Rose being an nutrient exhaustive crop, application of proper manure and fertilizer has to be done to obtain good plant growth and flower yield. It requires manuring and fertilizer application around plant periphery, because of most concentration of roots. In view of the escalating cost of fertilizers and hazardous polluting effects, there is an ever increasing awareness about the alternate agricultural system known as organic floriculture. Farmyard manure along with chemical fertilizer has increased flower yield in rose (Singh et al., 8). Ganeshe et al. (3) found beneficial effect of inoculation of Azotobacter. Plant growth and flower production enhanced due to application of nitrogen in rose (Singh et al., 7). Keeping these considerations in view, the present investigation was undertaken under the tarai conditions of Uttaranchal with a view to ascertain the role of farmyard manure, Azotobacter and nitrogen in relation to leaf nutrient status, plant growth and flower production of rose.

A field experiment was carried out at Floriculture Section, Department of Horticulture, G. B. Pant University of Agriculture and Technology, Pantnagar. A commercial cultivar Gruss-an-Teplitz was selected for this study and planting was done at 50 cm x 50 cm during October 1999. Plants were allowed to grow for one year and first pruning was done on October 15, 2000 by leaving three shoots on each plant, followed by common cultural practices. After attaining proper growth of plants, experimentation work was started on two-years old and subsequently three-year old plants during 2001–02 and 2002–03, respectively. Plant were pruned at 30 cm above the ground on October 15 by leaving four shoots, one in each direction during both the years. Treatments comprised farmyard manure (0 and 5 kg/m²), Azotobacter (inoculated and uninoculated) and nitrogen (20, 40 and 60 g/m²). Farmyard manure and Azotobacter were applied after pruning (during filling of pits), whereas nitrogen doses were given in the form of urea in two splits, i.e. 30 and 60 days after pruning. Common doses of phosphorus (50 g/m²) and potassium (30 g/m²) were applied as basal dose in the form of single superphosphate and muriate of potash, respectively during pit filling. Uniform cultural practices were adopted for all the treatments during both the years after experimentation. Four plants were taken per treatment in each replication. Experiment was laid out in a randomized block design with three replications. Leaves were taken for nutrient analysis at pea size of flower bud stage (Bhargava and Raghupathi, 2). Leaf area was measured with LI-COR, LI-3000 A portable leaf area meter. Plant height was measured at 180 days after pruning. Days taken to flowering were counted from date of pruning. Diameter of flower, number of petals/flower and average dry weight of flower were counted from flower harvested during first flush. Number and weight of flowers/plant were taken during first and second flush, whereas flowers were regularly harvested upto eleven months, i.e. September to calculate yield of flowers during both the years. Data thus obtained were pooled and subjected to statistical analysis.

Application of farmyard manure (FYM), Azotobacter and higher dose of nitrogen conspicuously increased leaf nutrient content of nitrogen, phosphorus and potassium and plant growth (Table 1). Significantly higher values on leaf area index (LAI) and plant height and leaf content of N, P and K were recorded with the application of farmyard manure (5 kg/m²) as compared with control. It could also be attributed to the fact that after proper decomposition and mineralization, the farmyard manure supplied available nutrients directly to the plant and also had solubilizing effect on fixed form of nutrients in the soil (Sinha et al., 9). Application of FYM in the soil provided additional nutrient to the plants as well as improved the physical and biological properties of the soil (Reddy and Swamy, 6) and enhanced plant growth and N, P and K content of leaf enhanced.

Higher values on leaf nitrogen, phosphorus, potassium and LAI, and plant height were observed in Azotobacter inoculated plants as compared with uninoculated. These results are in conformity in many respects with observation made by Ganeshe et al. (3) who noticed that inoculation of Azotobacter increased uptake of leaf N, P and K content in okra. Uptake of micronutrients (Fe, Zn, Cu and Mo) is influenced due to Azotobacter inoculation (Awasthi et al., 1). It augmented some role in this treatment to increase the leaf nutrient status and plant growth.

