BUYERS GUIDE

Spraying is a critical task for vineyards and orchards, and it is the most demanding task for a specialist tractor. The tractor’s performance and features make a real difference, not only to the spraying task, but also to overall vineyard or orchard costs, productivity and yield. A true specialist vineyard-orchard tractor is an engineering marvel with high performance and sophisticated features and functions in a compact package. So how do you pick the best tractor for your orchard or vineyard?

Max Allan, Inlon’s Landini Product Specialist, has spent over 43 years in the tractor industry with most of that experience focused on specialist tractors across several brands. Max has condensed his vast knowledge into a comprehensive Vineyard and Orchard Tractor Buyers Guide, which covers the key issues to consider when buying a new tractor.

1. PTO and Engine Performance for Spraying

PTO Speed

• Vineyard and orchard sprayers work most effectively within a narrow PTO speed band of +/-30 rpm maximum.
• For example, with 540 PTO, operating at only 510 rpm, you can see the difference in leaf coverage due to poorer atomisation.
• An accurately maintained PTO speed is key for optimal spray atomisation and the air volume and speed to maximise penetration and coverage into vines and especially into larger orchard trees.
• With PTO speed being a fixed ratio of engine speed, engine performance is critical.
• With changing ground conditions, spray loads and slopes, the engine lugs down, thereby changing PTO speed.
• The backup torque (or torque reserve) available from the engine determines the degree of lugging and thereby the degradation of PTO speed.
• This diagram shows the torque curve of two popular 85hp rated specialist tractors in Australia.

• In general, big-capacity long-stroke diesel engines give better torque performance than lower-capacity high-revving short-stroke engines.

Engine Performance

• The engine rpm at which the PTO speed is geared is also important.
• PTO speed geared at peak engine performance will correspondingly give peak PTO performance.
• Given the same increased load on the tractor, a flat torque curve results in greater lost rpm compared to a steeper curve. The degree of the torque slope and remaining reserve is what is referred to as the ‘torque backup’.
• For example:
  • An 85 hp tractor on the market has its rated engine performance at 2600rpm, yet the 540 PTO is geared to under 2200 rpm; the engine is well off its peak, with little torque backup remaining at 540 PTO.
  • By comparison, the Landini Rex 90F performance, with its 4.4 Litre Perkins engine, and PTO geared at 1948 rpm, has torque back up peak of 352 Nm of torque at 1400 engine RPM.
  • The Rex 120GT has peak torque of 416 Nm at just 1400 rpm.
• The nominal engine hp rating is a simple number that distracts from the important facts of the true nature of the engine torque and power performance.

Electronic Engine Control

• The gold standard for engine performance is electronic engine control whereby the engine and PTO rpm are precisely maintained utilising the full available engine power without lugging down on rpm.
• The Landini Rex 4-series, designed specifically for orchard and vineyard work, has electronic engine control.

Other PTO requirements to consider

• Although spraying is the most demanding PTO task, there are many light PTO tasks; an economy PTO mode improves fuel efficiency for that work.
• Optional 1000 rpm PTO is also needed for certain sprayers and harvesters.
• All such PTO configurations are available with Landini specialist vineyard and orchard tractors.
• The Landini Rex 4-series has 4-speed PTO as standard, offering peak and economy performance in both 540 and 1000 speeds.

2. Ground Speeds for Spraying

• When setting the spray application rate, having a range of ground speeds to choose from helps to optimise the spraying task on orchards and vineyards.
• A tractor with a 15-speed transmission may seem like enough at first glance, but in the critical working band of 3-10km/h, this may only effectively give you 5 working speeds.
• The Landini Rex with its 30-speed transmission gives 14 speeds in the 3‑10km/h band, almost 3 times the number of gears to choose from. The Landini 40-speed transmission gives even more speeds.
• And just as consistent PTO speed was critical for spray quality (penetration and coverage), accurate ground speed is critical for the rate of chemical per hectare.
• If the conditions ultimately cause excessive engine lugging, having another gear ratio close by to drop back a gear to maintain PTO speed is the lesser of two evils. The lower ground speed increases the application rate, and thereby chemical wastage, but maintains the spray quality. Ineffective spray quality is the worst-case scenario.
• For example, dropping ground speed from 4 to 3.7 km/h results in 8% wastage, dropping from 4 to 3km/h results in 33% wastage.

