The effects of garlic extract, its application methods and their interaction on growth and yield of potato, Solanum tuberosum (L.) Cv. Latonia

The study was conducted in the growing season of 2012–2013 at Al Barjsya area, Al Zubair district, during the period from October 1st 2012 to February 5th 2013, to study the effect of garlic extract, its application methods and their interaction on growth and yield of potato, Solanum tuberosum (L.) Cv. Latonia. The experiment was designed according to Randomized Completely Block Design (R. C. B. D.) in a three factorial experiment of 12 treatments resulted from the interaction of: three levels for the first factor (the concentrations of aqueous extract of garlic), two levels for the second factor (the application methods of garlic extract) and three replicates for each experimental unit. The results showed that the garlic extract concentration (250 mL L -1 ) was significantly better than (0 and 125 mL L -1 ) for most studied characteristics, whether for vegetative growth or for yield (quantitatively and qualitatively), in exception, the dry matter percentage of leaves was non-significantly affected. For the application methods, it was of a significant effect for all studied characteristics, except for both the percentage of dry matter of each leaves and tubers, where the applying to soil method was significantly superior over the spraying method. For the interaction among the first factor and second factor treatments, the effect was significant mostly for all characteristics, except for the dry matter of each leaves and tubers of potato plants and the average of tuber weight, the effect was not significant