Sustainable Irrigation Management of Ornamental Cordyline Fruticosa “Red Edge” Plants with Saline Water

The aim of this work was to analyze the influence of the salinity of the nutrient solution on the transpiration and growth of Cordyline fruticosa var. “Red Edge” plants. A specific irrigation management model was calibrated with the experimental data. An experiment was performed with four treatments. These treatments consisted of the application of four nutrient solutions with different electrical conductivity (ECw) levels ranging from 1.5 dS m−1 (control treatment) to 4.5 dS m−1. The results showed that day-time transpiration decreases when salt concentration in the nutrient solution increases. The transpiration of the plant in the control treatment was modelled by applying a combination method while the effect of the salinity of the nutrient solution was modelled by deriving a saline stress coefficient from the experimental data. The results showed that significant reductions in plant transpiration were observed for increasing values of ECw. The crop development and yield were also affected by the increasing salinity of the nutrient solution. A relationship between the ECw and the relative crop yield was derived

Model Simulation of Cucumber Yield and Microclimate Analysis in a Semi-closed Greenhouse in China

Adequate greenhouse environmental management is very important for improving resource use efficiency and increasing vegetable yield. The objective of this study was to explore suitable climate and cultivation management for cucumber to achieve high yield and build optimal yield models in semi-closed greenhouses. A fruit cucumber cultivar Deltastar was grown over 4 years in greenhouse and weekly data of yields (mean, highest and lowest) and environmental variables, including total radiation, air temperature, relative humidity, and carbon dioxide (CO2) concentration were collected. Regression analyses were applied to develop the relationships and build best regression models of yields with environmental variables using the first 2 years of data. Data collected in years 3 and 4 were used for model validation. Results showed that total radiation, nutrient, temperature, CO2 concentration, and average nighttime relative humidity had significant correlations with cucumber yields. The best regression models fit the mean, lowest, and highest yields very well with R2 values of 0.67, 0.66, and 0.64, respectively. Total radiation and air temperature had the most significant contributions to the variations of the yields. Our results of this study provide useful information for improving greenhouse climate management and yield forecast in semi-closed greenhouses

