Michele Raffaelli

Finger harrowing of durum wheat under different tillage systems

ABSTRACT The effect of finger-harrowing (FH) on weed control and yield of durum wheat (Triticum durum Desf) grown under conventional tillage (CT) or no-tillage (NT) was studied in 1995–96. Mechanical weeding—eight combinations between four tine adjustments and two treatment intensities (one or two passes)—was compared with post-emergence herbicide spraying and an unweeded control. Tine working depth was higher in CT than in NT due to lower soil dry bulk density, and increased with the theoretical aggressiveness of tine adjustments, but its correlation with short- and long-term effects on crop and weeds overall was poor, suggesting that tine adjustment was not a major factor involved. In 1995, durum wheat grain yield in FH was very low, because of high weed development in both tillage systems. In 1996, lower weed pressure resulted in FH grain yield, on average 3982 kg ha−1 for CT and 2809 kg ha−1 for NT, comparable with that obtained with herbicides. Durum wheat grain yield and weed biomass were much more affected by tillage system than by tine adjustment or harrowing intensity, and seemed mostly dependent on the lower crop competitive ability in NT, caused by reduced emergence, higher weed abundance and presence of aggressive weed species, Ammi majus in 1995 and Lolium multiflorum in 1996. Dependence of FH effect upon soil and weed conditions encountered seasonally in the two tillage systems suggests that, in low-input durum wheat, mechanical methods alone would not always guarantee adequate weed control and grain yield.

Unmanned Aerial Vehicle to Estimate Nitrogen Status of Turfgrasses

Spectral reflectance data originating from Unmanned Aerial Vehicle (UAV) imagery is a valuable tool to monitor plant nutrition, reduce nitrogen (N) application to real needs, thus producing both economic and environmental benefits. The objectives of the trial were i) to compare the spectral reflectance of 3 turfgrasses acquired via UAV and by a ground-based instrument; ii) to test the sensitivity of the 2 data acquisition sources in detecting induced variation in N levels. N application gradients from 0 to 250 kg ha-1 were created on 3 different turfgrass species: Cynodon dactylon x transvaalensis (Cdxt) ‘Patriot’, Zoysia matrella (Zm) ‘Zeon’ and Paspalum vaginatum (Pv) ‘Salam’. Proximity and remote-sensed reflectance measurements were acquired using a GreenSeeker handheld crop sensor and a UAV with onboard a multispectral sensor, to determine Normalized Difference Vegetation Index (NDVI). Proximity-sensed NDVI is highly correlated with data acquired from UAV with r values ranging from 0.83 (Zm) to 0.97 (Cdxt). Relating NDVI-UAV with clippings N, the highest r is for Cdxt (0.95). The most reactive species to N fertilization is Cdxt with a clippings N% ranging from 1.2% to 4.1%. UAV imagery can adequately assess the N status of turfgrasses and its spatial variability within a species, so for large areas, such as golf courses, sod farms or race courses, UAV acquired data can optimize turf management. For relatively small green areas, a hand-held crop sensor can be a less expensive and more practical option.

Innovative strategies for on-farm weed management in organic carrot

Weed management is often the most troublesome technical problem to be solved in organic farming, especially in poorly competitive crops like vegetables. A four-year (2000–2003) series of trials was established to assess the possibility of adopting an innovative non-chemical weed management system in organic carrot grown on the Fucino plateau, i.e., the most important carrot-growing area in Italy. The system utilized for physical weed control was based first on a false seedbed technique followed by pre-sowing weed removal, performed with a special 2 m wide 6-row spring-tine harrow. Prior to crop emergence, a pass with a flame weeder equipped with four 50 cm wide-open flame burners was also performed. Post-emergence weed control consisted of one or more hoeing passes with a purpose-designed 11-tine precision hoe equipped with spring implements (torsion weeders and vibrating tines), in addition to hand weeding. This innovative system was applied to a novel planting pattern (sowing in ten individual rows within 2 m wide beds) and compared to the standard management system of the area (sowing within 2 m wide beds but in five bands, use of spring-tine harrowing and flame weeding pre-emergence and of traditional hoeing post-emergence). The new system was tested in different commercial farms including both early and late-sown carrot. Assessments included machine operative characteristics, labor time, weed density and biomass, crop root yield and yield quality, and economic data (physical weed control costs and crop gross margin). Compared to the standard system, the innovative system usually resulted in reduced labor time (from 28 to 40%) and total costs for physical weed control (on average −416 € ha −1 ). Use of the precision hoe resulted in intra-row weed reduction ranging from 65 to 90%, which also led to a marked reduction in the labor required for hand weeding. In 2001 the two systems did not differ in terms of yield and yield quality, whereas in 2002 and 2003 the innovative system showed a higher mean density of carrot plants (from 28 to 55%), root yield (from 30 to 42%), and gross margin (from 40 to 100%). Carrot yield was higher in farms which adopted an early sowing whereas root commercial quality was somewhat variable between systems and years. In general, results obtained with the innovative management system look very promising.

