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• Basil (Ocimum basilicum L.) harvest and plant replacement methods in aquaponia

  91-98

  Judit Éva Lelesz

  István Csaba Virág

  Views:

  172

  The aim of the study is to investigate the potential of basil leaf mass production under aquaponic conditions with different harvest and plant replacement methods. Aquaponics is a combination of soil-less crop production hydroponics and aquaculture and it is can use and clean the wastewater of intensive aquaculture systems. Three groups were established in the 6 units during the six-week harvest and seedling rotation cycles. Group 1 individuals remain in the units throughout the breeding season. Group 2 individuals were replaced every 12 weeks, while Group 3 individuals were replaced every six weeks, at the same time as harvest. Data from the experiment were analysed to determine how the harvest and replacement protocol of basil plants influences the amount of leaves harvested, the percentage of leaves harvested relative to the plant stem, and the changes in plant height, SPAD and NDVI during harvest and replacement. A continuously maintained and harvested healthy basil stock under aquaponic conditions can provide a consistent leaf mass all year round without the extra cost of replacing and producing seedlings.

• Examination of the chlorophyll content of maize hybrids of different maturity groups at different N fertiliser doses

  159-162

  Péter Ragán

  Views:

  133

  Nitrogen fertilisation is a critical point of maize production. Five hybrids of different maturity dates were examined in a field experiment, three treatments (different application dates) and three basic fertiliser doses (0, 60, 120 kg ha^-1 N) were used. At the 6-leaf-stage of maize, each fertilisation level of the 2nd and 3rd treatment was given 30 kg N ha^-1 fertiliser active ingredient in addition to the basic fertiliser doses with the exception of the control plots and further 30 kg N ha^-1 fertiliser was applied at the 12-leaf-stage. The final fertiliser doses were 0, 90 and 150 kg N ha^-1 in the second treatment and 0, 120 and 180 kg N ha^-1 in the 3rd treatment. The whole amount of the basic fertiliser (ammonium nitrate) was applied in the spring, one month before sowing.

  The relative chlorophyll content of the maize leaves was measured, with a Minolta SPAD-502 measurement device. The measurements were carried out at the 6-leaf growth stage (V6) of maize on the youngest fully developed leaf of the 6^th, 7^th and 8^th plants from the second row of each plot.

  There were significant differences in the SPAD-readings measured at the V6 phenophase of maize between the hybrids (p<0.001) and the fertiliser treatments (p<0.05). The regression analysis did not show any correlation between the SPAD-values and fertilisation.

  The highest significant SPAD-reading and yield were obtained by applying 120 kg ha^-1 N. As a result of the regression analysis performed on yield, it can be concluded that the correlation between fertilisation and yield in the 1^st and 2^nd treatment was moderately close (r=0.439, r=0.480) and it was close in the 3^rd treatment (r=0.513). The correlation between the SPAD-readings and yield was the closes in the 2^nd treatment (r=0.639), while the SPAD-value had a 40.9% influence on yield (p<0.001).