INFLUENCE OF DIFFERENT NITROGEN INFLUENCE OF DIFFERENT NITROGEN FORM APPLICATION ON THE INCIDENCE FORM APPLICATION ON THE INCIDENCE

OF BER AND ELEMENTARY COMPOSITION OF BER AND ELEMENTARY COMPOSITION OF BELL PEPPERSOF BELL PEPPERS

Nada Parađiković1, Tihana Teklić1, Dražen Horvat1, Tomislav Vinković1, Andrej Gumze1

1 University J.J Strossmayer in Osijek, Faculty of Agriculture, Trg Svetog Trojstva 3, HR-31000 Osijek, Croatia

e-mail: nadap@pfos.hr

Sveučilište J. J. Strossmayera u OsijekuPoljoprivredni fakultet Osijek

Trg Svetog Trojstva 3p. p. 117

HR-31000 OSIJEKHRVATSKA

University of J. J. Strossmayer in OsijekFaculty of AgricultureTrg Svetog Trojstva 3POB 117HR-31000 OSIJEKCROATIA

Introduction Calcium is a very important nutrient in highly productive

fruit growing such as glasshouse-grown sweet pepper, but inadequate Ca supply manifests with clear symptoms, such as, for example, local decay of pepper fruits (blossom-end rot = BER),

Strong cell wall reflects adequate supply of calcium in plants, which ensures longer storage life of fruits, resistance of plants and fruits to diseases, allow longer roots and shoots function and higher tolerance on either lower or higher temperatures.

However, growth on substrates with high concentrations of NH4+, K+ and Mg2+ may result in insufficient absorption of calcium

The aim of this study was to compare the effect of different N forms on incidence of BER, yield and fruit quality of pepper fruits of the Cecil F1 cultivar in the region of East Croatia.

Material and methods In the region of East Croatia, located Gajić, Baranja,

(45049/N, 18044/E), the pepper plants (Capsicum annuum L., cv. Cecil F1, Rijk Zwaan) were grown in heated greenhouse, 3.0 plants m-2 on the substrate (soil), made of a mixture of turf, cattle and chicken manure and sand of the following chemical properties: humus 3,74 %, pH 6,09 (in 1M KCl), AL-P2O5 8,8-41,0 mg/100 g, AL-K2O 27,1- 47,8 mg/100 g of soil.

Standard fertilization was done prior to planting on entire trial plot of 100 m2 with 200 kg/ha 8:26:26 and 100 kg/ha of urea CO(NH2)2, whilst during fruit formation there were 30 fertigations system drop by drop, (over the period 15.03.-15.09.), by christalon (10x30 kg/ha 11:44:11, 4x30 kg/ha 20:20:20, 10x20 kg/ha 9:12:36 +3 MgO+ ME).

Growing plot was divided in two equal parts, N rate [500 mg N plant-1 week-1] NO3

- - dominated 4:1 ratio NO3- : NH4+,

and levels of NO3- -N [133,0 mgl-1], and levels of NH4

+ -N [35,0 mgl-1]. N rate [500 mg N plant-1 week-1] NH4

+ -dominated 1:4 ratio NO3- : NH4

+, and levels of NO3- - N [35,0

mgl-1], and levels of NH4+ - N [133,0 mgl-1].

NO3- dominatedNH4

+ dominated

There were 14 harvests of fruits (10.05. – 25.09.), and the results obtained with regard to the number and size of all fruits. Fresh weights of ripe pepper with and without BER were recorded for each plant, as well as total yield and yields per harvests were analyzed according to the standard statistical analysis (to determine significant differences between N-application rates within each N form).

Results and discussions Average values of the mass and fruits number, average

and yields per harvest (g/fruit) and percentages of commercial fruits, percentage of Ca in leaves and stems dry mass of the Cecil pepper cultivar in the studied treatments, are presented in the Table 1.

Table 1. Incidence of BER in pepper fruits under influence of N-form fertilization, Ca concentration in plants and temperature (data are means of 4 repetition)

* standard deviation

N-form Yield per harvest g/fruit Fruit number per plant Fruit number per plant with BER Ca % in leaves DM Ca % in stems DM Temperature °C

NO3- - 121,90 4,80 1,50 0,00 0,00 19

dominated 138,50 4,40 2,30 0,00 0,00 18

  129,00 7,00 1,30 0,00 0,00 19

  144,00 8,50 4,00 4,88 1,00 25

  146,40 10,00 4,00 4,84 1,70 26

  129,30 12,10 3,80 5,67 1,75 23

  149,50 11,10 5,30 7,98 1,80 27

  146,60 11,10 5,80 4,25 2,82 28

  154,80 10,30 3,50 0,00 3,50 27

  140,70 8,20 4,00 0,00 0,00 25

  146,30 9,30 4,30 0,00 0,00 24

  129,70 9,10 2,50 0,00 0,00 20

Mean 139,72 8,82 3,52 2,30 0,75 23,42

STDEV* 10,09 2,42 1,39 2,98 1,25 3,55

NH4+ - 122,10 5,00 1,60 0,00 0,00 19

dominated 140,00 5,70 2,80 0,00 0,00 18

  132,90 8,20 2,80 0,00 0,00 19

  145,70 9,20 4,80 4,05 1,47 25

  158,50 11,90 4,30 4,08 1,07 26

  156,30 12,30 5,50 3,87 1,05 23

  152,20 12,20 6,00 4,05 1,09 27

  151,00 11,70 6,50 5,60 1,12 28

  163,00 11,30 6,30 0,00 0,00 27

  151,50 8,60 6,50 0,00 0,00 25

  150,70 10,60 6,00 0,00 0,00 24

  139,30 10,50 3,00 0,00 0,00 20

Mean 146,93 9,77 4,67 1,80 0,48 23,42

STDEV* 11,60 2,48 1,71 2,27 0,61 3,55

By statistical analysis of total number of pepper fruits per plant it was determined:Simple linear correlation analysis for NO3

- - N fertilization, showed statistical significant and medium high-level correlation (r=0,639*) with total number of BER affected fruits and for NH4

+ - N fertilization showed statistical very significant and high-level correlation (r=0,829**) with total number of BER affected fruits.

Analysis between total fruit number per plant and total BER affected fruit number per plant showed statistical significant and high-level correlation (r=0,81**), and relations between NO3

- : NH4+ BER affected and unaffected are showed in Fig. 1

Fig. 1. Proportion of total number of pepper fruits

0

100

200

300

400

500

600

700

800

NO3 NH4

BER affected

BERunaffected

Conclusion Between fertilization level 500 mg N plant-1 week-1 with NH4

+ - N dominated and NO3

- - N dominated, there was no

significant difference in plant-biomass production, pepper yield, and the occurrence of BER. However, BER have appeared in high temperature conditions on this fertilization level in summer period. This is significant for further studies to increase our understanding of the complex interactions that might occur in relation of BER appearance and nitrogen fertilization.

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