scholarly journals Effect of Irrigation Scheduling on Gerbera Flower Yield and Quality

HortScience ◽  
2010 ◽  
Vol 45 (2) ◽  
pp. 265-270 ◽  
Author(s):  
Ioannis Tsirogiannis ◽  
Nikolaos Katsoulas ◽  
Constantinos Kittas
Keyword(s):  
Solar Radiation ◽  
Leaf Area ◽  
Control Method ◽  
Radiation Energy ◽  
Irrigation Scheduling ◽  
Quality Characteristics ◽  
Stem Length ◽  
Fresh Weight ◽  
Irrigation Frequency ◽  
Area Index

Better understanding of the effects of irrigation frequency and dose on flower production of gerbera plants (Gerbera jamesonii) can lead to optimal water management and crop yield. Measurements of greenhouse microclimate and production and quality characteristics of a gerbera crop were carried out under two irrigation frequency regimens in soilless cultivation in a greenhouse located in Arta, Greece. Irrigation scheduling was based on solar radiation and performed whenever accumulated solar radiation energy outside the greenhouse reached 1650 kJ·m−2 [high irrigation frequency (HIF)] or 3300 kJ·m−2 [low irrigation frequency (LIF)]. The amount of water applied was 0.125 mm and 0.250 mm for HIF and LIF, respectively. Stem fresh weight, length and thickness, and number of harvested gerbera flowers were measured along with crop evapotranspiration, crop leaf area, and greenhouse microclimate variables. Measurements started 8 months after transplanting and lasted 90 days (May to July). Leaf area, fresh weight, harvested cut flowers, and the main quality characteristics of gerbera flowers (stem length and flower diameter) were unaffected by the irrigation frequency. In the framework of the experiment, simple formulas for calculation of leaf area index were developed. Finally, a first approach study of an alternative remote sensing irrigation control method using a reflectance index was made and the results are presented.

Daminozide reduces mean weight of potato tubers but fails to increase uniformity

1988 ◽  
Vol 28 (3) ◽  
pp. 385 ◽  
Author(s):  
IA Rogers ◽  
BW Philp ◽  
TK Twigden
Keyword(s):  
Leaf Area Index ◽  
Leaf Area ◽  
Total Yield ◽  
South Australia ◽  
Stem Length ◽  
Tuber Weight ◽  
Potato Tubers ◽  
Fresh Weight ◽  
Area Index ◽  
Market Requirement

At 3 sites in South Australia daminozide reduced mean potato tuber weight by 9-13% (P<0.05). Total yield of potatoes was reduced by 6-11%, although the effect was significant (P< 0.01) at only 1 site (Purnong Landing, reduction 11%). There were no effects of daminozide on tuber number, uniformity of tuber weight, specific gravity of tubers (at 1 site) or yield of ware grade tubers (80-350 g fresh weight). However, daminozide increased yield of grades (90-130 g) by 40% and decreased yield of grades (260-350 g) by 32% (P<0.05). In achieving these results, rates of 0.85, 1.7, 3.4 and 6.8 kg a.i. ha-l of daminozide were about equally effective. We conclude that, unless there is a market requirement for tubers of 90-130 g in weight, daminozide should not be used for the cultivars Sebago, Exton and Coliban if haulms are killed by herbicide or disease from 15 to 30 days before natural plant senescence. Stem length and leaf area index were reduced early in the season by daminozide, but late in the season leaf area index was increased.

scholarly journals Effect of irrigation frequency on growth and production of a cucumber crop under soilless culture

2017 ◽  
pp. 863 ◽  
Author(s):  
Georgios Nikolaou ◽  
Damianos Neocleous ◽  
Nikolaos Katsoulas ◽  
Constantinos Kittas
Keyword(s):  
Solar Radiation ◽  
Dry Weight ◽  
Radiation Energy ◽  
Irrigation Scheduling ◽  
Soilless Culture ◽  
Nutrient Losses ◽  
Irrigation Frequency ◽  
Yield Production ◽  
Southern Cyprus ◽  
Multiple Measurements

