Savjeti maslinarima

Rak masline

03. 06. 2013.

Rak masline
(Pseudomonas syringae pv. savastanoi Smith.)

 

Rasprostranjenost i biljke domaćini
Rak masline je opasna bolest, a javlja se kao posljedica zaraze stabala s bakterijom Pseudomonas syringae. Bakterija je poznata od davnina i prisutna je u svim područjima gdje se maslina uzgaja, a ujedno ima i širiok krug domaćina
 

Znaci bolesti 
Masline zaražene bakterijom prepoznatljive su po izraslinama rakastog izgleda koje mogu biti prisutne na izbojima, mladim i starim granama, a ponekad i deblu. U početnom stadiju razvoja bolesti, izrasline su malene, veličine lješnjaka, zelene boje, sočne i glatke površine (slika 1.).


Daljnjim razvojem i rastom dosegnu veličinu oraha (slika 2.), poprimaju smeđu boju, raspucaju i postaju naborane s uočljivim udubinama (slika 3.).


Bakterija se sokovima širi u zdrave dijelove stabla gdje uzrokuje rast brojnih novih izraslina. One se međusobno spajaju u veće rakaste mase kojima mogu biti zahvaćene gotovo sve grane pa i debla pojedinih stabala maslina (slika 4.).


Životni ciklus uzročnika
Bakterija živi u rakastim izraslinama gdje se obilno razmnožava tijekom cijele godine. Raste i razmnožava se u rasponu temperatura  180 C - 300 C, a za ostvarenje zaraze  potrebna joj je relativna vlaga zraka preko 80%. Najveća brojnost bakterija je u  travnju i svibnju, te u listopadu i studenom. Zarazu najlakše ostvaruje preko otvorenih ozljeda, nastalih rezidbom, tučom, proljetnim mrazovima, vjetrom ili pak preko ožiljaka koji ostaju nakon berbe plodova ili otpadanja listova. Tijekom kiše bakterija se širi po svim dijelovima masline, od krošnje do korijena te kroz prisutne ozljede ulazi u stablo, ostvaruje zarazu, čije su posljedice rakaste izrasline, najčešće po mladim granama. Kada je bakterija jednom ušla u stablo, ono ostaje trajno zaraženo. Pojava znakova bolesti zavisi o razdoblju u kojem je zaraza ostvarena. Ukoliko je to u proljetnom, pojava rakastih tvorevina je moguća već nakon 15-20 dana, a u jesensko-zimskom, prvi znakovi bolesti uočljivi su tek 2-3 mjeseca nakon zaraze.

 

Štete
Štete od raka maslina se razlikuju na sadnicama i mladim maslinama od onih na odraslim stablima. Bolest je izuzetno opasna ako se javi u mladim nasadima jer u konačnici najčešće dolazi do ugibanja stabala.
Na odraslim stablima štete mogu biti različite jakosti. Kod slabe zaraze, na stablu su prisutni malobrojni, pojedinačni tumori, ne izazivaju sušenje grana, pa su štete zanemarive. Kod jakog napada bolesti, grane odraslih maslina su pune spojenih rakastih tvorevina, koje izazivaju njihovo sušenje i propadanje. Nadalje, zaražena stabla su slabije rodna, a plodovi smanjene kakvoće, što se negativno odražava i na kakvoću ulja. 

Obrana
U nasadima maslina obrana mora biti usmjerena na smanjenje mogućnosti  zaraze. Na prvom mjestu  je sprječavanje nastanka otvorenih ozljeda kroz koje bakterija ulazi u stablo. Zbog toga je kod berbe uputno izbjegavati udaranje po krošnji, rane nastale rezidbom je potrebno premazati voćarskim voskom, a ozljede nakon nevremena, tuče ili mraza što prije dezinficirati, to jest tretirati pripravkom na osnovi bakra. Nadalje, u zaraženim maslinicima, rezidbu bolesnih stabala treba obaviti na kraju, poslije rezidbe zdravih, čime se sprječava prijenos bakterije, alatom za rezidbu, s bolesnih na zdrava stabla. Rezidbom je potrebno ukloniti što je moguće više bolesnih grana,  potom ih što prije spaliti jer bakterija u njima živi do petnaest dana. Tretiranje stabala pripravcima na osnovi bakra umanjuje mogućnost zaraze bakterijom, pa je zbog toga, nakon berbe i rezidbe uputno napraviti jedno detaljno «kupanje» maslinika. Mogu se koristi svi pripravci na osnovi bakra.
Stručnjaci Instituta za jadranske kulture započeli su istraživanja učinkovitosti kombinacija nekih aminokiselina i baktericida na bakteriju uzročnika raka masline.

