Architettura e biomeccanica del pino domestico (Pinus pinea L.): implicazioni sulla stabilita.

In questo elaborato vengono studiati in modo dettagliato alcuni aspetti dell'architettura del pino domestico (Pinus pinea L.) strettamente correlati alla sua stabilità grazie ad alcune ricerche condotte in campo su piante di pino di varie età. L'obiettivo è conoscere meglio il comportamento di questa pianta in condizioni di sforzo critico data la sua importanza nel nostro paese

Innovative strategies and machines for physical weed control in organic and integrated vegetable crops

Weed control is one of the most serious problems in vegetable crops, limiting cultivated plants correct development, yields, product quality and farmers income. Therefore, the aim of this work was to set up and improve innovative strategies and machines for physical (mechanical and thermal) weed control in organic or “integrated” vegetables production in many important areas of Northern, Central and Southern Italy. Therefore, on-farm experiments were carried out since 1999 on fresh marketable spinach, processing and fresh market tomato, cauliflower, savoy cabbage, greenhouse cultivated leaf beet, garlic, chicory, fennel and carrot. These research activities started are still ongoing. The traditional farm weed management system was always compared to one or more innovative strategies that were defined according to the characteristics of the environment (i.e. soil type and conditions, water availability, etc.), typology of cultivation, crop rotation, expected technical and economical results. The innovative strategies were the combination among preventive methods (false or stale seed-bed technique), cultural methods (i.e. crop spatial arrangement that was often adjusted in order to improve operative machines effectiveness) and direct control methods (flaming, precision hoeing, etc.). Different kinds of specific implement such as flex tine and rolling harrows (patented by the University of Pisa, patent n. PI/2004/A/000071), and flamers (designed and realized by the University of Pisa) were used to perform false or stale seed-bed technique. Precision hoes equipped with rigid tools and hoeconformed rolling harrows, equipped with elastic tines for selective intra-row weed control, were used to perform post emergence interventions. The use of the innovative weed management systems always resulted in significant weed abundance reductions (from 70 to 100 %), relevant yield increases, high contractions of manpower requirement (from 20 to 80 %) and consequent relevant reductions of costs and increases of farmers gross incomes (from 15 to 75 %) in comparison with those obtained performing the standard systems. The results of these on-farm experiments emphasise that physical weed control can be effectively performed using the innovative machines designed and built at the University of Pisa. These machines can also be easily adjusted in order to be used in other crops and agricultural contexts. Moreover, the present versions of the machines, realized as “low-tech” implement in order to be available on the market at low costs, were recently modified within the RHEA Project, a 7th Framework Programme EU funded research project, in which an automatic and robotized hoeing-flaming machine able to perform VRA cross flaming was designed, fully realized and tested obtaining very promising results

Thermal weed control on horizontal and vertical surfaces in archaeological sites as an alternative to herbicides

Flaming could be an alternative weed management at archaeological sites because it controls a wide range of weed species without inducting future resistance. The aim of this study was to test the weed control efficiency of flaming on various horizontal and vertical surfaces of archaeological buildings. Working times and costs were recorded. Flaming performances were compared to the normal herbicide treatments and mowing. Results showed that repeated flaming reduced weed cover by 100%. Working times and total costs decreased by increasing the number of applications over time. This is because the repeated flaming applications deplete the weed root stocks, thus keeping the mortar between the stones or bricks and the building materials free from weeds and their seeds for a long time. The method involved zero toxicity for humans and animals, thus providing safe accessibility to the archaeological buildings and visitor pathways. The application of flaming did not cause any damage or change of colour to the treated materials, although specific, multidisciplinary studies on this subject will have to be conducted in the next future, in order to exclude any negative effect on the remains. The results of these studies showed that flaming is a viable alternative for controlling weeds growing on archaeological surfaces

Design of an automatic machine for variable rate application of flame weeding on maize.

