Impact of Various Types of Polluted Water, Rhizome Size and Water Depth on Sprouting of Common Cattail (Typha latifolia L.) Rhizomes

Three different studies were carried out in the Department of Weed Science, The University of Agriculture Peshawar, in January 2016 to examine the impacts of polluted water from various sources, water depths and rhizome size on the resprouting ability and establishment of common cattail rhizomes fragments after mechanical control. These experiments were arranged in Completely Randomized Design (CRD), replicated thrice. The selected experimental units were pots 20 inches wide and 12 inches deep. Typha latifolia L. rhizomes were placed in each pots and covered with a little silt to avoid it’s direct contact and desiccation from sunlight. The impacts of water quality on T. latifolia rhizomes sprouting were significant. Lowest ratio of sprouted and un-sprouted buds (50.00 % each), 1st sprout length (37.33 and 40 cm), average sprout length (17.47 and 16.96 cm), average biomass (9.99 and 10.27 g) and growth rate (0.172 and 0.196 g/day) were noted for saline water and industrial acidic effluents, respectively. However, highest rhizome sprouting was recorded for tap water applied as check followed by industrial effluent alkaline. The data regarding the impact of water depth on T. latifolia rhizome sprouting showed that sprouting (44.44 %), 1st sprout length (43.33 cm), average sprout length (20.99 cm), average sprout biomass (7.84 g), average diameter of the newly formed rhizome (0.24 cm) and growth rate (0.4233 g/day) were recorded for rhizomes placed at zero level water depth, while maximum buds sprouted at 4 inches water depth. Similarly, impact of rhizome size on resprouting revealed that minimum bud sprouting (44.44%), 1st sprout length (44.86 cm), average sprout length (0.93 cm) and biomass of newly formed rhizome (4.97 g) and minimum days to emergence (9) were noted for smaller rhizome length (2 buds) compared to longer rhizomes with 10 buds. Therefore, on the basis of our findings, saline and industrial effluent acidic, no standing water (zero water surface level) and shorter rhizome size resulted in least bud sprouting and minimized the chance of further infestation in an eco-friendly and ecological way without the use of herbicides. Whereas alkaline industrial effluents, standing water up to 4 inches and longer rhizome fragments enhanced sprouting and re-establishment of the T. latifolia and these strategies can be utilized where the aim is to grow and establish a good stand of T. latifolia for passive treatment and phytoremediation of industrial effluents, before draining the polluted water into fresh water bodies like rivers and streams.

Assessment of Chilling Requirement and Threshold Temperature of a Low Chill Pear (Pyrus communis L.) Germplasm in the Mediterranean Area

In temperate climates, bud break and shoot and flower emission of deciduous fruit tree species are regulated by precise chilling and heating requirements. To investigate this aspect, sixty-one accessions of European pear (Pyrus communis L.) collected in Sicily were phenotyped for three consecutive years for harvest date, bud sprouting and blooming to determine both the chilling requirements and the threshold temperature using the Chill Days model. The whole germplasm collection was grown in two different experimental fields located at 10 and 850 m above sea level representing two Mediterranean-type climates in which pear is commonly cultivated. Results revealed a mean threshold temperature of 6.70 and 8.10 °C for the two experimental fields, respectively, with a mean chilling requirement ranging from −103 and −120 days. Through this approach, novel insights were gained on the differences in chilling requirement for early flowering cultivars to overcome dormancy. Furthermore, to better dissect differences in chilling requirement between accessions, the sprouting bud rate of six cultivars was assessed on excised twigs stored at 4 ± 0.1 °C from 300 to 900 h followed by a period at 25 ± 0.1 °C varying from seven to twenty-eight days. Results of both experiments highlighted that Sicilian pear germplasm is characterized by a low chilling requirement compared to other pear germplasm, making Sicilian local accessions valuable candidates to be used for selecting novel cultivars, coupling their low chilling requirements with other traits of agronomical interest.

Reapplication of bud break promoters in ‘Fuji Suprema’ apple trees

The aim of this work was to verify the effectiveness of the reapplication of bud break producers on flowering, sprouting and production of ‘Fuji Suprema’ apple trees. The experiment was carried out in an experimental orchard located in the municipality of Caçador, SC, during 2016/2017 to 2019/2020 seasons. Treatments were applied at stages B and C, and those with reapplication, from 7 to 14 days after the first application. Phenology, axillary and terminal bud break, frui set, production per plant and average fruit mass were evaluated. Phenology was advanced in relation to control with the application of bud break promoters. However, treatments applied at stage B provided greater advance in relation to applications at stage C. In axillary and terminal bud break, all treatments were superior to control. In some seasons, the sequential application of bud break promoters increased bud sprouting compared to single application treatment. There is no reduction fruit set in treatments with sequential application in relation to single application. In plant production, sequential applications did not differ from single application. The average fruit mass was not altered by the sequential application of bud break promoters.

