Low Trellis Research Articles

Comparison of biomass in Czech hop cultivars ‘Premiant’ and ‘Sládek’ grown in low and tall trellises

Spring field operations in a tall wirework frame require excessive labor, which may be often difficult to have in an optimal time and a good quality. Especially stringing and training are expensive and lengthy field operations, which can cause problems with optimum timing of treatments against downy mildew, hop flea beetle and weevils. Effectiveness of Czech hybrid tall cultivars ‘Premiant’ and ‘Sladek’ grown in a low trellis was observed. The results in the third year of cultivation (2011) showed different distribution of hop biomass. Hop cones, leaves, laterals and bines were picked by hand and weighed. Distribution of the individual parts in ‘Premiant’ (P) and ‘Sladek’ (S) was compared: 1. Tall trellis: cones 36% in both cultivars, leaves 28% (P), resp. 31% (S), bine 19% (P), resp. 18% (S), laterals 17% (P), resp. 15% (S); 2. Low trellis: cones 13% (P), resp. 24% (S), leaves 37% (P), resp. 34% (S), bine 38% (P), resp. 25% (S), laterals 12% (P), resp. 17% (S). The height of a trellis severely influenced the yield potential of hop plants. Vegetative tops did not train themselves and started to bend after reaching the height of 3 m. If we compare the productivity of cones in the both tested cultivars we can conclude that ‘Premiant’ is less suitable for low trellis cultivation.

New and resurgent insect pests on low trellis hops

Abstract Selective insecticides have largely displaced broad‐spectrum products on cultivated hops, allowing a resurgence of historic pests and new ones to arise. The present study reports the incidence of 30 insect species from four insect Orders and 14 Families feeding on aphid susceptible and/or aphid‐resistant low trellis hop cultivars in south‐east England and at three West Midland sites. Three are Kent Red Data Book species [Adoxophyes orana (Lepidoptera: Tortricidae), Hypena rostralis (Lepidoptera: Noctuidae) and Psylliodes attenuatus (Coleoptera: Chrysomelidae)] and three are DEFRA biodiversity action plan priority insects [Acronicta rumicis, Melanchra persicariae (Lepidoptera: Noctuidae) and Spilosoma lubricipedia (Lepidoptera: Arctiidae)]. Six common lepidopteran species severely damaged hop cones (Adoxophyes orana, Autographa gamma, Epiphyas postvittana, Eupitheca assimilata, Mamestra brassicae and S. lubricipedia), whereas Biston betularia, H. rostralis, Melanchra persicariae and Phlogophora meticulosa did not. European corn borer (Ostrinia nubilalis) feeding on hops in Kent are the so‐called E‐pherotype. Lygocoris pabulinus (Hemiptera: Miridae) caged on developing flowering lateral shoots reduced numbers of developing hop cones by 38% and cone weight by 42%, whereas Liocoris tripustulatus caused no losses. Companion plants in the drive alleys between rows of hops reduced the incidences of L. tripustulatus and S. lubricipedia.

Yield and grape must quality of the IAC 138-22 ‘Máximo’ submitted to canopy management

ABSTRACT Grape cultivar IAC 138-22 'Máximo' grafted on IAC 766 ‘Campinas’ and IAC 572 ‘Jales’ rootstocks and trained in upright trellis was evaluated during consecutive summer and winter growing seasons for comparison different canopy management: a) branch thinning: comparison between one branch and two branches per spur and b) branch tipping: comparison between low and high upright trellis. The results obtained of the phytotechnical and physicochemical grape must characteristics allowed to confirm that there was no significant difference between rootstocks regarding branch thinning intensity and upright trellis height. The largest effect observed in canopy management was for yield values promoted by branch thinning. No effect was observed in the grape must physicochemical characteristics when the different treatments were compared in the same growing season. Regarding to the upright trellis height, larger values of soluble solids were obtained for the high trellis than in the low trellis. Winter growing season resulted in lower values of yield and greater values of total soluble solids and titratable acidity than in the summer growing season.

Influence of companion planting on damson hop aphid Phorodon humuli, two spotted spider mite Tetranychus urticae, and their antagonists in low trellis hops

