1,720,962 research outputs found
Improvement in pesticide application on greenhouse crops: results of a survey about greenhouse structures in Italy
No full textHorticultural crops in Italy are grown on about 33,000 hectares under frame. This type of cultivation, in plastic tunnel or in glasshouse, due to its peculiar conditions, is a very specific agro-system where diffusion of diseases and weeds is very likely. Therefore this cultivation system marks itself out because of a very high pesticide consumption, leading to heavy problems for the operator security. Therefore the choice of the type of sprayer and its way of use should be made taking into account some parameters, among other things the type of greenhouse. Within the framework of the Research Project about pesticide application in greenhouses started in 2005, a survey was taken about the situation of under frame cultivation in Italy. This was made by means of questionnaires which were filled up at 184 greenhouse growers in six Italian regions where under frame cultivation is very important. The survey regarded many features of the farms, and among them the type of structures. The results of the surveys pointed out the presence of a wide variety of types of structures, plants and spraying equipments; in particular, the most common type of structure resulted the multiple tunnel with plastic coverage fitted on an iron framework
PROSPETIVE DI MIGLIORAMENTO NELLA DISTRIBUZIONE MECCANICA DEI FITOFARMACI AL POMODORO IN COLTURA PROTETTA PER LA SALVAGUARDIA DELL'AMBIENTE E DELLA SALUTE
No full textObservations on the potential of microwaves for weed control
No full textField tests of a prototype microwave-based weed killer machine were conducted on Abutilon theophrasti, Panicum miliaceum, lucerne and oilseed rape pure stands. The approach can be considered a thermal weed control method, the microwave radiation causing dielectric heating of plant tissue water that eventually kills the plant. The method could overcome the limitations of other thermal methods, such as fire risk with flaming or the heavy loads required for hot water treatments. Species were effectively controlled by microwave irradiation, but their sensitivity and the evolution of damage symptoms over time differed. Lucerne showed no sigmoidal response and was the least affected by the treatment, while a log-logistic curve expressed the dose–response relationships of the other species quite well. The estimated microwave dose for a 90% dry weight reduction ranged from 1015 kJ m−2 in A. theophrasti to 3433 kJ m−2 in P. miliaceum. Energy cost evaluation indicated that increased efficiency is required for this technique to compete with other thermal methods. Microwave efficiency could be increased by a flux configuration that minimizes soil penetration and maximizes absorption by plants, which, in turn, depends on plant growth form
Improvement in Pesticide Application on Greenhouses Crops: Results of a Surveyabout Greenhouses Structure in Italy
No full textHorticultural crops in Italy are grown on about 33,000 hectares under frame. This type of cultivation, in plastic tunnel or in glasshouse, due to its peculiar conditions, is a very specific agro-system where diffusion of diseases and weeds is very likely. Therefore this cultivation system marks itself out because of a very high pesticide consumption, leading to heavy problems for the operator security.
Therefore the choice of the type of sprayer and its way of use should be made taking into account some parameters, among other things the type of greenhouse.
Within the framework of the Research Project about pesticide application in greenhouses started in 2005, a survey was taken about the situation of under frame cultivation in Italy. This was made by means of questionnaires which were filled up at 184 greenhouse growers in six Italian region where under frame cultivation is very important.
The survey regarded many features of the farms, and among them the type of structures.
The results of the surveys pointed out the presence of a wide variety of types of structures, plants and spraying equipments; in particular, the most common type of structure resulted the multiple tunnel with plastic coverage fitted on an iron framework
Effetto del volume e della polverizzazione sull'efficienza del recupero e sull'efficacia fitoiatrica di un'irroratrice a tunnel nei vigneti
No full textEvaluation of a fixed spraying system for phytosanitary treatments in heroic viticulture in north-eastern italy
Full text linkModern viticulture cannot be practiced without the use of plant protection products to control diseases like downy mildew, powdery mildew, and pests. In severely sloping vineyards, where mechanization is not possible, pesticide application is realized using spray guns, which is a laborious, expensive, and dangerous application technique. In these vineyards, where viticulture is defined as “heroic viticulture,” vine-growers could seriously take advantage of innovation in spray-technique applications. For this reason, several prototypes of a fixed spraying system (FSS) were realized in recent years. Two prototypes of a fixed spraying system were built in 2019 in two different vineyards in the Veneto region (north-eastern Italy). In both vineyards, the fixed spraying systems were used to perform pesticide application during the 2020 season to control downy mildew, powdery mildew, and pests. With this solution, both vineyards were successfully protected, resulting in comparable infection degrees and yields as the ones protected with airblast sprayers and spray guns. This study contributes to assert fixed spraying systems as an innovation that could improve working conditions, safety, timing, and performances of plant protection products’ application in heroic viticulture areas
Weed control by water steam using a self-propelled machine equipped with a condesation chamber
No full textDuring last years public concern about environmental pollution due to pesticides is growing and, among other consequences, this situation boosted research on physical weed control methods as an alternative to herbicides.
In the recent past researches have been carried out about the feasibility of the use of water steam, as a replacement of chemical weeding in particular conditions where no chemical residues are allowed, e.g. in organic farming.
Tests carried out with a steam jet directly on the weeds confirmed its effectiveness in killing weeds, but also showed high energy requirements and very low working speed, despite the high thermal contents of steam.
To improve weed control efficiency, a chamber where the steam can condense on the surfaces of the plants was developed, in order to exploit the high efficiency of latent heat transfer of condensing water steam, as suggested by a theoretical analysis.
Preliminary lab test confirmed the validity of this approach, showing a higher energy efficiency in respect to the direct application.
Following these encouraging results a self-propelled machine was equipped with a condensation chamber specifically designed to perform field tests on 5 species (two dicots and three grasses), to be treated at two different growth stages.
The dose-response curves obtained after treating the plots with 5 to 6 different travel velocities showed a good effectiveness. The dicots were effectively controlled with doses lower than 500 kJ m-2 (corresponding to 2 km/h travel speed), while maize was able to regrow after the treatment, requiring about twice the dose
Controllo della flora infestante mediante uso di vapore con una operatrice semovente equipaggiata con una camera di condensazione
No full textGoing Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
- …