An automatic operative machine for variable rate application (VRA) of flame weeding on maize was designed and built at the University of Pisa within the European Project “Robot fleets for Highly Effective Agriculture and forestry management” (RHEA). The machine was designed to conduct non-selective mechanical weed control between the crop rows and site-specific VRA of flaming in the intra row space. Flame weeding is applied by a pair of burners liquefied petroleum gas (LPG) fed, which work cross to the row, and is activated automatically only in presence of weeds. The machine was coupled with an autonomous tractor equipped with an optical sensor for real-time row crop and weed detection. Specific hardware and software provide information about the weed cover percentage detected and send these data to the operative machine. The LPG dose that has to be applied is chosen in real-time between two doses identified in the calibration phase to be effective on weed cover percentages lower or higher than 25%. In the case of 0% weed cover, burners are switched off. The burners ignition system was designed to be almost instantaneous in order to minimize all delays, which elapse between weed detection and the presence of the flame in the area that have to be treated. The almost instantaneous burners ignition system allows also to avoid the use of a pilot flame, which would be switched on for all the effective working time of the machine. The operative machine is equipped with and automatic steering system, which according to directional movement of two metallic wheels, allows maintaining the same trajectory of the autonomous tractor, and avoiding the accidental damage of the crop. A study aimed to find the optimal LPG doses for an effective weed control and which not lead to yield losses, as a consequence of damages occurred to maize plants treated at different development stages, was conducted in 2012 and 2013 at the experimental farm of the University of Pisa. Maize and weeds response to the application of five LPG doses was evaluated in terms of yield, weed density after the application and weed dry biomass at harvest. The optimal LPG doses estimated were useful for the automatic operative machine calibration. The site-specific VRA of flaming and the use of an almost instantaneous burners ignition system allow to reduce the LPG consumption compared to a continuous application and the presence of the pilot flame during turning, leading to a reduction of costs for the thermal weed management of heat-tolerant crops. The operative machine represent a new technology for precision agriculture, which if integrated with a proper perception system, independent from the autonomous tractor for the receiving of information needed for the automatic regulation of the LPG dose, could work coupled with a common tractor

Transplanting for conversion to warm season turfgrass.

Warm season turfgrass species (like bermudagrass) seem to be very suitable to Mediterranean climate conditions. They also give an excellent wear resistance to the sport pitches. Transplanting of pre-cultivated warm season turgrass plants (similar to horticultural nursery) is a promising technique which can be efficiently used for turf conversion. It is based on the quick ground cover capacity of these species by means of stolons and rhizomes. Transplanting can be performed both in tilled and untilled soil. A working yard for the conversion of a professional football pitch was assessed in order to evaluate the performaces. The transplant was performed with a 4-row mechanical transplanter which had been adjusted to work in the untilled mowed football pitch. The mechanical transplanter accommodates 4 back-seated operators and 4 walking operators who can manually transplant the plants in case of failure. The working speed of the tractor was less than 1 km h-1, theoretical working time was about 15 h ha-1, actual working time was 28 h ha-1, thus the work efficiency was about 0.52. Fuel consumption was about 28 kg ha-1. Such a low efficiency was due to the difficulty of the operators to remove the plants from the trays and supply the transplanter’s delivery system. In this concern, an automatic transplanter was modified in order to work in untilled soil within a second specific trial. This machine had an automatic system for removing the plants from the trays, like the most advanced robotic transplanters for vegetable crops. Moreover, a specific system for plant deposition in untilled soil was developed by mounting a double disc in front of the furrowers. Plant deposition was tested and a maximum variation of 6 cm in the row was assessed with respect to the expected value. This gap is completely in accordance with this kind of crop

A combined flamer-cultivator for weed control during the harvesting season of asparagus green spears.

Weed competition during spears harvesting reduces asparagus yields. The application of herbicides during this period is illegal, and alternative non-chemical practices are needed. This research tested the effectiveness and efficiency of a custom-built combined flamer-cultivator to control weeds (both in the inter- and intra- spears production bands) during the spears harvest season. It also analysed the effects of various liquefied petroleum gas (LPG) doses on total asparagus yield, mean spear weight, and total number of marketable spears. In both years, the asparagus spears were generally not damaged by flame weeding using LPG doses of between 43 to 87 kg/ha. The same LPG doses were effective in controlling weeds, showing the same total marketable yields as the weed-free control. At high LPG doses (e.g. 130 and 260 kg/ha), yields decreased as a consequence of the damage caused to the spears, resulting in a lower number of marketable spears. Flaming did not affect the mean spear weight, and can be applied repeatedly during harvesting to maintain the weeds at a level that does not lead to a yield reduction. The repeated use of the combined flamer-cultivator (every seven days) led to higher yields than plots where weed control was not conducted. The new machine can be used in a period when herbicides are not possible. Flaming could be introduced by asparagus producers as an alternative, or in addition to herbicides applied in the pre-emergence and post-harvest of spears

