Rotary Mower Research Articles

ANALYSIS OF ROTARY MOWER DESIGNS – CONDITIONERS

An integral operation of any technology of harvesting hay is mowing the grass, the quality of which depends on the collection of hay from a unit of area, as well as the growth of grass and the yield of grass in the following years. Modern rotary mowers are able to cut grass with high quality, regardless of the state of the stem. The main types of rotary mowers are disc and drum. Their productivity is 20-30% higher than the productivity of segment-finger mowers. The quality of hay largely depends on the drying speed of the vegetative organs of the mown plants. In order to equalize the drying speed of grass stems and leaves, rotary mowers are equipped with roller or impact (conditioners) flattening devices. The quality of grass flattening is affected by the material from which the rollers are made and the shape of their surface. With the same profile of the surface of the rollers, the efficiency of flattening with steel rollers is higher than with those covered with polymer materials. However, their work is accompanied by increased mechanical losses due to leaf breakage. In order to make the flattening rollers work smoother, rubber or polyurethane is applied to their surface. Fluted rollers flatten the grass more intensively than smooth rollers. Roller flatteners provide high-quality work when a layer of grass of uniform thickness is fed into the gap between the rollers. On the contrary, the number of unflattened stems increases. Roller-type tedders are less harsh on the grass than dynamic tedders, therefore, in order to reduce losses from breaking off leaves and inflorescences, they are recommended for working with leguminous grasses. Since the flattening devices of dynamic action are less sensitive to the unevenness of the mass supply, it is advisable to use them when mowing grasses with an uneven density of grass and cereal grasses.

Assessment of the Effects of Autonomous Mowers on Plant Biodiversity in Urban Lawns

Gaining information on the impact of lawn management with autonomous mowers on the floristic composition is crucial to improve their plant biodiversity. In this study, an autonomous mower with a reduced mowing frequency and a more sporadic mowing management system with a ride-on rotary mower were compared in terms of the effect on three dicotyledonous species (Phyla nodiflora, Lotus corniculatus and Sulla coronaria) transplanted onto stands of Bermuda and Manila grass. Regardless of the management system, P. nodiflora achieved the best results in terms of survival for both lawns (74.92 and 58.57% in Manila and Bermuda grass, respectively). In Bermuda grass, a higher percentage of surviving individuals was observed for the ordinary mower management system (42.59%), rather than with the autonomous mower (9.10%), while no differences emerged on Manila grass. On both Manila and Bermuda grass, a higher average percentage of coverage for single individual was observed for the ordinary mower management system (1.60 and 0.37%, respectively) compared to the autonomous mower system (0.55 and 0.08%, respectively). P. nodiflora had a higher percentage of individuals with flowers with the ordinary management system rather than with autonomous mower system both on Manila (60.73% and 33.90%, respectively) and Bermuda grass (48.66 and 3.32%, respectively). Despite a lower impact on the planted species being observed for the ordinary mower management system, encouraging results were obtained with the autonomous mower, for instance regarding the percentage of surviving individuals for P. nodiflora (33.95%) and L. corniculatus (22.08%) on Bermuda grass and the percentage of individuals with flowers for the same two species (33.90 and 13.59%, respectively) on Manila grass. Furthermore, the autonomous mower management system’s primary energy consumption over the year was lower compared to that of the ordinary system both on Manila (200.4 and 614.97 kWh ha−1 year−1, respectively) and Bermuda grass (177.82 and 510.99 kWh ha−1 year−1, respectively).

