Marinice Oliveira Cardoso

Avaliação de repolhos de verão na várzea do estado do Amazonas

A field experiment was carried out at Embrapa Amazonia Ocidental (Agroforestry Research Center for the Western Amazon) in Iranduba county, AM, from September to December 1995, to evaluate nine cultivars of summer cabbage: Uniao, Master, Shutoku, Saiko, Sooshu (control), XPH - 5786, XPH - 5787, XPH - 5904 e XPH - 5909 in a Low Humic Gley soil, floodplain ecosystem. The first five cultivars are commercial cabbage and the others experimental hybrids. The experimental was laid out in a randomized block design with four replicates and twenty plants, at planting distances of 0.80 m x 0.40 m. Due to the native high levels of nutrients in floodplain soils, only N and B fertilizers were used. Necessary irrigation and cultural practices were conducted for cabbage cultivation. Hybrids Saiko (12.5 kg) and Sooshu (15.0 kg) produced highest yields per plot and the lowest by hybrids Master (7.0 kg) and cv. Uniao (6.0 kg). Hybrids Sooshu (810.6 kg), Shutoku (719.1 g) and Saiko (698.0 g) produced the greatest head weight. Hybrids Saiko and Shutoku produced the most compact heads. In hybrids Shutoku and Saiko heads were slightly flattened, a trait of commercial preference, and flattened in Sooshu (control); and in the other cultivars were slightly lengthened in shape. For depth of core (core length/longitudinal diameter) only hybrids Master and Shutoku had depreciated values (0.62 and 0.64, respectively). The most early hybrids were Sooshu (75 days), Shutoku (84 days), Saiko (84 days), and cv. Uniao (85 days) and the latest hybrid XPH-5787 (92 days). It was concluded that the hybrid Saiko produced the most consistent set of desirable characteristics with good adaptation to the soil and climatic conditions of the floodplain ecosystem. It is recommended that his hybrid be tested in larger experimental areas, in this ecosystem.

Growth, nutrition and yield of eggplant as affected by doses of cattle manure and magnesium thermophosphate plus cow urine

The stem growth, nutrition, and fruit yield of eggplant grown with different doses of cattle manure (CM) and magnesium thermophosphate (MT) were studied, according to the Central Composite Matrix of Box (8.3-518; 8.3-3,018; 48.3-518; 48.3-3,018; 0.0-1,768; 56.6-1,768; 28.3-0.0; 28.3-3,536; 28.3-1,768). Potassium sulfate (KS) was also used (24 g plant-1), as well as a cow urine (COU) solution (10 L 100 L-1 H2O, 500 mL plant-1), applied five times in topdressing. Two additional treatments were used: MT without COU and triple superphosphate + urea (TS plus Ur), both with nutrient levels (CM, P2O5, and KS) corresponding to the combination 28.3-1,768. The experimental design was blocks at random, with three replications. CM doses improved plant height (PH) (29.1 t ha-1 of CM; 69.84 cm) and stem diameter (37.8 t ha-1; 19.8 mm), fitting into a quadratic model. However, due to the positive interaction between CM and MT, PH increased up to 86.87 cm when the same CM dose was combined with 3,536 kg ha-1 of MT. CM doses had also a quadratic effect over number of fruits, fruit production per plant, average fruit weight (AFW), and yield, with respective maximum values corresponding to 53.4 t ha-1 (13 fruit), 55.8 t ha-1 (2,822 g plant-1), 47.8 t ha-1 (210 g fruit-1), and 48.8 t ha-1 (34.3 t ha-1), without significant effects of MT. N and P foliar contents did not change with treatments. CM doses increased K, Ca, and S, and decreased Mg foliar contents. But, concerning Ca, was observed negative interaction of MT. COU showed no effect over the characteristics analyzed. The effect of TS + Ur was larger than that of MT + COU on PH and production indexes, except for AFW, but did not differ from them as to macronutrient foliar contents.

Web blight (Thanatephorus cucumeris): a new disease on leaves of okra plants

Arq. Inst. Biol., v.84, 1-5, e0252016, 2017 ABSTRACT: In an experiment on organic production of okra (Abelmoschus esculentus (L.) Moench) that was carried out from September 2013 to January 2014, in Manaus, Amazonas state, Brazil, we observed large chlorotic, necrotic, helical, discontinuous, dark or light-brown lesions with partial detachment of the injured area on the adaxial surface of leaves located in the median and basal portions of the plants. A whitish mycelium mantle covers the lesions on the leaves at the abaxial surface at high moisture conditions. Using morphological characteristics, Koch’s postulates, and phylogenetic analyses of the ITS-5.8S rDNA region, we identified that the fungus causing the lesions on the okra leaves was Thanatephorus cucumeris (Frank) Donk (asexual stage of Rhizoctonia solani Kuhn of the anastomosis group AG-1 ID). This is the first report of T. cucumeris causing web blight on okra in Brazil, and probably in the world. So far, T. cucumeris was described on okra only on post-harvest pods rotting and seedlings’ damping off.

Nitrogen applied in okra under non-tightness grown and residual fertilization

The aim of this study was to evaluate, in the Amazonian rainy season, the effect of nitrogen applied in okra under non-tightness grown and residual fertilization. The trial was carried out in the Embrapa Amazonia Ocidental, in Iranduba, Amazonas state, Brazil, between October/2010 and February/2011, in dystrophic Yellow Argisoil, medium texture, using pits with residual fertility. The experimental design was of randomized blocks with four repetitions (two lines with four plants, spacing of 1.5x1.0 m) and four main treatments (urea: 0.0; 20.0; 40.0 and 60.0 g plant -1 corresponding to 0.0; 60.0; 120.0 and 180.0 kg ha -1 of N, respectively, in two portions) using cv Dardo. Besides two additional treatments: chicken manure (1.0 L pit -1 , with the cv Dardo) and cv Santa Cruz-47 (with urea rate of 40.0 g plant -1 ). Micronutrients in pits and dripping system irrigation were applied. All the studied traits had significant quadratic response with the increase of the urea rates. The highest estimated value for the plant height (39.7 cm), canopy diameter (86.2 cm), fruit number (36.0 un plant -1 ), fruit average mass (17.3 g), harvest number within production cycle (26.4 un cycle -1 ) and of the yield (4051 kg ha -1 ) were observed with (g plant -1 of urea): 48.3; 43.5; 38.5; 49.7; 32.7; and 40.5, respectively. Those original traits contributed reasonably poised for plant overall performance (PC1), but subordinate there was antagonism between harvest number and fruit number versus fruit average mass and canopy diameter (PC2). The chicken manure showed positive response compared to the control treatment, but didn’t differ from urea rates for all these characteristics. When compared to cv Dardo, the cv Santa Cruz-47 only presented higher values to canopy diameter and number of harvests. The economical efficiency maximum dose was 40.2 g plant -1 of urea (120.6 kg ha -1 of N), with net income per hectare equal to 2.09 tons of okra fruits.