3. Tractor Dimensions

• A specialist vineyard or orchard tractor must have compact dimensions to fit between the vineyard rows or under the orchard tree canopy without damaging the crop, trees, or the tractor.
• Packing the engine performance into such compact dimensions is a major engineering challenge.
• As land and water costs drive narrower plantings and pressure to optimise irrigation, compact tractor dimensions will continue to be important.
• Sometimes a will-fit solution is used with a conventional farm tractor with narrow wheels to fit into a vineyard with wider row spacings, but this puts a heavier tractor on narrow wheels with tracks running closer to the plant lines.
• Soil compaction has detrimental effects on root development and water penetration that eventually require rehabilitation, but more importantly, creates unseen effects on irrigation costs and yield.
• Stronger root development can also improve plant resilience to heat stress.
• The Landini Rex 120GT delivers 110 hp performance in a package under 1.58 metres running on low compacting 420/70R24 rear tyres, with a maximum cabin height of 2.26 metres.
• Another key dimension is the tractor’s turning circle for the repeated headland turns at the end of each row. Balancing wheelbase and driver comfort with tractor stability to give the field agility needed is a further challenge.
• Some vineyard and orchard specialist tractors have complex solutions to steering performance, with more wearing parts, longer wheelbase and axle gearing.
• These solutions often affect tractor stability when turning on slopes.
• The Landini Rex has a steering angle of more than 55 degrees and has proven performance in Australian conditions.

4. Cabin for Spraying

• A spray tractor needs a cabin that is up to the task of keeping spray chemicals out of the cabin while having appropriate dimensions to fit under the tree canopy conditions.
• A cabin needs effective sealing, filters with locations that do not clog with spray and dust, and a rear window wiper.
• The Landini Rex 4-series has the option of the new Category-4 pressurised cabin with a control system to maintain and monitor positive cabin pressure.

5. Hydraulics, Linkage and Electrical Services

• A comprehensive range of hydraulic configurations and options are essential for specialist vineyard-orchard tractors.
• An independent power steering pump ensures the hydraulic flow to remotes is not affected by steering activity.
• High flow capability is important for demanding hydraulic implements such as sprayers, pruners, sweepers and trimmers.
• The Landini Rex provides flow to the remotes of 52 Litres/minute, with the option of triple-pumps for flow of 69 Litres/minute to the remotes.
• Flow of 52 Litres/minute will handle over 95% of situations, but higher flow may be needed for more demanding sprayers such as over-row sprayers and those with additional hydraulic fans.
• It is important to understand the engine rpm at which the hydraulics system is rated. If the PTO gearing requires a substantial reduction in engine rpm to match 540, there is a corresponding reduction in the actual hydraulic flow from the remotes.
• Other aspects to hydraulics to consider include:
• A generous number of hydraulic outlets for the operation of a wide range of attachments that have hydraulic functions such as booms, blowers and motors.
• Centrally located remotes for front mounted pruners and sweepers.
• Hydraulic remotes with motor flow control, kick-out, float and detent functions are all essential with some attachments.
• Hydraulic levelling of linkage arms and top link is critical when working in narrow rows or on slopes
• Many of these features are standard on Landini specialist vineyard and orchard tractor ranges or available as options.
• A generous and capable electrical capability is also needed for some attachments and 85 Amp alternators are standard across the Landini specialist vineyard and orchard tractor range.

6. Steering, Driveline and Braking

• Pulling fully loaded spray carts (for example up to 4000 Litres and 5.5 Tonnes) is demanding for a specialist tractor, especially on slope conditions.
• Driveline features such as front and rear axle differential locks, and generous tyre sizes improve traction to make this task safe and stable while minimising soil damage.
• A braking system that relies on 4WD engagement for front wheel braking can be ineffective with a limited slip diff or one without diff-locks; if one front wheel loses traction, the braking action on the other wheel is lost as the loose wheel rotates backward.
• Independent front and rear axle brakes significantly improve vehicle control and safety, which is standard across the Landini vineyard-orchard tractor range.

7. Ergonomics

• Spending many working hours in the cabin, creature comforts become important to reduce fatigue and errors and maintain productivity.
• Generous tyre sizes and tractor footprint assist ride quality, but an air suspension seat is key.
• An adjustable steering wheel enables it to better suit the individual operator’s size and reach.
• Ergonomically laid-out controls within easy reach are important for those vineyard or orchard tasks that are repeated each row.
• Optional electronic linkage control simplifies raising and lowering at the press of a button.

8. Costs and Benefits

• Your purchase budget and the various price choices for a tractor are always important considerations.
• However, after realising the potential effects an ill-fitting tractor can have on chemical, irrigation and labour costs per year, yield and fruit quality, the tractor price may be a factor better considered in another way.
• Consider the purchase using equipment finance over the productive life of the tractor. For example, a $5,000 price difference is equivalent to just $90/month over 5 years. In the context of $200,000 in chemical and irrigation costs per year, just 10% improvement in these costs far outweighs the investment.

Summary