Integrated effects of NPK fertilizers and organic manures on the growth, yield and nutrient content of sunflower (Helianthus annus L.)

Abstract

Four field experiments were conducted separately at the Research Farm of Charfasson Govt. College, Bhola during rabi season in (2015-2016) and (2016-2016) using four rates of each of cow dung (CD), rice bran (RB), vermicompost (VC) (0.0, 2.5, 5.0, 7.5 t ha-1), poultry litter (PL) (0.0,1.5, 3.0, 4.5 t ha-1) and NPK (0.0, 50, 100, 150% RDF) alone and in combination on sunflower (Helianthus annus L. var. keroni-2). Sixteen treatments, in triplicate, were arranged into a completely randomized block design. Results showed that the growth and yield attributes, composition and quality of seeds (oil and protein) of the crop increased with increasing rate of the amendments significantly (P< 0.05) over the control and the variation between the treatments were also significant irrespective of the sources of amendments in most of the cases. Generally, combination of the treatments showed better performance than their individual application. Highest values of growth parameters due to application of CD, RB, PL and VC were 208.4, 196.0, 204.3, 198.4 for height (cm); 41.2, 45.5, 44.8, 45.3 for leaf number (plant-1); 410.3, 384.4, 376.4, 381.0 for leaf area (cm2); 12.8, 13.6, 13.6, 14.6 for LAI; 60.7, 67.3, 63.8, 72.4 for stem (g plant-1); 12.8, 16.0, 12.7, 18.9 for root (g plant-1); 25.3, 24.0, 21.5, 19.2 for leaf (g plant-1); 10.0, 5.8, 8.7, 7.7 for petiole (g plant-1); 19.3, 18.0, 32.6, 38.3 for inflorescence (g plant-1) and 121.3, 127.7, 134.0, 153.9 for total dry matter (g plant-1), respectively. Most of the values were recorded in combined treatments of 150% NPK with 7.5t ha-1 of CD, RB; 4.5t ha-1 of PL respectively. However, in the NPK+VC treated plants the highest dry matter yields were found in 150% NPK alone. Concentration and uptake of NPKS measured in different parts of sunflower increased due to treatments of organic and inorganic fertilizers applied alone and in combination significantly (P< 0.05) with increasing level of rates irrespective of the sources of organic manures. Maximum values of NPKS concentration (%) in different organs of sunflower were 1.33, 0.33, 1.85, 0.19 for stem; 1.08, 0.38, 2.04, 0.18 for root; 3.45, 0.67, 4.12, 0.18 for leaf; 1.99, 0.62, 3.0, 0.22 for petiole; 0.73, 0.68, 2.25, 0.23 for inflorescence and 4.95, 0.94, 0.75, 0.26 for seed due to application of CD, 1.22, 0.35, 1.90, 0.18 for stem; 1.17, 0.35, 2.41, 0.16 for root; 3.98, 0.43, 4.28, 0.24 for leaf, 1.04, 0.65, 3.00, 0.22 for petiole; 2.16, 0.58, 2.21, 0.26 for inflorescence and 5.24, 0.83, 1.60, 0.47 for seed due to application of RB, 0.65, 0.42, 1.80, 0.17 for stem; 1.02, 0.54, 1.54, 0.18 for root; 4.47, 0.57, 3.14, 0.20 for leaf; 2.60, 0.64, 3.20, 0.32 for petiole; 1.30, 0.95, 2.19, 0.32 for inflorescence; 5.18, 0.86, 1.02, 0.31 for seed due to PL, 0.42, 0.23, 1.95, 0.12 for stem; 0.57, 0.33, 2.66, 0.20 for root, 2.61, 0.42, 2.77, 0.19 for leaf; 2.30, 0.65, 2.65, 0.20 for petiole; 0.76, 0.71, 2.21, 0.26 for inflorescence and 4.86, 0.69, 1.08, 0.16 for seed measured from VC treated plants, respectively. The highest concentrations of NPKS of different organs of sunflower at maturity, were found significantly (P< 0.05) in combined treatment of 5.0, 7.5t ha-1 of CD, RB, VC or 3.0 and 4.5t ha-1 PL with 150% NPK, respectively, in most of the cases. However, their uptake pattern also followed the same trend as in concentration and was the reflection of dry matter yield of growth attributes. Seed yield (g plant-1) was also recorded to be maximum in 7.5t ha-1 of CD (64.7), RB (46.0), 5t ha-1 VC (57.61) and 4.5t ha-1 of PL (44.4) with 100 and 50% NPK showing an appreciable variation among the treatments of organic amendments. However, the proportion of NPK fertilizers required to less dose than dry matter yield to achieve the maximum seed yield. Similarly, number of seed also followed the same trend as in seed yield. The highest diameter of inflorescences were observed in the treatment, 5.0t ha-1 (CD, RB, VC) and 3t PL ha-1 with 150% NPK in all the cases. Variation in yield attribute like weight of 100 seeds also followed to be the same trend as in yield of seed. The higher value of seed attribute was recorded in combined treatments of 7.5t ha-1 of CD (9.8g) and VC (7.53g) with 100 and 150% NPK respectively. However, the values recorded from plant treated with 5t ha-1 of RB (7.3g) and 3t ha-1 of PL (7.4g) with 100 and 150% NPK were very similar but requirement of organic manures less dose for RB and PL. Content of oil and protein increased variably due to variation in treatments. The highest content of oil in seed ranged from 51.8 to 46.9% when 5.0 and 7.5t ha-1 of CD and VC with 150 and 100% NPK, respectively, were applied. However, the content of oil derived from seeds of plants treated with RB and PL with 150 and 100% NPK, respectively, remained in between CD and VC treated seed oil of sunflower. Protein content also followed the same pattern as in oil. The highest content of protein varied not very appreciably ranging from 33.9 (RB+100% NPK) to 30.2% (CD+150% NPK). Intermediate protein content was recorded as 31.8 and 31.0% yielded from PL 3.0t ha-1 and VC 5.0t ha-1 together with 150% NPK respectively. Appreciable variation in B: C ratio due to variation in treatment combinations was observed. B: C ratio ranged from 3.62 to 2.51 when both CD and RB at the rate of 7.5t ha-1 together with 50 and 100% NPK were applied respectively. However, B: C ratio returned from VC (3.35) and PL (2.58), were observed very close, due to treatment of 5.0 and 4.5t ha-1 with 100 and 50% NPK respectively.