Samenvatting

The increasing temperature of the past years has a negative impact on the agricultural sector. This is affecting crop growth negatively, as a result from the heat and drought stress the crops are experiencing. Moreover, the experienced heat and drought stress results in erosion of the soil,
causing nutrient deficit. Since these abiotic stress factors are arising more frequently, and the need for environmentally friendly solutions increase, aims this study for the development of a suitable biostimulant for Zea mays to enhance the tolerance in heat and drought stress
conditions, as well as nutrient deficit, separately. The following products are tested as a biostimulant and applied as a seed coat; Spirulina platensis extract (SPE), Azospirillum brasilense extract (ABE), L-proline, product A and, Product B. The eƯiciency of the biostimulants is tested by measuring germination rate and uniformity, leaf surface and shoot length, relative water content (RWC) determination, photosynthetic activity, ROS production and total protein content determination. The SPE coated seedlings experiencing nutrient deficit showed a significant (α = 0.1) increase in chlorophyll A content (p = 0.0143), chlorophyll ratio (p = 0.1024) and content (p = 0.1024). The product A and L-proline coated seedlings also showed an increase in chlorophyll A content with p = 0.0065 and p = 0.0077, respectively. Product A showed an increase in relative water content for both conditions. This study presents the foundation for biostimulant development for Zea mays; however, further specific research is necessary to obtain more insights into the stress response in relation to the biostimulant, as well as in-depth analysis of stress related proteins and optimalisations of experiments are needed to increase the reliability.