Chemical weed management programs for cycloxydim-tolerant maize in Iran

In order to introduce new chemical weed management program in maize weed control in Iran, a study was conducted during 2014 and 2015. Experiment were carried out in a randomized complete block design with three replications. 15 treatments of the common maize herbicides, including nicosulfuron, foramsulforon, eradicane and 2,4-D + MCPA were applied in their recommended doses, moreover the treatments related to cycloxydim with dicamba + tritosulfuron were used with different doses and in different times along with two control treatments (weedy and weed-free). Treatments contained 75-150 g a.i. ha-1 of cycloxydim, showed similar results with the common treatments including nicosulfuron, foramsulforon, eradicane and 2,4-D + MCPA. However, treatments with high doses of cycloxydim, had a significant reduction in weed density and weed biomass. There were no significant differences between the effects of treatments on maize grain yield and biomass. Despite the acceptable weed control of the combined treatment of cycloxydim with dicamba plus tritosulfuron, maize canopy could overcome weed growth. Based on the results and by considering cycloxydim efficacy in controlling perennial grassy weeds in maize plantation, this chemical is a suitable option during different growing stages of weeds and maize. Finally, the application of 200-300 g a.i. ha-1 of cycloxydim combined with dicamba plus tritosulfuron was the best option from an economic and environmental safety points of view

Uzorci iz banke gena Instituta za kukuruz 'Zemun Polje' koji poseduju sterilnu citoplazmu

In an attempt to search a total of MRI Gene bank, with about 5000 accessions, for the potential presence of the restorer cytoplasm for the gene ms10 in maize, unintendently we discovered 70 independent sources of cytoplasmic male sterility. These sources are randomly distributed among Yugoslav open-pollinated varieties, as well as introduced lines and heterozygous materials. This makes 1,4% of the total number of accessions, and raises a question of the evolutionary significance of the sterile cytoplasm into a population. This could be a barrier against foreign pollen, not carrying the appropriate restorer gene.U pokušaju da pretražimo celokupnu banku gena Instituta za kukuruz "Zemun Polje", sa ukupno oko 5000 uzoraka, na potencijalno prisustvo restorer citoplazme za gen mslO (Vidaković i sar, 2002), koja još nije nađena ni kod jedne biljne vrste ni za jedan od poznatih ms gena, slučajno smo otkrili 70 nezavisnih izvora citoplazmatičke muške sterilnosti. Ovo čini 1,4% ukupne biljne raznovrsnosti prisutne u našoj banci gena. Ovi izvori su nađeni kako među slobodnooprašujućim sortama sa područja bivše Jugoslavije, tako i među introdukovanim homo- i beterozigotnim materijalima. Ovako visok procenat uzoraka sa sterilnom citoplazmom pokreće pitanje njene evolucione koristi, kao neku vrstu barijere koja štiti dotičnu sortu od introdukcije stranog polena koji ne poseduje odgovarajući restorer gen

Dopuna Eckhardt-ove metode prevođenja hibrida kukuruza na muški sterilnu osnovu uzimajući u obzir mogućnost probijanja sterilnosti majčinske komponente

It is given a scheme of the conversion of the mother and father of a maize hybrid with three checking of the possibility of the late break of sterility of the mother component. Only hybrids with stable sterility are recommended for the practical use. The scheme is needed a 6 years, so researchers should be careful in choosing hybrids for conversion and the starting point for it.Prevođenje komercijalnih linija kukuruza na sistem proizvodnje semena na muški sterilnoj osnovi radi se po metodi Eckhardt-a (1954). S obzirom na vrlo čestu pojavu probijanja muške sterilnosti (the late break of sterility), koja je po svoj prilici kvantitativno svojstvo (Tracy i sar., 1991), smatrali smo da bi Eckbardt-ovu šemu trebalo dopuniti testovima majčinske komponente na stabilnost muške sterilnosti u područjima gde će se proizvoditi prevedeni hibridi čija je ona majka, kao i testovima povraćaja fertilnosti i fenotipske stabilnostii prevedenog hibrida