Compared boron uptake and translocation in cotton cultivars

The mobility of boron (B), a commonly deficient micronutrient in cotton, has been shown to be low in the plant phloem. Nevertheless, studies have indicated that cotton cultivars can respond differently to B application. A greenhouse experiment was conducted to compare B absorption and mobility in cotton cultivars grown in nutrient solution. Treatments consisted of three cotton cultivars (FMT 701, DP 604BG and FMX 993), and five B rates (0.0, 2.5, 5.0, 10.0, and 20.0 µmol L-1). Plant growth and development were monitored for four weeks from the appearance of the first square. The time of onset and severity of B deficiency symptoms varied among cotton cultivars. Initial B uptake of cv. DP 604BG was lower than of the other cultivars, but a greater amount of available B in the nutrient solution was required to prevent deficiency symptoms in this cultivar. Boron deficiency impairs cotton growth, with no differences among cultivars, regardless of the time of appearance and intensity of B deficiency symptoms.

Absorption and Translocation of Boron Applied to Aerial Tissues of Fruiting `Reliance' Peach Trees

Natural and 10B-enriched boric acid solutions were sprayed on whole trees or certain parts of `Reliance' peach trees (Prunus persica L. Batsch) to estimate the uptake and translocation of B. The tissues were analyzed for total B and 10B: 11B ratio. The single or multiple spray treatments of 233 mg B/liter applied at full bloom (FB), FB + 2 weeks, and FB = 4 weeks did not increase B concentrations in leaves or stems collected 45,75, and 105 days following FB. Individual limbs sprayed with 0,200,400,600, or 1200 mg B/liter did not affect B concentrations in six aerial plant parts harvested 3 days following treatment. Boron uptake and translocation were also studied by applying 30 μl of 600 mg B/liter from 10B-enriched boric acid as spot treatments to various peach plant parts. Leaves, stems, and fruit absorbed 10B and translocated it to nontreated tissues. However, only a small amount of 10B was absorbed by 3 days after treatment.