Effects of nitrogen and plant density on dwarf sunflower hybrids

Abstract

This research was carried out to determine the seed yield and some yield components of two dwarf hybrids as compared to one standard-height sunflower hybrid (Helianthus annuus L.) at different nitrogen rates and planting densities. The study was carried out under natural rainfed conditions at the Thrace Agricultural Research Institute in Edirne-Turkey between 1999 and 2001. The experiments were set up in split-split plots in a randomized complete block design with three replications. The main plot treatments were three different-height sunflower hybrids, DW-1, DW-2, and Trakya-80. The sub plots were three levels of nitrogen, 0, 60, and 120 kg N/ha. The sub-sub plots were three planting densities, 10 × 70 (142,850 plants/ha), 15 × 70 (95,230 plants/ ha), and 20 × 70 cm (71,430 plants/ha). Based on marginal economic analyses, the economically optimal seed yield per hectare was obtained at 50 kg N/ ha for DW-1 and at 80 kg N/ha for DW-2 and Trakya-80. In all three hybrids, increasing plant densities decreased 1000-seed weight, hull percentage, and head diameter but increased test weight in natural rainfed conditions. The highest seed yield in both dwarf hybrids was obtained with the spacing of 15 × 70 cm (95,230 plants/ha). The results of this research show that nitrogen and plant density have significant effects on seed yield and some yield components of different-height sunflower hybrids.

Yield and Quality of Intercropped Sunflower with Soybean Under Different Sunflower Plant Spacings and Slow – Release Nitrogen Fertilizer Rates in Sandy Soil

“…It seemed that intercropping soybean with sunflower plants that spaced at 20 cm between hills (50% soybean + 100% sunflower) increased intra-specific competition between sunflower plants for basic growth resources especially solar radiation which reflected on little dry matter accumulation during sunflower growth and development compared to the others. Similar results were obtained by Sûzer [32] who investigated that increasing sunflower plant densities per unit area decreased 1000-seed weight and head diameter.…”

Evaluation of Different Methods of Sowing of Sunflower at Farmers’ Field in Central Plain Zone of Punjab

“…This might be due to the fact that plants grown at lower population reduce the overall competition between flower plants and thus, afforded them more efficient utilization of available resources to grow well and to increase yield attributes of sunflower plants (Radwan et al, 1996). The results obtained were in agreement with Olowe (2005) and Suzer (2010).…”

OILCROP-SUN Model for Nitrogen Management of Diverse Sunflower (<i>Helianthus annus</i> L.) Hybrids Production under Agro-Climatic Conditions of Sargodha, Pakistan

“…In our country, total cultivation area is limited because production is low due to lack of proper management practices and production technologies [4]. Because farmers are not known about good cultivars, proper nitrogen requirement, plant spacing and irrigation in order to produced high seed and oil yield per hector Pakistan is depended on cultivation of exotic sunflower hybrids, the newly local developed hybrids did not receive much attention due to lack of seed sector [5]. There are various factors are responsible for obtaining the higher yield for sunflower.…”