Three irrigation frequencies were applied on a soilless cucumber crop, in a greenhouse located in the coastal area of southern Cyprus. Irrigation scheduling was based on solar radiation and performed whenever accumulated solar radiation energy outside the greenhouse reached 1.3 MJ m-2 [High Irrigation Frequency (HIF)], 1.9 MJ m-2 [Medium Irrigation Frequency (MIF)] and 3.0 MJ m-2 [Low Irrigation Frequency (LIF)]. The amount of water applied was 0.192 Kg m-2, 0.288 Kg m-2 and 0.448 Kg m-2 for high, medium and low irrigation frequencies, respectively. Appropriately, the total volume of water applied was identical in each of the three cases.  In order to study the effects of irrigation frequency on cucumber crops, multiple measurements were taken; the  fresh and dry weight of plant organs (i.e. leaves, stem and fruit), marketable fresh yield production, and microclimate variables for a 75 day period, beginning in April and ending in June. The results revealed that the irrigation frequency did not influence the cucumber crop’s growth and production. Plants at LIF were facing water stress conditions, as estimated from leaf temperature and stem micro variation measurements. However, HIF increased the transpiration rate of the plants, resulting in less water and nutrient losses.

scholarly journals Growth and Flower Quality of Single-node Cutting Rose `Versillia' Under Irrigation Control by Integrated Solar Radiation in Aeroponics

HortScience ◽  
2004 ◽  
Vol 39 (4) ◽  
pp. 764B-764
Author(s):  
Joo Hyun Lee* ◽  
Yong-Beom Lee ◽  
Kang Pal Kwon
Keyword(s):  
Solar Radiation ◽  
Control Method ◽  
Stem Length ◽  
Control Methods ◽  
Fresh Weight ◽  
Single Node ◽  
Irrigation Control ◽  
Flower Quality ◽  
Better Than

This study was conducted to determine the growth and flower quality of single-node cutting rose `Versillia' under two different irrigation control methods (time clock and integrated solar radiation). The frequency of irrigation was controlled by time clock and integrated solar radiation of 1.25 and 2.09 and 3.35 MJ·m-2 in aeroponics. Photosynthesis was the highest in the integrated solar radiation of 2.09 MJ·m-2 and 1.25 MJ·m-2 the lowest in the integrated solar radiation of 3.35 MJ·m-2. The growth of single-node cutting rose `Versillia' at 1.25 MJ·m-2 and 2.09 MJ·m-2 was better than 3.35 MJ·m-2 for stem length and fresh weight. Root activities of single-node cutting rose were significantly higher at 2.09 MJ·m-2 and 1.25 MJ·m-2 than those at 3.35 MJ·m-2. The irrigation control method using integrated solar radiation of 1.25-2.09 MJ·m-2 showed a improvement of plant growth and flower quality.

scholarly journals A Canopy Transpiration Model Based on Scaling Up Stomatal Conductance and Radiation Interception as Affected by Leaf Area Index

Water ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 252
Author(s):  
Muhammad Shahinur Alam ◽  
David William Lamb ◽  
Nigel W. M. Warwick
Keyword(s):  
Stomatal Conductance ◽  
Leaf Area Index ◽  
Leaf Area ◽  
Festuca Arundinacea ◽  
Radiation Energy ◽  
Scaling Up ◽  
Controlled Environment ◽  
Canopy Conductance ◽  
Individual Layer ◽  
Area Index

Estimating transpiration as an individual component of canopy evapotranspiration using a theoretical approach is extremely useful as it eliminates the complexity involved in partitioning evapotranspiration. A model to predict transpiration based on radiation intercepted at various levels of canopy leaf area index (LAI) was developed in a controlled environment using a pasture species, tall fescue (Festuca arundinacea var. Demeter). The canopy was assumed to be a composite of two indistinct layers defined as sunlit and shaded; the proportion of which was calculated by utilizing a weighted model (W model). The radiation energy utilized by each layer was calculated from the PAR at the top of the canopy and the fraction of absorbed photosynthetically active radiation (fAPAR) corresponding to the LAI of the sunlit and shaded layers. A relationship between LAI and fAPAR was also established for this specific canopy to aid the calculation of energy interception. Canopy conductance was estimated from scaling up of stomatal conductance measured at the individual leaf level. Other environmental factors that drive transpiration were monitored accordingly for each individual layer. The Penman–Monteith and Jarvis evapotranspiration models were used as the basis to construct a modified transpiration model suitable for controlled environment conditions. Specially, constructed self-watering tubs were used to measure actual transpiration to validate the model output. The model provided good agreement of measured transpiration (actual transpiration = 0.96 × calculated transpiration, R2 = 0.98; p < 0.001) with the predicted values. This was particularly so at lower LAIs. Probable reasons for the discrepancy at higher LAI are explained. Both the predicted and experimental transpiration varied from 0.21 to 0.56 mm h−1 for the range of available LAIs. The physical proportion of the shaded layer exceeded that of the sunlit layer near LAI of 3.0, however, the contribution of the sunlit layer to the total transpiration remains higher throughout the entire growing season.

scholarly journals Effect of Organic Manures on Growth, Rhizome Yield and Quality Attributes of Turmeric (Curcuma longa L.)