The effects on population development of damson-hop aphid Phorodon humuli and two-spotted spider mite Tetranychus urticae from planting drive rows with grass (2002-3 only), Brassica juncea, Phacelia tanacetifolia (2004-6 only), a meadow-mix of grass and flowering plants were compared with a bare soil control on aphid-susceptible low trellis hop (Humulus lupulus L.) cultivars First Gold (FGO) and Herald (HER) in 2002-4 and on partially aphid-resistant cultivar Boadicea (BOA) in 2004-6. Aphid and mite natural enemies were monitored from beat and foliage samples. Irrespective of ground cover treatment, generalist predators prevented damaging aphid populations from developing on BOA each year, and a combination of aphid–specific and generalists on FGO/HER in two of the three years experiments. Fewest migrant aphids settled, and lower aphid populations ensued, on FGO/HER with meadow-mix than other treatments, but the difference was insufficient to prevent peak populations of ca 1000 per leaf in 2004. Numbers of aphidiid parasitoids reflected aphid population densities on leaves with the highest numbers on FGO/HER in 2004, and none on BOA in any year. Seven species of primary parasitoids were recorded, dominated by Aphidius matricariae and A. picipes (95%), and eight species of hyperparasitoids which became increasingly prevalent as the season progressed. Spider mite population densities remained below ten actives per leaf in all but one year. They were regulated by a combination of phytoseiid mites (six species dominated by Typhlodromus pyri) and insect predators. Hops with meadow-mix had the highest population densities of spider mites, but also the highest numbers of phytoseiids. Although companion plants depressed average cone weight by ca 18% compared with the bare soil control, that loss may be preventable by using additional fertilizers, in which case permanent meadow-mix would provide a suitable companion plant treatment for biological control of both P. humuli and T. urticae on aphid-resistant low trellis cultivars such as BOA, but used alone is unreliable on aphid-susceptible cultivars.

Hydraulic Circuit of Mechanical Pruner Drive for Hops on Low Trellises

Abstract A mechanical pruner serves for pruning new hopvine shoots in spring. The later yield depends on the right timing and quality of pruning. That is why hop pruning is one of the most important agrotechnical procedures. A double-disc mechanical pruner used on high trellises cannot be used on low trellises due to its large size. Abroad, for pruning hops on low trellises a specially adapted sprinkler is used (chemical pruning). With regard to the effort to minimize the chemical environmental burden, we opted for the design of the mechanical pruner. Firstly, the low trellis, mechanical pruner, and also elements used in the design of hydraulic circuit are described. Next part of the paper is devoted to the input requirements for both the hydraulic circuit and the mechanical pruner designs. Then a description of an adapted inter-axle carrier used for the experimental model of the hop mechanical pruner and of the effected field measurement follows, along with interpretation of the measured data. These data are depicted in clearly arranged graphs showing the dependency of pressure and hydraulic oil flow on the cutting disc rotational frequency.

TRIALS WITH GROWING HOPS ON LOW TRELLIS IN THE CZECH REPUBLIC IN 2009-2011

The lack of labor for spring works, which escalated in the Czech Republic in 2007, brought about the renewal of the idea of hop growing on low trellis. A low trellis system was built in the hop garden of the Hop Research Institute in Saaz. The plants were planted in autumn 2008. In 2009-2011, the yield and the chemical composition of hop cones of the experimental varieties, mainly Premiant and Sladek, were established. The First Gold variety represented the control variety. The three-year production results showed that only the Sladek variety was able to achieve profitability when this type of cultivation was used. The paper is concluded with a summary of the use of the Czech mobile hop picking machine HUN-30 in the Czech hop growing areas.

Impact of Producer Risk Preferences on Selection of Fresh-Market Apple Training Systems

Two important choices for apple growers are which cultivar to grow and which training system to use. Stochastic dominance analysis was used in an economic evaluation of a 10-year study in Pennsylvania (USA) comparing three cultivars (‘Crimson Gala’, ‘Ginger Gold’, and ‘Fuji’) grown on four training systems (vertical axe, slender spindle, 4-wire low trellis, and offset V-axe). Stochastic dominance accounts for grower risk attitude in such decisions. Because of consistently high yields and prices, ‘Fuji’ is the only cultivar that ranks highly across all risk attitude categories. For growers willing to accept more risk for higher reward, offset V-axe and vertical axe are preferred training systems. Trellis systems are preferred by growers seeking to minimize risk.

Low-complexity Trellis-based Iterative Decoding of Arithmetic Codes with Image Transmission Application

In this paper, a novel joint source channel (JSC) decoding technique is presented. The proposed approach enables iterative decoding for serially concatenated arithmetic codes and convolutional codes. Iterations are performed between Soft Input Soft Output (SISO) component decoders. For arithmetic decoding, we proposed to employ a low complex trellis search technique to estimate the best transmitted codeword and generate soft outputs. Performances of the presented system are evaluated in terms of PER, in the case of transmission across the AWGN channel. Simulation results show that the proposed JSC iterative scheme leads to significant gain in comparison with a traditional separated decoding. Finally, the practical relevance of the proposed technique is validated under an image transmission system using the SPIHT codec.

