Agricultural Plant Protection Research Articles

Cytogenetic effect of herbicides on plant cells

Background Herbicide application for weed control is an integral part of the method for chemical plant protection in agriculture. Herbicides are known to be used partially only for weed destruction (as to various assessments from 5 to 40 % of applied preparation amount) and the rest of their amount remains in an environment and due to high stability is not able to undergo quick physicochemical and biological degradation. Being a factor of man's impact on the environment, herbicides can play a role of toxicants under certain conditions, with manifestation of their effect on different organisation levels of living organisms.

Soil properties, but not plant nutrients (N, P, K) interact with chemically induced resistance against powdery mildew in barley

AbstractChemically induced resistance is a promising method of plant protection against diseases, which can be triggered by systemically acting chemical inducers such as BTH (benzo(1, 2, 3)thiadiazole‐carbothioic‐acid‐S‐methylester). BTH is commercially distributed as a 50 % formulation, called Bion®. The uncertain success of Bion® application in controlling infection by powdery mildew is a major obstacle in using induced resistance for plant protection in agriculture. This study aimed to investigate the effect of soil properties, selected macronutrients (N, P, and K), and addition of organic matter on induced resistance and to identify possible factors responsible for the high variability of BTH effect under field conditions. A pot experiment under open‐air conditions was set up using the pathosystem Hordeum vulgare cv. Ingrid / Blumeria graminis f. sp. hordei race A6. The different soils strongly affected the resistance of barley plants against powdery mildew after BTH treatment. The infection of barley by powdery mildew was lower than on all other soils when grown on an acid forest soil which was limed up to pH 4.9, even after BTH treatment. A reproducible induction of pathogen resistance by BTH was shown only on a mineral soil (Kleinlinden) with a negligible C content. Application of N, P, and K did not consistently affect the induction of resistance by BTH. The addition of green manure and compost led to an enhanced variability of resistance induction on the soil “Kleinlinden”. Possible effects of soil microflora on resistance induction are discussed.

Molecular biology and genetics of protective fungal endophytes of grasses.

Clavicipitaceous endophytes, a group of seedborne fungal symbionts of C3 grasses, may be the most widespread agents of biological plant protection in agriculture, and the unwitting use of them in pasture grasses has continued for many centuries. Endophytes have been recognized in species of the Pooideae (the cool-season grasses) for nearly a century (1), but the agricultural and ecological importance of these associations has been appreciated only in recent decades. Those with evolutionary affinities to the teleomorph (sexual form) Epichloë typhina (Pers: Fr.) Tulasne (family Clavicipitaceae) are referred to as “clavicipitaceous endophytes” (here abbreviated c-endophytes) and can be particularly important for the fitness, competitiveness and persistence of their grass hosts under conditions of biotic or abiotic stress (2–4). The most intensely studied of these interactions have been the tall fescue (Festuca arundinacea Schreb.) and perennial ryegrass (Lolium perenne L.) symbiota. The multitude of fitness enhancements conferred by the c-endophytes (Table 1) are, in no small measure, contributory to the excellent persistence of these grasses in temperature pastures. However, since it was determined that they were associated with livestock toxicosis (5,6), the endophytes have not been considered desirable by pastoralists. The most immediate goal of much of the present endophyte research is to identify or generate strains that cause minimal toxicosis to livestock, but still confer most of their protective benefits upon the host grasses.KeywordsTall FescuePerennial RyegrassNeurospora CrassaErgot AlkaloidIndole AlkaloidThese keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

On the development of IPM in Germany

At the end of the 1950's, chemical plant protection in agriculture found itself in a serious crisis. The appearance of insect populations resistant to chemicals, the provocation of pest outbreaks by insecticide treatments, and finally the problem of insecticide residues, all increased in importance to an alarming extent. The search for alternative control methods produced the idea of Integrated Pest Management (IPM). This envisaged not only the integration of natural biological defense mechanisms with the counter-measures developed by humans but also the inclusion of agricultural production methods. Smith and Reynolds (1966) expressed this as follows: the final analysis, however, we must integrate not only chemical and biological control but all control procedures and agricultural production practices into a single coordinated pattern aimed at profitable production of high quality products. The development of IPM in Germany forestry took a very different course. This can be explained in that, in the 18th Century, ways had to be found to achieve sustained wood production because of the increasing scarcity of timber (Von Carlowitz, 1713 ). An additional difficulty was that the stand rotation time of the stands was extremely long, 100 or more years, compared with agriculture, and that there was considerable danger from insects for the whole duration. After it had become evident that the management of German forests from a purely economic viewpoint did not result in the greatest possible advantage for society, the idea of a form of management close to nature', which had been expressed much earlier, became increasingly meaningful (KiSnig, 1849 ). Although these efforts were directed at first only to a continuous supply of wood production, they also represented the beginning of preventative forest protection. Consistent development of preventative protection has led to the present position where, in contrast to agriculture, direct forest protective measures are the exception rather than the rule in our forests. In other words, forest protection in our country consists first and foremost of preventive silvicultural measures, called 'Waldhygiene' (Schimitschek, 1969). Only when this basic protection is insufficient are additional measures integrated into it according to the specific knowledge available. The

A manual for organizations of agricultural and forest plant protection in China

A manual for organizations of agricultural and forest plant protection in China