Comparison of cover crop termination methods for small-scale organic vegetable production: effect on soil fertility and health

Termination methods and the timing of the termination of the cover crops are critical factors determining the efficacy of cover crops in improving soil fertility and quality. We hypothesized that different termination methods will produce varying quantities of organic residue which will affect microbial diversity and thereby nutrient cycling and availability. The objective of this study was to compare termination methods (roller-crimper, flail mowing, rotary mowing, sickle bar mowing, and occultation using black tarps) for fall-grown cover crop combination (hairy vetch-cereal rye) under organic vegetable production. Field experiments were carried out in three consecutive years (2018–2021) and soil samples were collected from 0 to 15 cm and processed for analysis. Soil organic matter content, nutrients, health parameters, enzymes, and microbial diversity were measured. Flail mowing significantly enhanced the potentially mineralizable nitrogen, available phosphorus, and active carbon. Total Phospholipid Fatty Acid (PLFA) analysis showed a 24% increase for flail mowed, 17% for rotary mowed, and 15% for sickle bar mowed termination methods. There was a significant increase in active carbon content which ranged from 38.9% (rotary mowed), 25.4% (sickle bar mowed), 23.5% (flail mowed), 16.4% for crimper rolled method, and with 2.8% (occultation) respectively. Individual termination methods had varying effects on select enzyme activities. Results indicated that integrating cover crops has the potential to modify soil microbial community structure and increase soil enzyme activities. In this study, flail mowing appeared to be a good method for managing cover crops of choice in terms of soil microbial functionality and fertility.

Moving grassy stand stalks in the process of mowing with a drum mower

Purpose. To describe the processes associated with the movement of cut grass stalks during the operation of a rotary drum mower and to establish directions for improving the process of forming a swath of grass. Methods. The methodological basis of research is the basic provisions of classical mathematics and agricultural mechanics, scientific developments of domestic and foreign scientists, achievements of practitioners in the problems of improving the quality of work, energy, and environmental efficiency of the drum rotary mower. In the research process, a set of methods is used, including: ­ monographic in the analysis of research on processes related to the operation of a rotary drum mower and the movement of mown grass stalks at the same time; ­ analytical when describing the processes of deviation and movement of individual stalks of cut grass. Results. The stalks of the grass stand are moved even before the start of cutting, namely, they are deflected by the cover of the protective apron. It was established that the amount of deviation along the width of the mower is different, and the tangents of the angles of the maximum and minimum value of the deviations are determined by dependencies (2) and (3), respectively. The process of stem movement after mowing is divided into stages, the characteristic zones in which mowing occurs are highlighted, the differences in the action of forces characteristic of these zones are characterized. The movement of the stem while lowering it to the surface of the disk for transportation is described, taking into account the properties of the stem and the action of the knife. The height of the rise of the stem after cutting and the time of its descent to the disk were determined. Conclusions 1. The process of interaction of the mower with the stalk from its deviation to the beginning of the descent from the disk for transportation is divided into stages. The movement of the cut stem at each of the stages is characterized. The stage of movement of the stem after cutting is described taking into account the mass of the stem and its properties (length of the stem, coefficients of friction and slippage). 2. The cut stems, touching the transport disk with the cut part, are placed on it perpendicular to the radius of the disk and transported in several layers. 3. For reliable capture and transportation of stems by disks, it is advisable to equip the latter with radial vanes that will grasp the stems in the direction perpendicular to the radius-vector of the disk and will not resist the descent of the stems to the periphery of the disk. Keywords: drum mower, stem, forces, sliding coefficient, stacking of the stem, disk for transportation, equation, center of mass.

DYNAMIC PROCESSES OF A HAND-HELD MOTORIZED MOWER DURING THE START OF THE MOWING PROCESS

From the point of view of revitalization of agrarian processes in our country, the perspective of its development showed us that animal husbandry remains one of the priority sectors, which is due to the production of animal husbandry products. Based on this, the problem of producing rough feed for mining conditions remains a problematic issue in small farms and peasant farms, where it is impossible to use large-capacity machines and food production is still done manually. The purpose of the research is the methodology of calculating the internal dynamic processes of a small power hand motorized rotary mower during the start of the mowing work process. The scientific paper presents the dynamic load of a small power hand motorized mower at the moment of starting mowing, which is highly dependent on the work of the working body, so as to perform the mowing process with quality and less losses.