New Constructions of High-Performance Low-Complexity Convolutional Codes

In this paper, new constructions of low trellis complexity convolutional codes are presented. New codes are found by searching into a specific class of time varying convolutional codes, which is shaped by some basic properties and search restrictions. An efficient technique for obtaining minimal trellis modules for the proposed codes is provided. Finally, new low complexity convolutional codes of various code rates and memory sizes are tabulated.

Decision-Feedback Sequence Estimation for Time-Reversal Space–Time Block-Coded Transmission

In this correspondence, we consider three different decision-feedback sequence-estimation (DFSE) schemes originally proposed for single-input-single-output channels for time-reversal space-time block coding (TR-STBC). The first scheme is called unwhitened DFSE (U-DFSE) and performs reduced-state sequence estimation based on the output of the spatio-temporal matched filter (MF), typically employed in TR-STBC. The second approach improves upon U-DFSE by subtracting a bias term caused by anticausal interference from the U-DFSE metric. In the third scheme, the noise component in the output of the spatio-temporal MF is first whitened using a prediction-error filter and, subsequently, whitened DFSE (W-DFSE) is performed. As a relevant example, all three DFSE schemes are compared for the global system for mobile communications/enhanced data rates for GSM evolution (GSM/EDGE) system and typical channel profiles. Our results show that for binary modulation (as used in GSM) U-DFSE and its improved version can approach the performance of W-DFSE for the full range of delay spreads relevant for GSM and EDGE. On the other hand, for high-level modulation (as used in EDGE) only W-DFSE gives a satisfactory performance, if a low trellis complexity is desired.

An efficient space-frequency coded OFDM system for broadband wireless communications

We propose an efficient space-frequency coded orthogonal frequency-division multiplexing (OFDM) system for high-speed transmission over wireless links. The analytical expression for the pairwise probability of the proposed space-frequency coded OFDM system is derived in slow, space- and frequency-selective fading channels. The design criteria of trellis codes used in the proposed system are then developed and discussed. It is shown that the proposed space-frequency coded OFDM can efficiently achieve the full diversity provided by the fading channel with low trellis complexity, while for traditional space-frequency coded OFDM systems, we need to design space-time trellis codes with high trellis complexity to exploit the maximum achievable diversity order. The capacity properties of space-frequency coded OFDM over multipath fading channels are also studied. Numerical results are provided to demonstrate the significant performance improvement obtained by the proposed space-frequency coded OFDM scheme, as well as the excellent outage capacity properties.

On (n, n-1) convolutional codes with low trellis complexity

We show that the state complexity profile of a convolutional code C is the same as that of the reciprocal of the dual code of C in case that minimal encoders for both codes are used. Then, we propose an optimum permutation for any given (n, n-1) binary convolutional code that will yield an equivalent code with the lowest state complexity. With this permutation, we are able to find many (n, n-1) binary convolutional codes which are better than punctured convolutional codes of the same code rate and memory size by either lower decoding complexity or better weight spectra.

The twisted squaring construction, trellis complexity, and generalized weights of BCH and QR codes

The structure of the twisted squaring construction, a generalization of the squaring construction, is studied with respect to trellis diagrams and complexity. We show that binary affine-invariant codes, which include the extended primitive BCH codes, and the extended binary quadratic-residue codes, are equivalent to twisted squaring construction codes. In particular, a recursive symmetric reversible design of the BCH codes is derived. Using these constructions, the parameters of the minimal trellis diagram of the BCH codes are determined, including the componentwise state-space profile and trellis complexity. New designs and permutations that yield low trellis complexity for the quadratic-residue codes are presented. Generalized Hamming weights are derived from these constructions. As an example, the (48, 24, 12) quadratic-residue code is analyzed, a strictly componentwise optimal permutation is derived, and the corresponding state-space profile and complete generalized Hamming weight hierarchy are obtained.

PERFORMANCE OVER 10 YEARS OF 4 APPLE CULTIVARS IN INTENSIVE ORCHARD SYSTEMS

In 1981, four apple cultivars were established as a low trellis hedgerow on 11.9 or free-standing central leaders on 11.7 at the recommended or half the recommended spacing with the close planted trees either root pruned or hedged. The trellis had a higher trunk area (TCA)/ha (31%), yield/ha (41%) and tree efficiency (19%). `Lawspur Rome Beauty' had the highest TCA/ha, cumulative yield/ha and greatest tendency toward biennial bearing of the 4 cvs. `Smoothee Golden Delicious' trees in the central leader system were less efficient (kg/cm2) than in the trellis system. Hedging increased cumulative yield/ha compared to standard spaced trees with root pruned trees intermediate. Training trees to the trellis increased the density of both spurs and shoots and resulted in a higher leaf area index. Central leader trees of `Smoothee' and `Red Chief' had higher light transmission levels than the trellis, while the trellis trees had higher light levels with `Lawspur'. Return over total cost was negative for years 1-10 for all systems. Cumulative NPV for `Redchief' hedged on central leader equaled `Lawspur' at the standard spacing on trellis and exceeded all other combinations.

