No abstract

No abstract

Tea leaves have economic importance in preparation of the popular beverage of the world "tea". Bird's eye spot disease of tea leaves creates significant revenue loss in tea trade of many tea plant cultivating countries. Management of this disease by silver (AgNps) and copper (CuNps) nanoparticles that are biosynthesised by efficient antagonists was studied. The biocontrol agents like Pseudomonas fluorescens, Trichoderma atroviride and Streptomyces sannanensis were evaluated for nanoparticle synthesis against Cercospora theae isolates namely KC10, MC24 and VC38. Initially, the freshly prepared extracellular AgNps showed high disease control (59.42 - 79.76%), but the stability of antagonistic property in stored nanoparticles were significantly high in CuNps (58.71 - 73.81%). Greenhouse studies on various treatments imposed also showed reduced disease incidence percentage of 13.4, 7.57 and 10.11% when treated with CuNps synthesized by P. fluorescens, T. atroviride and S. sannanensis respectively. Various treatment schedule in fields suggested the use of Bionanocopper@1.5 ppm for highest yield (3743 kg/ha) with 66.1% disease prevention. The results suggest the use of biosynthesised CuNps using Streptomyces sannanensis for controlling the tea plant pathogens causing foliar disease with higher stability in releasing the antagonistic activity during sporadic disease incidence of bird's eye spot disease in tea plants.

No abstract

Dry soil conditions at soybean planting results in poor stand establishment, which often necessitates replanting. We conducted a study to identify soybean genotypes that can maintain germination rates and possess better root morphology under water stress. We tested 41 Plant Introductions (PI) for germination and seedling root traits under controlled environmental conditions at five water potentials: 0.00, −0.27, −0.54, −0.82, and −1.09 MPa (no, low, mild, severe, and extreme water stress, respectively). The same genotypes were tested for emergence and seedling root traits under field conditions in South Carolina (2021 and 2022) and North Carolina (2022). Among the 41 genotypes evaluated, PI 398566 and PI 424605A maintained higher germination percentages (≥63%) under water stress. The same genotypes were ranked among the top 15 genotypes for root traits (total-root and fine-root (diameter between 0.25 and 0.50 mm) length, surface area, and/or volume) under water stress. Furthermore, they had relatively higher emergence percentages under field conditions (≥35% under dry soil conditions). The superior genotypes identified in this study (PI 398566 and PI 424605A) that had better germination and root morphology under water-stress and no-stress conditions and better emergence would be useful for developing varieties with drought tolerance during the emergence phase.