Shrimp farm waste reduces the deleterious effects on sunflower seedlings under drought stress

Abstract

The aim of this study was to evaluate the effects of organic solid shrimp waste (SSW) on germination, stem diameter and leaf number of sunflower plants under conditions of water stress. Further studies assessed the effects on organic solute contents and soluble proteins. Sunflower seeds were sown in buckets containing: sand;sand + manure/organic fertilizer mixed; sand + 7 g SSW and sand + 1 4 g SSW. The plants were subjected to daily watering close to field capacity and with 16 days after sowing (DAS) half of each group of seedlings was subjected to irrigation suspension. Under drought stress conditions, the average of leaf number of treatments with SSW in substrate was 49 % higher than sand treatment at 21 DAS. Additionally, it was verified that the leaves of the plants with 1 4 g SSW were capable to increase the contents of soluble proteins and proline comparad to the sand treatment at 21 DAS. The use of SSW in the substrate has provided an improvement in the parameters: number of leaves, stem diameter and the production of organic solutesand proteins when compared to plants growing in a substrate of sand or sand + manure/organic fertilizer mixed.