Physical weed control in processing tomatoes in Central Italy

Tomato is a very important vegetable crop in Italy. Improving the means of production for processing organic tomatoes could help guarantee better profits for farmers and, at the same time, enhance environmental management and safeguard consumers’ health. Weed control, in particular within crop rows, is one of the main problems in organic farming, and thus also for the organic cultivation of tomato. The aim of this study was to develop innovative strategies and equipment for effective physical weed control in processing tomatoes. A conventional weed management system incorporating herbicides was compared with an alternative system relying exclusively on physical control during three growing seasons (2006–2008) on a farm located near Pisa, Italy. The crop was transplanted mechanically onto paired rows. The conventional strategy consisted of three different chemical treatments, two post-transplanting PTO-powered rotary hoe passes and several hand-weeding treatments on the paired rows. The alternative system included a stale seedbed technique (performed by a rolling harrow pass and one flaming treatment), two post-transplanting precision hoeing treatments and several hand-weeding treatments. All the machines for the alternative system were adjusted and set up for processing tomatoes transplanted in paired rows. Each physical treatment (mechanical and thermal) within the alternative system allowed an ‘instantaneous’ (just before/just after) weed control from 50 to 100%, while the alternative strategy as a whole achieved values of weed dry biomass at harvest ranging from 22 to 126 g m −2 . However, the alternative system required a total labor input that averaged 50% higher than the conventional strategy. The conventional system had on average more effective weed control than the alternative system, but both strategies controlled weeds effectively. Weed biomass at harvest averaged 36 and 68 g m −2 for conventional and alternative strategies, respectively. On the other hand, the alternative system generally led to a significant increase in fresh crop yield (+13% average yield for the 3 years).

Physical weed control in protected leaf-beet in central Italy

In Central Italy leaf-beat is a typical and very important protected cultivation. In leaf-beet protected cultivation weed control is one of the most important problems, because of it’s quite long crop cycle (about 4-5 months). The aim of this research was to set up an efficient non-chemical weed control strategy performed with innovative machines built and set up by the University of Pisa. A two-year (2006-2007) “on-farm” experimental trials were carried out in Crespina (PI). A conventional weed management technique (consisting in one pre-transplanting chemical treatment) was compared to an innovative physical weed control strategy (consisting in stale seedbed technique, in some post emergence precision hoeing and in-row hand-weeding treatments). In the conventional technique the leaf-beat was manual transplanted, while in the innovative strategy it was sowed with a precision pneumatic planter. All the innovative machines for physical weed control were adjusted and set up for the protected cultivation. In the two year trials similar yields were recorded for the two systems in comparison. Total labour time (for weed management and crop planting) was appreciably lower in the conventional system in the first year of experiment (-67%), while, in the second year, some improvement in the innovative technique allowed to reach lower values with respect to the conventional technique (-40%). Weed dry biomass at harvest was significantly lower for innovative system (on average -50%).

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.

Autonomous Mower Saves Energy and Improves Quality of Tall Fescue Lawn

Battery-powered autonomous mowers are designed to reduce the need of labor for lawn mowing compared with traditional endothermic engine mowers and at the same time to abate local emissions and noise. The aim of this research was to compare autonomousmower with traditional rotary mower on a tall fescue (Festuca arundinacea) lawn under different nitrogen (N) rates. A two-way factor experimental design with three replications was adopted. In the study, four N rates (0, 50, 100, and 150 kg ha) and two mowing systems (autonomous mower vs. gasolinepowered walk-behind rotary mower equipped for mulching) were used. As expected, N fertilization increased turf quality. At the end of the trial, the autonomous mower increased turf density (3.2 shoots/cm) compared with the rotary mower (2.1 shoots/cm) and decreased average leaf width (2.1 mm) compared with the rotary mower (2.7 mm). Increased density and decreased leaf width with autonomous mowing yielded higher quality turf (7.3) compared with the rotary mower (6.4) and a lower weed incidence (6% and 9% cover for autonomous mower and rotary mower, respectively). Disease incidence and mowing quality were unaffected by the mowing system. The autonomous mower working timewas set to 10 hours per day ( 7.8 hours formowing and 2.2 hours for recharging) for a surface of 1296 m. The traditional rotary mower working time for the same surface was 1.02 hours per week. The estimated primary energy consumption for autonomous mower was about 4.80 kWh/week compared with 12.60 kWh/week for gasoline-powered rotary mowing. Based on turf quality aspects and energy consumption, the use of autonomous mowers could be a promising alternative to traditional mowers.

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 workwere two flaming treatments and two steaming treatments performed at four different doses together with two chemical treatments with glufosinateammoniumherbicide 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.

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, theoretical working time was about 15 h ha, actual working time was 28 h ha, thus the work efficiency was about 0.52. Fuel consumption was about 28 kg ha. 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.

An Automatic Machine Able to Perform Variable Rate Application of Flame Weeding: Design and Assembly

An Automatic Machine Able to Perform Variable Rate Application of Flame Weeding: Design and Assembly Christian Frasconi, Michele Raffaelli*, Luis Emmi, Marco Fontanelli, Luisa Martelloni, Andrea Peruzzi Department of Agriculture Food and Environment, University of Pisa, via del Borghetto 80, 56124 Pisa, Italy Spanish National Research Council, Centre for Automation and Robotics (CSIC-CAR) Arganda del Rey, Madrid, Spain michele.raffaelli@unipi.it