Abstract
Experiments were conducted to explore the inter-relationships of Zn and P in alfalfa and the effects of the relationship on seed production. The study was conducted with plants grown in the greenhouse at the Texas A&M University Research Center at El Paso. Varying rates of P[subscript 2]O[subscript 5] and Zn fertilizers were applied to a soil selected on the Research Center. Laboratory work was conducted at Texas A&M University. In the initial experiment alfalfa plants were fertilized with 0, 224, 448, 896 and 1792 kg/ha of P?ééO?éà and 0, 17 and 34 kg/ha of Zn in a factorial design. Concentrations of P in shoots and roots were found to be essentially the same. Higher rates of P?ééO?éà were associated with lower Zn concentrations in the shoots. Concentrations of Zn in the roots were higher than in the shoots and were affected by the rate of Zn application. The possibility of P inhibition of Zn translocation from roots to shoots was suggested. The succeeding experiments all had rates of 0 and 1792 kg/ha P?ééO?éà applied in combination with rates of 0 and 34 kg/ha Zn application. Shoots were clipped and analyzed for P and Zn concentrations prior to any further treatments. Significant differences for Zn concentration were found in all succeeding experiments. Levels were higher than in earlier experiments. Plants in one experiment were allowed to mature with no further treatment and seed were harvested. Significant differences were found between Zn treatments for the number of seed produced. Significant differences were found between combination P?ééO?éà and treatments for the number of seeds produced per pod. An IAA spray was applied to plants in one experiment. The general effect was to remove any differences between treatments. Number of seeds and number of pods were reduced with IAA treated compared to no treatment. Seeds per pod increased slightly when no Zn had been applied. ...
Lindsey, Kenneth Edward (1973). Phosphate-induced zinc deficiency in seed production in Medicago sativa L. Doctoral dissertation, Texas A&M University. Texas A&M University. Libraries. Available electronically from
https : / /hdl .handle .net /1969 .1 /DISSERTATIONS -156894.