Effects of maize seed treatments with imidacloprid and thiametoxam on the plant spacing and grain yield

The abundance of pests and the rate of plant damages are controlled by the maize seed treatments with insecticides, as a preventive measure and a measure leading towards the lower population. It is expected that insecticides are efficient when used in relatively small dosages and that are not phytotoxic to seeds and young plants. The aim of the present study was to test the efficiency of imidacloprid and thiametoxam via both, the maintenance of plant spacing and obtained grain yield and also to check the response of certain hybrids to the seed treatment with systemic insecticides. Eight commercial ZP hybrids, four medium early maturity and four full season hybrids, were selected to test imidacloprid (Gaucho 350 FS - 1.0 l per 100 kg seeds) and thiametoxam (Cruiser 350 FS in the amount of 0.6, 0.9 and 1.0 l per 100 kg seeds). Seeds of all hybrids, including the control, were treated with the fungicide Maxim XL 035-FS (150g/100 kg seeds). Strip trials were performed in six locations in south Banat in the 2004-2007 period. The number of plants ha-1 at harvest and grain yield (t ha-1 at 14% moisture), in four replications of 10 m2 each, were recorded and then indices of plant spacing and grain yields for each hybrid over locations and years were calculated. The indices were estimated by the formula of values of plant spacing and the yield in treatments/ values in the control. Plant spacing: the average number of plants in the treatment with imidacloprid Gaucho 600 FS (63 hybrids/locations) and the control was 48,627 ha-1 and 47,812 ha-1, respectively, while the positive difference amounted to 815 plants ha-1 in the treatment. The index of plant spacing was 103.2, and it varied over hybrids, locations and years from 74.9 to 161.4. The corresponding values in the treatment with Cruisera 350 FS (70 hybrids/locations) and the control were 49,945 ha-1 and 49,749 ha-1, respectively. A positive difference in favour of the treatment amounted to 196 plants ha-1. The index of pla
Nakon prelaska sa višegodišnje monokulture na gajenje kukuruza u plodoredu, pa i u ponovljenoj setvi, brojnost populacije kukuruzne zlatice se smanjila ispod ekonomskog značaja. Ostale su aktuelne samo autoktone zemljišne štetočine.Tretiranje semena kukuruza insekticidima, predstavlja preventivnu meru zaštite od žičnjaka i grčica, kao i od ptica koje vade klijance. Cilj ispitivanja bio je, da se testira efikasnost imidakloprida i tiametoksama preko očuvanja sklopa, ostvarenog prinosa zrna i proveri reagovanje osam hibrida na tretman semena navedenim sistemičnim insekticidima. Sklop biljaka: kod imidakloprida Gaucho 600 FS na 63 (hibrid x godina x lokalitet) pozitivna razlika iznosila je 815 biljaka/ha a kod tiametoksama Cruisera 350 FS 196 biljaka/ha. Indeks sklopa bio je 103.2, kod prvog i 100.4 kod drugog insekticida. Prinos zrna: primenom imidakloprida Gaucha 600 FS ostvarena je pozitivna razlika od 364 kg/ ha, a kod primene tiometoksama Cruisera 350 FS 570 kg/ha. Na osnovu prosečnih vrednosti ostvarenog sklopa biljaka i prinosa zrna može se zaključiti da su svih osam hibrida pokazali tolerantnost na oba ispitivana insekticida, uz napomenu da nekonzistentnost rezultata treba šire analizirati.