Olsztyn University of Agriculture and Technology, Department of Crop Production,
10-728 Olsztyn, Poland
Abstract
Results of two-years lasting strict field experiments (carried out during seasons 1997 and 1998) are given. The trial was performed using fractional factorial design 25–1.The aim of the studies was to determine the response of white mustard to sowing date (early or delayed); soil sulphur application before sowing (0 or 35 kg S per ha); foliar nitrogen nutrition (0 or 6 kg N per ha); weeding (no or trifluraline) and pest control (no or 3 times application of pyrethroids).
Among studied factors sowing date affected seed yield at the highest degree. Delaying of the sowing date (by 3 weeks from the optimal date) resulted in seed yield reduction by 34% (i.e. 24 kg of seed per day of delaying). Favourable effects of sulphur application on yield revealed only on the early sowing date. Sulphur application to the soil decreased yield of late sown plants by 18%. Pest control strongly affected seed yield. Insecticide application resulted in the increase of white mustard seed yield by 5% compared to the treatment without pest control. The effects of other experimental factors on yield of studied crop were within the experimental error.
KEYWORD: Sinapis alba, sowing, fertilization, weeding, pest control
Introduction
Most important oil crops grown in Poland belong Cruciferae and two gender Brassica and Sinapis. Within gender Brassica oilrape is the most important (spring and winter forms), whereas in gender Sinapis – white mustard (Rumińska et al 1993). Aseptic properties of white mustard seeds due to presence of glucosinolanes – mainly sinalbine are widely known. Mustard is rather susceptible to day length and the other important factor determining its yield is sowing date. Nitrogen fertilization is also factor differing mustard seed yield (Jasińska and Kotecki 1994). Studies carried by Ladek et al (1998) showed that efficacy of applied nitrogen is closely related to crop stand density. White mustard has relatively high competitive ability to weeds. This ability might be reduced in the result of drought or improperly done tillage practices. The aim of presented studies was to determine the role of some agrotechnical factors in yield and determining the correlation strength between studied factors.
Materials and MethodS
Trial was carried out in seasons 1997 and 1998 of the experimental field belonging to Olsztyn University of Agriculture and Technology (NE Poland). Experimental design was based on factorial fractional model type 25-1 . Factors and their levels are listed below:
* active substance – trifluralin
Choice of mentioned above design of experiment was resulted from big number of experimental factors (n=5). This design was introduced to experimental practise in 40’s by Finney (1946) and was commonly used in some industrial experiments (Oktaba 1980). Randomization of experimental treatments according to the number of factors, method of block splitting and information enabling of an estimation of possible main and interaction effects were published by Box et al (1978) and Gołaszewski, Szempliński (1998).
The experiment was performed on Luvisol with medium content of silt originated from medium clay of pHKCl 6.4-6.5. Contents of available nutrients were as follows: P was ranged from 12.0 to 14.0 mg of P2O5 per 100 g of the soil (Egner-Riehm); K from 12.5 to 15.0 mg K2O per 100 g of the soil (Egner-Riehm) and Mg from 7.6 to 4,4 mg Mg per 100 g of the soil (Schachtschabel). Before sowing the following amounts of fertilizers were applied: 35 kg P2O5 per ha (as triple superphosphate) and 75 kg K2O per ha (as 57% potassium salt) and 60 kg of N per ha (urea). Sulphur was applied (factor B, level 1) as potassium sulphate.
White mustard seeds cv. Borowska were sown in late April (early date) and in middle May (delayed date) in sowing rate 9 kg ha-1 in row space 20 cm. Plot area to harvest amounted to 9 m2. In plots with full pest control (factor D, level 1) seed were treated with seed dressing Super Homai 70 DS (active substances methyle tiafanat, tiuran and diazinone). During crop growth and development in plots with full pest control three times insecticides were applied: (Decis 2.5 EC – deltametryna, Fastac 10 EC –alfacypermetryna and Sumi Alpha 050 EC – esfenwalerat) whereas in plots without pest control no insecticide was applied. In plots with weeding (factor D, level 1) Triflurotox 250 EC was used.
Results
Insect injuries on white mustard plant
The level of injuries done by pest infecting stems and pods were relatively small and recorded only on 1-3% stems and 1-2% pods. Level of injuries recorded of stems and pods was not related to experimental factors. The most harmful pest noted on white mustard plant was Meligethes aeneus F. This pest destroyed 64 blooms per plants in unprotected treatments and 52 blooms per plants on plots with full pest control (Fig. 1). Applied pyrethroids saved 12 blooms per plants, i.e.1032 blooms per 1 m2. The other experimental factors did not affect injuries done by Meligethes aeneus F.
