Plant growth regulators biodegradable hydrogels containing various systems development and agricultural applications

In the present work, a serie of the gelatin / chitosan hydrogel synthesized by using glutaraldehyde (GA) cross-linker was researched for agricultural purposes. Percentage of gelation and swelling / decomposition behaviors of hydrogel samples that prepared in different rates of gelatin-chitosan, were examined. Prepared hydrogel samples can be gel in high values and rates of their gelation somewhat decreasing based on increasing in chitosan amount were determined.Swelling behaviors of hydrogels with time were examined in solution of Britton-Robinson buffer (pH=7,0).The swelling values of all hydrogels increasing with time and reaching a stability level of swelling value in about 24 hours were observed. When increasing the amount of chitosan, the swelling value is decreased with time, and according to our findings, the most swelling hydrogel at 30 ºC, pH = 7.0 is included more amount of gelatin.Variation of the swelling behavior of hydrogels with temperature was examined in constant pH among 4-50 ?C. It was observed that swelling values increase with increasing temperature, and reaching the highest value at 40 °C.Variation of the swelling behavior of hydrogel samples with pH was examined. It was observed that hydrogels which includes more gelatin content, were very swollen at low pH values, when increasing pH, swelling values were decreased, and were raised at the beginning from pH = 5.0 again. Also, when increasing chitosan amount in hydrogels, the values of swelling did not effect from the pH of medium.Decomposition behaviors of hydrogels were evaluated at 30°C and pH = 7.0 against time. It was observed that the hydrogel which includes minimum amount of chitosan, was decomposed in 20 days, while the hydrogel which maximum amount of chitosan, was decomposed approximately 76 days.Agricultural practices of gelatin-chitosan hydrogels were evaluated in three stages. In the first stage, JK-7, JK-11 and JK-15 hydrogels that have different values of swelling, was selected. Salicylic acid (SA) and gibberellic acid (GA3) to these hydrogels was loaded. It was determined that hydrogels were completed releasing SA among 3 and 18 days, and releasing GA3 among 24 and 60 hours. In the second stage, study of intermittent release as a putative model was realized to measure releasing amounts of hydrogels in the soil. For this work, JK-11 and JK-15 hydrogels that have slower releasing, was selected. Intermittent releasing of SA and GA3 from hydrogel of JK-15 is slower than that of JK-11 hydrogel. In the third stage of the study, SA and GA3 that incarcerated in the hydrogels of JK serie, was aimed to use of agricultural areas. As a result of the experiments of swelling and releasing has decided to use three types of hydrogels that have different values. A serie of JK-7, JK-11 and JK-15 hydrogels that included different amounts of SA and GA3, was prepared. In addition, tomato seeds with JK-11 and JK-15 hydrogels that loaded SA, and scarlet sage (Salvia) and wild eggplant seeds with JK-11 and JK-15 hydrogels that loaded GA3, were covered. Effects of hydrogels to the output of seedlings in the seeds were investigated in all samples. Gelatin hydrogels with loaded GA3 were determined very productive to the output of seedlings in wild eggplant seeds.