scholarly journals Effect of greenhouse microclimate and water quality on nutrient uptake in pepper hydroponic crop

2021 ◽  
Author(s):  
Ανδρέας Ροπόκης

The nutrient to water uptake ratios, henceforth termed “uptake concentrations” (UC), remain relatively constant over time under similar climatic conditions for a particular plant species and developmental stage. Under greenhouses with low temperature (LT) conditions, the uptake of nutrients may be altered in a different manner than that of the water and thus their UC may be different than in greenhouses with standard temperature (ST) conditions. In the Mediterranean regions, sweet pepper is frequently cultivated in unheated greenhouses in which the temperature during the winter may drop to suboptimal or even lower levels. In these areas, the available irrigation water frequently contains sodium chloride but also calcium bicarbonate, which at excessively high concentrations in closed hydroponic crops can impose Ca accumulation in the recycled NS and concomitantly negatively affect fruit yield and quality of the produce.Taking the above into consideration there were established three studies:In the first study, pepper plants of the cultivars ‘Sammy’ and ‘Orangery’, self-grafted or grafted onto two commercial rootstocks ('Robusto' and 'Terrano'), were cultivated in a greenhouse under either ST or LT conditions. The aim of the study was to test the impact of grafting and greenhouse temperature on total yield, water use efficiency and nutrient uptake. The LT regime reduced yield by about 50% in ‘Sammy’ and 33% in ‘Orangery’, irrespective of the grafting combination. Grafting of ‘Sammy’ onto both 'Robusto' and 'Terrano' increased the total fruit yield by 39% and 34% compared with the self-grafted control, while grafting of ‘Orangery’ increased yield only when the rootstock was ‘Terrano’. The yield increase resulted exclusively from enhancement of the fruit number per plant. Both the water consumption and the water use efficiency were suppressed by the LT regime but the temperature effect interacted with the rootstock/scion combination. The LT increased the UC of K, Ca, Mg, N, and Mn, while it decreased strongly that of P and slightly the UC of Fe, and Zn. The UC of K and Mg were influenced by the rootstock/scion combination but this effect interacted with the temperature regime. In contrast, the Ca, N, and P concentrations were not influenced by the grafting combination. The results of the present study show that the impact of grafting on yield and nutrient uptake in pepper depend not merely on the rootstock genotype but on the rootstock/scion combination.In the second study, mean UC of macro- and micronutrients were determined during five developmental stages in different pepper cultivars grown in a closed hydroponic system by measuring the water uptake and the nutrient removal from the RNS. The experiment was conducted in a Mediterranean environment and the tested cultivars were ‘Orangery’, ‘Bellisa’, ‘Sondela’, ‘Sammy’ self-grafted and ‘Sammy’ grafted onto the commercial rootstock `RS10'. ‘Sondela’ exhibited significantly higher ΝΟ3, Μg, Ca and B UC in comparison with all other cultivars, while Bellisa exhibited higher K UC. The UC of all nutrients were similar in the grafted and the non-grafted ‘Sammy’ plants. The UC of macronutrients estimated in the second study (mmol L-1) ranged from 2.4 to 3.7 for Ca, 1.0 to 1.5 for Mg, 6.2 to 9.0 for K, 11.7 to 13.7 for N, and 0.7 to 1.1 for P. The UC of N, K, Ca and Mg were appreciably higher than the corresponding values found under Dutch climatic conditions, while that of P was similar in both environments during the vegetative stage and higher thereafter. The UC of Fe, Zn and B tended to decrease with time, while that of Mn increased initially and subsequently decreased slightly during the reproductive developmental stage.In the third study, irrigation water containing 1.5, 3.0, 4.5 and 6.0 mM was used to prepare NS in a closed hydroponic crop of sweet pepper cultivated in RNS. The aim of the study was to determine maximum Ca levels that do not harm the crop and to simulate the pattern of Ca accumulation when the Ca concentration in the irrigation water is excessive. At 1.5 mM Ca, no Ca accumulation was observed in the RNS, while at 3.0, 4.5 and 6.0 mM the Ca concentration in the RNS, and concomitantly in the root environment, increased to 17, 28 and 37 mM, corresponding to 6.4, 9.0 and 10.8 dS m-1. The accumulation of Ca in the RNS affected both tissue nutrient concentrations and UC of Ca, S and Mg, but this was not the case for N and K. Growth, yield and plant water uptake were restricted at moderate and high external Ca levels. Our results showed that in soilless sweet pepper crops with zero discharge of fertigation effluents, the Ca concentration in the irrigation water should be lower than 3.0 mM to avoid yield restrictions due to salinity.