Fig. 1. The effects of pest control on number of damaged blooms
Yield components of white mustard seed
The effects of factors under study on yield components is presented in table 1.
Table 1
Statistical analysis of yield components of white mustard
* - significant differences at P=0,05; ** - significant differences at P=0,01; n.s. – not significant differences
Plant number per 1 m2 was significantly higher on delayed sowing date (better emergences) (Table 2).
Table 2 Relation between sowing date and yield components
Sowing date |
Plants number before harvest per m2 |
Number of pods per plant |
Seeds number per pod |
Weight of 1000 seeds (g) |
Early |
82.4 |
45.1 |
4.34 |
9.65 |
Late |
91.0 |
29.7 |
4.40 |
8.65 |
Pods number per plant was also related to sowing date (Table 1). On later sown plants lower number of pods was set by 34% compared to early sowing date. Early sown plants of white mustard produced ca. pods 3700 per 1 m2, whereas in conditions of delayed sowing it was 2700 pods per 1 m2. In pod of white mustards 3.96 to 4.78 seeds were set. This yield component was the most differentiated by pest control and S fertilization (Table 1). Sulphur application resulted in increase of seed number per pod (by 6%) only in the conditions of an absence of herbicide usage (Fig. 2). Plants treated with herbicide responded to S application by the reduction of seed number in pod (Fig. 2). Late sowing date resulted in decline of 1000 seeds weight by 11% (Table 2). Foliar nutrition with N applied to late sown plants reduced 1000 seeds weight by 4% whereas nitrogen applied to early sown mustard did not affect this yield component (Fig. 3). Weeding contributed to increase of 1000 seeds weight only when N foliar nutrition was applied. In treatments where herbicide was not applied foliar applied N reduced weight of 1000 mustard seeds by 4% (Fig. 4).
Fig. 2. Relation between S fertilization, weeding and seed number per pod
Fig. 3. Relation between sowing date, N application and weight of seeds
Fig. 4. Relation between N aplication, weeding and weight of 1000 seeds
Yield of white mustard seeds
Delaying of the sowing date by 3 weeks resulted in yield reduction by 34% i.e. 24 kg of seeds per 1 day of delaying (Fig. 5).
Fig. 5. Relation between the sowing date and yield of white mustard
Favourable effects of S application revealed only in early sown treatments (Fig. 6). Sulphur applied for early sown plants increased seed yield by 9% whereas soil application of sulphur for late sown plants resulted in yield decrease by 18% (Fig. 6). Applied insecticides (three times) resulted in increase of white mustard seed yield by ca. 5% in relation to plots without insecticides (Fig. 7).
Fig. 6. Relation between sowing date, S application and white mustard seeds yield
Fig. 7. Relation between pest control and white mustard seeds yield
Foliar N nutrition and chemical weeding contributed to yield increase only in the conditions of early sowing (Table 3). In the conditions of delayed sowing date crop response to herbicide application and foliar N nutrition in terms of the reduction obtained yield was 11 and 10%, respectively (Table 3).
Table 3 Yield of white mustard (dt seeds per ha)
Date of |
Foliar N nutrition |
Weeding | ||
sowing |
no |
6 kg N ha-1 |
no |
Triflurotox |
Early |
14.1 |
15.3 |
14.7 |
14.7 |
Late |
10.3 |
9.2 |
10.2 |
9.2 |
Conclusions
1. Yield of white mustard seeds is determined by sowing date and pest control. Delaying of sowing date by 1 day resulted in yield reduction by 24 kg of seeds.
2. Favourable effects of foliar N nutrition and herbicide application on obtained seed yield was revealed only in the conditions of early sowing date.
3. The most important pest on white mustard appeared to be Meligethes aeneus F.. Insecticides application did not fully protect against its infestation. Pyrethroides application resulted in the reduction of bloom injuries by ca. 19% what contributed to yield increase by 5% (irrespectively of sowing date).
References
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3. Gołaszewski J., Szempliński W. 1998. Fractional factorial desing as the method in elaboration of field crop production technology (in Polish) . Rocznik Nauk Rolniczych, 113: 77-93.
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5. Ladek A., Wałkowski T., Szwak A. 1998. Wpływ zróżnicowanego nawożenia azotowego i gęstości wysiewu na plony 3 typów gorczycy białej. Oil Crop, XX „unpublished data”.
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