원적색광이 추가된 군락 내 보광 하에서 재배한 온실 착색단고추의 생육, 수확량 및 과실 품질

학위논문(박사) -- 서울대학교대학원 : 농업생명과학대학 농림생물자원학부, 2022. 8. 손정익.Far-red light (FR, 700-750 nm) has been used as a supplemental light source for horticultural crops due to its physiological activity related to phytochrome-mediated responses, called ‘Shade avoidance response (SAR).’ Interlighting is a method of supplemental lighting that has directly compensated for the lack of light in the middle and lower canopies. This study analyzed the effect of interlighting with an additional FR on photosynthesis, yield, and fruit qualities in sweet peppers. In the winter and summer period, three light treatments were treated: natural light (NL), red-blue interlighting (RB), and adding far-red with RB (RBFR). The RBFR was set to adding 55 µmol m-2 s-1 of FR to 71 µmol m-2 s-1 of RB (red: blue = 8:2). Daily light integral of NL in winter and summer was 16.6 and 32.2 mol m-2 d-1, which was about twice as high in summer. The shoot dry weight and fruit yields of RBFR were 20% and 17% higher than those in RB in winter, but no significant differences in growth, yield, and morphology were observed in summer. Therefore, the interlighting RB or RBFR did not show any yield increase in the summer of sufficient background light. To examine the adequate FR dose under the RB background, five FR light doses were treated (0, 20, 40, 60, and 80 µmol m-2 s-1: FR 0, FR 20, FR 40, FR 60, and FR 80) in winter season. Adding FR to RB increased the total shoot dry mass and the highest under FR 60 of intensity. The three-dimensional simulation revealed that supplemented far-red increased total assimilation due to light-favored morphology. However, FR accelerated the leaf senescence with a faster decrease in photosynthetic capacity of Vcmax, and Jmax, and reducing the total assimilation increment from morphological acclimation. FR 60 also showed a faster yield increase due to accelerated reproductive structure at the initial growth stage. Higher R: FR of solely RB interlighting may be less effective in increasing yield, leading to inefficient responses such as late reproductive development and higher biomass allocation to leaves. Adding FR increased yield from a small dose of FR 20 to FR 80, but saturated at 60 µmol m-2 s-1 of FR intensity. In addition to yield, fruit quality attributes such as soluble sugar, ascorbic acid, and carotenoid contents were analyzed in two sweet pepper varieties of red and yellow fruits in the winter season. Adding FR had increased yield and individual fruit size, but TSS showed no significant difference by FR. In carotenoids, RB and RBFR were higher than those under NL, but the increment under RBFR was lessened in red and yellow fruits by 24% and 18% than under RB, respectively. Additional FR lighting may have a trade-off relationship between fruit yield and carotenoid content. This study is meaningful in that the overall effect of adding far-red to red-blue interlighting was evaluated in greenhouses, and the results will help derive an optimal growth of sweet pepper by precisely controlling the lighting spectrum.원적색광(Far-red, FR, 700-750 nm)은 '음지 회피 반응(Shade avoidance response)' 이라는 피토크롬이 매개하는 다양한 생리적 활성에 관여하고 있기 때문에 원예작물 보광에 추가되고 있다. 수관 내부 보광(Interlighting)은 중단 및 하단부 작물 수관에 의 광 부족을 보완하기 위한 조명 방법이다. 본 연구에서는 착색단고추의 광합성, 수확량 및 과일 품질에 대해 FR이 추가된 수관 내부 보광의 효과를 분석했다. 먼저, 겨울과 여름 기간에 자연광, 적색-청색 수관 내부 보광(RB) 및 RB에 FR을 추가한(RBFR)의 3가지 광 처리를 매일 12시간의 광 주기로 처리했다. 겨울과 여름의 일적산광(DLI)은 16.6과 32.2 mol m-2 s-1로 여름에 약 2배 높았다. RBFR에서는 겨울의 RB보다 작물의 건물중과 과실수량이 20%, 17% 높았으나 여름에는 생육, 수확량 및 형태형성에 유의한 차이가 관찰되지 않았다. RB보광 하에서 FR의 적절한 선량을 조절하기 위해 100 µmol m-2 s-1의 RB 하에서 5가지 FR 조건 (0, 20, 40, 60, 80 µmol m-2 s-1: FR 0, FR 20, FR 40, FR 60, FR 80)에 대하여 그 효과를 분석하였다. 겨울 작기에 RB에 FR을 추가하면 FR 60 조건에서 가장 큰 총 건물중의 증가를 보였다. 시뮬레이션 결과는 건물증 증가가 개선된 광형태형성으로 인한 것임을 보여주었다. 그러나 FR은 잎 노화를 가속화하고 Vcmax와 Jmax의 광합성 능력의 더 빠른 감소를 가져와 형태적 순응으로 인한 총 동화 증가를 감소시켰다. 그 외에도 높은 FR 광도는 초기 생육 단계에서 가속화된 생식생장 구조로 인해 더 빠른 수확량 증가에 기여하였다. 단독 RB 수관 내부 보광의 더 높은 R: FR 비율은 수확량 증가에 덜 효과적일 수 있으며, 이는 늦은 생식생장 진행 및 잎에 바이오매스 할당을 높게 분배하는 등의 수확량에 비효율적인 생리 반응과 연계될 수 있다. FR을 추가하면 FR 20의 소량부터 FR 80까지 모두 수확량 증가에 기여했지만 이 효과는 60 µmol m-2 s-1 세기에서 포화되었다. 겨울 작기에 대한 결과를 중심으로, 적색과 노란색 두 가지 착색단고추 품종에서 과실 수확량, 유리당, 아스코르브산, 카로테노이드 함량 등의 과실 품질을 분석하였다. FR을 추가하면 전체 수확량과 개별 과일 크기가 개선되었으나, TSS는 FR에 의해 유의한 차이를 나타내지 않았다. RB와 RBFR의 카로테노이드 함량은 자연광에서 보다 전반적으로 개선되었지만 RBFR에서의 카로테노이드 증분은 RB보다 적색 및 노란색 품종에서 각각 24%와 18% 감소하였다. 따라서 추가 FR 보광은 과일 수확량과 카로테노이드 함량 사이에 상충 관계가 있을 수 있다. 본 연구는 원적색광을 적색-청색 보광에 추가했을 때의 전체적인 효과를 온실에서 평가하였다는 점에서 의의가 있으며, 본 연구결과는 군락 내 보광 스펙트럼을 정밀하게 제어함으로써 착색단고추의 최적 생육을 위한 광 환경을 도출하는데 도움이 될 것이다.ABSTRACT i CONTENTS iv LIST OF TABLES vii LIST OF FIGURES viii GENERAL INTRODUCTION 1 LITERATURE REVIEW 4 Plant response to far-red radiation Application of far-red light in horticulture Supplemental inter or intra-canopy lighting Growing sweet pepper in a greenhouse LITERATURE CITED 8 Chapter 1 15 ABSTRACT 15 INTRODUCTION 17 MATERIALS AND METHODS 20 RESULTS 28 DISCUSSION 37 CONCLUSIONS 45 LITERATURE CITED 46 Chapter 2 55 ABSTRACT 55 INTRODUCTION 57 MATERIALS AND METHODS 61 RESULTS 76 DISCUSSION 89 CONCLUSIONS 98 LITERATURE CITED 99 Chapter 3 107 ABSTRACT 107 INTRODUCTION 109 MATERIALS AND METHODS 112 RESULTS 122 DISCUSSION 133 CONCLUSIONS 141 LITERATURE CITED 142 GENERAL DISCUSSION 148 LITERATURE CITED 152 GENERAL CONCLUSIONS 155 ABSTRACT IN KOREAN 156 APPENDIX 158박