Agronomy ◽  
2019 ◽  
Vol 9 (2) ◽  
pp. 110 ◽  
Author(s):  
Andreas Ropokis ◽  
Georgia Ntatsi ◽  
Constantinos Kittas ◽  
Nikolaos Katsoulas ◽  
Dimitrios Savvas

In areas characterized by mild winter climate, pepper is frequently cultivated in unheated greenhouses in which the temperature during the winter may drop to suboptimal levels. Under low temperature (LT) conditions, the uptake of nutrients may be altered in a different manner than that of the water and thus their uptake ratio, known as uptake concentration, may be different than in greenhouses with standard temperature (ST) conditions. In the present study, pepper plants of the cultivars “Sammy” and “Orangery”, self-grafted or grafted onto two commercial rootstocks (“Robusto” and “Terrano”), were cultivated in a greenhouse under either ST or LT temperature conditions. The aim of the study was to test the impact of grafting and greenhouse temperature on total yield, water use efficiency, and nutrient uptake. The LT regime reduced the yield by about 50% in “Sammy” and 33% in “Orangery”, irrespective of the grafting combination. Grafting of “Sammy” onto both “Robusto” and “Terrano” increased the total fruit yield by 39% and 34% compared with the self-grafted control, while grafting of “Orangery” increased the yield only when the rootstock was “Terrano”. The yield increase resulted exclusively from enhancement of the fruit number per plant. Both the water consumption and the water use efficiency were negatively affected by the LT regime, however the temperature effect interacted with the rootstock/scion combination. The LT increased the uptake concentrations (UC) of K, Ca, Mg, N, and Mn, while it decreased strongly that of P and slightly the UC of Fe and Zn. The UC of K and Mg were influenced by the rootstock/scion combination, however this effect interacted with the temperature regime. In contrast, the Ca, N, and P concentrations were not influenced by the grafting combination. The results of the present study show that the impact of grafting on yield and nutrient uptake in pepper depend not merely on the rootstock genotype, however on the rootstock/scion combination.


2016 ◽  
Vol 65 (1-2) ◽  
pp. 53-59
Author(s):  
Borivoj Pejić ◽  
Ksenija Mačkić ◽  
Srdjan Pavković ◽  
Branka Ljevnaić-Mašić ◽  
Miroljub Aksić ◽  
...  

Summary The objective of the study, conducted in Vojvodina a northern part of the Serbia Republic, was to analyse the effect of drip irrigation on yield, evapotranspiration and water productivity of watermelon (Cirullus lanatus Thunb.) grown with plasticulture. Irrigation was scheduled on the basis of water balance method. Daily evapotranspiration was computed using the reference evapotranspiration and crop coefficient. The yield of watermelon in irrigation conditions (37,28 t/ha) was significantly higher compared to non irrigated (9,98 t/ha). Water used on evapotranspiration in irrigation conditions was 398 mm and 117 mm on non irrigated variant. The crop yield response factor of 1,04 for the whole growing season reveals that relative yield decrease was nearly equal to the rate of evapotranspiration deficit. The values of irrigation water use efficiency and evapotranspiration water use efficiency were 9,93 kg/m3 and 10,29 kg/m3 respectively. The determined results could be used as a good platform for watermelon growers in the region, in terms of improvement of the optimum utilization of irrigation water.


2022 ◽  
Vol 32 (1) ◽  
pp. 21-27
Author(s):  
Osama Mohawesh ◽  
Ammar Albalasmeh ◽  
Sanjit Deb ◽  
Sukhbir Singh ◽  
Catherine Simpson ◽  
...  

