WEED MANGEMENT IN CEREALS ACCORDING TO THE PRINCIPLES OF GOOD AGRICULTURAL PRACTICE AND INTEGRATED PLANT PROTECTION

Integrirano suzbijanje korova podrazumijeva integraciju preventivnih i kurativnih mjera njegova suzbijanja. Osim poznavanja specifične biologije korovnih vrsta, dobra gospodarska praksa podrazumijeva i dobro poznavanje tehnologije uzgoja kulture, specifične zahtjeve prema agroekološkim uvjetima, poznavanje kritičnog razdoblja zakorovljenosti te svih biotičkih i abiotičkih čimbenika koji utječu na učinak herbicida i ostalih nekemijskih mjera suzbijanja. Za suzbijanje korova u strnim žitaricama registriran je relativno veliki broj herbicidnih pripravaka, i to u oba roka primjene u odnosu na nicanje korova i usjeva (pre-emergence i post-emergence) ali i sezonski (jesen i proljeće). Međutim, jedino integrirani pristup suzbijanja utemeljen na načelima dobre gospodarske prakse osigurava dobar učinak na korove, izbjegavanje fitotoksičnih učinaka na usjev, kao i sprječavanje onečišćenja okoliša (podzemnih i površinskih voda). S obzirom na oštre zahtjeve EU-a o redukciji unosa pesticida u okoliš, istražuju se alternativne mjere suzbijanja korova, poput suzbijanje korova laserom, uzgoj kompetitivnih kultivara, digitalne tehnike u suzbijanju korova i dr. Zahtjevna biologija korova zahtjeva dugoročne, temeljite i dosljedne mjere suzbijanja koje će osim kratkoročna očuvanja prinosa strnih žitarica i dugoročno smanjiti potencijal korova u tlu.Integrated weed management involves the integration of preventive and curative control measures. In addition to knowledge of the specific biology of weed species, good agricultural practice requires a good knowledge of cultivation technology, specific requirements according to agroecological conditions, knowledge of the critical period of weed control, and all biotic and abiotic factors that influence the effect of herbicides and other non-chemical control measures. A relatively large number of herbicides are registered for weed control in cereals, both for application periods related to weed and plant emergence (pre-emergence and post-emergence) and for season (fall and spring). However, an integrated approach based on the principles of good agricultural practice only ensures a good effect on weeds and avoids phytotoxic effects on crops and pollution of the environment (groundwater and surface water). In view of the strict EU equirements to reduce pesticide use in the environment, alternative weed control measures are being researched, such as laser weed control, competitive cropping, digital techniques for weed control, etc. Challenging weed biology requires long-term, thorough, and consistent control measures that reduce weed potential in the soil over the long term while maintaining small grain yields in the short term

BIOLOGY AND ECOLOGY OF CEREAL WEED Alopecurus myosuroides Huds. (black‐grass)