Crop response of greenhouse soil-grown cucumber to total available N in a Nitrate Vulnerable Zone

Intensive vegetable production in soil is commonly associated with low N use efficiency (NUE) and consequently appreciable N losses that have negative environmental impacts. Improved N management practices for intensive vegetable crops require detailed knowledge of crop response to N supply. This study evaluated the effects of increasing total available N (TAN, i.e. the sum of soil mineral N at planting, N mineralized from organic matter, and mineral fertilizer N applied by fertigation) on cucumber grown in soil in a greenhouse. Parameters assessed were: yield, dry matter production (DMP), crop N uptake, nitrogen use efficiency (NUE) and potential NO3− leaching loss. The study was conducted in three growing seasons, in autumn, spring and late spring. Three commercial cultivars were examined, in the Late Spring crop, to assess possible cultivar differences. Five N treatments were applied, in the Autumn and Spring crops, as different N concentrations in nutrient solution that were applied in all irrigations throughout the crops. The applied N concentrations were N1: 0.7–1.0 mmol L-1, N2: 4.7–5.7 mmol L-1, N3: 12.1–13.8 mmol L-1, N4: 16.3–17.6 mmol L-1 and N5: 19.7–21.1 mmol L-1. The cultivar ´Strategos´ was used in both crops. Three N treatments (N1: 2.4 mmol L-1; N2: 8.5 mmol L-1and N3: 14.8 mmol L-1) were continuously applied throughout the Late Spring crop to three different cultivars (´Strategos´, ´Padrera´, and ´Mitre´). Total and marketable yield, relative to maximum value, and DMP were strongly related to TAN in linear-plateau relationships for the three growing seasons and three cultivars. Using relationships that include data from the three cropping seasons and the three cultivars, TAN values for maximum DMP, total yield, and marketable yield were 222 ± 15 kg ha−1, 221 ± 14 kg ha−1 and 228 ± 15 kg ha−1, respectively, for the Autumn, Spring and Late Spring crops. The relationships of crop N uptake to TAN, and DMP to crop N uptake, were described by a logarithmic equation. The relationship of N uptake efficiency to TAN (i.e. N uptake/TAN) was described by an exponential decay equation. Considering all crops and cultivars, these relationships were described by individual equations with R2 values of 0.75-0.96. The consistency of these relationships indicate that there are general responses of greenhouse-grown cucumber to N, which is not affected by growing season or cultivar. Measured NO3− leaching losses were low because of good irrigation management. Residual mineral N was considered to be indicative of the potential NO3− leaching loss; residual soil mineral N increased exponentially with TAN, being 196 and 330 kg N ha−1 for the highest N treatments in the Autumn and Spring crops, respectively. The information provided by this study will enable the total N supply (TAN) to be matched to cucumber crop N requirements thereby reducing excessive N supply and consequent negative environmental impacts