Use of Flaming to Control Weeds in ‘Patriot’ Hybrid Bermudagrass

Flaming could be an alternative to the use of chemical herbicides for controlling weeds in turfgrass. In fact, the European Union has stipulated that chemical herbicides should be minimized or prohibited in public parks and gardens, sports and recreational areas, school gardens, and children’s playgrounds. The aim of this research was to test different doses of liquefied petroleum gas (LPG) to find the optimal flaming dose that keeps a ‘Patriot’ hybrid bermudagrass (Cynodon dactylon · Cynodon transvaalensis) turf free of weeds during spring green-up, but also avoids damaging the grass. Five LPG doses (0, 29, 48, 71, and 100 kgha–1) were applied in a broadcast manner over the turf experimental units using a selfpropelled flaming machine. This equipment is commercially available and usable by turfgrass managers. Treatments were applied three times during the spring to allow the maximum removal of weeds from the turfgrass. Data on weed coverage, density, biomass, and turfgrass green-up were collected and analyzed. Results showed that 3 weeks after the last flaming, the greatest LPG doses used (i.e., 71 and 100 kgha–1) ensured the least amount of weeds (range, 5–16 weeds/m2) of low weight (range, 7– 60 gm–2) and a low weed cover percentage (range, 1% to 5%), whereas the green turfgrass coverage was high (range, 82% to 94%). At the end of the experiment, the main weed species were horseweed (Conyza canadensis), field bindweed (Convolvulus arvensis), narrow-leaved aster (Aster squamatus), and black medic (Medicago lupulina). Flame weed control is a promising technique to conduct weed control in turfgrass. Further studies could be conducted to investigate the use of flaming in other species of warm-season turfgrasses

Autonomous rotary mower versus ordinary reel Mower-effects of cutting height and nitrogen rate on manila grass turf quality

High-quality sports turfs often require low mowing and frequent maintenance. Sports turfs often consist of hard-to-mow warm season turfgrasses, such as zoysiagrass (Zoysia sp.) or bermudagrass (Cynodon sp.). Although autonomous mowers have several advantages over manually operated mowers, they are not designed to mow lower than 2.0 cm and are consequently not used on high-quality sports turfs. All autonomous mowers are only equipped with rotary mowing devices and do not perform clipping removal. An ordinary autonomous mower was modified to obtain a prototype autonomous mower cutting at a low height. The prototype autonomous mower was tested on a manila grass (Zoysia matrella) turf and compared its performance in terms of turf quality and energy consumption with an ordinary autonomous mower and with a gasoline reel mower. A three-way factor experimental design with three replications was adopted. Factor A consisted of four nitrogen rates (0, 50, 100, and 150 kghaL1), factor B consisted of two mowing systems (autonomous mower vs. walk-behind gasoline reel mower with no clipping removal), and factor C consisted of two mowing heights (1.2 and 3.6 cm). Prototype autonomous mower performed mowing at 1.2-cm mowing height whereas ordinary autonomous mower mowed at 3.6-cm mowing height. The interaction between the mowing system and mowing height showed that the turf quality was higher when the turf was mowed by the autonomous mower and at 1.2 cm than at 3.6 cm. Autonomous mowing not only reduced the mowing quality, but also reduced the leaf width. Lower mowing height induced thinner leaves. Nitrogen fertilization not only increased the overall turf quality, reduced weed cover percentage, but also reduced mowing quality. Autonomous mowers also had a lower energy consumption if compared with the reel mower (1.86 vs. 5.37 kWh/ week at 1.2-cm mowing height and 1.79 vs. 2.32 kWh/week at 3.6-cm mowing height, respectively). These results show that autonomous mowers can perform low mowing even on tough-to-mow turfgrass species. They could also be used on highquality sports turfs, thus saving time as well as reducing noise and pollution

