Saber Gilani; Naser Askari; Hossein Meighani; Amanollah Soleimani; Reza Ghahremani
Abstract
Optimizing light and nutrient supply has a key role in seedling quality and yield of cucumber seedlings. The combined effects of light quality {blue (B), white [W; 41% B, 39% intermediate, and 20% red (R)], RB [red (80%) and blue (20%)], and red (R)} and EC value of the nutrient solution (1, 1.7, and ...
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Optimizing light and nutrient supply has a key role in seedling quality and yield of cucumber seedlings. The combined effects of light quality {blue (B), white [W; 41% B, 39% intermediate, and 20% red (R)], RB [red (80%) and blue (20%)], and red (R)} and EC value of the nutrient solution (1, 1.7, and 3 ds m-1) were evaluated on the growth and physio-logical responses of cucumber seedlings. The measurements were aimed at the growth rate, biomass distribution, water status, seedling quality, yield, and concentration of photosynthetic pigments, protein, proline, potassium, and phosphorous. The results showed that the effects of light quality on cucumber seedlings depended on the EC values of the nutrient solution. The RB treatment at EC 1.7 of the irrigation water had the highest value of seedling quality parameters and the maximum amount of osmolytes, elements, and pigments, showing adequate water performance. Moreover, in contrast to the conventional seedling production, yield and biomass production increased by 70% and 92%, respectively, in the transplanting phase. This probably resulted from a more efficient elemental uptake, higher biomass distribution, and low vegetative growth in the seedling production phase. These results can contribute to seedling production of vegetables as an efficient protocol for yield productivity. In sum, our findings showed that determining the ideal light spectrum for seedling growth should be considered together with the EC of the nutrient solution.
Amin Reza Jamshidi; Ahmad Ghazanfari Moghaddam; Fatameh Mozafari Ghoraba
Abstract
The development of aeroponic cultivation technology has led to more efficient use of water and plant nutrients for producing high quality agricultural commodities. In this research, cucumbers were grown in columnar aeroponic systems for nine weeks and the effect of spraying rate and spraying duration ...
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The development of aeroponic cultivation technology has led to more efficient use of water and plant nutrients for producing high quality agricultural commodities. In this research, cucumbers were grown in columnar aeroponic systems for nine weeks and the effect of spraying rate and spraying duration on the cucumber average yield and water usage efficiency were investigated. The experiments were performed using factorial experiment based on completely randomized designs. The spraying rate had three levels of 125, 250 and 375 mL/min, and the spraying durations were 10, 15 and 20 min. During the experiment, the spraying pumps were turned off for 15 min between each spraying time. Then, the two factors were simultaneously optimized using response surface methodology to maximize fruit yield and water usage efficiency. The ANOVA results showed that both responses were significantly affected by the main effects of the factors (α = 0.01) and by their interaction effects (α = 0.05). The comparison of first and second-order models to show the average yield and water usage efficiency as functions of sparing rate and sparing time indicated that the second-order models fitted with higher accuracies (R2> 80%) to the experimental data than the first-order model. Simultaneous optimization showed that the most suitable spraying rate was 233.37 mL/min and for the spraying duration, it was 16.06 min. At the optimum conditions, the average yield per plant yield was 2.96 kg and the water usage efficiency was 110.37 kg/m3.
