| Popis: |
Attempts are being made to minimize the use of synthetic chemicals such as fungicides. There is an interest toward the use of environmentally-friendly products to minimize impact of toxic residuals on human, animals, and environment. Two-season field experiments were conducted in 2018 and 2019to investigate the effectiveness of foliar sprayings of three products [potassium silicate (PS), perbicarbonate (PB), and peroxyacetic acid (PAA)] as singular or sequential treatments (totaling 10 treatment combinations) on growth (plant height, number of leaves, number of branches, leaf area), yield, yield attributes (number of pods plant -1, pod length, pod weight), chlorophyll a, b, and carotene contents, and resistance of okra plants (cv. Baladi) to powdery mildew disease. All treatments were significantly reduced powdery mildew infection with highest resistance observed with PAA+PS or PAA+PB, or PB+PAA treatments. Growth characteristics were enhanced by most treatments with the highest increases detected with singular PS or PAA treatments and with sequential PB+PS treatment. PS was superior in increasing the number of leaves, branching number, and leaf areas. The only treatments that significantly increased total yield were PAA+PB, PAA, PS, PS+PAA, and PAA+PS with the former two treatments giving the highest total yield. In conclusion, foliar spraying of okra with singular or sequential treatments with PS, PAA, and PB significantly improved plant resistance to powdery mildew infection. Nevertheless, singular PS or PAA treatments as well as sequential PB+PS, PAA+PS, PS+PAA, and PAA+PB treatments were the most effective in improving growth and yield while controlling powdery mildew disease. |
