Vase Form Research Articles

Universal method for holographic grating recording: multimode deformable mirrors generating Clebsch–Zernike polynomials

Recording methods for making aberration-corrected holographic gratings are greatly simplified by use of a plane multimode deformable mirror (MDM) upon one of the two recording beams. It is shown that MDM compensators easily provide the superposition of many interesting active optics modes, which we have named Clebsch-Zernike modes. When we apply only a uniform loading or no loading at all onto the rear side of the MDM clear aperture, the available Clebsch-Zernike modes are made to belong to a subclass of the Zernike modes that includes the three modes of the third-order aberration theory as well as a well-defined part of the Zernike higher-order modes. Such a recording method is considered to be universal, since it does not require the use of a sophisticated optical system such as a compensator. Active optics 12-arm MDM's in the vase form have been designed from the elasticity theory. The design of six-arm MDM's is currently carried out with theoretical results. As an example of the method, the recording of three holographic gratings of the Hubble Space Telescope Cosmic Origins Spectrograph has been investigated. Substantial improvements in image quality have been found by use of a six-arm MDM as recording compensator. The result is that aberrations of much higher order can simultaneously be corrected so that the residual blur images of the spectra occupy areas approximately 10 (direction of dispersion) x 3 (cross dispersion) = 30 times smaller--also in terms of pixel number--than those obtained by our American colleagues. Therefore the active optics recording method appears to provide substantial gains in resolving power and in sensitivity: (i) For all three gratings the spectral resolution would be increased by a factor of 10, and (ii), in addition, for the two higher dispersion gratings, the limiting magnitude on the sky appears to be increased by a magnitude of approximately 1-1.2.

Tree Structure and Pruning Response of Six Peach Growth Forms

The response of young, nonbearing peach [Prunus persica (L.) Batsch] trees to pruning was studied in six distinct growth forms including semidwarf, spur-type, upright, columnar or pillar, weeping, and standard. Two years after field planting, pillar and upright trees were trained to slender spindle. Semidwarf, spur-type, and standard trees were trained to the open or delayed vase form. Weeping trees were pruned in a manner similar to the Lepage hedge for pear. Branch density before pruning was highest in semidwarf, spur-type, and upright trees and lowest in pillar trees. Standard, semidwarf, and spur-type trees reacted similarly to pruning, but semidwarf trees produced as much wood in the following season as had been pruned off, and produced large numbers of fruiting branches. The small size of semidwarf trees suggested their use for medium-density plantings (MDPs). Pillar trees needed only light pruning. No major cuts were necessary and many fruiting branches were produced even on nonpruned trees. The pillar canopy was 60% thinner and required 50% fewer pruning cuts than the standard canopy and may be particularly suited to high-density plantings (HDPs). The upper canopy of weeping trees grew more than most other forms. They were intermediate in branch density and required an intermediate amount of pruning. Most striking was the unique canopy form of weeping trees, which may be used in developing new training systems. The results of this study suggest that new growth forms have the potential to reduce pruning and training requirements for peach, particularly in MDPs and HDPs. This potential suggests further investigation and exploitation of alternate peach tree growth forms.

省力栽培を前提として果樹の樹形 ＶＩＩＩ 樹形を異にするナシ園の草刈りについて

Comparison of mowing by a rotary cutter mounted to a tractor and by a walking type hammer knife mower was carried out in three tree forms that were the hedgerow and the Y form, both forms aimed for easy tractor operation, and the vase form, a common practice.The tractor ran parallel to tree rows in the hedgerow and the Y form, making turns on head lands adjacent to tree rows.In the vase form, it ran back and forth between tree rows, making turns within the orchard. It also backed to mow grass as close as possible to pillars, stay wires and tree trunks.The walking type hammer knife mower ran parallel to tree rows in all the tree forms; In case of the hedgerow and the Y form, it made turns on the head land, while in the vase form, it made turns within the orchard and weaved to dodge the tree trunks.When mowing was done by a rotary cutter mounted to a tractor, operation hours in the hedgerow and the Y form were respectively 41% and 33% of that in the vase form.On the other hand, when mowing was done by a walking type hammer knife mower, operation hours in the hedgerow and the Y form were somewhat shorter than in the vase form. but the difference was small.This was due to the small difference in time required for the straight drive which accounted to about 90% in all three tree forms.When mowed by a rotary cutter mounted to a tractor, land left unmowed was about double of that mowed by a walking type hammer knife mower, owing to 1) the difficulty for the rotary cutter to mow close to tree trunks, pillars and stay wires of the trellis, and to 2) the unnecessarily wide overlapping of mowing path between tree rows.Land left unmowed can be reduced by 1) closer operation of the cutter to trees through proper management of shoots in the hedgerow and pulling up the trellis by wires in the Y form, 2) reduction of overlapping of mowing path to the minimum required.Operation hours can be reduced by using herbicides near tree trunks, pillars and stay wires.In the vase form, mowing by a hammer knife mower was more labour saving than mowing by a rotary cutter mounted to a tractor. In the Y form and the hedgerow (the new tree forms), mowing by a rotary cutter mounted to a tractor was more labour saving than mowing by a hammer knife mower.It is apparant that labor efficiency is about 1.5-1.8 times better when a rotary cutter mounted to a tractor is used in the new tree forms compared to when a hammer knife mower is used in the vase form.