Alopecurus myosuroides Huds. (mišji repak) učestala je jednogodišnja uskolisna korovna vrsta u usjevu ozimih žitarica. Povećanim brojem rezistentnih populacija u zapadnoj Europi na različite mehanizme djelovanja herbicida sve se veća važnost pridaje poznavanju biologije i ekologije ove vrste. Nicanje mišjeg repka odvija se u jesen i u proljeće. Veći dio populacije (80 %) ponikne ujesen te je suzbijanje mišjeg repka usmjereno na to razdoblje. Jedinke koje poniknu ujesen naprednije su u razvoju te razvijaju veći broj izbojaka, posljedično i veći broj klasova koji nose sjemenke. Proljetne jedinke češće su alternativni domaćini opasnog patogena Claviceps purpurea. Mišji repak dobro podnosi niske temperature, a niče već na 0 °C (biološki minimum). Biološki vodni potencijal (minimalna količina vode u tlu potrebna za nicanje) za ovu vrstu iznosi ‐1,50 MPa. Za razliku od vrste Apera spica‐venti koja se također pojavljuje u usjevu ozimih žitarica, Alopecurus myosuroides najčešće se pojavljuje na teškim, glinastim tlima s visokim sadržajem vode, a Apera spicaventi niče na lakšim i pjeskovitim tlima. Optimalna je dubina za nicanje mišjeg repka 0 do 2 cm. Zbog toga vrsta predstavlja veći problem u no‐till sustavima obrade, gdje se nerijetko pojavljuje u većoj gustoći. Obrada je jedna od najučinkovitijih nekemijskih mjera suzbijanja mišjeg repka, ali ipak ne i najpouzdanija. Varijabilnosti u učinkovitosti nekemijskih metoda suzbijanja kao što je obrada tla, povezuju se s biologijom vrste (različit stupanj dormantnosti), klimatskim uvjetima i agrotehnikom proizvodnje. Pouzdano i učinkovito suzbijanje postiže se kombinacijom nekemijskih mjera s herbicidima različitog mehanizma djelovanja (antirezistentna strategija).Alopecurus myosuroides Huds. (black‐grass) is annual weed species in winter cereal crops. With an increasing number of resistant populations in Western Europe on various herbicides mode of action, interest in the biology and ecology of this species has increased. The black‐grass emergence is divided in two phases: autumn and spring emergence. The majority of the population (80 %) emergences in the autumn and the control of blackgrass is focused on this period. Plants emerged during the autumn develop more tillers and consequently a larger number of seed heads with seed. Spring individuals are more likely to be alternative hosts of the pathogen Claviceps purpurea. Blackgrass is a typical winter species and is well adjusted to low temperatures and its base temperature is estimated to 0 °C. The base water potential (the minimum amount of water in the soil needed to promote the germination) for this species is ‐1.50 MPa. Unlike the morphologically similarity to Apera spicaventi which also occurs in winter cereals, Alopecurus myosuroides occurs most in heavy, clay soils with high water content, while Apera spica‐venti emerges in lighter and sandy soils. The optimum soil depth for the black‐grass emergence is 0‐2 cm (surface layer of soil). For this reason, the species is a bigger problem in no‐till processing systems, where it often occurs at higher density. Ploughing is one of the most effective non‐chemical measures to suppress the blackgrass, but is not the most reliable. Variability in the effectiveness of nonchemical methods such as ploughing is associated with the biology of the species (different degree of dormancy), climatic conditions and farming practices. Reliable and effective suppression is achieved by combining nonchemical measures with chemical measures using herbicides with different mode of action (anti‐resistant strategy)

WEED MANGEMENT IN CEREALS ACCORDING TO THE PRINCIPLES OF GOOD AGRICULTURAL PRACTICE AND INTEGRATED PLANT PROTECTION

Integrirano suzbijanje korova podrazumijeva integraciju preventivnih i kurativnih mjera njegova suzbijanja. Osim poznavanja specifične biologije korovnih vrsta, dobra gospodarska praksa podrazumijeva i dobro poznavanje tehnologije uzgoja kulture, specifične zahtjeve prema agroekološkim uvjetima, poznavanje kritičnog razdoblja zakorovljenosti te svih biotičkih i abiotičkih čimbenika koji utječu na učinak herbicida i ostalih nekemijskih mjera suzbijanja. Za suzbijanje korova u strnim žitaricama registriran je relativno veliki broj herbicidnih pripravaka, i to u oba roka primjene u odnosu na nicanje korova i usjeva (pre-emergence i post-emergence) ali i sezonski (jesen i proljeće). Međutim, jedino integrirani pristup suzbijanja utemeljen na načelima dobre gospodarske prakse osigurava dobar učinak na korove, izbjegavanje fitotoksičnih učinaka na usjev, kao i sprječavanje onečišćenja okoliša (podzemnih i površinskih voda). S obzirom na oštre zahtjeve EU-a o redukciji unosa pesticida u okoliš, istražuju se alternativne mjere suzbijanja korova, poput suzbijanje korova laserom, uzgoj kompetitivnih kultivara, digitalne tehnike u suzbijanju korova i dr. Zahtjevna biologija korova zahtjeva dugoročne, temeljite i dosljedne mjere suzbijanja koje će osim kratkoročna očuvanja prinosa strnih žitarica i dugoročno smanjiti potencijal korova u tlu.Integrated weed management involves the integration of preventive and curative control measures. In addition to knowledge of the specific biology of weed species, good agricultural practice requires a good knowledge of cultivation technology, specific requirements according to agroecological conditions, knowledge of the critical period of weed control, and all biotic and abiotic factors that influence the effect of herbicides and other non-chemical control measures. A relatively large number of herbicides are registered for weed control in cereals, both for application periods related to weed and plant emergence (pre-emergence and post-emergence) and for season (fall and spring). However, an integrated approach based on the principles of good agricultural practice only ensures a good effect on weeds and avoids phytotoxic effects on crops and pollution of the environment (groundwater and surface water). In view of the strict EU equirements to reduce pesticide use in the environment, alternative weed control measures are being researched, such as laser weed control, competitive cropping, digital techniques for weed control, etc. Challenging weed biology requires long-term, thorough, and consistent control measures that reduce weed potential in the soil over the long term while maintaining small grain yields in the short term