Uticaj ozimih međuuseva i različitih jarih useva na strukturu zemljišta tipa černozem

The intensive form of agricultural production often leads to disruption of physical, chemical and biological properties of the soil. Therefore, in recent years there has been an increasing focus on research and finding ways to preserve the soil with management practices that support soil conservation. The research was conducted on the experimental field of the Institute for Field and Vegetable Crops Novi Sad on Rimski Šančevi. The experiment was set up as a randomized block design. The winter cover crops consisted of the combined intercrops: Triticale (×Triticosecale Wittm. ex A. Camus) and winter pea (Pisum sativum ssp. arvense L.) (T+P), solo winter fodder pea crop (Pisum sativum ssp. arvense L.) (P) and a control without winter cover crops (sole or mixtures)(Ø). The experiment with winter cover crops was divided into two blocks. In the first block, the winter cover crops were chopped and plowed, while treatments in the second block were mowed using a rotary mower and the fodder was removed for feeding ruminants. After ploughing and preparing the soil for sowing, sowing of spring crops (soybean, maize and sudan grass) was carried out on all varieties in the subsequent sowing period. This research aims to determine the influence of different types of winter cover crops and spring crops from subsequent sowing period on the physical properties of Chernozem with a special emphasis on soil structure. It was determined that values of MWD on the treatments where the mixture of cover crops (T+P plowed) ranged from 1.11 mm to 1.39 mm, which indicated a better aggregates stability compared to the control treatments where no cover crops were sown. Due to variable root morphology and water requirements, which may alter soil structure, it is required to pay more attention to the adaptation of management strategies through the use of cover crops as well as the selection of their mixes.

Harvesting Technologies and Costs of Biomass Production from Energy Crops Cultivated on Farms in the Małopolska Region

This study aimed to assess biomass production costs from perennial energy crops, such as Miscanthus giganteus, Sida hermaphrodita, and coppiced willow, in selected agricultural holdings. This assessment was based on applied technologies for harvesting the biomass of the energy crops mentioned above. The scope of the study included research on ten farms located in Małopolska and establishing the possibility of biomass production from selected energy crops in these entities. Biomass production costs have been estimated using the computer application “Bioalkylation”. The result of the research was the answer to the question: what can be the cost range of biomass production from perennial energy crops for the crops Miscanthus giganteus, Sida hermaphrodita, and coppiced willow as the most popular plants? The study shows that production costs depend primarily on the harvesting technology used and the machinery used in the farm. The harvest with rotary mowers, small presses, and windrows was applied regarding Miscanthus giganteus and Sida hermaphrodita. The costs of biomass production were, on average, 424.7 EUR ha−1 for Miscanthus giganteus and 278.9 EUR ha−1 for Sida hermaphrodita. Concerning tonne, this was 37.6 EUR t−1 for Miscanthus giganteus and 30.0 EUR t−1 for Sida hermaphrodita, respectively. In the case of harvesting energy willow, in the form of whole shoots, inefficient and labour-intensive technologies using chainsaws and combustion cutters were applied. The biomass production costs were thus the highest among the assessed plants and amounted, on average, to 612.1 EUR ha−1, which in terms of tonne corresponded to a value of 30.6 EUR. The obtained results and the analysis presented in the paper may help in planning the cultivation of perennial energy crops in order to obtain biomass used for heating purposes on a farm.

Suggestions on increasing the germination seeds of pasture fodder plants

One of the problems in the seed production of pasture forage plants is low seed germination. Existing pasture improvement technologies and technical means for seed production, harvesting, post-harvest handling, and storage of pasture forage plants are analysed. Suggestions for improving seed germination have been developed: it is advisable to place the seed crops between the forest belts; to improve seed germination, it is necessary to make a preliminary harvest of seed crops with spreading the mass on the stubble; the mechanised collection of seed heaps using a rotary mower with an active heap separator increases the germination rate by reducing mechanical damage to the seeds and enriching the soil with organic matter; the seed sowing process has a positive effect on the germination rate of the seed produced, in addition to reducing cleaning costs.