2012 ◽  
Vol 10 (1) ◽  
pp. 16-22 ◽  
Author(s):  
M. Z. U. Kamal ◽  
M. N. Yousuf
Keyword(s):  
Leaf Area ◽  
Dry Matter ◽  
Curcuma Longa ◽  
Dry Weight ◽  
Fresh Weight ◽  
Area Index ◽  
Yield Attributes ◽  
Organic Manures ◽  
Neem Cake ◽  
Yield And Quality

The investigation was carried out to evaluate the effect of different organic manures on turmeric with reference to vegetative growth, biomass production, rhizome yield and its attributes of turmeric (Curcuma longa L.). Turmeric showed better response to the application of organic manures. Plant with neem cake application had the taller plant (79.30 cm), maximum number of tillers per plant (5.40), leaf number (5.40), leaf area (44.09) leaf area index (0.429), fresh weight of halum ( 190.05g), fresh weight of root (49.13 g), fresh weight of rhizome per plant (256.21 g) and dry weight of halum (15.21g), dry weight of root (7.32 g), dry weight of rhizome per plant (40.35 g), total dry matter yield (6.85 t ha-1) than those received other types of manures. Moreover, yield attributes such as number of mother rhizomes per plant-1 (1.75), more number of primary rhizomes per plant-1 (5.19), secondary rhizomes per plant-1 (18.03) and tertiary rhizomes per plant (7.69) were also highly accelerated by neem cake application. Similarly, the same treatment expressed the best in terms of size of mother rhizome (7.69 cm), primary rhizome (21.86 cm) and secondary rhizomes (7.05 cm).All these parameters in cumulative contributed to  produce the highest estimated fresh rhizomes yield & cured rhizomes yield (29.48 t ha-1, 5.59 t ha-1 respectively). The highest curing percentage (20.28) was observed in T3 treatment having mustard cake@ 2.0 t/ha. Thus, organic manure like neem cake was best fitted natural fertilizer for turmeric cultivation.DOI: http://dx.doi.org/10.3329/agric.v10i1.11060The Agriculturists 2012; 10(1): 16-22

scholarly journals Solar radiation use efficiency by soybean under field conditions in the Amazon region

2009 ◽  
Vol 44 (10) ◽  
pp. 1211-1218 ◽  
Author(s):  
Paulo Jorge de Oliveira Ponte de Souza ◽  
Aristides Ribeiro ◽  
Edson José Paulino da Rocha ◽  
José Renato Bouça Farias ◽  
Renata Silva Loureiro ◽  
...  
Keyword(s):  
Solar Radiation ◽  
Leaf Area ◽  
Biomass Production ◽  
Amazon Region ◽  
Field Conditions ◽  
Radiation Use Efficiency ◽  
Area Index ◽  
Natural Field ◽  
Use Efficiency ◽  
Radiation Use

The objective of this work was to evaluate the efficiency of soybean (Glycine max) in intercepting and using solar radiation under natural field conditions, in the Amazon region, Brazil. The meteorological data and the values of soybean growth and leaf area were obtained from an agrometeorological experiment carried out in Paragominas, Pará state, during 2007 and 2008. The radiation use efficiency (RUE) was obtained from the ratio between the above-ground biomass production and the intercepted photosynthetically active radiation (PAR) accumulated to 99 and 95 days after sowing, in 2007 and 2008, respectively. Climatic conditions during the experiment were very distinct, with reduction in rainfall in 2007, which began during the soybean mid-cycle, due to the El Niño phenomenon. An important reduction in the leaf area index and biomass production was observed during 2007. Under natural field conditions in the Amazon region, the values of RUE were 1.46 and 1.99 g MJ-1 PAR in the 2007 and 2008 experiments, respectively. The probable reason for the differences found between these years might be associated to the water restriction in 2007 coupled with the higher air temperature and vapor pressure deficit, and also to the increase in the fraction of diffuse radiation that reached the land surface in 2008.

