Effect of Nitrogen and Phosphorus Levels on Growth and Yield of Guar Plant (Cyamopsis tetragonoloba L.) to Changing Planting Rows Spacing in Jiroft

Cluster bean with the English name of Cluster bean and the scientific name of Cyamopsis tetragonoloba L. is an annual and summer plant of the legume family that has a high drought tolerance and is a suitable product for hot and semi-arid regions (Ashraf et al, 2005). Based on their results on guar gum, the researchers showed that the highest grain yield and biological yield were obtained at a row spacing of 45 cm (Jagtap et al., 2011). Determining the desired row spacing in the field as one of the important agricultural activities has an effective role in how light is distributed in vegetation as well as intra-plant competition. Due to the geographical location and climatic conditions of Jiroft, which is one of the hot and dry regions of the country, it is necessary to identify and cultivate plants that are specific to these regions in accordance with the existing conditions, So Guar as food, industrial, fodder products. And the drug can be included in the summer cultivation pattern. Therefore, the present study was designed and conducted to investigate the effect of nitrogen and phosphorus levels on the growth and yield of this plant at different planting row spacing and achieve the best treatments (such as planting row spacing, nitrogen and phosphorus) in southern Kerman province (Jiroft region).

This study was performed to evaluate the effect of nitrogen and phosphorus levels on growth and yield of guar gum at different planting densities, as factorial layout based on a randomized complete block design with three replications in two cropping years 2019-2020 and 2020- 2021 in the Agricultural Research and Training Center and Natural Resources of Jiroft. Nitrogen at three levels (20, 60 and 100 kg/ha pure nitrogen) from urea and phosphorus fertilizer source at two levels (zero and 75 kg/ha P2O5 source) from mono potassium phosphate fertilizer source and row spacing at three levels (30, 45 and 60 cm) were considered.Measurement traits in this study included: plant height, number of seeds per pod, number of pods per plant, number of branch, 1000-seed weight, pod length and seed yield. Data were collected and normalized and then analyzed using SAS software and the means were compared with LSD test. EXCEL software was used to draw the relevant shapes.

The results showed that the interaction of nitrogen, phosphorus and spacing between rows had a significant effect on all studied characteristics in terms of number of branch and pod length. The highest seed yield from 60 and 75 kg application of nitrogen and phosphorus, respectively, with observance of 45 cm row spacing at 4250 kg/ha, and the lowest seed yield of treatment were 20 and 0 kg application of nitrogen and phosphorus, respectively observance of row spacing of 60 cm at 1800 kg/ha. According to the results, nitrogen and phosphorus fertilizer levels have little effect on seed yield and yield is mainly affected by row spacing, so high nitrogen and phosphorus levels are not necessary (Patel et al., 2002).

The results showed that the interaction of nitrogen, phosphorus and spacing between rows had a significant effect on all studied characteristics in terms of number of branch and pod length. The highest seed yield from 60 and 75 kg application of nitrogen and phosphorus, respectively, with observance of 45 cm row spacing at 4250 kg/ha, which compared to 20 and 0 kg application of nitrogen and phosphorus, respectively observance of row spacing of 60 cm increased by 42.Therefore, application of 60 kg/ha nitrogen and 75 kg/ha of phosphorus and planting distances of 45cm will create favorable conditions for maximum yield, which will be suitable in the climatic conditions of southern Kerman and similar areas, and guar can a low-water plant, in terms of water consumption, it should be included in the planting pattern of low-water plants.