Development and Performance Evaluation of an Engine Operated Mower

Unquestionably, Ethiopia is still taking the primary place in its livestock resource impending compared African countries. Nonetheless, due to numerous motives the nation has yet subjugated from its commercial likely for years. Although, much of the forage produced in the country is harvested directly by grazing animals, a small portion is manually harvested and carried to the animal. The main of the work was developing and evaluating performance of an engine operated mower which is pushed manually in field. The developed rotary mower has three wheels, two front wheels and one rear wheel. The rear wheel was used for steering at the end of farm land. The pulley on an engine was connected to the pulley shaft carrying blade and the vertical rotation on the engine converted in to horizontal on the blade by twisting the belt. This mower is used to reduce the charge and power requirement for domestic perseverance. This mower is fabricated using locally obtainable material and spare parts and thus, it is effortlessly maintained. This mower might be the way out to the difficulties faced by a small scale farmer regarding price and labor requirement. Earlier this machine was tested in farm and was found that the price of mowing using this mower is widely fewer comparing to labor-intensive mowing.

ИССЛЕДОВАНИЕ МОДИФИЦИРОВАННОГО РАБОЧЕГО ОРГАНА КОМБИНИРОВАННОЙ РОТАЦИОННОЙ КОСИЛКИ

Currently, there are practically no mechanization tools on the market that combine grass removal (mowing) and the levelling loosening of the upper soil layer, while cutting the root systems contained in the soil in one pass. The purpose of the study was to provide a theoretical rationale of the modifi ed design of the working tool of the combined rotary mower, as well as to conduct its laboratory and fi eld studies. Complex theoretical, laboratory and fi eld studies were carried out using the equipment of the Department of Technological and Transport Machines and Complexes, the Department of Technology of Processing and Storage of Agricultural Products of Tver State Agricultural Academy and recognized methods of experimental research. In the course of theoretical studies, the main parameters of the new working tool were determined, which enabled two technological processes to be carried out in one pass: grass mowing and cutting with loosening of the top soil layer (0…10 cm). On the basis of the obtained data, a workable model of the working tool was designed. When tested in laboratory conditions, regardless of the operating modes and the initial state of the cultivated soil, improved agrophysical properties were observed in terms of absolute humidity and saturation with root residues. It was found that the most optimal level of absolute humidity for the impact of the working tool on soils of light-loamy granulometric composition was 20%, while the best structural and density indicators were observed at all values of soil saturation with root residues; thgey averaged 2.24 units and 1.26 g/cm3. It has been established that at low operating speeds, it is advisable to use a higher rotation speed of the working tool (at 150 rpm), at the same time, with an increase in speed, the speed of rotation should be reduced (to 110 rpm). As a result of fi eld experiments, convincing data were obtained on the feasibility of using a new working tool that provides eff ective mowing of grassland vegetation (the purity of the stem cut is 95.6%) and loosening of the surface layer of the soil (0…10 cm), increasing the structural coeffi cient by 26.8% while optimizing the density and grinding of root systems. The next stages of the study include developing and manufacturing a workable design of a combined rotary mower prototype that ensures the optimal energy intensity of performance and the required quality of technological processes.