 

dr. Miro Katalinić

Comment Komentari (3) Share

Komentari
SWHVwGuYTcrFCmtx by Joyelle

In awe of that answre! Really cool! http://xqfndp.com [url=http://xiyzigh.com]xiyzigh[/url] [link=http://sgdsdlmyq.com]sgdsdlmyq[/link]

OlSPoipXGaRQhux by Steven

Cool Beans, Jason! Perhaps I should <a href="http://jzdmwgizt.com">exaplin</a> that a bit. This is an expression I picked up from a former co-worker of mine. She was one of those extra perky, happy, positive kind of people who are either very annoying or a delight to be around. Kelly was an absolute delight because she was genuine and I loved working with her. I don’t think I’ve used that expression in many, many years, but your comment propelled it from the storage locker of colloquialisms in my brain to front and center.Like you I’m very happy with my Kindle, reading longer in the evenings because it’s so much easier on the eyes than a computer screen and buying more books because of the reduced price over print versions and because these books are not more “things” I have to find a place for.Thanks for stopping in again, for commenting and for subscribing!Just a heads up to all: this week’s post on The Write Stuff this about publishing your blog on Kindle, with screens shots of how they look and how to navigate as well as step by step instructions and reasons why you might want to do this. AND, an upcoming post here on The Prattle will be a review of my Kindle, what I like about it, what I don’t (short list!) and why anyone who reads a lot will want to consider getting one.

