Effects of Calcium Containing Foliar Fertilizers on DPL449BR Cotton in the Palo Verde Valley, 2005

Abstract

Seven foliar fertilizers containing calcium were applied to DPL449BR cotton in the Palo Verde Valley on June 24, 2005, immediately after three consecutive days of level one stress. Plants had been blooming prior to application and had several open blooms per plant at time of application. All treatments increased level of leaf chlorophyll by at least 7.4% when compared with the untreated check as with a Minolta 502 SPAD meter on July 7, with greatest (21.3%) increase noted from Calcium Metalosate®. No statistical differences were noted for this parameter on July 13, and by July 21 highest mean leaf chlorophyll content was noted from untreated cotton. Leaf chlorophyll was lowest in untreated cotton on July 25 however. Shortest stigma lengths beyond anthers on July 13 was noted in treatments with highest amounts of calcium applied per acre, while all treatments had numerically fewer abnormal flowers than the untreated check on July 21. Treatments resulted in slightly taller plants than the untreated check on July 6 and 21, and more nodes on July 6. Most treatments also resulted in more fruiting nodes per plant on July 21 and August 4. Greatest height:node ratios were noted in CalMax® treated cotton on all three sample dates. Highest retention percentages were noted in untreated cotton on July 6 and August 4. All treatments resulted in numerically more fruiting structures/plant than the untreated check on July 21, although only CalMax® treated cotton had significantly more. Most treated cotton had fewer such structures per plant on August 4 than on July 21, however such structures in untreated cotton increased during this time. Calcium Metalosate® was the only treatment that resulted in more seed cotton/acre than the untreated check. Calculated lint yields varied, and reflected the single datum turnout percentage for each treatment derived from commercial ginning of modules. Wide variation in turnout data do not appear to be supported with differences in cotton quality data, as similar economics were noted for all cotton lint on a per pound basis.