Extended abstract
Introduction: Germination and seedling emergence are among the most critical developmental stages in crop plants, significantly influencing subsequent growth stages in the field. These traits are directly linked to seed vigor and potential. The application of organic and biofertilizers can enhance seed and seedling vigor, enabling them to withstand environmental stresses such as drought and aridity. To investigate this, the effects of drought stress and fertilizer treatments on germination indices of two plant species—red bean (Phaseolus vulgaris L.) and jicama (Pachyrhizus erosus (L.) Urban)—were examined.
Materials and methods: The seeds of jicama and red bean (Goli variety) were subjected to four levels of drought stress (0, -6, -9, and -12 bar) and four fertilizer treatments: control (no fertilizer), optimal biological fertilizer (EM), optimal organic vinasse fertilizer, and a combination of biological and organic fertilizers (at optimal levels). The experiment was conducted as a factorial design in a completely randomized arrangement with three replications at the University of Shahrekord during the 2022-2023 growing season.
Results: The results revealed that the triple interaction of plant species, fertilizer treatments, and drought stress had a significant effect (p < 0.01) on germination percentage, germination rate, seed vigor index, shoot and radicle length, as well as fresh and dry weights of shoots and radicles. Under non-stressed conditions, the jicama species treated with combined fertilizers exhibited the highest mean values for germination percentage (100%), germination rate (42.48 seeds/day), seed vigor index (8.55), shoot length (5.66 cm), shoot fresh weight (0.694 g), shoot dry weight (0.125 g), radicle fresh weight (0.772 g), and radicle dry weight (0.109 g). Under moderate drought stress (−9 bar), the mean radicle length of jicama treated with combined fertilizers was 6.333 cm.
Conclusion: In this study, the application of fertilizer treatments enhanced greater tolerance to water stress conditions and reduced water potential, while drought stress treatments led to a decline in the examined traits in both bean species. However, the jicama species demonstrated superior drought stress tolerance compared to the red bean, making it a more suitable option for cultivation under drought stress conditions
Highlights:
- The novelty of jicama in Iran and the lack of information on the germination and growth characteristics of this plant.
- Due to the presence of rotenone in jicama seeds, there was no information on how this compound interacts with fertilizer treatments to affect seed germination traits—an aspect investigated in this study.
- Since jicama is a multipurpose plant with both seed and tuber uses, there was no available data on how its germination traits compare to those of a similar plant, such as beans.
