Timing of micronutrient demand and acquisition by maize (Zea mays L.) is nutrient specific and associated with key vegetative and reproductive growth stages. The objective of this study was to determine the fate of foliar-applied B, Fe, Mn, Zn, and Fe/Zn together, evaluate the effect of foliar micronutrients applied at multiple rates and growth stages on maize grain yield, and determine their apparent nutrient recovery efficiency (ANR). Five Randomized Complete Block Design (RCBD) experiments were conducted in 2014 and 2015 at five locations across Nebraska. Total dry matter was collected at 5–6 stages, and separated into leaves, stalk, and reproductive tissue as appropriate to determine micronutrient uptake, partitioning, and translocation. Foliar B, Mn, Zn, and Fe/Zn had no effect on grain yield for most application time by rate levels, though, at the foliar Mn site, there was a 19% yield increase due to a V18 application of 0.73 kg Mn ha⁻¹ which corresponded with reduced Mn uptake in maize grown in control plots. At the foliar Zn site, there was 4.5% decrease in yield due to a split foliar application of 0.84 kg Zn ha⁻¹ total, applied at V11 and V15 stage, which increased leaf Zn concentrations greater than the established toxic level. Only the Fe site had consistent grain yield response and was the only experiment that had visual signs of micronutrient deficiency. Regardless of application time from V6 to R2, there was a 13.5–14.6% increase in grain yield due to 0.22 kg Fe ha⁻¹ foliar application. Most micronutrients had limited or no translocation, however, early season applications of B, prior to V10, had significant mobilization to reproductive tissues at or after VT. Foliar Mn, Zn, and B application had ANR LSmeans of 9.5, 16.9, and 2.5%, respectively, whereas the Fe/Zn mix had negative ANR LSmeans of −9.1% Fe and −1.3% Zn which indicate suppression. These data highlight the importance of confirming a micronutrient deficiency prior to foliar application, guide specific growth stages to target with specific micronutrients, track the fate of foliar-applied micronutrients, and describe the variable effect of foliar-applied micronutrients on grain yield.

Penstemon seed often shows an inconsistent or a low germination percentage. Although most select cultivars are propagated by cuttings, for export to other countries, seed is preferred. Three experiments were conducted to determine if soaking seed in gibberellic acid (GA ₃ ) would increase seed germination of Penstemon digitalis cv. Husker Red. GA ₃ concentrations used were 0, 10, 50, 100, 200, and 500 mg·L ⁻¹ (first experiment); 0, 500, 1000, and 1500 mg·L ⁻¹ (second experiment); and 0, 500, and 1000 mg·L ⁻¹ (third experiment). The first and second experiments were conducted in a growth chamber, whereas the third experiment was conducted in both a growth chamber and greenhouse with seeds either covered or not covered by the mix. In all experiments, GA ₃ increased the percentage and rate of seed germination. The 1000 mg·L ⁻¹ GA ₃ was the best treatment. In the third experiment, percentage and rate of seed germination were the highest for seeds grown inside of the growth chamber, probably as a result of the consistency of temperatures and darkness. In the greenhouse, the percentage of seeds that germinated and the rate of germination were similar whether or not the seeds were covered with mix and whether they received either the 500 or 1000 mg·L ⁻¹ GA ₃ treatment.

Nebraska soils are generally micronutrient sufficient. However, critical levels for current yields have not been validated. From 2013 to 2015, 26 on-farm paired comparison strip-trials were conducted across Nebraska to test the effect of foliar-applied micronutrients on maize (Zea mays L.) yield and foliar nutrient concentrations. Treatments were applied from V6 to V14 at sites with 10.9 to 16.4 Mg ha⁻¹ yield. Soils ranged from silty clays to fine sands. Soil micronutrient availability and tissue concentrations were all above critical levels for deficiency. Significant grain yield increases were few. Micronutrient concentrations for leaf growth that occurred after foliar applications were increased 4 to 9 mg Zn kg⁻¹ at 5 of 17 sites with application of 87 to 119 g Zn ha⁻¹, 12 to 16 mg kg⁻¹ Mn at 2 of 17 sites with application of 87 to 89 g Mn ha⁻¹, and an average of 8.1 mg kg⁻¹ Fe across 10 sites showing signs of Fe deficiency with application of 123 g foliar Fe ha⁻¹. Foliar B concentration was not affected by B application. Increases in nutrient concentrations were not related to grain yield responses except for Mn (r = 0.54). The mean, significant grain yield response to 123 g foliar Fe ha⁻¹ was 0.4 Mg ha⁻¹ for the 10 sites with Fe deficiency symptoms. On average, maize yield response to foliar Fe application can be profitable if Fe deficiency symptoms are observed. Response to other foliar micronutrient applications is not likely to be profitable without solid evidence of a nutrient deficiency.

