The Impact of Applying Phosphorus and Mycorrhiza on the Morphological Parameters of Cotton Roots and Shoots, as well as Their Phosphorus Uptake and Dry Matter Yield

This study aimed to investigate the effects of P and mycorrhiza application on cotton root and shoot morphological parameters, P uptake and dry matter yield. The hypothesis to be tested is mycorrhiza and P applications increase cotton growth yield and P uptake. The experiment was established under greenhouse conditions in May 2022 and harvested in July 2022, as a pot experiment. In the experiment, two P levels (0 mg P2O5 kg-1, and 50 mg P2O5 kg-1) three mycorrhizae species (control (without mycorrhiza), indigenous mycorrhiza (IM) and Rhizophagus Clarus (Rh. Clarus)) inoculated with May 505-cotton (Gossypium hirsutum L.) variety were used with three replications. Before harvesting, plant height and stem diameter were measured, at harvest; shoot, root, and total dry matter weight (DW) were obtained. The P content of the root and shoot parts of the plant was determined by ICP-OES. Plant root morphological characteristics were determined, and Mycorrhizal Dependency (MD) was calculated by the DW yield of cotton. The JMP8 statistical program was used for ANOVA analysis and LSD test. Results showed that there was no statistically significant difference in terms of plant height, but P and mycorrhiza treatments made a significant difference in terms of stem diameter. In addition, mycorrhiza application made a significant difference in plant dry weight yield. As a total dry weight yield, the IM application has 45.1 g pot-1 and Rh. Clarus had 47.38 g pot-1 total DW yields. The results showed that mycorrhiza and P applications increased root growth parameters. In addition, P and mycorrhiza treatments improved root morphological characteristics on average. The cotton was found to be an 8.0 to 12.3% MD, and MD was lower in P-treated pots (8.1%) compared to non-P-treated pots (11.3%). Mycorrhiza inoculation and 50 mg P2O5 kg-1 dual applications seem to be suitable for cotton growth.