Paricá (Schizolobium amazonicum) can be used for rehabilitation of degraded lands, timber manufacturing markets. However, for its planting, high-quality seedlings should be used. Thus, this study aimed to evaluate the effect of different types of paclobutrazol (PBZ) application and two shading levels on high-quality seedling production. As there was no replication of cultivation environments, we considered each one of them as an experiment. For each environment (35 and 50% shading screen), a completely randomized design was adopted, testing combinations of two types of PBZ application (direct seed immersion in 0.005% PBZ solution; substrate hydration with 0.005% PBZ solution; and 50% seed hydration and 50% substrate hydration; plus, a control), with five replications and five seedlings per plot. The environments were evaluated by analysis of groups of experiments. Seedling growth was evaluated. Under 50% shading, Paricá seedlings had better growth conditions. Application of 100% PBZ in substrate provided compact seedlings with larger dry root phytomass, besides being more practical.
This research evaluated protected environment and substrates for jatoba seedling. Two protected environments were used: (i) black shading screen on the sides and roof; and, (ii) black shading screen on the sides and thermal-reflective aluminized screen on the roof. In each environment the following substrates formulated with cattle manure (M) and vermiculite (V) were tested: 100% M; 90% M + 10% V; 80% M + 20% V; 70% M + 30% V; 60% M +40% V; 50% M + 50% V; 40% M +60% V; 30% M + 70% V; 20% M + 80% V; 10% M + 90%V. The environment protected with black shading screen was more favorable for the formation of jatoba seedlings, resulting in seedlings with higher shoot height and root collar diameter and, therefore, higher quality. Recommendation is to use substrates containing up to 30% of cattle manure to produce high quality jatoba seedlings.
Papaya is characterized as one of the most important crops in Brazil. Thus, good quality seedlings are essential for formation of orchards in agricultural production. This study aimed to evaluate shading levels and substrate compositions for production of papaya seedlings. Growing environments were evaluated with 0, 18, 35, and 50% shading and substrates from combinations (%) of hillside soil (HS), cattle manure (CM), Bioplant ® (BP), washed fine sand (FS), and super fine-grained vermiculite (FV). As there was no replication for the growing environments, the group of experiments were analyzed using a 4 × 4 factorial arrangement (4 shades × 4 substrates), with five replications. Growth and biometric relationships were analyzed. Substrates consisting of 30% HS + 15% CM + 20% BP + 20% FS + 15% FV and 45% HS + 0% CM + 20% BP + 20% FS + 15% FV, as well as environments with 18 and 35% shading formed seedlings with higher plant heights, diameters, phytomass, and Dickson quality indices. The results showed that substrates with a higher content of hillside soil and lower content of cattle manure, associated with an environment with 18 or 35% shading, provided high-quality seedlings.
Seed priming is a practice for improving the expression of seed physiological potential. Such technique consists of synchronizing and reducing the time of seed germination by controlled hydration. The aim of this study was to evaluate the effect of seed-priming with different sugar sources and concentrations on the physiological quality Urochloa brizantha seeds and initial seedling performance. Before treating, seeds were scarified chemically with concentrated sulphuric acid (H2SO4) for 5 minutes to overcome physical dormancy. The experimental design was completely randomized in a 3 x 6 factorial scheme consisting of priming using three sugar sources (glucose, sucrose, and maltose) and six concentrations (zero [water control], 2%, 5%, 10%, 15%, and 20%), with four replicates. The seeds were primed by direct immersion for 2 hours at 25 ºC and, after hydration, they were dried for moisture equilibrium recovery. Seed germination, vigor, viability, and initial seedling growth were evaluated. The results showed that glucose was the source able to promote beneficial effects on the germination of U. brizantha cv. MG-5 seeds. Moreover, the supply of glucose at the concentrations of 2 and 5% for physiological conditioning increased seedling dry phytomass.
The aim of this study was to evaluate protected cultivation environments with different levels of shading and application of foliar chemical agents, on growth, photosynthetic pigments and seedling quality of Capsicum frutensens L. The experiment was developed at the State University of Mato Grosso do Sul, University Unit of Cassilândia, with chili pepper. Three cultivation environments (screen of 18, 35 and 50% of shading) and six leaf chemical agents were used [(1) controlwithout application; (2) Nitrogen (N) 1%; (3) Paclobutrazol 50 mg L-1 + N 1%; (4) Auxin 0.05 g L-1 + N 1%; (5) Gibberellin 0.05 g L-1 + N 1%; and (6) Auxin 0.05 g L-1 + Gibberellin 0.05 g L-1 + N 1%]. Each environment was considered an experiment in which the completely randomized design was adopted and, afterwards, a joint analysis of the same was carried out. The growth and the biometric relations were evaluated. The leaf nitrogen application positively influences the growth and chlorophyll content of pepper seedlings; the application of nitrogen + growth regulator via foliar produces seedlings with higher growth and biometric relations in environments with 50% shading. For the production of seedlings with desirable morphological and physiological aspects, it is recommended to use a foliar application of paclobutrazol + nitrogen in an environment with 50% shading.
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