省力栽培を前提とした果樹の樹形 ＶＩＩ 樹形を異にするナシの年間栽培労力

Annual working hours in Japanese pear orchards were compared between two training systems designed for easier tractor operation and one common training system. They were the Y form training, the hedgerow training and the vase form training.Annual working hours were somewhat less in the Y form training and the hedgerow training than in the vase form training.However, the difference was not as large as expected. The main cause of this small difference owing to 1) scanty tractor operation in all three training systems and 2) limitations in machine operations in the hedgerow due to the situation of the hedgerow, i. e. the northern side of the northernmost row had to be mowed by hand and spraying for pest control had to be done over a fence from a road outside the orchard.In the year 1984, total working hours per 10a were, about 243 hours in the vase form, about 224 hours in the Y form, about 250 hours in the hedgerow, with the Y form being somewhat labour saving. All three training systems experimented in our orchard required less working hours compared to statistical data on Japanese pear growing farmlands.However, total working hours per yield were the same as the statistical data for the vase form, but about 20% higher for the hedgerow and about 110% higher for the Y form.The reason why working hours per yield were higher in the hedgerow were that 1) it required more fertillizer due to dense plantation, 2) more mowing and pest control than the vase form and Y form due to the situation of the orchard. The reason why working hours per yield was higher in the Y form was that the yield was lower due to the aftermath of the typhoons in 1982, as mentioned in a previous report3).In the year 1985, total working hours per 10a were, about 216, 172, and 194 hours for vase form, Y form, and hedgerow respectively. That in the latter two were somewhat shorter than in the vase form.Working hours in all three systems were about 80% of statistical data.However, total workig hours per yield were, about 108 hours per ton for vase form and Y form, about 80% of the statistical data. Total working hours per yield were about 85 hours/t for the hedgerow, less than 80% of vase form and Y form, about 60% of statistical data, showing that Y form and hedgerow would be largely labour saving if yield of 2 tons per 10a is maintained.In Y form and hedgerow, trees of proper vigour could produce higher yield than trees of vase form constantly with less working hours.For the pursuit of higher yield and labour saving training systems, investigation of not only plant physiological and ecological aspects, but detailed research on working hours of work such as soil management, spraying, harvesting, etc. are also required. Detailed investigation on working hours of Japanese pear culture in the three training systems are in progress and will be reported in the near future.

省力栽培を前提とした果樹の樹形 ＶＩ 樹形を異にするナシの生育および収量

In Japan, Japanese pears are usually planted in either pergolas or vase form training. However, in these orchards, there are some difficulties in operating tractors, as the authors have reported in a previous paper. We have proposed a Y form training, suitable for tractor operation. The hedgerow training is also suitable for tractor operation. In order to prove the superiority of the latter two training systems, Japanese pears “Kousui” were planted in vase form, Y form, and hedgerow trainings, and working hours were recorded on each working process.Here we report the growth and yield of the trees, before reporting the working hours in order to present a better understanding of the trees used to compare the working hours.The increase of tree girth in the Y form and the hedgerow were about 2/3 of that in the vase form.The yield per 10a in the Y form was about the same or higher than that in the vase form.The yield per 10a in the hedgerow was over 3 times the yield in the vase form during the early stage (3-5 years after plantation), but gradually decreased (6-8 years after plantation) to about the same as that in the vase form. However, when the yield in the early stage was controlled to match the vigour of the tree, the yield could be maintained at a higher rate than in the vase form.

Tree Forms for Labor Saving Farm Work

Annual working hours in Japanese pear orchards were compared between two training systems designed for easier tractor operation and one common training system. They were the Y form training, the hedgerow training and the vase form training.Annual working hours were somewhat less in the Y form training and the hedgerow training than in the vase form training.However, the difference was not as large as expected. The main cause of this small difference owing to 1) scanty tractor operation in all three training systems and 2) limitations in machine operations in the hedgerow due to the situation of the hedgerow, i. e. the northern side of the northernmost row had to be mowed by hand and spraying for pest control had to be done over a fence from a road outside the orchard.In the year 1984, total working hours per 10a were, about 243 hours in the vase form, about 224 hours in the Y form, about 250 hours in the hedgerow, with the Y form being somewhat labour saving. All three training systems experimented in our orchard required less working hours compared to statistical data on Japanese pear growing farmlands.However, total working hours per yield were the same as the statistical data for the vase form, but about 20% higher for the hedgerow and about 110% higher for the Y form.The reason why working hours per yield were higher in the hedgerow were that 1) it required more fertillizer due to dense plantation, 2) more mowing and pest control than the vase form and Y form due to the situation of the orchard. The reason why working hours per yield was higher in the Y form was that the yield was lower due to the aftermath of the typhoons in 1982, as mentioned in a previous report3).In the year 1985, total working hours per 10a were, about 216, 172, and 194 hours for vase form, Y form, and hedgerow respectively. That in the latter two were somewhat shorter than in the vase form.Working hours in all three systems were about 80% of statistical data.However, total workig hours per yield were, about 108 hours per ton for vase form and Y form, about 80% of the statistical data. Total working hours per yield were about 85 hours/t for the hedgerow, less than 80% of vase form and Y form, about 60% of statistical data, showing that Y form and hedgerow would be largely labour saving if yield of 2 tons per 10a is maintained.In Y form and hedgerow, trees of proper vigour could produce higher yield than trees of vase form constantly with less working hours.For the pursuit of higher yield and labour saving training systems, investigation of not only plant physiological and ecological aspects, but detailed research on working hours of work such as soil management, spraying, harvesting, etc. are also required. Detailed investigation on working hours of Japanese pear culture in the three training systems are in progress and will be reported in the near future.