Field experiments were conducted to study affects of pH and hardness of spray water on efficacy of a herbicide combination (terbuthylazine + mesotrione) influenced by several pH adjusters and adjuvants in Debrecen, Hungary in 2008, 2009 and 2010. Favourable or unfavourable effects of pH and hardness of spray water could be observed under field
...conditions. Evaluation of weed control efficacy is suitable for examination of affects of spray water pH and hardness on herbicides. The terbuthylazine and mesotrione herbicide combination is suitable to control monocotyledonous and dicotyledonous weed species, however, significant effects of hardness and pH of spray carrier was observed only in control of monocotyledonous weeds. Certain pH adjusters (e.g. ammonium nitrate) can lessen harmful affects of water hardness effectively. Significant loss of efficacy of sensitive herbicide was found in hard water (by about 50-60%), and surfactants was not able to eliminate that harmful affect. However, biological activity was the same as in soft water with ammonium nitrate which can overcome the antagonism of salts. That pH adjuster had a more significant affect on the efficacy of the herbicide than the surfactant had in that experiment.
The necessity of application of hybrid specific crop production technology has been confirmed not only by trial results but also by the experiences gained from the agricultural practice. For this reason it is essential to test and collect data in field trials about the specific agronomic traits of the corn hybrids belonging to different maturit
...y groups and genotypes. Corn hybrids are tested for their responses to sowing time, plant density and fertilizer supply; sensitivity to herbicides; and lately, the resistance to the damages caused by the larvae of corn root worm. Last but not least, mention should be made of the differences in the responses of the corn hybrids to the damages caused by drought stress. Based on the trial results, suggestions for the hybrid specific corn production are compiled and made public for the experts and farmers engaged in corn growing. Corn hybrids may deliver maximum yields on the impact of specific crop production technology only in case if it relies on carefully done general production technology including soil cultivation, seed bed preparation and weed control. Similarly, precision crop production technology may advance the yield increase in economic way if it is constantly drawing on the source of research results.