As a floriculturist, when I first decided to grow strawberries ( Fragaria × ananassa ) in the greenhouse, I thought it would be a snap. After all, I could practice what I preach to my classes in that I would use all the sustainable growing tricks from floriculture, create a production time line and it would be ready, set grow. However, moving a field-grown summer crop into a greenhouse as a winter crop was not the same as moving a winter greenhouse-grown crop outside for the summer. Not only were the plants typically grown in lush field soil, but also the fertilizer recommendations were not directly translatable (i.e., parts per million nitrogen). The pesticides used were not licensed for greenhouses and of course, there were no clues as to schedules of what to do when. Finally, there were the mystery problems that occurred. With high gas prices and the interest in local food production, it seems probable that over the next 5 to 10 years, more and more fruit, vegetables and even nut plants will be moved into greenhouse and high tunnel production. The purpose of this article is to identify the kinds of information needed to make a “smooth” transition from field to greenhouse for alternative crops, like strawberries, grown during nontraditional seasons.

All living organisms need essential nutrient elements to survive and thrive. For plants, of the 14 essential nutrient elements, over half show deficiency symptoms that include chlorosis. However, this is for plants with green leaves. For purple leaf basil, there has been no reported research on how microelement deficiency is expressed, diagnosed and/or corrected. The purpose of this research was to visually and quantitatively identify micronutrient element deficiencies, specifically, iron (Fe), manganese (Mn) and zinc (Zn), in ‘Red Rubin’, a purple leaf basil. To do this, three cultivars of basil, Italian Large Leaf, a green leaf basil; Aromatto, a mottled purple and green leaf basil; and Red Rubin, a purple leaf basil, were grown for 13–16 weeks. The experiment design was a split-plot with four treatments and the three cultivars. Data included visual observations, relative greenness (SPAD) measurements and tissue nutrient analysis. ‘Red Rubin’ leaves had similar SPAD values to both of the other cultivars. When Fe, Mn or Zn was deficient, purple pigment was lost. However, visual deficiencies such as yellowing and an increase in green color either veinally, interveinally or on the leaf margins varied. Based upon overlapping symptoms and based on tissue analysis, it is possible that there exists a 3-way or even 4-way interaction/balance among the minor elements Fe, Mn, Zn and possibly copper (Cu).

Nitrogen response was compared in two Plectranthus species, Plectranthus parviflorus and Plectranthus ambiguus , which differ substantially in their phenotypic reaction to nitrogen limitation. The leaves of the former species gradually yellow during the nitrogen stress but are retained on the plant. This species copes with nitrogen deficiency also by gradual hydrolysis of starch grains. The latter species, P. ambiguus, responds by abscission of lower leaves. As plant hormones cytokinins are involved in nitrogen response as well as in regulation of the chlorophyll content, their dynamics were followed to explore the fast responses as well as the impact of nitrogen treatment. Both plant species responded to nitrogen deficiency/supplementation in similar ways, by downregulation and upregulation, respectively, of active cytokinins. However, the different phenotypic reactions imposed by nitrogen limitation were associated with specific regulation of cytokinin pool accompanying the stress response by the two species. The increase of the active cytokinins on nitrogen resupply was faster and stronger in the regreening species, P. parviflorus than in P. ambiguus . However, the P. ambiguus plants maintained higher basal levels of all cytokinin metabolites as well as chlorophyll content when compared with P. parviflorus . Nitrogen deficiency was associated in this species with accumulation of cis -zeatin-type cytokinins, which preceded abscission of lower and later on of middle leaves. The achieved results indicate that phenotypic variations in the response to nitrogen deficiency/supplementation are associated with significant quantitative and qualitative differences in the cytokinin pool.