Colored shading nets have been increasingly studied in semi-arid crop production systems, primarily because of their ability to reduce solar radiation with the attendant reductions in air, plant, and soil temperatures. However, there is a paucity of research concerning the impact of colored shading nets on various crops grown under semi-arid environments, particularly the sweet pepper (Capsicum annum) production system. This study aimed to investigate the effects of three colored shading net treatments (i.e., white, green, and black shading nets with 50% shading intensity and control with unshaded conditions) on the growth and instantaneous water use efficiency (WUE) of sweet pepper. The results showed that all colored shading nets exhibited significantly lower daytime air temperatures and light intensity (22 to 28 °C and 9992 lx, respectively) compared with the control (32 to 37 °C and 24,973 lx, respectively). There were significant differences in sweet pepper growth performance among treatments, including plant height, shoot dry weight, leaf area, leaf chlorophyll content, and vitamin C in ripened fruit. The enhanced photosynthetic rates were observed in sweet pepper plants under the colored shading nets compared with control plants. WUE increased among the colored shading net treatments in the following order: control ≤ white < black < green. Overall, the application of green and black shading nets to sweet pepper production systems under semi-arid environments significantly enhanced plant growth responses and WUE.


1989 ◽  
Vol 29 (1) ◽  
pp. 111 ◽  
Author(s):  
AM Grieve

The comparative patterns of water and nutrient uptake, soil salinity and water use efficiency resulting from 2 irrigation systems were studied in a 20-year-old Valencia orange orchard in Sunraysia on the Murray River. A conventional full ground cover system with the sprinklers in the middle of the rows operated at 14 day intervals (peak water demand), was compared with a partial (60-65%) ground cover system using under-tree micro-sprinklers operated at 7-day intervals. Irrigation applications were calculated to replace water depleted from the soil (including a leaching fraction) and were scheduled using tensiometers. During the 4 years of the experiment, approx. 10% less water was applied using micro-sprinklers. The average measured values for the crop coefficients were 0.62 (micro-irrigated) and 0.64 (full ground cover) during midsummer. Measurement of soil water extraction patterns by plant roots showed that only 5% of water use occurred below 1.0 m in under-tree microsprinkler irrigated trees, whereas 17% of water was taken up below this depth by trees irrigated with the mid-row system. Water uptake was limited by water availability rather than root density and declined sharply in mid-row irrigated trees during the second half of the 14-day irrigation cycle, when lower values of soil matric potential and shoot water potential were observed. Root distribution reflected these water uptake patterns with the highest density of fine roots in the 30-60 cm layer. Fertiliser injection with the micro-sprinkler system significantly increased the efficiency of N and P uptake compared with surface application, whereas leaf K levels were lower under micro-irrigation. Soil and plant levels of Na and C1 were low and unaffected by irrigation system during the experiment indicating adequate leaching of salt occurred with both systems. Fruit yield averaged 12% (5 t/ha) higher from micro-irrigated trees due to higher fruit numbers in light crop years. Tree growth was depressed in micro-irrigated trees suggesting a change in the partitioning of photosynthetic energy from vegetative to reproductive growth. The net effect of micro-irrigation was to increase water use efficiency by 22%, from 3.56 to 4.34 t fruit per ML applied water. No adverse effects on orchard productivity were observed following conversion from full to partial wetting of the soil surface. Under-tree micro-irrigation can therefore be recommended as a practical and efficient system for citrus irrigation in the irrigation areas of the Murray River.


