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No período de 1990 – 2000 ocorreram modificações no setor produtivo de hortaliças da Grande La Plata, Argentina a partir da adoção de cultivo protegido e de um conjunto de tecnologías complementares. O grau de incorporação destas novas tecnologías e seu êxito produtivocomercial tem sido heterogêneo conforme o tipo de produtor e suas posibilidades de adaptação a estas mudanças. A hipótese é que aqueles produtores que adotaram novos pacotes tecnológicos com êxito, desenvolvendo um perfil empresarial mais nítido, tem contado com o apoio técnico de um profissional. O objetivo buscado neste trabalho é conhecer a heterogeneidade quanto ao manejo tecnológico-comercial das unidades produtivas hortícolas e a incidência do assessoramento técnico dentro delas. Durante os meses de fevereiro a maio de 2004 se realizaram 30 sondagens a horticultores em tres zonas representativas do Cinturão Hortícola de La Plata. Se determinaram 10 variáveis (4 próprias do produtor e 6 referidas a produção-comercialização) que foram submetidas a técnicas multivariantes e bivariantes de ordenamento e classificação. Se identificaram tres grandes grupos de unidades produtivas hortícolas em função das tecnologías utilizadas, das formas de acesso ao conhecimento técnico e dos canais de comercialização utilizados. Não se encontrou vinculação entre as variáveis próprias do produtor e o manejo técnicocomercial da unidade produtiva. Conclui-se que os assessores técnicos tem influído favoravelmente na adequação dos novos modelos tecnológicos, com maior preponderância em estabelecimentos empresariais.

Approximately 100 000 tomato plants under greenhouse cultivation in New South Wales were surveyed in June 2001 for Potato spindle tuber viroid (PSTVd). Bioassay, electrophoresis and molecular analysis confirmed the presence of PSTVd in two plants on a single property. A successful eradication plan was undertaken.

It has been believed in eggplants cultivation that the lusterless (Tsuyanashi) fruit is produced by the soil water shortage. But it seems that the reasoning has failed to satisfy all of the observations on the growth condition of eggplants at the farm.In this study author examined the loss of luster or reddish brown coloring on the skin in relation to the growth factors, i.e. greenhouse temperature, soil moisture, plant training, and concentration of the fruiting regulator hormone.The study highlighted the higher day and night greenhouse temperature as the major factor in the production of the lusterless fruits, and the soil moisture shortage was supporting the process. The following mutual interactions between the factors were also contributing to increase the lusterless fruits production, i.e. 1) temperature and soil moisture, 2) temperature and plant training, and 3) temperature, soil moisture and plant training. More amount of fruits lost luster by the longer aging on the fruit after the flowering. Furthermore the poor soil moisture and the lean concentration of the fruiting regulator hormone increased the size of lusterless area on a fruit.On the other hand, the reddish brown coloring of the fruit was caused by the poor plant training which led over growth and luxuriant branch development of the plant.

An experiment was conducted to evaluate the effects of air ion treatment on tomato plants (Lycopersicon esculentum P. Miller) in terms of: (1) growth and health; (2) fruit yield and quality; and (3) economic factors. The plants were grown by a commercial greenhouse (G.H.) grower employing soilless culture techniques. An air ion generator and emitters were installed in such fashion that 864 plants were exposed to a high negative air ion density flux, while 576 plants grew in an area which received relatively few ions. Normal operational procedures, with certain modifications, were employed for plant culture, feed/irrigation, and environmental control.

厩肥の連続施用 (5t, 50t/10a) 下で4作, 次いで無施用で2作トマトを栽培し, 土壌の物理性の変化について調査した.厩肥施用によって固相率の低下と気相率の上昇がみられ, また50t施用区では5t施用区に比較して, 気相率, 液相率が高く, 固相率が低かった.土層は厩肥施用量に応じて厚くなった.厩肥50t施用は, 大団粒割合を増加させたが, 5t施用ではその割合が低下した.第1層の硬度は, 厩肥5t施用区で変化しなかったが, 50t施用区で低下した.第2層では, 両区とも増加したが, 増加の割合は5t施用区で顕著であった.50t施用区の透水性は, 第1層で作付回数とともに上昇したが, 第2層ではやや低下した.一方, 5t施用区の第1層では, 第3作まで上昇した後急激に低下し, 第2層では第3作まで急激に低下したのちほぼ一定となった.第6作後の第1層における最大容水量は, 原土に対し50t区で14.6%, 5t区で3%増加した.また, pF0.0～1.7およびpF3.0以上の水分量は, 50t施用区で多く, pF1.7～3.0の水分量は両区でほぼ同じであった.以上の結果から, 10a当り5t程度の厩肥施用は土壌の物理性の改良にほとんど効果がないが, 50t施用では顕著であることが示唆される.

