Osetljivost paradajza, paprike i krastavca na rezidualno delovanje klomazona i imazamoksa

Abstract

Ispitivanje osetljivosti paradajza, paprike i krastavca na klomazon i imazamoks u zemljištima tipa ilovača i peskuša u kojima je vlažnost održavana na 20, 50 i 70% PVK, izvedeno je metodom biotesta u kontrolisanim uslovima. Kao parametri osetljivosti biljaka na klomazon mereni su sveža i suva masa izdanka i sadržaj pigmenata (hlorofil a i b i karotenoidi), dok su za utvrđivanje osetljivosti na imazamoks mereni sveža masa izdanka, sveža masa i dužina korena i sadržaj proteina rastvorljivih u vodi. Postojanost klomazona i imazamoksa u zemljištu praćena je 10, 20, 30, 40, 50 i 70 dana nakon primene herbicida biotest metodom, dok je količina ostataka klomazona utvrđivana i gasno-masenom spektrometrijom. Na osnovu analize dobijenih rezultata utvrđeno je da je najmanju osetljivost na prisustvo klomazona u zemljištu ispoljila paprika, nešto osetljiviji bio je krastavac, dok se paradajz može svrstati u kategoriju biljaka veoma osetljivih na ovaj herbicid. U početnim danima degradacije inhibicija merenih parametara bila je izraženija u peskovitom, nego ilovastom zemljištu. Takođe, za istu koncentraciju i istu vlažnost zemljišta, utvrđena količina klomazona analitičkom metodom, bila je veća u peskovitom zemljištu. Količina klomazona opadala je u funkciji vremena u oba tipa zemljišta. Nakon 70 dana degradacije i u ilovači i u peskuši utvrđene su relativno ujednačene količine klomazona kao i vrednosti EC50 praćenih parametara. Na osnovu utvrđenih inhibicija vegetativnih parametara konstatovana je značajna osetljivost sve tri biljne vrste na prisustvo imazamoksa u zemljištu. Paprika i paradajz su ispoljili prilično ujednačenu osetljivost, dok se krastavac može svrstati u grupu veoma osetljivih biljaka. Rezultati ukazuju da su parametri korena pouzdanije merilo osetljivosti biljaka na prisustvo imazamoksa u zemljištu. Različite koncentracije imazamoksa izazvale su promene u sadržaju proteina rastvorljivih u vodi kod sve tri biljne vrste. Na osnovu dobijenih odgovora nije bilo moguće uspostaviti zavisnost promene sadržaja proteina sa porastom koncentracije herbicida. U početnim danima degradacije, u svim varijantama ogleda, zabeležene su visoke vrednosti inhibicije parametara korena. Nakon 70 dana degradacije, utvrđene vrednosti inhibicije merenih parametara bile su nešto izraženije u peskovitom nego ilovastom tipu zemljišta, kao i u varijantama u kojima je vlažnost zemljišta održavana na 70% PVK.

The sensitivity of tomato, pepper and cucumber to clomazone and imazamox in loamy and sandy soils of 20, 50 and 70 % field capacity was examined in a bioassay under controlled conditions. Fresh and dry weight of shoots and pigment contents (chlorophyll a and b and carotenoids) were measured as parameters of plant sensitivity to clomazone, while fresh weight of shoots, fresh weight and length of roots and content of water soluble proteins were measured to examine plant sensitivity to imazamox. Clomazone and imazamox persistence in soil was checked 10, 20, 30, 40, 50 and 70 days after herbicide application, while clomazone residues were determined by gas chromatography mass spectrometry (GC-MS). Data showed that pepper was the least sensitive plant to soil-incorporated clomazone, cucumber was slightly more sensitive, while tomato falls in a category of plants highly sensitive to the herbicide. The measured parameters were more distinctly inhibited in sandy than in loamy soil in the first few days of degradation. Also, clomazone levels detected by the analytical method under identical concentrations and soil moisture were higher in sandy soil. Clomazone levels decreased with time in both soil types. After 70 days of degradation, clomazone levels and EC50s of the measured parameters were similar in loamy and sandy soils. Data for the inhibition of vegetative parameters showed that all three plant species were significantly sensitive to imazamox in soil. Pepper and tomato demonstrated fairly regular sensitivity, while cucumber may be classified as a highly sensitive plant. The results showed that the root parameters were more reliable indicators of plant sensitivity to imazamox in soil. Different imazamox concentrations caused changes in contents of water soluble proteins in all three plant species. The response data revealed no clear dependence of protein contents on rising herbicide concentrations. In the initial days of degradation, the inhibition of root parameters had high values in all trials variants. After 70 days of degradation, inhibition of the measured parameters was slightly more pronounced in sandy than in loamy soil and in trial variants with 70 % field capacity.