gGiXnNkrvzNlOU by Lisa

Education should not be about ifiromatnon-cramming (as it is now) but about bio-neural-development ... exercising the growing minds of young people, teaching them paradigms, methods, and philosophies, ... but only data-stuffing where and when necessary. (everybody forgets crammed-in data)The difference between gifted and non-gifted students has little to do with academic difficulty but everything to do with the students' mental pick-up rate and styles of thinking.Unfortunately, too many schools and teachers merely make gifted classes super-honors ... massively increased workloads, extra material, but insufficient divergence.Schools must be careful not to assume that academic performance actually defines a child ...Some people's minds only are developed far enough to do repetitive tasks well ... schools need to identify these task-thinkers and 1: try to stretch their mental capacity and 2: give practical real-world-survival training to those who will not self-motivate into further education. Some people's minds are capable of more complicated thinking, but may still not have the neural development (yet) to do complex tasks rapidly shortly after first-sight. This neural type, unpushed, generally becomes our trade-workers (electricians, builders, etc), These procedural thinkers grow into employment where they can work within and around what they have already done, but new anything tends to distress them. Once past the age of 16 or so, they are probably stuck in their mental limits, but many may just be undeveloped, and I have met a great many adults of vastly higher intelligence than they believe themselves to have. Too many people have their innate creativity and intelligence drummed out of them by rule+repetition-oriented schooling.The above two categories ... task-oriented and procedural circular thinkers are the vast majority of people and as such, I refer to them as "normals" ... these people really need their schooling to focus on either expanding undiscovered capabilities and/or readying them for handling adult long-term survival. They are in "regular" classes ... but should be more aimed towards life-preparatory classes.Beyond the circular thinkers above, you get the linear thinkers, capable of forming connections and chains of understanding, who dig into the why and how and seek to make things work or work better ... they can take ideas and follow them, pulling in ifiromatnon resources and solving significant problems. University education is specifically geared to giving these linear-chain-makers their tools and teaching them the patters and paradigms with which to solve problems they will see and be faced with. Some of the most brilliant people ever have been linear-thinkers and have made great strides for humanity ... generally in engineering, math, science, medicine, research, etc, creating what soon-will-be. (Mostly, this category is describing analytic left-brainers.)Similarly, the inverse but nearly identical group to the chain-makers are the pattern-finders who see the interconnections in things and are generally adept in communicating those patterns. These tend towards thinking patters more like webs or root/tree structures and often have strong people and communications skills. These web/tree thinkers are best at seeing patters in people, history and language, and generally become teachers, communicators, writers, historians, etc. Society (wrongly?) values them less beacuse they connect what-is and what-was rather than building our future as the linears do. (Except the web/tree thinkers who become lawyers, who have created laws that assymetrically boost their take-home-pay.) (Mostly, this category is describing communicative right-brainers.)The above two categories are what all schooling aims to support ... they are the "academic types" and excel in schools, and many of them are ideal to become aducators. These are the students for whom advanced / honors / AP classes are ideal. Many of these kids are/were falsely called "gifted" just because they are very quick-witted or very academically advanced. This is common in today's school system but very misguided and wrong ... because ...Then there are the gifted kids ... not the "very-bright" kids with very fast minds and great calculative speeds ... but the truly gifted kids, who think in leaps and non-dimensional patterns, who are generally _not_ traditionally academic ... those whose minds race, cannot sit still, and who are so totally misunderstood by everyone around that nowadays, are typically drugged with ritalin. These kids may never be academic, but they are the Einsteins that we are crippling. These gifted kids do not care about a topic unless they are _interested_ ... and absolutely cannot stand repetition, need to see how things apply, interrelate, and interconnect. They tend to be fantastically overbright but underdeveloped, driven yet unmotivated. These kids need more than teachers, they need mentors and generally need massive personal attention, especially to actually get them through a set series of topics. Teaching a roomful of un-ritalin-ed truly gifted kids is like herding cats, on catnip, past a field full of mice. Realistically, these kids are probably better off being homeschooled if possible, since linear teachers cannot withstand the raging minds of the truly gifted child. In this category are not just the typical nerd/geek leap-thinkers and lightning-branchers that explore every side topic but the "ADD/ADHD" types who need to be mentored druglessly into managing their own neurology and the autistic/aspergers genuises who need even more mentoring than the ADD kids. These gifted kids with thinking linears cannot comprehend or follow are the next discovery-makers, the innovators, the people who ask more then "why? ... but "why not?" ... more than "how?" into "what if?" These future Einsteins break more rulea than they follow and would be terribly disruptive in any sane class setting. They need attention that would cripple a normal or honors class, but will reward the society that manages their development with overwhelming breakthroughs.(NB: acceleratingly since WWII, with the advent of mass personal mobility and social upheaval, the pattern of increasingly high-IQ people marrying and having kids is causing an unhandleable growth in "ADD", Autie, Aspie, and non-linear-geniuses.)If it is not obvious by the above paragraphs of argumentative pontification, I am an Aspergers autistic who has lived through academic disasters, such as failing Latin the entirety of my freshman year in high school ... and in that same year, coming in 5th in the state in the standardized Latin exams (my teacher was quite distressed at this). I am now in my 30s but had never even heard of Aspergers until about 10 months ago ... so I went through all of my educational years in gifted classes "held back" (meaning 'on-topic', repetitive) by the inclusion of very-bright-linears. Indeed, I would argue (at length) that my classes were super-honors extra-work classes rather than exploratory mind-expanding forays of discovery. When "gifted" just means more work and more material, you just get more burnout and less genius. If "gifted" means bulk memorization and reams of problems, that has nothing to appeal to the free-ranging mind seeking to grok relativistic quantum physics (one of my pet fascinations) or how the history of China et al ties into their current foreign policy and regional behaviour (another).Gifted kids either burn-out on over-work or check-out. Some (like me) never checked-in to start with. It is amazingly hard to get good grades in english writing classes when the non-deterministic grading allws the teacher's pet to turn in garbage and do well (she experimented and proved this) while an Aspie like me raises the teacher's ire by reading about physics and writing in compound polycomplex sentence structures, even if I did avoid the megapolysyllabic verbiage. :)The best thing to do with gifted kids is not heaping on massive amounts of piled-up busywork but to induce them to expand their thinking in ever more complex ways, such as by combining chemistry, physics and history by looking at how mettalurgy and the technologies each marginal advance enabled revolutionized the civilizations that discovered them, and how those advances marched across the landscape as civilizations traded or counter-conquered each other. If you really want to help gifted kids, target their best known number one weakness: confidence in public speaking and the capacity to organize thoughts out loud in very little time. No gifted program I was ever near had organized classes in debate (or brevity, as is obvious), much less the ideal debate format, which forces the student to argue one side then convincingly argue the other side, thus learning that truth is a triple-edged sword (sorry, Vorlon (Babylon5) reference).Also, try teaching things in a better order ... I've taught calculus to very-normal 10 and 11 year olds ... they got it easily ... only then did I start explaining trig to them ... they had an easier time with differential equations (explained using simple car accelerations paradigms) than with anything related to trig. In fact, I was teaching these kids how to understand algebra and graphing using differential/calculus examples ... similar to how the fastest way to pick up and get good at many computer games is to start by playing on the hardest level for a while ... then the easier levels seem incredibly easy.Similarly, kids can be taught out-of-subject in combined-education, like my earlier example of how mettalurgy has shaped history and how historical events have shaped and moved technology. Similarly (but not politically correct), look at how the language a society is brought up speaking and the philosophy or religion they are raised with can affect historical events, trends, patterns and technological developments or responses to particular occurances. Which leads to the obvious problem that when teachers use out-of-subject crossover material, they have broad leeway to inject their personal politics and philosophies into their teaching ... which brings us right back to homeschooling or its co-op equivalent, especially for the super-bright linear and the wildly-non-linear thinking kids.Our education system unfortunately follows the oriental philosophy (without meaning to) that "the nail that sticks out gets hammered down" and gifted kids really "stick out" is our schools. There is a solution, but I'm not rich enough yet ... once I can get one of my major inventions sold, I intend to create a "school for the gifted."