engleski

The effect of the amount of preparations applied in the control of suckers on the yield and unit value of virginia tobacco

During seven years, 1990-1996, in three different experiments, research was done on the effect of applied quantities of sucker control agents on the yield and unit value ov Virginia tobacco. The research included preparations with a contact (Fair 85 in a concentration of 3, 1 and 4, 2 %) contact-systemic (FST 7 in quantities of 12, 16, 20 and 24 l/ha) and systemic action (Royal MH30 in quantities of 8, 10, 12, and 15 l/ha ; and CMH in quantities of 6.5, 8.1, and 12.2 l/ha). Results of research have given convincing confirmation of the necessity of applying agricultural measure for topping and qualitative application for suckers control. In a two experiment, 1991-1992, with topping and a double application of sucker control agents, a greater yield was achived, up to 20-60 %, and tobacco quality as estimated by visual inspection was higher by 2-54 %. The research has shown that in the conditions in which the experiments were carried out (north west Croatia), for successful suppression of the growth of suckers in the second application it is not necessary to apply the maximum factory recommended amount of systemic or contact-systemic products. When the products Royal MH30 and FST7 were applied, only e tendencies towards better results were observed when higher amounts were applied, and the oposite tendency with application of CMH. During research in all the procedures, better economic results were accompanied by a lower average number and lower average weight of suckers per plant.

flue-cured tobacco; suckericides; yield; visually estimated quality

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