Browsing by Subject "fertigation"
Now showing items 1-2 of 2
-
(2011)Plants absorb water best from fertigation solution with low nutrient concentration. Yet, in intensive greenhouse production high nutrient concentrations are used in fertigation to avoid nutrient deficiencies and decrease in yields. In split-root cultivation the root system of a plant is separated into two growing medium compartments, in which case the other half receives fertigation solution with high EC (electrical conductivity) and the other with low EC. Especially greenhouse cucumber, susceptible to water supply problems caused by salinity of growing medium, is found to benefit from this technique in increased yields. The objective of this study of split-root cultivation of greenhouse cucumber conducted in MTT Agrifood Research Finland was to improve the technique especially in respect of EC of fertigation solutions. In addition to single-root and traditional split-root cultivation there were two split-root treatments in which fertigation solution concentrations were reversed in intervals to improve functioning of root systems. Effects of different EC combinations on vegetative growth between above- and underground parts of greenhouse cucumber and morphology and anatomy of roots were studied in a separate experiment. Results demonstrated that split-root cultivation increased cucumber yields up to 16% but had no effect on uptake of water or nutrients over the whole cultivation period. The most of spiked fruits were formed in single-root cultivation which refers to water supply problems during the highest need for transpiration. The technique didn’t affect plants’ vegetative growth or structure. Petiole sap nitrate and potassium analyses indicated that nutrient concentrations of fertigation solutions had no effect on nutrient uptake of roots. Different EC combinations had a greater effect on root weight than on shoot weight or stem growth in greenhouse cucumber. Petiole sap analyses suggested that nutrients were allocated variously in different EC combinations. The osmotic stress caused by high ECs led to changes in root morphology and anatomy. Results indicated that split-root cultivation enhanced the sink strength of developing fruits in relation to other sinks without affecting vegetative growth. When sides of fertigation solutions of low and high EC were switched during cultivation, the root system was able to take water and nutrients flexibly and economically, in which case significant yield increases were achieved in greenhouse cucumber production. Splitting root system probably affects plants’ hormone metabolism and can impair growth of roots without impairing their functioning, whereupon assimilates are allocated more efficiently to the growth of aboveground plant parts.
-
(2012)The aim of this research was to find out how split-root fertigation affects the tield and quality of greenhouse tomato grown under modern greenhouse conditions. The aim was to find out if split-root fertigation produces bigger and better quality crop than traditional fertigation. In addition water use efficiency was compared between the split-root and traditional fertigation approaches. The study was conducted at MTT Agrifood Research Finland (Piikkiö) during 3.4.- 24.11.2009 in greenhouse. In split-root fertigation approach the roots of the tomato plants were divided into two comparments where the other compartment was fertigated with low electrical conductivity (EC) solution and the other on with concentrated EC solution. In traditional fertigation treatment the roots were also divided into two compartments but both parts were fertigated with solutions of equal EC. In split-root fertigation plant is able to take water from dilute solution and nutrients from concentrated solution. High EC can inrcease tomatos quality but decrease yield. Split-root fertigation enables use of high EC and low EC solutions to achieve the best quality tomatoes and most yield. During the cultivation period, the EC values of the nutrient solutions were maintained in their target values for almost all the time. The traditional fertigation approach produced more marketable yield and first class yield in number of fruits per plant than the split-root approach. The differences in the two approaches were statistically significant. One of the most factors that decreased the volume of marketable yield by was blossom-end rot. Water use efficiency was calculated by dividing the marketable yield by the volume of the water used during growth season. The split-root fertigation approach produced 164 g/l and the traditional fertigation 171 g/l of fruits per used litre of water. However, the difference was not statistically significant. Further research on split-root fertigation is needed. Based on the literature it the concentrated compartment in the split-root fertigation system may induce drought stress signals, which eventually reduc optimal production.
Now showing items 1-2 of 2