Maria do Céu Monteiro da Cruz

Frequência de irrigação utilizando polímero hidroabsorvente na produção de mudas de maracujazeiro-amarelo

The seedlings production of quality fruit species is carried in a protected environment, and frequent irrigation is needed due to air temperature variations and to keep the substrate moist. Thus, this study was carried out to evaluate different irrigation frequencies and the incorporation of hydro-absorbent polymer in the production of yellow passion fruit seedlings in two substrate types. The seedlings were produced in polyethylene bags of 650 mL in a greenhouse. It was used a factorial scheme 2 x 2 x 3, distributed in a completely randomized design with four replications and five plants per plot, and one per container. The factors studied were two doses of the polymer Hidroplan-EB®/HyB-M: 0 and 3 g L-1, two substrates: soil + manure in the ratio 3:1 (v / v) and Bioplant ®, and three intervals of water replacement: daily irrigation, irrigation in alternate days and irrigation every two days. To analyze the comparative effect of polymer incorporation to substrates, the evaluation was performed when the seedlings issued the first vine, which is the ideal stage for field planting. The polymer incorporation in the substrates provided higher seedling size, which was evidenced by the higher dry matter production. Furthermore, these seedlings even with lower irrigation frequency showed similar size to the seedlings that received daily irrigation and leaf area with higher capacity of dry mass production. Thus, irrigation of yellow passion fruit seedlings can be carried with less frequency, with an interval of one day, with the hydro absorbent polymer incorporation in both substrates. The formation of yellow passion fruit seedlings was anticipated in the substrates that had polymer incorporation, achieving adequate size for field planting before those produced without the polymer.

Carbohydrate levels in the leaves and production consistency of the Ponkan tangerine when thinned out with Ethephon

Management practices that maintain carbohydrate reserves in tangerines are necessary in order to ensure good yields. This experiment was carried out with the object of evaluating the levels of carbohydrates in the leaves, and consistency in the production of the Ponkan tangerine (Citrus reticulata Blanco) when subjected to chemical thinning with five concentrations of Ethephon for three consecutive years. The Ponkan tangerine evaluated had been grafted onto Rangpur lime (Citrus limonia Osbeck), cultivated with a spacing of 6.0 x 3.0 m and were 12 years old. The Ethephon concentrations tested were: 0; 200; 400; 600 and 800 mg L -1 , applied in January of 2009; 2010 and 2011, when the fruits were of 25 to 30mm in transverse diameter. The experimental design was of randomized blocks, with four blocks and four plants per plot. The levels of soluble leaf carbohydrate, starch and total carbohydrates were evaluated during flowering and harvesting. Fifteen days after application of the concentrations, the percentage of thinning was evaluated. Production, pending load and alternate bearing were evaluated when harvesting. Chemical thinning with Ethephon favors the maintaining of leaf carbohydrates in the Ponkan tangerine. The most effective concentration in reduncing the alternate bearing in the Ponkan tangerine is 600 mg L -1 of Ethephon.

PLANTAS HOSPEDEIRAS DE Thyrinteina arnobia (LEPIDOPTERA: GEOMETRIDAE) AFETAM O DESENVOLVIMENTO DO PARASITOIDE Palmistichus elaeisis (HYMENOPTERA: EULOPHIDAE)1

O objetivo deste trabalho foi avaliar a eficiencia do parasitismo e a biologia da prole do parasitoide Palmistichus elaeisis Delvare e La Salle (Hymenoptera: Eulophidae) em pupas de Thyrinteina arnobia Stoll (Lepidoptera: Geometridae) quando criadas em plantas de Psidium guajava ou Eucalyptus cloeziana. Ovos de T. arnobia foram coletados e colocados em sacos de tecido tipo organza envolvendo galhos de plantas de P. guajava (T1) e E. cloeziana (T2) ate as lagartas alcancarem a fase de pupa. Trinta pupas de cada tratamento foram individualizadas em tubos de vidro e expostas ao parasitismo por quatro femeas de P. elaeisis por 24 h. Avaliaram-se a emergencia da progenie do parasitoide por pupa; a porcentagem de parasitismo, pupas mortas e de adultos de T. arnobia emergidos; a duracao do ciclo de vida (ovo-adulto);a longevidade; a razao sexual; e o tamanho da capsula cefalica e do corpo do parasitoide. A porcentagem de parasitismo, a emergencia de P. elaeisis por pupa, a longevidade das femeas e o tamanho da capsula cefalica e do corpo dos machos do parasitoide foram menores quando seu hospedeiro foi criado em plantas de eucalipto. Isso pode ter ocorrido devido a grande quantidade de compostos do metabolismo secundario presentes nesta planta, que podem ser acumulados no corpo do herbivoro ao se alimentar, afetando negativamente o inimigo natural. Palmistichus elaeisis mostrou-se mais adaptado a mirtacea nativa da America P. guajava.