2017 ◽  
Vol 68 (8) ◽  
pp. 726 ◽  
Author(s):  
Farid Golzardi ◽  
Amirsaleh Baghdadi ◽  
Reza Keshavarz Afshar

Shortage of fresh water and drought stress are important factors limiting crop productivity in semi-arid and arid regions. Irrigation management needs to be optimised to improve irrigation water-use efficiency (IWUE), and thus, agricultural sustainability in these climates. A field experiment was conducted at two semi-arid locations in Iran to evaluate the impact of irrigation regime (applied after crop evapotranspiration of 70 mm (I70), 100 mm (I100) or 130 mm (I130)) and irrigation method (applied to every furrow (EFI) or variable alternate furrow (AFI)) on yield and IWUE of maize (Zea mays L.). Yield response to irrigation rate was quadratic. Kernel yield was 8476 kg ha–1 under I70, and this reduced by 12.3% under I100 and 27.7% under I130. Yield reduction due to water stress was attributed to decline in both kernel number and kernel weight. Implementation of AFI resulted in a significant saving in irrigation water. At I70, 31% less water was used with AFI than with EFI. Irrigation water saving was even greater under I100 and I130 when AFI was implemented. Regardless of irrigation regime, IWUE under AFI was always greater than under EFI (1.32 vs 1.03 kg m–3 for grain and 3.30 vs 2.47 kg m–3 for biomass production). In addition, plants were shorter with a longer root system under AFI, and the role of carbohydrate remobilisation in kernel filling was greater under AFI consistently among irrigation regimes. The results indicated good potential of AFI for development of water-saving strategies for maize production in semi-arid climates.


HortScience ◽  
2009 ◽  
Vol 44 (3) ◽  
pp. 810-814 ◽  
Author(s):  
Francisco M. del Amor ◽  
María D. Gómez-López

An experiment was carried out to assess the influence of three types of substrate on the growth and yield of sweet pepper (Capsicum annuum L.). Plants were grown during three cycles (2005, 2006, and 2007) in coconut coir dust (CC), urea formaldehyde foam (UF), and rice hull (RH) amended with polyacrylamide gel (water absorber). Growth parameters, dry weight (DW) of vegetative and generative parts, intercepted radiation, water uptake, total fruit yield, and quality parameters were analyzed. Plant height, total leaf fresh weight, and stem diameter were higher in CC and lower for the RH substrate, which also showed lower yields and fruit quality. Accumulated dry matter was modeled according to water uptake and substrate using a linear function. Upper and lower limits in water use efficiency, between 2.5 and 5.7 g DW/L, are linked to the irrigation strategies and crop seasons. Light use efficiency (LUE) under different conditions was also determined to predict plant dry matter and a unique value was obtained for the three substrates (LUE = 0.91 g/MJ). Three different irrigation strategies were proposed for each substrate as a function of intercepted radiation and defining an α coefficient (expressed in mm/m2/MJ) that coupled crop and climate components. These crop characterization and prediction tools could help to optimize plant growth and yield for environmentally friendly substrates.


Agronomy ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 228
Author(s):  
Ikram Ullah ◽  
Hanping Mao ◽  
Ghulam Rasool ◽  
Hongyan Gao ◽  
Qaiser Javed ◽  
...  

This study was conducted to investigate the effects of various irrigation water (W) and nitrogen (N) levels on growth, root-shoot morphology, yield, and irrigation water use efficiency of greenhouse tomatoes in spring–summer and fall–winter. The experiment consisted of three irrigation water levels (W: 100% of crop evapotranspiration (ETc), 80%, and 60% of full irrigation) and three N application levels (N: 100%, 75%, and 50% of the standard nitrogen concentration in Hoagland’s solution treatments equivalent to 15, 11.25, 7.5 mM). All the growth parameters of tomato significantly decreased (p < 0.05) with the decrease in the amount of irrigation and nitrogen application. Results depicted that a slight decrease in irrigation and an increase in N supply improved average root diameter, total root length, and root surface area, while the interaction was observed non-significant at average diameter of roots. Compared to the control, W80 N100 was statistically non-significant in photosynthesis and stomatal conductance. The W80 N100 resulted in a yield decrease of 2.90% and 8.75% but increased irrigation water use efficiency (IWUE) by 21.40% and 14.06%. Among interactions, the reduction in a single factor at W80 N100 and W100 N75 compensated the growth and yield. Hence, W80 N100 was found to be optimal regarding yield and IWUE, with 80% of irrigation water and 15 mM of N fertilization for soilless tomato production in greenhouses.


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