In recent years, energy saving in greenhouse cultivation has been an objective of many researches. One of measures for energy saving is an accurate control of a room temperature to avoid excessive heating. To achieve such an accurate control with small heaters used in greenhouses, it is necessary to repeat firing and extinguishing with short time intervals.It has been said that the heat efficiency of the hot water boiler drops with the decrease of the heating load factor due to the increase of the heat loss from the boiler surface. Little is known, however, on the effect of the frequency of the intermittent firing on the heat efficiency, or on the difference of the heat efficiencies between intermittent firing and continuous firing. The objective of this study is to evaluate the heat efficiency at the intermittent firing.First of all, we evaluated the heat loss caused by the unburned carbon particles, carbonhydrates and imperfect combustion at the start and end of burning and results were compared with those at the continuous combustion. The measurements showed that the unburned carbon particles appeared only at the start of firing and the period of the appearance was less than 1 second. This means that the effect of unburned carbon particles on the heat loss is negligibly small, if the heater burns for more than 1 minute. The heat loss due to unburned carbonhydrates and imperfect combustion which was estimated from their maximum concentrations during combustion was less than 0.5% and was also negligibly small, if the heater burns at the appropriate air ratio. These results show that firing or extinguishing brings about only a negligible heat loss.After long period of the intermittent firing had been conducted, the heat efficiency at the continuous combustion dropped only 4-5% from the initial value for a type of the hot-air heater easily accumulating soot. It dropped less than 1% from the initial value for a type of the hot-air heater hardly accumulating soot. These results show that the effect of long term intermittent firing on the heat efficiency is less than the value so far estimated without measurements. One of the reasons of this phenomena may be that most part of the heat generated by the heater is exchanged on the surface of the combustion chamber where the soot accumulates hardly.

Seedlings of Quercus rubra were cultivated outdoors and in a polyethylene-covered greenhouse. Their development over the first growing season was monitored and compared, taking into consideration factors such as the time of sowing (fall or spring). Height, root-collar diameter, and oven-dry mass of tops and roots were significantly greater in greenhouse-cultivated seelings. However, the differences were reduced when the seedlings were sown later in the spring. Analysis of top-root ratios showed that the balance of seedlings was not affected by greenhouse cultivation. The results of this study the rapid growth of the seedlings produced in. the greenhouse lead us to reconsider our current production standards. Key words: Grading criteria, greenhouse production, morphological quality, nursery stock. Quercus rubra, seedling production.

Measurements of leaf thickness and δ13C value were obtained for twenty species and three intergeneric hybrids of the Crassulaceae. The data include plants growing in their native habitats and also in greenhouse cultivation. There is a strong relationship between leaf thickness and leaf δ13C values. The plants with the thickest leaves of ca. 7 to 11 mm had δ13C values ranging from -11.5‰ to -13.8‰. Plants with leaves that were thinner than 2.0 mm all had δ13C values that were more negative than -23‰. Plants having intermediate leaf thickness possessed intermediate δ13C values. The leaf tissue of four genotypes spanning the range of leaf thicknesses all exhibited a two-fold or greater nocturnal increase in titratable acidity. It appears that the differences in leaf thickness and δ13C values among the tested species are genetically determined.

ÖZET Sonbahar sera hıyar yetiştiriciliğine uygun çeşit seçimi amacı ile 1983 ve 1984 Sonbaharında Antalya Maram Fı, Minibar (KO728) Fı, Hylares Fı çeşitleri ile dört tekerrürlü olarak tesadüf bloklara deneme desenine göre yapılan denemelerde Maram Fı çeşidi diğerlerine nazaran daha iyi sonuçlar vermiştir. Bu nedenle Sonbahar sera hıyar yetiştiriciliğinde Maram Fı çeşidi üreticilere tavsiye edilir. SELECTIG A CUCMBER VARIETY FOR GLASSHOUSE PRODUCTION IN AUTUMN Astudy was carried out in Antalya in autumn 1983 and 1984 with three cucumber varieties, Maram Fı, Minibar (KO728) Fı and Hlares Fı, as four replicates according to the randomized bloke design in order to select the variety that is the most suiteble for glasahouse cucumber production in autumn. As a result Maram variety proved to be the best whwn compared wtih other varieties so, Maram Fı can be recomended to the producers who wish grov cucumbers under glasss in autumn. 25

A survey is presented of the literature on greenhouse climate control, positioning the various solutions and paradigms in the framework of optimal control. A separation of timescales allows the separation of the economic optimal control problem of greenhouse cultivation into an off-line problem at the tactical level, and an on-line problem at the operational level. This paradigm is used to classify the literature into three categories: focus on operational control, focus on the tactical level, and truly integrated control. Integrated optimal control warrants the best economical result, and provides a systematic way to design control systems for the innovative greenhouses of the future. Research issues and perspectives are listed as well.

In production of Satsuma mandarin (Citrus unshiu Marc.) grown on greenhouse cultivation, management of day and night temperature and soil water content is important to improve yield and quality of the fruits. In this study, in order to optimize greenhouse environment for Satsuma mandarin production, we conducted dynamic analysis of effects of soil water content, day temperature and night temperatures on fruit growth and mass accumulation through phloem and xylem into a fruit.

収穫直前に発生するトマト果実の裂果について発生要因を探るため,埼玉県滑川町の農業生産法人において3年間の果実収量,裂果率,および当該地域の気象条件を踏まえ,温室内における気象条件の推移と裂果発生との関係について調査検討した。トマト果実の裂果は,例年4月から6月に発生頻度が高くなるが,温室内の気温および湿度が大きく変動する時期であり,1日における,気温および湿度も日ごとに大きく変動する。これら日中の気温および湿度から飽差を算出し裂果発生との関係について検討した結果,日毎の飽差の差と裂果発生との間には正の相関がみられた。このことから,裂果の発生には,飽差の変動が関与している可能性が示唆された。, Fruit cracking occurring just before harvesting is one of the most delicate problems in tomato greenhouse cultivation. In this study we investigated the relationship between fruit cracking and meteorological factors in the greenhouse. As a result, it was suggested that the sharp fluctuations of temperature and humidity of the greenhouse were closely associated with fruit cracking. In particular the vapor pressure of deficit (VPD) in the greenhouse calculated from value of temperature and humidity was indicated to have a significant correlation with fruit cracking. Therefore the control of VPD can be a possible countermeasure to suppress Tomato fruit cracking.