Organic Kale and Cereal Rye Grain Production Following a Sunn Hemp Cover Crop

A four-year field experiment was initiated in 2011 at the EV. Smith Research Station, in central Alabama, to determine the effect of sunn hemp (Crotalaria juncea L.) termination methods on organically grown kale (Brassica oleracea, var. acephala L.) for fresh market and cereal rye (Secale cereale L.) for grain. Three different termination methods for the sunn hemp cover crop were chosen: (1) rolling/crimping with an experimental two-stage roller/crimper, (2) rotary mowing, and (3) rotary mowing with incorporation (disking). Kale plots were harvested in the winter and rye plots were harvested in the following spring. Kale plots were fallow from January to June (kept mowed) until planting sunn hemp again across all plots in late spring of the next growing season. Over four growing seasons, average sunn hemp biomass (dry basis) was 10,981 kg ha−1 with plant height of 2.4 m. The average C/N ratio of sunn hemp was 23:1. Sunn hemp biomass amounts differed among growing seasons (from 5589 to 14,720 kg ha−1) due to different weather conditions. Kale yield also varied across growing seasons, with the highest yield of 17,565 kg ha−1 measured in 2012 and the lowest (3915 kg ha−1) in 2014 due to massive weed pressure. Generally, sunn hemp residue management affected kale yield, with greater yields measured for mowed and incorporated residue (15,054 kg ha−1) compared with lower yields for mowed (6758 kg ha−1) and rolled sunn hemp (5559 kg ha−1). Lower yields were related to poor kale seed-to-soil contact (hair pinning) from large amounts of sunn hemp residue on the soil surface. Over four growing seasons, cereal rye grain yield varied among growing seasons, with an average yield of 1358 kg ha−1. Moreover, sunn hemp residue treatments affected grain yield, with greater yields for rolled (1419 kg ha−1) and mowed residue (1467 kg ha−1) compared with a lower yield (1187 kg ha−1) for mowed and incorporated sunn hemp residue.

Measurement of turf height and growth using a laser distance device

AbstractGrowth or yield is an important characteristic to measure in crop science experiments. Turf researchers often use rulers or harvest grass clippings to measure growth and yield, respectively. Rising plate meters or floating disk meters are used for nondestructive measurements of forage canopy height to estimate herbage biomass, but this technique is not commonly used by turf scientists. Using the rising plate concept and integrating new technology, our objective was to develop an easy‐to‐construct, low‐cost device that could rapidly and accurately measure canopy height, growth, and estimate yield in turf research. A device called the “Turf Height Tester” with a floating platform and a laser distance measurement tool was constructed within a US$167 budget. The tester was able to precisely measure recently mown turf canopy height at the tested bench heights of 4.9–10.2 cm. The Turf Height Tester was advantageous for comparing the growth of turfgrasses with contrasting growth rates, and turf response from N fertilizer applications in a nondestructive manner. The tester, which outputs data via Bluetooth to the nearest 0.1 mm, correlated well with other turf canopy height measuring tools but had a lower CV. Collecting ∼18 measurements per minute, the tester allows for data collection from 1.8 plots per minute (includes 5 pre‐ and 5 post‐mowing measurements) compared with the more labor‐intensive practice of harvesting and weighing grass clippings from a rotary mower with a bagging attachment at 0.2 plots per minute. Further, there was a strong relationship across experiments (R2 = .62–.94) between growth measurements using the tester and dry matter clipping yield.

Experimental Assessment of the Impact of Agricultural Machinery on Wood Turtles (Glyptemys insculpta)

The wood turtle (Glyptemys insculpta) is a threatened species that uses agricultural fields, in part, to nest, bask, and feed. This use of anthropogenic habitats has resulted in the injury and death of individuals during crop harvest. Turtles have been exposed to hay harvests for over a century but the increased use of rotary disc mowers may have increased mortality rates to unsustainable levels. Mitigation measures have focused on raising blade height to minimize contact with turtles but these measures are based on the dimensions of the largest turtles and the effects of agricultural machinery on subadults, juveniles, and hatchlings have not been quantified. We sought to quantify how different agricultural machinery affects wood turtles at multiple life stages through experimental trials using 2 mower types. Cantaloupe (Cucumis melo) halves were used as turtle proxies to avoid actual harm to turtles. We found that rotary disc mowers resulted in a significantly greater injury to adult (i.e., female, male, and subadult) and young (i.e., juvenile and hatchling age class) proxies at low grass heights (10–20 cm) compared with sickle cutter bar mowers. Young proxies were found to be essentially unaffected by the sickle mower at all grass heights, but they were highly affected by the rotary disc mower at grass heights from 10 to 18 cm. If blade heights were to be raised to reduce the risk to wood turtles, a minimum blade height of 17 cm would be needed to obtain > 50% of adults remaining undamaged during harvest and a minimum height of 15 cm would be needed for young turtles.