scholarly journals Irrigation scheduling techniques and irrigation frequency on capsicum growth and yield

DYNA ◽  
2019 ◽  
Vol 86 (211) ◽  
pp. 42-48
Author(s):  
Leandro Candido Gordin ◽  
Ceres Duarte Guedes Cabral de Almeida ◽  
José Amilton Santos Júnior ◽  
Ênio Farias de França e Silva ◽  
Alexsandro Claudio Dos Santos Almeida ◽  
...  
Keyword(s):  
Irrigation Management ◽  
Irrigation Scheduling ◽  
Growth And Yield ◽  
Irrigation Frequency ◽  
Area Index ◽  
Moisture Sensor ◽  
Soil Moisture Sensor ◽  
Soil Sensors ◽  
Management Techniques ◽  
Factorial Design Experiment

The present study aimed to evaluate different irrigation scheduling strategies on capsicum growth and yield inprotected environment. The experiment was carried out at the Northeastern of Brazil. Five irrigation scheduling techniques to define water depth (weighing lysimeter, Hargreaves-Samani equation, Piché evaporimeter, tensiometer and soil moisture sensor) andtwo application frequencies (F1-once a day and F2-alternating frequency) were tested. A completely randomized factorial design experiment was installed in a 5 x 2 factorial scheme, with eight replicates. It was observed that the variables stem diameter and leaf area index were influenced by the irrigation scheduling techniques, and treatments based on Hargreaves-Samani and lysimeter scheduling methods led to the lowest values. Fruit biometric parameters were significantly affected only by the Hargreaves-Samani treatment. It can be concluded that both irrigation scheduling techniques and frequencies influenced capsicum growth and yield. Furthermore, irrigation management techniques based on soil sensors caused the highest yields.

scholarly journals Water and Soil Nutrient Dynamics of Huanglongbing-Affected Citrus Trees as Impacted by Ground-Applied Nutrients

Agronomy ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 1485 ◽  
Author(s):  
Alisheikh A. Atta ◽  
Kelly T. Morgan ◽  
Said A. Hamido ◽  
Davie M. Kadyampakeni ◽  
Kamal A. Mahmoud
Keyword(s):  
Leaf Area ◽  
Sap Flow ◽  
Untreated Control ◽  
Soil Nutrient ◽  
Irrigation Scheduling ◽  
Summer Season ◽  
Stem Water Potential ◽  
Area Index ◽  
Available N ◽  
Citrus Trees

The decrease in the rate of inflow and outflow of water—and thereby the uptake of plant nutrients as the result of Huanglongbing (HLB or citrus greening)—leads to a decline in overall tree growth and the development of nutrient deficiencies in HLB-affected citrus trees. This study was conducted at the University of Florida, Southwest Florida Research and Education Center (SWFREC) near Immokalee, FL from January 2017 through December 2019. The objective of the study was to determine the effect of rootstocks, nutrient type, rate, and frequency of applications on leaf area index (LAI), water relations (stomatal conductance [gs], stem water potential [Ψw], and sap flow), soil nutrient accumulation, and dynamics under HLB-affected citrus trees. The experiment was arranged in a split-split plot design that consisted of two types of rootstocks, three nitrogen (N) rates, three soil-applied secondary macronutrients, and an untreated control replicated four times. LAI significantly increased in response to the secondary macronutrients compared with uncontrolled trees. A significantly greater gs, and thus a decline in Ψw, was a manifestation of higher sap flow per unit LA (leaf area) and moisture stress for trees budded on Swingle (Swc) than Cleopatra (Cleo) rootstocks, respectively. The hourly sap flow showed significantly less water consumption per unit LA for trees that received a full dose of Ca or Mg nutrition than Ca + Mg treated and untreated control trees. The soil nutrient concentrations were consistently higher in the topmost soil depth (0–15 cm) than the two lower soil depths (15–30 cm, 30–45 cm). Mobile nutrients: soil nitrate–nitrogen (NO3-N) and Mg2+ Mg2+, Mn2+, Zn2+, and B leached to the lower soil (15–30 cm) depth during the summer season. However, the multiple split applications of N as Best Management Practices (BMPs) and optimum irrigation scheduling based on reference evapotranspiration (ETo) maintained soil available N (ammonium nitrogen [NH4-N] and NO3-N) below 4.0 mg kg−1, which was a magnitude 2.0–4.0× less than the conventional N applications. Soil NH4-N and NO3-N leached to the two lower soil depths during the rainy summer season only when trees received the highest N rate (280 kg ha−1), suggesting a lower citrus N requirement. Therefore, 224 kg ha−1 N coupled with a full Ca or Mg dose could be the recommended rate for HLB-affected citrus trees.

