The objectives of this work were to a) determine vermicompost effect on bulbification dynamics in terms of garlic (Allium sativum L.) bulb dry weight and sucrose metabolism and b) evaluate the impact of vermicompost on garlic bulb yield and quality. The treatments were soil (control) and 1 soil: 1 vermicompost (by volume). The use of vermicompost as a substrate caused early bulbing (18 to 20 days) and lengthened bulb filling period. Bulb filling period corresponded to an increase in the total soluble carbohydrates and a later modification in nonstructural carbohydrate distribution patterns regarding fructan (scorodose) metabolism. The vermicompost treatment increased scorodose accumulation, which was directly related to the harvest index, resulting in greater yield and bulb quality. Bulb quality was not modified in terms of bulb pungency and soluble solids content by the use of vermicompost.

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Knowledge about the specific characteristics of floral transition process in oregano (Origanum vulgare L.) is scarce. Photoperiod is one of the environmental factors regulating oregano development. The aim of this study was to evaluate anatomical changes associated with the phenological transition from vegetative to floral stages of O. vulgare L. subsp. vulgare (Compacto ecotype) and O. vulgare L. subsp. hirtum (Link) Ietsw. (Criollo ecotype), in response to day length variations. These two traditional subspecies were grown under natural and artificially 6-h extended photoperiod. Phenology and internal floral transition did not follow a single evolution pattern, since these processes respond to complex geneenvironment interactions. In the oregano subspecies studied, transition from vegetative to reproductive stages presented an intermediate step, consisting of the formation of an inflorescence meristem. Thus, floral transition occurred gradually and acropetally along the floral axis. Within the floral meristem, the appearance of reproductive perianthic pieces also occurred acropetally. Extended photoperiod seemed to act as a signal accelerating the floral transition process of the meristems, which confirms that oregano is a long-day plant. In addition, phenological and anatomical analyses confirmed that Criollo ecotype was most sensitive to photoperiodic lengthening, as evidenced by an earlier bud development all along the floral branch.

Soybean plants (Glycine max L. Merrill) that had reached full nodulation were submitted to physiological water stress by using polyethylene glycol (PEG 6000). Gibberellin A and/or abscisic acid were sprayed in an attempt to alleviate or mimic the stress. After rewatering the plants, endogenous growth inhibitors in the root system, nitrogenase activity (as per root or nodule basis), number of nodules per plant, and the fresh and dry weight of nodules and roots per plant and per treatment were investigated. Drought depressed both nodulation and nitrogenase activity and increased the levels of growth inhibitors in roots. However, ABA increased symbiotic N2 fixation activity in control plants growing in field capacity and also partially reversed the deleterious effects of drought. Gibberellin A had no action on control plants but annulled the effects of ABA. There was no correlation between the levels of growth inhibitors promoted by exogenous application of growth regulators and the nitrogenase activity and weight of nodules. Thus, the diminution in nodulation and the reductive capacity of the system is not due to inhibitors accumulated in roots by the effect of drought.