IMPROVEMENT OF PERFORMANCE AND YIELD QUALITY OF POTATO PLANT VIA FOLIAR APPLICATION OF DIFFERENT BORON RATES AND DIFFERENT POTASSIUM SOURCES

It is known that potassium (K) and boron (B) elements play a vital role as sizing agents for potato tubers. Awareness of the role of K and B elements as well as the good management of their fertilization process for potato crops can prompt optimized fertilization approaches for higher returns. Thus, this research paper aimed to assess the effect of foliar application of K at rate of 750 mg K2O L-1 via different K sources [control (without K foliar application), potassium sulphate (K2SO4, 48.0 % K2O), potassium humate (10.0%K2O), potassium silicate (K2SiO3, 60.0 %K) and potassium citrate (K3C6H5O7, 45.0 % K2O)] as main plots and foliar application of B which added as boric acid (H3BO3, 17.0 % B) at three rates [0.0 (control), 40.0 and 80.0 mg L-1) as sub main plots on performance and yield quality of potato plant during two successive seasons of 2020/2021 and 2021/2022. The findings indicate that potato plants sprayed with potassium silicate had the best performance and yield quality compared to that treated with other K sources, while untreated plants recorded the lowest performance and yield quality. Potassium citrate came in the second order followed by potassium humate then potassium sulphate form. Regarding B foliar application, the performance and yield quality of potato plants increased as the rate of B increased. In other words, the best performance and yield quality for potato plants were recorded under combined treatment of potassium silicate and B at rate of 80.0 mgL-1. Generally, it can be concluded that potassium silicate form is the fastest and best form of potassium in potency and absorption inside the plant to stimulate and activate vital processes, increase the percentage of solids in tuber crops and sizing via spraying. As well as foliar application of B at rate of 80.0 mgL-1 causes the transfer of most of the sugars and carbohydrates from the vegetative mass to the tubers.