Evaluation the Quantitative Characteristics of Potato Cultivars Affected Foliar Application of Indole-3-Acetic Acid and Weed Management

Using plant hormones is an effective way to increase potato yield. Some plant hormones, such as gibberellic acid, cytokinin, and auxin, can stimulate the growth of potato roots and leaves, and among their other effects are regulating plant growth and development.
This experiment was conducted in order to assess the effect of growth regulator (IAA hormone foliar application) and weed control on growth indices, crop production and morphological traits of the potato cultivars during two crop years in Bardsir region.
This research was done at the Bardsir agricultural college, Kerman province(Iran) in 2017-2018 cropping seasons. The study was consisted of a split factorial using Randomized Complete Block Design (RCBD) with three replications. The two potato cultivars (Milva and Sante), as the first factor placed in the main plots, and three levels of foliar spraying of indole acetic acid (IAA) hormone (including of non-use, 200 and 400 ppm), and weed control (including of the pre-emergence application of metribuzin herbicide with an amount of 750 g.ha-1, the two-stage application of metribuzin in the form of split [the pre-emergence application (500 g.ha-1) + the post emergence application (250 g.ha-1)], manual weeding and without weed control were factorially as the secondary factor were also placed in sub-plots.
The results showed that increasing auxin from no consumption to 400 ppm significantly increased dry and fresh weight of potato tuber, tuber diameter, tuber yield, dry biomass and leaf area index. The application of auxin at 400 ppm significantly increased the weed biomass at the time of potato harvest. The highest leaf area index of 3.46 was observed in Milva cultivar when 400 ppm of indole-3-acetic acid was used. Weed control during the two-step application of metribuzin was recorded with an increase ratio of 15 to 39% compared to the control without treatment.
The highest yield of potato tuber was obtained under two-step application conditions of metribuzin and 400 ppm auxin at the rate of 38055.33kg.ha-1.