KARACHI, April 28 (Reuters) - The Karachi Cotton Association on Wednesday 28 April fixed the official spot rate, or base price, for Grade 3 cotton at 7,180 rupees per maund (40 kg).

The Grade 3 cotton has a staple length of 1-1/16" (inches) and micronaire value between 3.8 to 4.9 NCL (no control limits) which represents fine to coarse classes of cotton varieties.

In the kerb market the key crop varieties traded in the range of 6,600 to 6,900 rupee per maund.

Following are the grade and staple margins for the period April 1 to 30.
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GRADE STAPLELENGTH
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31/32" 1" 1-1/32" 1-1/16" 1-3/32" 1-1/8"
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Super 0 +123 +246 +370 +493 +616
1 -123 0 +123 +246 +370 +493
2 -246 -123 0 +123 +248 +370
3 -370 -246 -123 BASE +123 +246
4 -493 -370 -246 -123 0 +123
5 -616 -493 -370 -246 -123 0
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