DEVELOPMENT OF A MOWER FOR THE MULLING OF OPTIMUM TREES OF TREES IN

The article describes the current state of soil retention near the trees of the intensive garden. The disadvantages of the main soil retention systems in perennial fruit plantations and the inappropriateness of using a wide range of systemic and contact chemicals for the cultivation of fruit and berry crops are noted. It is established that the most rational and accessible system of soil retention in gardens is sod-humus with mowing vegetation as mulch. The disadvantages of the lack of technical means in the field of horticulture are noted: decrease of labor productivity, lack of harvest by 40-50%, the main restraining factor of introduction of modern highly efficient technologies. The design and technological scheme of the rotor mower has been developed for mulching of the accessory strips of trees in intensive gardens, which will allow to increase the water, temperature, air regime of the soil, to activate microbiological activity in it, to ensure the reduction of erosion processes. The hydraulic drive of the rotary mower is offered, which will allow to mow, grind and send the plant mass into the adjacent area of the garden for mulching more qualitatively.

КОНСТРУКТИВНЫЕ ОСОБЕННОСТИ УСТРОЙСТВА ДЛЯ ОБРАБОТКИ КОРМОВЫХ ТРАВ В ПРОЦЕССЕ СКАШИВАНИЯ

For the treatment of fodder grasses during mowing on modern mowers install various conditioners designed to accelerate their wilting. The most extended among them are pressing rollers and shafts, equipped, as a rule, with various hammer-type beats. However, these conditioners installed on rotary mowers have a difficult drive, high mass and price. It is possible to eliminate these lacks by the use of a new conditioner [1], developed in the Federal Williams Research Center for Fodder Production and Agroecology (Moscow region), and equipped with beats for mechanical action on the stalks of grasses in the process of mowing. Beats are represent a pieces of round-link chains fixed in the upper part of cylindrical hollow drums installed vertically on the cutting discs of the rotary mower. The innovative dynamic action conditioner to the rotary mower KR-2,4M provides acceleration of field drying of the mowed grasses due to strengthening of moisture output by plants, especially the traumatized stalks which usually dry more slowly, than leaves. The constructive features of the conditioner and the principle of its action are described.

Energetic Aspects of Turfgrass Mowing: Comparison of Different Rotary Mowing Systems

Turfgrass mowing is one of the most important operations concerning turfgrass maintenance. Over time, different mowing machines have been developed, such as reel mowers, rotary mowers, and flail mowers. Rotary mowers have become the most widespread mowers for their great versatility and easy maintenance. Modern rotary mowers can be equipped with battery-powered electric motors and precise settings, such as blade rpm. The aim of this trial was to evaluate the differences in power consumption of a gasoline-powered rotary mower and a battery-powered rotary mower. Each mower worked on two different turfgrass species (bermudagrass and tall fescue) fertilized with two different nitrogen rates (100 and 200 kg ha−1). The battery-powered mower was set at its lowest and highest blade rpm value, while the gasoline-powered mower was set at full throttle. From the data acquired, it was possible to see that the gasoline-powered mower had a much higher primary energy requirement, independent of the turf species. Moreover, comparing the electricity consumption of the battery-powered mower over time, it was possible to see that the power consumption varied according to the growth rate of both turf species. These results show that there is a partial waste of energy when using a gasoline-powered mower compared to a battery-powered mower.