Aplicação de cianamida hidrogenada na quebra da dormência das gemas de videira da variedade Merlot

The objective of the experiment was to evaluate the effect of hydrogenated cyanamide (0%, 2%, 4% and 6%) on breaking dormancy and production of the Merlot vine variety. Variables: number of shoots and bunches, sprouting and fertility index, bunches mass, yield, 0Brix and cost benefit ratio. The doses of 4 and 6% increased bud sprouting without affecting their fertility. Except for the fertility index, the Merlot variety showed a linear response to the application of hydrogenated cyanamide (Dormex®) to the other parameters evaluated, however, the results varied little between the doses of 4 and 6%, indicating the most adjusted dose as 4% considering productivity per hectare.

Metabolic Regulation and Development of Energy Cane Setts upon Auxin Stimulus

Energy cane is a bioenergy crop with an outstanding ability to bud sprouting and increasing yield in ratoon cycles even in marginal lands. Bud fate control is key to biomass production and crop profits due to vegetative propagation and tiller dependency, as well as phenotype plasticity to withstand harsh environmental conditions. During the establishment stage (plant cane cycle), energy cane has a tendency for low root:shoot ratio, which might hamper the ability to cope with stress. Auxin is known to modulate bud sprouting and stimulate rooting in sugarcane. Hence, we treated a slow and a fast bud sprouting energy cane cultivars with auxin or controls (with and without water soaking) for 6 h prior to planting and evaluate plant growth parameters and metabolic profiling using two techniques (gas chromatography with time-of-flight mass spectrometer and nuclear magnetic resonance) to characterize the effect and identify metabolite markers associated with bud inhibition and outgrowth. Auxin inhibited bud burst and promote rooting in setts changing the root:shoot ratio of plantlets. Metabolome allowed the identification of lactate, succinate and aspartate family amino acids as involved in bud fate control through the potential modulation of oxygen and energy status. Investigating environmental and biochemical factors that regulate bud fate can be incremental to other monocot species. Our study provides new insights into bud quiescence and outgrowth in cane hybrids, with the potential to leverage our understanding of yield-related traits, crop establishment and adaptation to global climate change.

Effects of Salicylic Acid and Calcium Chloride on Heat Tolerance of Poinsettia

Exogenous application of either salicylic acid (SA) or calcium chloride (CaCl2) to alleviate heat stress has been extensively studied. However, the effects of combined SA and CaCl2 treatment on the heat tolerance of poinsettia have been poorly studied. This study investigated the role of a foliar spray comprising SA and CaCl2 in managing heat tolerance of three poinsettia (Euphorbia pulcherrima Willd.) cultivars, Noel, Winter Rose (WR), and Ice Punch’ (IP). Plants were pretreated with SA, CaCl2, or combined SA and CaCl2 and then exposed to a temperature of 42 °C for 1 hour. Changes in the relative injury (RI) percentage, malondialdehyde (MDA) content, and antioxidant enzyme activities were determined. All plants were then placed in an environment-controlled greenhouse for 14 days and evaluated. Lateral bud sprouting (%), new leaf numbers, and phenotypic appearance were recorded. Results revealed that the three poinsettia cultivars varied in their appearance, morphological growth patterns, and ability to tolerate high-temperature stress. Plant growth of ‘Noel’ was more robust than that of ‘WR’ and ‘IP’, which were considerably affected by heat stress, resulting in brown, withered leaves and defoliation. In general, the effects of the combined application of SA and CaCl2 on heat-tolerant ‘Noel’ were superior to those of individual applications and no treatment (for control groups) in terms of the RI percentage, lateral bud sprouting (%), and appearance under heat stress. Application of combined SA and CaCl2 for ‘Noel’ plants was more beneficial for enhancing catalase activity and resulted in the effective alleviation of decreased malondialdehyde content under heat stress. Treatment including 200 μΜ SA and 10 mm CaCl2 may alleviate heat stress and may prove useful in breeding programs focused on improving poinsettia cultivars.

Assessing Rooting Media and Hormone on Rooting Potential of Stem Cuttings of Bougainvillea

An experiment was conducted at Lamjung Campus, Lamjung to assess the rooting performance and bud sprouting of Bougainvillea, an evergreen ornamental vine. The study was conducted in partially controlled environment with two factorial treatments considering factor A in four levels(coco peat + sand, sand + FYM, garden soil, garden soil + FYM and garden soil )and factor B (with and without NAA 3000ppm) were arranged in completely randomized design (CRD) with three replication during September- November, 2016. 18 cuttings having 15 cm in length with 4 buds were planted in each treatment. Root length (7.83cm) found in Sand & FYM was significantly different to other media but rooting percentage (77.77%) was found statistically at par with other media except garden soil. Effect of hormone was found non-significant on total sprouted plant, sprout diameter and number of sprouts/cuttings whereas other parameters were affected significantly. Interaction effect of rooting media and hormone significantly affects root length (11.6cm) and rooting percentage (83.33%) which was found on sand & FYM along with NAA 3000ppm followed by Garden soil & FYM in combination with NAA 3000ppm while others parameters were non-significant. Thus it is advisable to use a good rooting media along with application of NAA 3000 ppm for better rooting in cuttings.