Manipulating Light Quality, Light Intensity, and Carbon Dioxide Concentration to Optimize Indoor and Greenhouse Production of Annual Bedding Plant Seedlings

Annual bedding plant seedlings (plugs) are commonly produced in northern latitudes during the late winter and early spring when the natural daily light integral (DLI) in greenhouses is below recommended levels. Greenhouse supplemental lighting (SL) provides a means of increasing the DLI, with high-pressure sodium (HPS) lamps representing the current industry standard. However, low-profile and high-intensity light-emitting diode (LED) fixtures have recently emerged as a possible alternative for greenhouse SL. Additionally, due to the emission of very little radiant heat, LEDs may be used for sole-source lighting (SSL) applications where plants are produced on vertical shelving units in warehouses or shipping containers and in close proximity to the fixtures. Thus, with the development of LEDs for horticultural applications, the possibility of producing seedlings indoors using multi-layered, vertical production systems has become an increasingly realistic possibility. Therefore, the objectives of this research were to 1) compare HPS and LED SL sources in a commercial greenhouse for the propagation and finishing of annual bedding plant seedlings (Expt. 1); 2) evaluate the effects of various LED light qualities and intensities in a SSL environment on the morphology, nutrient uptake, and subsequent flowering of coreopsis (Coreopsis grandiflora ‘Sunfire’), pansy (Viola ×wittrockiana ‘MatrixTM Yellow’), and petunia (Petunia ×hybrida ‘Purple Wave’) seedlings (Expt. 2); and 3) determine the morphological and physiological responses of petunia ‘Dreams Midnight’ seedlings to the interactive effect of light intensity, light quality, and carbon dioxide (CO2) concentration under LED SSL (Expt. 3). In Expt. 1, both seedlings and finished plants produced under LED and HPS SL were comparable in quality, while seedlings produced under no SL were of significantly lower quality. In Expt. 2, light intensity was the dominant factor in determining seedling quality, with higher light intensities generally leading to seedlings that were more compact with greater dry mass accumulation. The inclusion of far-red wavelengths during propagation was also found to reduce the time to flower for pansy ‘MatrixTM Yellow’. In Expt. 3, petunia ‘Dreams Midnight’ seedlings grown under LED SSL with a red:blue light ratio (%) of 90:10 and light intensity of 300 μmol·m–2·s–1 had greater dry mass accumulation and leaf area (LA) than those under the light ratio of 50:50 at the same light intensity. However, seedlings produced under a light ratio of 50:50 and light intensity of 300 μmol·m–2·s–1 displayed the highest Rubisco efficiency (), photosynthesis at operating Ci concentration (AOP), electron transport rate (ETR), and maximum net photosynthetic rate (An,max). A trend of increased dry mass accumulation and decreased for seedlings produced at a CO2 concentration of 900 μmol·mol-1 was also observed compared to 450 μmol·mol–1. From results obtained in a commercial greenhouse, low-profile LEDs for greenhouse SL may be used as an alternative to traditional HPS lamps. However, the possibility of spectral manipulation in a greenhouse environment for desired growth responses appears to be limited when the relative contribution of SL from LEDs to DLI is low. For SSL production, while petunia ‘Dreams Midnight’ seedlings showed significantly higher , AOP, ETR, and An,max under increased intensities of blue radiation, the increased LA observed under a higher percentage of red radiation ultimately led to increased light interception and greater dry mass accumulation. While the response is highly dependent on species and cultivar, the inclusion of far-red radiation under SSL may also be beneficial if accelerated flowering upon transplant is desired for plants with a long-day photoperiodic response. Additionally, while the CO2-enriched environment led to higher dry mass accumulation, acclimation responses, such as reduced , may limit potential gains from this input. The present research provides deeper insight into the morphological and physiological responses of bedding plant seedlings to light and CO2 in controlled environments, and establishes a foundation for future research to investigate how to best optimize these inputs

