biological humification of plant and animal organic matter and through the biological activities of microorganisms (Fahramand et al, 2014). Several researchers indicated that HA application as foliar spray enhanced the plant growth, nutrient uptake and yield and improved the quality of some crops.…”