scholarly journals Improved Irrigation Management of Sweet Orange with Huanglongbing

HortScience ◽  
2017 ◽  
Vol 52 (6) ◽  
pp. 916-921 ◽  
Author(s):  
Said A. Hamido ◽  
Kelly T. Morgan ◽  
Robert C. Ebel ◽  
Davie M. Kadyampakeni
Keyword(s):  
Soil Water ◽  
Leaf Area ◽  
Sweet Orange ◽  
Irrigation Management ◽  
Irrigation Treatment ◽  
Irrigation Scheduling ◽  
Water Dynamics ◽  
Stem Water Potential ◽  
Area Index ◽  
The Impact

Because of the decline in production and negative economic effects, there is an urgent need for strategies to reduce the impact of Huanglongbing (HLB) on citrus [Citrus ×sinensis (L.) Osbeck]. The objective of this study was to evaluate the impact of different irrigation schedules on total available soil water (TAW) and water uptake characteristics of citrus trees affected by HLB in central and southwest Florida. The study was initiated in Jan. 2014 for 2 years on 5-year-old sweet orange trees located in three commercial groves at Arcadia, Avon Park, and Immokalee, FL. Each grove had three irrigation scheduling treatments including the University of Florida, Institute of Food and Agricultural Sciences (UF/IFAS) recommendations, Daily irrigation, and an Intermediate treatment. All groves received similar volumes of water per week based on evapotranspiration (ETo) reported by the Florida Automated Weather Network. Sap flow (SF) measurements were taken for two trees per treatment for at least 10 days per site (twice/year). During those periods, leaf area, leaf area index (LAI), and stem water potential (Ψ) were determined. Also, TAW was determined using drainage curve and capacitance soil moisture sensors installed at incremental soil depths of 0–15, 15–30, and 30–45 cm. Results showed significant differences in average SF, LAI, Ψ, and TAW measurements among treatments. Diurnal SF value under daily irrigation treatment increased by 91%, 51%, and 105% compared with UF/IFAS irrigation in Arcadia, Avon Park, and Immokalee, respectively. Soil water contents (WCs) under daily treatment increased by 59%, 59%, and 70% compared with UF/IFAS irrigation treatment in Arcadia, Avon Park, and Immokalee, respectively. Our results indicated that daily irrigation improved tree water dynamics compared with IFAS or Intermediate irrigation scheduling treatments and reduced tree stress with the same volume of water.

scholarly journals The effect of light availability on leaf area index, biomass production and plant species composition of park grasslands in Warsaw  

2013 ◽  
Vol 59 (No. 12) ◽  
pp. 543-548 ◽  
Author(s):  
P. Dąbrowski ◽  
B. Pawluśkiewicz ◽  
Kalaji HM ◽  
Baczewska AH
Keyword(s):  
Solar Radiation ◽  
Leaf Area Index ◽  
Leaf Area ◽  
Light Availability ◽  
Vegetation Coverage ◽  
Light Conditions ◽  
Area Index ◽  
Sward Height ◽  
Poa Trivialis ◽  
Leaf Density

How light conditions affect development of park grasslands is a question that has not been satisfactory addressed. The aim of this study was therefore determination of the level to which unfavorable light conditions influence grassy parks area and relationships between parameters which determine state of turf grasses. Researches were conducted in two parks in Warsaw, in various light conditions and included measurement of: leaf density, sward height, leaf area index (LAI), and botanical composition of the communities. The leaf density of shaded areas did not exceed 70%. LAI value varied from 0.5 to 0.9-fold lower than in the areas in half-shade and in sun. The participation of basic lawn species at Skaryszewski Park was higher under shade, while at Łazienki Kr&oacute;lewskie was higher in full-sunlight areas. The state of tested grassy areas in limited solar radiation does not satisfy the requirements of recreational and representational functions. The development processes of vegetation coverage were inhibited at the sites of lower solar radiation. LAI was influenced by both leaf coverage and sward height. Agrostis stolonifera and Poa trivialis may be recommended to create grass areas under limited solar radiation.

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