Risco do cultivo de campo de pepino decapado causado por condições desfavoráveis de duração de brilho solar

Solar energy, accessible to plants during sunshine from the sunrise to the sunset is of key importance in productivity of agrocenoses. The aim of the work was to determine risk of pickling cucumber cultivation caused by an unfavorable course of sunshine duration in Poland on the basis of a 40-year research period 1966-2005. The research into the subject was undertaken due to frequent occurrence of sunshine deficiency in Poland and its high temporal and spatial variability. Effect of solar conditions described by sunshine duration in the five development stages on the quantity of the total and marketable yield of cucumber with consideration of a linear trend of an independent variable was determined by means of multiple regression analysis. The accuracy of the equations was evaluated on the basis of, among other things, determination coefficient, average relative forecast error and the indexes: mean bias error (MBE), mean absolute bias error (MABE) and root mean square error (RMSE). Cucumber (Cucumis sativus L.) yield was confirmed for the period from the end of emergence to the beginning of flowering and from the beginning of harvesting to the end of harvesting. Cucumber yield was lower by 18% than the multiannual average in the years 1966-2005 every 1.5-2 years -in the case of the occurrence of the shortage in the period from the end of emergence to the beginning of flowering and by 12-15% every 2-3 years in the period from the beginning of harvesting to the end of harvesting. In four years, out of the 40 considered ones, simultaneously in both cucumber development stages, unfavorable solar conditions occurred, causing reduction by at least 5% in the total yield of the plant in Poland, and in three years - the marketable yield.A disponibilidade de energia solar para as plantas desde o nascer ao por do sol é de fundamental importância para todo agronegócio. O objetivo deste trabalho foi determinar o risco da produção de pepino (Cucumis sativus L.) decapado causado pelo curso desfavorável de duração da radiação solar na Polônia, baseado em um período de 40 anos de pesquisa (1966-2005). A pesquisa foi realizada pelo fato da ocorrência frequente de deficiência de insolação na Polônia e sua alta variabilidade temporal e espacial. O efeito das condições solares descritas pela duração da insolação foi estudado em relação às produtividades total e comerciável de pepino, considerando uma tendência linear de uma variável independente. A precisão das equações foi avaliada com base no coeficiente de determinação, erro médio relativo de precisão e índices: erro médio de bias, erro médio absoluto de bias e raiz do erro médio quadrado. A produtividade foi analisada a partir da emergência até o início do florescimento e do inicio ao fim da colheita. A produtividade de pepino foi 18% menor em relação a media multianual dos anos 1966-2005 cada 1,5-2 anos - nos casos de falta de insolação no período emergência-florescimento e 12-15% menor a cada 2-3 anos na colheita. Com exceção de quarto dentro dos 40 anos estudados, houve condições desfavoráveis de insolação em ambos os estádios estudados, causando uma redução de no mínimo de 5% da produção total da planta na Polônia e, excetos três anos - da produção comercial

