L’effet du KNO3 appliqué par voie foliaire, comparé au KCl appliqué dans le sol, sur le rendement du coton a été évalué dans le cadre d’une étude Beltwide de trois ans. Les rendements ont été calculés en moyenne sur les sites d’étude du potassium foliaire dans 12 États de la Cotton Belt aux États-Unis. Dans les traitements à faible teneur en K du sol, le potassium a été appliqué sous forme de KCl selon les analyses de sol effectuées avant la plantation et pour les traitements à forte teneur en K du sol, cette dose recommandée a été doublée. Le taux foliaire était de 11,2 kg/ha/ pulvérisation de KNO3 appliqué quatre fois à des intervalles de 10 à 14 jours après la première fleur. Tous les traitements ont montré des augmentations de rendement par rapport au contrôle (Figure 1).
SHAPE * MERGEFORMAT <v:rect
id="Rectangle_x0020_9" o:spid="_x0000_s1026" style='width:14.65pt;height:14.65pt;
visibility:visible;mso-wrap-style:square;mso-left-percent:-10001;
mso-top-percent:-10001;mso-position-horizontal:absolute;
mso-position-horizontal-relative:char;mso-position-vertical:absolute;
mso-position-vertical-relative:line;mso-left-percent:-10001;mso-top-percent:-10001;
v-text-anchor:top' o:gfxdata="UEsDBBQABgAIAAAAIQC75UiUBQEAAB4CAAATAAAAW0NvbnRlbnRfVHlwZXNdLnhtbKSRvU7DMBSF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=
" filled="f" stroked="f">
Figure 1. Augmentations moyennes du rendement du coton, calculées sur 12 États de la Cotton Belt.
