Cocopeat, a by-product of the coconut (<em>Cocos nucifera </em>L.), is an important soilless media that contains high potassium (K), sodium (Na), and electrical conductivity (EC) depending on its source. M...Cocopeat, a by-product of the coconut (<em>Cocos nucifera </em>L.), is an important soilless media that contains high potassium (K), sodium (Na), and electrical conductivity (EC) depending on its source. Methods for extracting these elements and thus lowering EC are yet to be standardized. This study was therefore carried out to investigate two extraction methods of these elements in cocopeat. A greenhouse pot experiment was carried out at the Climate and Water Smart Agriculture Centre of Egerton University, Kenya. It was laid out in a 5 × 4 factorial completely randomized design. Five soaking durations (12, 24, 36, 48, and 72 hours) and four calcium nitrate (Ca(NO<sub>3</sub>)<sub>2</sub>) levels (0, 60, 100, and 150 g) were used. The experiment was done in two folds: the leachate and treated cocopeat examination for their chemical properties. The General Linear Model procedures were used for Analysis of Variance at (P ≤ 0.05). The results showed that the addition of Ca(NO<sub>3</sub>)<sub>2</sub> 100 g extracted significantly more K and Na in the leachate than Ca(NO<sub>3</sub>)<sub>2</sub> 0.0 g and 60 g. The EC levels in the leachate increased with the application levels of Ca(NO<sub>3</sub>)<sub>2</sub> while the pH levels were reducing. In the treated cocopeat, Ca(NO<sub>3</sub>)<sub>2</sub> 100 g and soaking duration 36 hours significantly reduced K and Na and sufficiently supplemented Ca and N. Irrespective of Ca(NO<sub>3</sub>)<sub>2</sub> and soaking durations, after the cocopeat is washed, the EC and pH values fall within their suitable ranges. There was a strong negative correlation between Ca and Na, Ca and K, and between Na and EC. Also, strong positive correlation between Ca and N and Ca and EC. Effective supplementation of Ca and N, and optimal reduction of K and Na by 78.44% and 92%, respectively can be achieved with 100 g of Ca(NO<sub>3</sub>)<sub>2</sub> 1.5 kg<sup>-1</sup> of cocopeat in 15 liters of water with a soaking duration of 36 hours.展开更多
Eggplant(Solanum melongena L.)is a plant native to tropical regions of Southeast Asia.The water crisis and drought on the one hand and eggplant greenhouse crop development as one of the most popular fruit vegetables f...Eggplant(Solanum melongena L.)is a plant native to tropical regions of Southeast Asia.The water crisis and drought on the one hand and eggplant greenhouse crop development as one of the most popular fruit vegetables for people on the other hand,led to the need for more research on the use of saline water and water stress to optimize salinity level and their impact on eggplant evapotranspiration and encounter better yield and crop quality.The objective of the present study was to investigate the interactions of water salinity and hydroponic growth medium on qualitative and quantitative properties of eggplant and its water-use efficiency.The study used the factorial experiment based on completely randomized design with three replications of four levels of water salinity(electrical conductivity of 0.8(control),2.5,5,and 7 dS m^(-1))and three growth media(cocopeat,perlite,and a 50–50 mixture of the two by volume).Total yield,yield components,evapotranspiration,and water-use efficiency were determined during two growing periods,one each in 2012 and 2013.All of these indices decreased significantly as water salinity increased.Water with of 0.8 dS m^(-1) produced an average eggplant yield of 2510 g per plant in 2012 and 2600 g in 2013.The highest yield was observed in cocopeat.Water with 7 dS m^(-1) reduced yield to 906 g per plant in 2012 and to 960 g in 2013.Lowest yield was observed in perlite.The highest evapotranspiration values occurred in cocopeat at the lowest salinity in both years.Cocopeat and the cocopeat–perlite mixture were equally good substrates.The mixture significantly improved the quantitative and qualitative properties of eggplant yield.展开更多
文摘Cocopeat, a by-product of the coconut (<em>Cocos nucifera </em>L.), is an important soilless media that contains high potassium (K), sodium (Na), and electrical conductivity (EC) depending on its source. Methods for extracting these elements and thus lowering EC are yet to be standardized. This study was therefore carried out to investigate two extraction methods of these elements in cocopeat. A greenhouse pot experiment was carried out at the Climate and Water Smart Agriculture Centre of Egerton University, Kenya. It was laid out in a 5 × 4 factorial completely randomized design. Five soaking durations (12, 24, 36, 48, and 72 hours) and four calcium nitrate (Ca(NO<sub>3</sub>)<sub>2</sub>) levels (0, 60, 100, and 150 g) were used. The experiment was done in two folds: the leachate and treated cocopeat examination for their chemical properties. The General Linear Model procedures were used for Analysis of Variance at (P ≤ 0.05). The results showed that the addition of Ca(NO<sub>3</sub>)<sub>2</sub> 100 g extracted significantly more K and Na in the leachate than Ca(NO<sub>3</sub>)<sub>2</sub> 0.0 g and 60 g. The EC levels in the leachate increased with the application levels of Ca(NO<sub>3</sub>)<sub>2</sub> while the pH levels were reducing. In the treated cocopeat, Ca(NO<sub>3</sub>)<sub>2</sub> 100 g and soaking duration 36 hours significantly reduced K and Na and sufficiently supplemented Ca and N. Irrespective of Ca(NO<sub>3</sub>)<sub>2</sub> and soaking durations, after the cocopeat is washed, the EC and pH values fall within their suitable ranges. There was a strong negative correlation between Ca and Na, Ca and K, and between Na and EC. Also, strong positive correlation between Ca and N and Ca and EC. Effective supplementation of Ca and N, and optimal reduction of K and Na by 78.44% and 92%, respectively can be achieved with 100 g of Ca(NO<sub>3</sub>)<sub>2</sub> 1.5 kg<sup>-1</sup> of cocopeat in 15 liters of water with a soaking duration of 36 hours.
文摘Eggplant(Solanum melongena L.)is a plant native to tropical regions of Southeast Asia.The water crisis and drought on the one hand and eggplant greenhouse crop development as one of the most popular fruit vegetables for people on the other hand,led to the need for more research on the use of saline water and water stress to optimize salinity level and their impact on eggplant evapotranspiration and encounter better yield and crop quality.The objective of the present study was to investigate the interactions of water salinity and hydroponic growth medium on qualitative and quantitative properties of eggplant and its water-use efficiency.The study used the factorial experiment based on completely randomized design with three replications of four levels of water salinity(electrical conductivity of 0.8(control),2.5,5,and 7 dS m^(-1))and three growth media(cocopeat,perlite,and a 50–50 mixture of the two by volume).Total yield,yield components,evapotranspiration,and water-use efficiency were determined during two growing periods,one each in 2012 and 2013.All of these indices decreased significantly as water salinity increased.Water with of 0.8 dS m^(-1) produced an average eggplant yield of 2510 g per plant in 2012 and 2600 g in 2013.The highest yield was observed in cocopeat.Water with 7 dS m^(-1) reduced yield to 906 g per plant in 2012 and to 960 g in 2013.Lowest yield was observed in perlite.The highest evapotranspiration values occurred in cocopeat at the lowest salinity in both years.Cocopeat and the cocopeat–perlite mixture were equally good substrates.The mixture significantly improved the quantitative and qualitative properties of eggplant yield.