The Developing Blueberry Industry in China

The present situation of blueberry industry in China was summarized. The six main blueberry cultivation areas in China were reviewed and practical suggestions were made. Reference and guidance for water management of rabbiteye blueberry in Yangtze river basin was provided, and water physiological characteristics and water requirement of blueberry were also clarified so as to provide scientific management of blueberry. Effects of vinegar residue on soil physical and chemical properties, enzymatic activities, growth of blueberry, nutrient uptake, and fruit quality were studied. The effect of vinegar residue on the growth of blueberry and the mechanism revealed from the perspective of soil amelioration were also discussed from the results

On the photosynthetic responses of crops to intracanopy lighting with light emitting diodes

Key words: Cucumis sativus, intracanopy lighting, light-emitting diodes (LEDs), light distribution, light interception, light quality, photosynthesis, photosynthetic acclimation Assimilation lighting is a production factor of increasing importance in Dutch greenhouse horticulture. Assimilation lighting increases production levels, improves product quality and opens possibilities for year round production. As a drawback, this use of assimilation lighting increases energy inputs and CO2-emission. Intracanopy lighting (with LEDs) is a technique to enhance the light use efficiency by changing the position of (a part of ) the lamps from above to within the canopy of greenhouse grown crops. Intracanopy lighting (IL) firstly reduces reflection and transmission losses of the supplemental lighting on crop level. These losses are high in traditional top-lighting systems, hence IL yields a higher light absorption on crop level. Secondly, IL creates a more homogenous vertical light distribution which can result in higher light use efficiencies. The aim of present study was to obtain insights in photosynthetic acclimation in response to irradiance level and spectrum in the framework of the applicability of LEDs as light source for intracanopy lighting in indeterminate growing vegetable crops. Intracanopy lighting may vary in (1) position within the crop, in (2) irradiance level and in (3) spectrum. Leaves deeper in the canopy are older. If leaf age negatively affects the photosynthetic capacity (Amax), then potential positions of IL-lamps reduce. By growing tomato plants horizontally so that irradiance was similar for all leaves from 0-70 days old, it is concluded that during the normal life-span of tomato leaves in cultivation, irradiance and not ageing is the most important factor affecting Amax. In winter, natural irradiances are low so that new developing leaves acclimate to low irradiances. Later on in their life time these leaves could be exposed to higher irradiances owing to IL. The question arose if cucumber leaves which develop under low irradiance can acclimate to a moderate irradiance. Acclimation of photosynthesis occurred within 7 days but photosynthesis at moderate irradiance and Amax did not reach to that of leaves developed under moderate irradiance. This reveals the importance of photosynthetic acclimation during the leaf developmental phase for crop productivity in scenarios with realistic, moderate fluctuations in irradiance that leaves can be exposed to. By growing plants under seven different combinations of red and blue light, blue light is shown to have both a qualitative and a quantitative effect on leaf development. Only leaves developed under red light (0% blue) displayed a dysfunctional photosynthetic operation (“red light syndrome”), which was largely alleviated by only 7% blue. Quantitatively, leaf responses to an increasing blue light percentage resembled responses associated with an increase in irradiance. Leaves developed under red light exposed to a mixture of red and blue (RB) completely recovered within 4 days after exposure to RB-light but remained limited in other leaf parameters, showing limitations in plasticity due to constraints arising from the prior leaf development. Leaves developed under RB also revealed the “red light syndrome” within 7 days of red illumination. Lastly, the effects of intracanopy lighting with LEDs on the production and development of a cucumber crop was investigated in winter. In the IL-treatment, LEDs supplied 38% of the supplemental irradiance within the canopy; the remaining 62% was supplied as top lighting by High-Pressure Sodium (HPS) lamps. The control was 100% top lighting (HPS lamps). Intracanopy lighting resulted in a greater Amax for leaves at deeper canopy layers but did not increase total biomass or fruit production. This was partly due to a reduced light interception caused by extreme leaf curling, which counteracted the expected higher light absorption by the crop, and partly to a lower dry matter partitioning to the fruits, and thus a greater dry matter partitioning to the leaves compared to the control. The effect of these factors on fruit yield was quantified using a explanatory crop model. Model calculations revealed a large negative effect on the fruit yield due to the greater partitioning to the leaves, whereas the negative effect of leaf curling was small. The effect of a greater Amax at deeper canopy layers was slightly positive. The last however might have indirectly caused the greater partitioning to the leaves as the greater Amax was associated with a preserved leaf mass per area. </p