The biology and ecology of barnyardgrass (Echinochloa crus-galli L. P. Beauv)

Koštan (Echinochloa crus-galli L.) jednogodišnja je korovna vrsta iz porodice Poaceae. Uspješnost te vrste kao korova ogleda se u velikoj sjemenskoj proizvodnji, laganom širenju sjemena, izraženoj dormantnosti sjemena, mogućnosti cvatnje pri različitim uvjetima fotoperiodizma te u razvijanju biotipova rezistentnih na herbicide. Stoga se koštan smatra jednom od najvažnijih jednogodišnjih korovnih vrsta u svijetu. U Hrvatskoj je najučestaliji jednogodišnji uskolisni korov okopavinskih usjeva. Koštan je kozmopolitska vrsta s arealom rasprostranjenosti od 63° sjeverne do 55° južne geografske širine. Sposoban je prilagoditi se različitim klimatskim uvjetima te mu biološki temperaturni minimum, ovisno o klimatu, varira od 5,5 do 10,8° C. Može nicati u uvjetima visokog vodnog stresa (-0,97 MPa) kao i u širokom rasponu pH tla (4,7 - 8,3). Svojom prisutnošću u usjevu, ovisno o gustoći i razvojnom stadiju kulture, znatno utječe na smanjenje potencijalnog prinosa okopavinskih te povrtlarskih kultura.Barnyardgrass (Echinochloa crus-galli L. ) is annual narrow-leaved weed from the Poaceae family. The success of this weed species may be attributed to large seed production, easy seed dispersal, seed dormancy, ability to flower under different photoperiods and existence of biotypes resistant to herbicides. Therefore, barnyardgrass is considered one of the most important weed species in the world. In Croatia it is ranged on the first place of the most common annual narrow-leaved weed in summer crops. Barnyardgrass is a cosmopolitan species with an area of distribution of 63 °N to 55 °S latitude. It is capable of adapting to different climatic conditions and its biological minimum varies, depending on climate, from 5.5 to 10.8 ° C. It can germinate even at high water stress conditions (-0.97 MPa) as well as in a wide pH range of soil (4.7-8.3). With its presence in crop, depending on the density and growth stage of crop, it can significantly reduce potential yield of row and vegetable crops

Modification of the structural and optical properties of commercial ZnO powder by mechanical activation

Mechanical activation was used as a method for modification of the structural and optical properties of commercial ZnO powder. For this purpose zinc oxide powder was mechanically treated by grinding in a high-energy vibro-mill in a continual regime in air up to 300 minutes. Starting and modified ZnO samples were characterized using XRD, BET and TEM measurements. Optical properties of these samples were investigated by Raman and photoluminescence (PL) spectroscopy. The color of commercial ZnO powder was white while mechanically activated ZnO powder was dark yellow, indicating the presence of nonstoichiometry. In the Raman spectra of non-activated sample Raman modes of bulk ZnO were observed, while the spectra of modified samples point out structural and stoichiometric changes. The PL spectra of modified samples excited by 325 and 442 nm lines of a He-Cd laser show great difference with respect to the spectra of the original sample. This study confirms that change in the defect structure of the ZnO crystal lattice introduced by mechanical activation affects the optical properties of this material