Glêidson Bezerra de Góes

Crescimento de meloeiro e acúmulo de nutrientes na planta sob irrigação com águas salinas

This study was conducted in a greenhouse at the Environmental Sciences Department of the Federal Rural University for the Semi-Arid. Four soil types, traditionally used for cantaloupe production in the Mossoro Region, were used and irrigated with solutions corresponding to eight electrical conductivities (EC = 100; 250; 500; 750; 1,250; 1,750; 2,250 and 3,000 µS cm-1) and two sodium adsorption ratios [SAR = 4 and 12 (mmol L-1)1/2], combined as salinity treatments. The experiment was a factorial arrangement of 4 x 8 x 2 (four soils, eight EC and two SAR), with three replicates, and 192 experimental units, in a randomized block design. Plant characteristics (fresh and dry matter production and mineral composition) were evaluated. Fresh and dry cantaloupe production was reduced with increased water salinity in two successive crops, leading to plant death a few days after transplanting in the second cycle. Increased water salinity elevated Ca, Mg, Na, K and Cl accumulation in the plants. Saline water use increased salinity and sodicity of all studied soils, diminishing cantaloupe growth.

Growth and yield of forage sorghum cv. BR 601 under green manure

The effect of green manure on growth and yield of forage sorghum BR 601 was studied in a trial carried out at the UFERSA, Mossoro, RN, Brazil. The experimental design was completely randomized blocks in a scheme of split plots in time, with three replications. Treatments tested were seven legume species, Mucuna aterrima, Canavalia ensiformis, Cajanus cajan, Dolichos lab-lab, Crotalaria juncea, Crotalaria spectabilis, and Vigna unguiculata, a mixture of the legumes plus corn, sorghum and sunflower, and spontaneous vegetation as a control. For each treatment the amount of fresh mass, dry mass and contents of N, P, K, Na, Ca and Mg in shoots were determined, from which the amount of nutrients accumulated per hectare was calculated. Fresh mass of shoot, dry mass of shoot, plant height and number of leaves of sorghum, sowed after incorporation of green manures, were evaluated at 20, 40, 60, 80 and 100 days after seeding. Mucuna aterrima was the best option as a green manure because of its better performance in all characteristics evaluated at the end of sorghum cycle. Also recommended are Crotalaria juncea, and Dolichos lab-lab which had the higher dry mass and amount of nutrients in shoots.

Influência do silício na suscetibilidade de Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae) ao inseticida lufenuron e no desenvolvimento de plantas de milho

With the objective of evaluating the effects of silicon in the efficiency of the insecticide lufenuron on the control of Spodoptera frugiperda and on the development of corn plants, two experiments were conducted, one being in laboratory and the other in the field. The treatments consisted of applications of silicic acid associated or not with different rates of the insecticide lufenuron. In the laboratory-conducted experiment, the completely randomized design in 2 x 3 factorial scheme (with or without silicon x rates of lufenuron) with five replicates was utilized, but the field experiment was in randomized blocks with six treatments in 2 x 3 factorial scheme (with and without silicon x dosages of lufenuron) and five replicates. In laboratory, the mortality of fall armyworm, both at 24 and 48h before the application of the insecticide and after application, was evaluated. The damages caused by the larvae and the agronomic characteristics of corn plants were also evaluate in the field. The results showed that silicon interacted positively with the insecticide lufenuron in the control of S. frugiperda, enabling a reduction of the insecticide dosage and it strengthened the plant structure for increasing the stem diameter.

Sorgo forrageiro em sucessão a adubos verdes na região de Mossoró, RN - DOI: 10.5039/agraria.v5i2a683

Forage sorghum behavior in succession to green manures was studied in the region of Mossoro, RN, Brazil. The experiment was carried out in a complete randomized block design with three replications. Treatments tested were seven legume species ( Mucuna aterrima , Canavalia ensiformis , Cajanus cajan , Dolichos lab-lab , Crotalaria juncea , Crotalaria spectabilis, and Vigna unguiculata ) and a mixture of the legumes plus corn, sorghum and sunflower, and spontaneous vegetation as a control. Forage sorghum cultivars BR 601 and IPA 467 were sowed after soil incorporation of green manures. Determinations included dry mass of green manure shoot and of sorghum leaves, and also contents of N, P, K, Na, Ca and Mg from green manure shoot and sorghum leaves. In relation to the control, all green manures improved dry mass of forage sorghum, and the best performance was provided by Mucuna aterrima . Mixture of green manure species did not show advantage in relation to isolated species. In this experiment it was not possible to determine the influence of green manures on soil fertility or sorghum nutrition.