Studies on procedures for calculating the base temperature and effects of temperature regimes on tomato transplant development and yield

In the prediction of crop development, the procedures to calculate the base temperature in heat unit systems are tedious and deficient in theoretical bases. Little information is available on effects of temperature regimes or temporal temperature distributions on crop development. The objectives of this dissertation were: 1) to develop new procedures for calculating the base temperature in heat unit systems for any crop, 2) to study the effects of temperature regimes for tomato seedlings in the preceding developmental stage on the succeeding developmental stage, 3) to study effects of temperature regimes for tomato transplants before transplanting on the subsequent yield in the field. Tomatoes were planted on different dates in the greenhouse under three temperature levels (average temperatures for each developmental phase were at 17-19 C, 21-23 C, 24-26 C in 1991 and 18-20 C, 20-22 C, and 22-24 C in 1992) and rotated among three temperature levels in such a way that all transplants received approximately the same temperature accumulation at the time of transplanting. Seedling emergence and the time of appearance of the first to sixth leaf were defined as developmental stages 1-6. Seedling emergence to the first and second, the first and second to the third, the third to the fourth, the fourth to the fifth, and fifth to the six leaf appearance were defined as developmental phases 1-6. Temperature and solar radiation were measured. Average temperatures and the number of days for each developmental stage and phase were recorded. Transplant height, stem diameter, leaf length, and weight were measured. When transplants reached the sixth developmental stage, they were transplanted to the field of the University of Tennessee Plant Field Science Laboratory at Knoxville. Tomato fruits were divided into six groups according to fruit size based on the Los Angeles system. Fruit yield and fruit number were measured in each of six groups. The results of this research showed that the four proposed formulas for calculating the base temperature in heat unit systems were superior to the previous procedures in terms of simplicity and mathematical bases. Temperature regimes experienced in the preceding developmental stage affected the succeeding developmental stages. The prediction of seedling development in the greenhouse considering effects of the preceding temperature regimes on the succeeding developmental stages was more accurate than that without considering such effects. Tomato seedling development was controlled by both temperature accumulations and the way temperature accumulations were achieved. Fruit yield and fruit number were significantly affected by temperature regimes experienced by seedlings in the greenhouse before transplanting. A sharp change in temperature regimes either from low to high or from high to low before the fourth leaf appearance appeared to have negative effects on fruit yield in the field. Temperature in the ranges of 18-21 C for seedling emergence and 19-22 C for the first and second leaf appearance resulted in the best quality of transplants

Greenhouse Management for Better Vegetable Quality, Higher Nutrient Use Efficiency and Healthier Soil

Greenhouse cultivation provides an artificially controlled environment for the year-round production of vegetables, and has played an increasingly important role in agriculture production systems in recent decades. Recent works have shown that improving greenhouse conditions can promote the growth of vegetables and enhance the uptake of nutrients, leading to better vegetable quality. Meanwhile, greenhouse conditions not only directly influence soil nutrient cycling processes and properties, but also indirectly affect them by regulating vegetable root growth and plant–soil interactions. This Special Issue features twelve original research articles that deal with the effects of novel greenhouse practices and strategies on the yield and quality of horticulture crops, as well as greenhouse soil properties. Among these publications, three studied the effects of fertilizers, including organic and macro- and micro-nutrient fertilizers, on the growth and nutrient uptake of vegetables. Two articles described the effects of water and nutrient supply using irrigation or hydroponic supplying systems on the yield and quality of vegetables. Four articles investigated the effects of environmental conditions (mainly light and temperature) on the growth and quality of vegetables. In terms of degenerated greenhouse soil, three articles showed how reductive soil disinfestation decreased soil salinity, improved soil quality, and inactivated soil-borne pathogens