Page 32 - 22 Cotton SA magazine

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High yield increases in the boron/potassium improvement compared to the controls. However,
combination treatments at the lower and higher the high potassium with boron treatment achieved
potassium dosages were not observed in the strength values of 29,2 gms/tex, which is
combination treatments of the calcium/boron marginally higher than the others.
trial. Interestingly, the yield increases in the A summary of the results is given in Table 1.
calcium/boron treatments were confounded by Treatments did not differ significantly. Fibre
the boron additions. length values were quite long and the strength
In Figures 3 and 4, the strength values values were within the acceptable ranges of
obtained for the two trials were compared. above 28 gms/tex. The micronaires achieved
Although all the strength values were above in the calcium/boron trial were somewhat in
28 gms/tex, there did not seem to be a significant the higher range (normal is 3,5–4,9), while
those of the potassium/boron trial
Table 1: Yield and fibre quality results for the respective trials. were between 4,0 and 4,1. The
spinning consistency index (SCI)
Calcium/boron Potassium/boron was high in the potassium/boron
trial trial trial (Table 1).
Gin out turn (GOT %) ±45% ±41% The yield increase when
Yield range of all treatments (kg/ha) 4 500–4 750 5 400–6 000 potassium was applied (Figure 2)
Strength (gms/tex) 28,0–28,7 28,2–29,2 was as high as approximately 600
UHML (inches) 1 1 / 8 ”–1 5 / 32 ” 1 1 / 4 ” kg/ha in the lower potassium-only
Micronaire 4,7–5,0 4,0–4,1 treatment (K1B0) and the higher
Spinning consistency index (SCI) 128–132 148–153 potassium/boron (K2B2) treat-
ments. This can mean a significant
increase in income per hectare
Figure 1: Seed cotton yield (kg/ha) of the calcium/boron (CaB) trial. for the farmer. At an average
seed cotton price of ±R8,00/
kg it can result in an additional
average gross income of
R4 800/ha more.
Although the boron addi-
tion showed an increase in crop
yield, it did not have an influ-
ence on fibre strength when
comparing treatments. The trial
could be expanded by testing
the treatment effects on cotton
under drought stress. Although
Figure 2: Seed cotton yield of the potassium/boron (KB) trial. the calcium treatments showed

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