The maximum nitrogen, phosphorus and potassium content of leaf were recorded with the application of higher dose of nitrogen (60 g/m²) followed by moderate dose (40 g N/m²) and minimum were recorded with the lower dose of nitrogen, i.e. 20 g/m². Plant growth was also influenced significantly due to nitrogen application. Maximum plant height and LAI were recorded with higher dose of nitrogen (60 g/m²) followed by moderate dose of nitrogen (40 g/m²) and minimum with lower nitrogen (20 g/m²). Significant difference among all these treatments (20, 40 and 60 g N/m²) was observed on all these parameters. Nitrogen is a main constituent of chlorophyll and involved in various important physiological processes like photosynthesis and increased vegetative growth at higher concentration. Nitrogen increased the total leaf area of plants causing high dry matter accumulation (Potti and Arora, 5). In a comprehensive study, Verma et al. (10) observed that application of nitrogen significantly increased uptake of N, P and K content in carnation leaves. These results are also experimentally substantiated with the findings of earlier workers (Nagaraju et al., 4; Singh et al., 7) in rose.

Various flowering parameters and flower yield were significantly influenced with application of farmyard manure, inoculation of Azotobacter and nitrogen (Tables 2 and 3). Application of farmyard manure significantly influenced the flowering and yield attributes. It is observed that application of farmyard manure delayed flowering. Application of 5 kg/m² farmyard manure resulted in delayed flowering, whereas diameter of flower, number of petals/flower and average dry weight of flower were significantly higher with the application of farmyard manure as compared with control.

Application of farmyard manure also enhanced flower yield. All the yield parameters were significantly influenced due to application of farmyard manure except number of flowers/plant during second flush (Table 3). Significantly higher values on number of flowers/plant during first flush and weight of flowers/plant during both the flushes were recorded with the application of farmyard manure. However, application of FYM failed to exert any significant effect on number of flowers/plant during second flush. Significant difference between FYM treatment and control was recorded on yield of flower/m². Increase in flowering and yield attributes with application of farmyard manure might be attributed to good physical and biological condition of soil (Sinha et al., 9) and found beneficial in rose flower production (Singh et al., 8).

Flowering attributes were significantly influenced due to inoculation of Azotobacter. Maximum number of petals/flower was also recorded with Azotobacter treatment as compared with uninoculated, whereas inoculation of Azotobacter significantly delayed flowering. However, flower diameter and average dry weight of flower could not influenced significantly due to Azotobacter inoculation. A perusal of data presented in Table 3 showed that inoculation of Azotobacter significantly influenced the flower yield of rose, whereas number of flowers/plant during both the flushes and weight of flowers/plant during second flush were not influenced due to inoculation of Azotobacter. Significant increase was observed on weight of flowers/plant during first flush and flower yield/m² due to inoculation of Azotobacter as compared with uninoculated. This might be attributed to good plant growth due to inoculation of Azotobacter. Inoculation of Azotobacter influenced the secretion of growth promoting substances especially cytokinins, which helps in cell division, branching and development of side buds (Waithaka and Dana, 11). Enhancement in yield of flowers with inoculation of Azotobacter have been observed by Singh et al. (7) in rose.

Maximum days were taken to flowering in the higher dose of nitrogen (60 g/m²) followed by moderate dose (40 g/m²). Number of petals/flower, diameter of flower and average dry weight of flower were found maximum with the application of higher dose of nitrogen (60 g/m²) and minimum with lower dose, i.e. 20 g/m² (Table 2). Study of the data (Table 3) indicated that flower yield of rose significantly influenced due to application of nitrogen. Maximum number of flowers and fresh weight/plant were recorded with the higher dose of nitrogen (60 g/m²) during both the flushes. Higher dose of nitrogen also resulted maximum yield of flowers/m² followed by moderate dose, i.e. 40 g/m² and minimum was with lower dose of nitrogen (20 g/m²). The increased flowering attributes with higher dose of nitrogen might be due to the better nutrient status of leaf and good plant growth due to adequate application of nitrogen in the present investigation. It is well known fact that nitrogen is an important constituent of nucleotides, phosphatides, enzymes, hormones etc., which have great importance in plant metabolism, augmented crucial role in enhancement of plant growth and resulted in higher flower yield. Present finding is also corroborated with the results obtained by Singh et al. (8) who noticed pronounced increase in flower yield with application of higher dose of nitrogen in rose.

References