Effect of Foliar Application of Micronutrients on Plant Growth and Seed Germination of Four Okra Cultivars

In the present study, the effect of foliar application of micronutrient fertilizers on okra plants was examined. Four okra cultivars ('Boyiatiou', 'Veloudo', 'Clemson' and 'Pylaias') were sprayed weekly throughout the duration of the cultivation with two commercial micronutrient fertilizers (F-1 and F-2) [e.g. M-1=control (0 ml); M-2= 40 ml (20 ml of each fertilizer); M-3 = 80 ml (40 ml of each fertilizer). From the results of the present study, it was observed that plant height of 'Boyiatiou' and 'Pylaias' was increased by application of M-2 whereas plant height of 'Clemson' and 'Veloudo' was either unaffected or reduced. Flower induction increased at both micronutrient levels (M-2 and M-3) only in 'Pylaias'. Pod set was higher in treatment M-3 in 'Veloudo' and 'Pylaias' and resulted in higher seed yield. Pod length and diameter were not affected by micronutrient application, as well as 100-seed mean weight and moisture content; however the number of seeds per pod in 'Pylaias' was significantly lower in M-2 and M-3 than in M-1, whereas the percent seed germination of all cultivars was higher following micronutrient application. Germination differed between the control and the micronutrient treatments at all times of harvest and plant parts. In conclusion, the main value of foliar application of micronutrients was to increase germination percentage and reduce hardseedness, especially for cv. 'Veloudo', since the occurrence of hard seeds in susceptible cultivars reduces germination, and therefore seed quality. In some cultivars ('Pylaias' and 'Veloudo' here) micronutrients may also increase seed yield by increasing pod set.