José Carlos Sorgato

Ocorrência de Naupactus cervinus (Boheman) em cafezal na região da Zona da Mata Mineira

Naupactus cervinus is a species highly polyphagous that has already been registered causing damages to many crops in several States of Brazil. This paper aims to register, for the first time, the occurrence of N. cervinus in coffee trees in the State of Minas Gerais, as well as to describe damages and infestation in a coffee plantation. An infestation was observed in a coffee sprout re-plantation, variety Catuai, in the area of Zona da Mata of Minas Gerais. In feeding, adults of N. cervinus cut out the borders of tender leaves giving them an aspect of moon in first quarter. One verified an average of 2,1 ± 0,3 insects for tree and the majority of analyzed plants was inside the class of plants with less than 25% of attacked leaves.

Luminosidade e imersão em água na aclimatização intermediária de Dendrobium phalaenopsis

Dendrobium phalaenopsis is an ornamental orchid that presents good germination and development in asymbiotic culture medium. However its ex vitro adaptation still requires studies, since the dehydration of seedlings may delay its growth and development. This study aimed to investigate the effects of the water immersion and two luminosity conditions in the intermediate acclimatization of D. phalaenopsis. Plants were divided into sets of 40, and immersed in distilled water during 0, 12, 24, 36, 48, 60, 72 or 84 hours. After each immersion period the plants were transferred to containers and allocated inside a growth room for intermediate acclimatization during 30 days. A set of 20 plants from each period of immersion and from the control remained under white fluorescent light (18.9 µmol/m2/s) and the other 20 plants remained under white fluorescent light + red fluorescent light (14.85 µmol/m2/s). Plants were acclimatized in a greenhouse (162.0 µmol/m2/s) for 10 months. As immersion time increased, a decrease in fresh weight and length of pseudobulbs relation occurred, as well as in the number of roots of the plants grown under white light + red light. On the other hand, plants grown under white light did not respond to immersion time. Immersion in distilled water, regardless of light conditions, is not recommended for D. phalaenopsis.

APLICAÇÃO FOLIAR DE GA3 NO CRESCIMENTO E DESENVOLVIMENTO DE Passiflora edulis Sims f. flavicarpa Degener

With the knowledge that the exogenous application of gibberellins can alter physiological processes modifying the growth and development of plants as they function asregulator of cell division and elongation, the aim of this study was to evaluate the growth and development of Passiflora edulis Sims f. flavicarpa Degener grown under light of 650 µmol m-2 s-1 for nine months andsubjected to weekly sprays with GA3. The experimental design was completely randomized with five treatments (0.0, 1.5, 3.0, 15.0 and 30.0 mg L-1 GA3) and ten repetitions. The substrate used was composed of a mixture (1:1:1 by volume) of washed coarse sand, chaff of washed coal and dystroferric red latosol organized in pots with a capacity of 5L. The concentrations of GA3 influenced (p<0.05) most of the variables except the length of the main stem to the insertion of the first lateral stem, the number of lateral stems, the number of nodes of the main stem to the insertion of the first stem side, the number of nodes of the main stem to the insertion of the first tendril and the first three-lobed leaf, at the beginning of flowering, the number of lateral stems issued by the plant at the beginning of flowering and the number of nodes from the base of the main stem up the insertion of the first flower buds. Concentration of around 15 mg L-1 caused higher plant length, greater length, greater number of nodes of the plant, and higher fresh and dry weight of plants. The use of 30 mg L-1 GA3 anticipated the issuance of the first tendril and the first three-lobed leaf and produced a greater number of flower buds. Exogenous use of GA3 at concentrations of 30 mg L-1 was more effective in inducing floral that the evocation of Passiflora edulis Sims f. flavicarpa Degener.

Cultivation period, lighting conditions and BAP concentrations on in vitro induction shoots of Dendrobium phalaenopsis Deang Suree.

The technique of in vitro micropropagation allows the production of large amounts of plants. However, some aspects of the orchid’s in vitro micropropagation are still poorly studied. This study analyzed the lighting conditions, time of cultivation and BAP concentrations on in vitro budburst of Dendrobium phalaenopsis Deang Suree. Therefore, a quantitative analysis of biometric parameters of plants grown during 90 and 180 days on ½ MS medium under different lighting conditions (18.90 mol m-2 s-1, 14.85 mol m-2 s-1, 9.45 mol m-2 s-1) and concentrations of BAP (0; 0.5; 1; 1.5; 2; 2.5 e 3 mg L-1). The best results of budburst were obtained during 180 days, under white fluorescent light (18.90 mol m-2 s-1) and using 1.5±0.1 mg L-1 of BAP.

LUMINOSITY AND WATER IMMERSION IN THE INTERMEDIATE ACCLIMATIZATION FOR Dendrobium phalaenopsis Deang Suree

Dendrobium phalaenopsis Deang Suree has good germination and development in asymbiotic culture medium, however his ex vitro adaptation still requires studies, because it causes dehydration of plants, delay their growth and development. The objective of this work was to study the combined effect of the immersion time in distilled water plant and two luminosity conditions in the treatment of intermediate acclimatization to D. phalaenopsis . Plants were divided into sets of 40, being subjected to immersion for 0, 12, 24, 36, 48, 60, 72 or 84 hours. After each immersion period the plants were transferred for containers containing the substrate planting and later allocated in growth room for intermediate acclimatization for 30 days. A set of 20 plants from each period of immersion and from the control remained under white fluorescent light (18.9 µmol m -2 s -1 ) and the other 20 plants remained under white fluorescent light + red fluorescent light (14.85 µmol m -2 s -1 ). After this period, the plants were subjected to acclimatization in greenhouse for 10 months. While immersion time increased the increments of fresh weight, pseudobulbs number and the roots number of plants grown under white light + red light decreased, while plants grown under white light did not show response with respect to immersion time. Absence of immersion in distilled water independently of luminosity condition is beneficial to plants of D. phalaenopsis Deang Suree.