Steaming and flaming for converting cool-season turfgrasses to hybrid bermudagrass in untilled soil

Turfgrass species can be classified into two main groups: cool-season and warm-season species. Warm-season species are more suited to a Mediterranean climate. Transplanting is a possible method to convert a cool-season to a warmseason turfgrass in untilled soil. It generally requires the chemical desiccation of the cool-season turfgrass. However, alternative physical methods, like flaming and steaming, are also available. This paper compares flaming, steaming, and herbicide application to desiccate cool-season turfgrass, for conversion to hybrid bermudagrass (Cynodon dactylon x C. transvaalensis) in untilled soil, using transplanting. Two prototype machines were used, a self-propelled steaming machine and a tractor-mounted liquefied petroleum gas flaming machine. Treatments compared in this work were two flaming treatments and two steaming treatments performed at four different doses together with two chemical treatments with glufosinateammonium herbicide applications. The cool-season turfgrass species were tall fescue (Festuca arundinacea) and perennial ryegrass (Lolium perenne). The desiccation effect of the various treatments on cool-season turf was assessed by photographic survey 15 days after treatment. The percentage cover of hybrid bermudagrass was visually assessed at 43 weeks after planting. Steaming and flaming effects on both parameters were described by logistic curves. The highest doses of steaming and flaming almost completely desiccated cool-season turf, and similar hybrid bermudagrass cover was established by both the methods as the chemical application (50% to 60%). Thus both flaming and steaming may be considered as valid alternatives to herbicides aimed at turf conversion

Techniques and machines for conservation and organic agriculture: the S.M.O.C.A. project.

The combination of low environmental impact farming techniques and conservation agriculture techniques is considered not feasible due to some limitations, mainly including is the strong dependence of conservation cropping systems by chemical control of weeds and the use of mineral fertilizers, which are considered essential for supporting to acceptable levels of crop productions. In order to apply the techniques of reduced tillage also in organic and integrated agriculture, is therefore indispensable, on one hand, the availability of specific versatile and efficient machines for non-chemical cover-crop management, weed control and sod-seeding/planting, on the other hand, the optimization of cropping systems in function of improved nutrient cycling and preventive weed control. The SMOCA project (Smart Management Conservation of Organic Agriculture) aims to integrate organic cropping systems and conservation agriculture techniques in three different scenarios (arable open field, open field vegetables and orchards) thanks to development of machines and technical itineraries that allow to apply the reduced tillage techniques even in the absence of pesticides. Within this project, prototypes of machines were realized in order to implement conservation cropping systems with high energy efficiency. For each scenario, three technical itineraries were compared: - control (INT): based on integrated agriculture without use of conservation agriculture techniques. The use of agrochemicals is allowed in accordance with the disciplinary for integrated production; - organic system (ORG): based on the organic agriculture, involves the use of cover crops (managed as green manure) and soil tillage. The non chemical management of weed flora is achieved with preventive methods and direct methods (mechanical and thermal weed control); - organic and conservation system (ORG +): based on the deep integration between the principles of conservation agriculture and organic farming. The system aims to achieve an almost continuous coverage of the soil through the use of no-tillage techniques and cover crops managed as living or dead mulches. The study of the overall sustainability of the different systems in comparison is conducted by means of a detailed analysis of the following aspects: - agronomic; - energy and environmental; - economic. The environmental effect of the compared systems will be mainly assessed through the study of the following aspects: greenhouse gas emissions, nutrient balance, preservation of soil quality, biological nitrogen fixation, conservation of water resources in the soil and the life cycle assessment (LCA). The efficiency and the impact of different management techniques are also continuously monitored on the orchard and vegetable crops through the study of the fruits of growth dynamics, thanks to an innovative methodology that uses a network of growth sensors spatially distributed in the field. The final product quality is also evaluated through the analysis of their levels of nutraceutical compounds. The research project is still ongoing and the prototypes of machines realized are presented in this paper