The Multi-Trellis Software Architecture and the Intelligent Cardiovascular Monitor

A real-time, intelligent cardiovascular monitor is complex. It must process multiple waveforms, recognize artifacts, extract pertinent parameters, recognize a patient's clinical state, analyze the problem and formulate a response. This paper presents the multi-trellis (a collection of process trellises), a software architecture for building such a monitor. A process trellis is a uniform hierarchical framework for heterogeneous program modules. The multi-trellis extension allows one to compile several process trellis programs with widely varying run-time requirements into a single executable program that it is efficient, predictable and usable. Our prototype consists of two process trellises. The lower trellis contains processes to analyze three different analog signals: the blood pressure from a non-invasive monitor and an arterial catheter, and the ECG. The upper trellis contains processes to help detect evolving hemodynamic trends, identify abnormalities, and present a succinct summary to the clinician. Our prototype shows that the multi-trellis is a demonstrably useful software architecture for building these real-time, intelligent monitors.

PERFORMANCE OF MECHANICAL ROOT PRUNING OR HEDGING IN AN INTENSIVE ORCHARD

In 1981, four apple cultivars were established as a low trellis hedgerow on M.9 or free-standing central leaders on M.7 at the recommended or half the recommended spacing with the close planted trees either root pruned annually at bloom or hedged in August. Planting at half the spacing and annual summer hedging 2 sides decreased TCA 25% and canopy volume 51% with no effect on shoot growth, while annual root pruning decreased TCA 34%, canopy volume 50% and shoot length 25%. Planting at half spacing and either hedging or root pruning reduced yields per tree. Efficiency as measured by yield TCA was decreased by hedging and as measured by yield/m3 canopy volume was increased by both treatments with hedging having the greatest effect. The cumulative yield/ha was increased by both hedging and root pruning with no difference between them. Fruit size was decreased by close planting and root pruning caused a greater decrease than hedging. Close planting increased the number of spurs and shoots and LAI per unit volume of canopy with no difference between hedging or root pruning. `Empire' outproduced `Smoothee' and `Delicious' on the trellis and `Lawspur' had higher yields than any other cultivar in the central leader.

Effects of Defoliation, Trellis Height, and Cropping Stress on the Cold Hardiness of Concord Grapevines

The cold hardiness of bark and compound buds of culturally stressed <i>Vitis labruscana</i> Bailey 9Concord9 grapevines was investigated in southwestern Michigan. Defoliation, pruning severity, and cluster thinning influenced cane and bud hardiness. The effect of trellis height on cane hardiness was inconclusive, though some increased hardiness was noted for low trellis buds. Complete defoliation by hand in August delayed acclimation in the fall and gave more rapid deacclimation in the spring. Effects of defoliation on cane and bud hardiness were more pronounced during the second year of treatment. Pruning severity was the most important factor influencing cane and bud hardiness in undefoliated plants. Field observations emphasized the importance to greater hardiness of balanced pruning at 30 + 10 severity as opposed to (60 + 10) pruning. Cluster thinning increased hardiness levels that had been depressed by 60 + 10 pruning, particularly when vines were defoliated. The greater sensitivity of underpruned vines seemed to be a result of the overproduction of fruit. With most treatments, the tertiary bud was as hardy as the secondary bud, or slightly hardier.

Effects of Defoliation, Trellis Height, and Cropping Stress on the Cold Hardiness of Concord Grapevines

The cold hardiness of bark and compound buds of culturally stressed <i>Vitis labruscana</i> Bailey 9Concord9 grapevines was investigated in southwestern Michigan. Defoliation, pruning severity, and cluster thinning influenced cane and bud hardiness. The effect of trellis height on cane hardiness was inconclusive, though some increased hardiness was noted for low trellis buds. Complete defoliation by hand in August delayed acclimation in the fall and gave more rapid deacclimation in the spring. Effects of defoliation on cane and bud hardiness were more pronounced during the second year of treatment. Pruning severity was the most important factor influencing cane and bud hardiness in undefoliated plants. Field observations emphasized the importance to greater hardiness of balanced pruning at 30 + 10 severity as opposed to (60 + 10) pruning. Cluster thinning increased hardiness levels that had been depressed by 60 + 10 pruning, particularly when vines were defoliated. The greater sensitivity of underpruned vines seemed to be a result of the overproduction of fruit. With most treatments, the tertiary bud was as hardy as the secondary bud, or slightly hardier.