Effects of close cutting on ground cover and quality of a polystand of Manilagrass and cool season turfgrasses

Warm season turfgrasses can be grown successfully in the transition zone, but dormancy occurs to some extent during the winter. Overseeding with cool-season turfgrasses is necessary if winter dormancy of warm season turfgrasses is not tolerated. The increasing availability of zoysiagrass cultivars has enabled this genus to be considered suitable for low-maintenance golf courses, especially for golf tees and golf fairways. On the other hand, zoysiagrasses have the most rigid leaves of all turfgrass species, followed by bermudagrasses and by the other warm season turf species. Thus, to have a high mowing quality, mowers working constantly on zoysiagrasses require more sharpening than mowers working on other grasses. Rotary mowers are not suitable for mowing at low heights and often result in scalping, while reel mowers perform optimal mowing at a short height (below 2.5 cm) but require accurate management and frequent sharpening. Autonomous mowers have proven to produce a superior turf quality compared with traditional walk-behind rotary mowers, but no autonomous mower has ever been tested at a low mowing height on an overseeded warm season turfgrass. Because of this, the trial was carried out to simulate a golf tee overseeded with cool season turfgrasses, with low input fertilisation rates and with one of the most difficult turf species to mow; i.e. Zoysia matrella (L.) Merr. The trial was carried out in San Piero a Grado (Pisa, Italy) from October 2016 to October 2018. After a two-year period the best turf quality was achieved with Festuca rubra L. ssp. cultivars among the overseeded species, especially during fall. In many cases turf quality increased after manila grass green up since the combination of both cool season and warm season species gave a higher quality to the turfgrass, due to the finer leaf texture and higher shoot density of some cool season species. Moreover, recovery of manila grass ground cover was satisficing. In conclusion, a polystand of manila grass and Festuca rubra ssp. could be suitable for golf tees with low-input management.

Spread of Xanthomonas fragariae in strawberry fields by machinery

The spread of Xanthomonas fragariae in a strawberry field by mowing and runner cutting machinery was studied in the Netherlands during autumn. The blades of a rotary mower became heavily contaminated after trimming the leaves of symptomatic plants. Use of a contaminated mower resulted in infection of plants that were initially free of X. fragariae, even at a distance of 4 m (i.e. 10 mother plants) from the symptomatic plants. Directly after mowing, the pathogen could be detected on damaged leaves at a density of 103–105 cells g−1. Infections were established, although 3 months after mowing symptoms were still absent. There were indications that the use of the mower resulted in the spread of infected leaf material from symptomatic plants to neighbouring beds. Spread by a runner cutting machine was also studied. Again, after cutting the runners of symptomatic plants, high numbers of X. fragariae cells were recovered from debris on the discs of the machine. During cutting, the cut ends of runners of plants initially free of X. fragariae became contaminated, even at a distance of 4 m from the symptomatic plants, but only at low densities of 103 cfu g−1. Three months after stolon cutting, infections were detected in some of the cut plants.

Comparison between Different Rotary Mowing Systems: Testing a New Method to Calculate Turfgrass Mowing Quality

Poor quality in turfgrass mowing is highlighted by the shredded leaf tips with necrotic tissues that give an unsightly brownish colour to the turf and may also lead to turf disease. Mowing quality is also typically assessed by visual rating, thus the score depends on the person doing the assessment. To make the evaluation of mowing quality not subjective, an innovative method was developed. The aim of the trial was to examine the effects of different mowing systems and two different nitrogen rates (100 and 200 kg ha−1) on two turfgrass species in order to test the new mowing quality calculation. Three different mowing systems were used: a battery-powered rotary mower set at 3000 rpm and 5000 rpm respectively and a gasoline-powered rotary mower set at full throttle. The battery-powered mower at low blade rpm produced a poorer mowing quality and turf quality than the gasoline-powered mower and battery-powered mower at high rpm, which produced a similar mowing quality and turf quality. Leaf tip damage level values showed a significant correlation with the results of the visual mowing quality assessment. Lower leaf tip damage level values (slightly above 1) corresponded to higher visual mowing quality scores (around 8).

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 kg·ha−1), 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 high-quality sports turfs, thus saving time as well as reducing noise and pollution.