Botany

Micrasterias
fimbriata

BA410

PlanFluar 10x

Moticam 10
Botany

Crystals in
Larix decidua

BA410E

PlanApo 40x
pol. lam.

Moticam 10 stack
Zoology

Parnassius apollo
part of wing

BA310E

PlanApo 20x

Moticam 10 stack
Histology

Femur cross
section

BA310E

PlanApo 20x

Moticam 10
Pathology

Haemolysis
streptococcus
sepsis

BA410

PlanAchro 100x o.i.

Moticam 5
Microbiology

Onion mitosis

BA410 

PlanAchro 60x

Moticam 5
Zoology

Barnacle on
mussel

SMZ-171

Stereo

Moticam 10 stack
General

Tumbled gems

SMZ-171

Stereo

Moticam 10 stack
Pathology

Eimeria stiedae
in liver

BA410 
PlanFluar 20x

Moticam 10
Microbiology

Penicillium with
conidiophores

BA310E

PlanApo

Moticam 10
Histology

Artery

BA410

PlanAchro 10X

Moticam 5
General

Urea crystals

BA410

PlanFluar 20x
pol lam

Moticam 10

Eating corn smut?

  • Ustilago zeae
Common smut of corn, caused by Ustilago zeae (now known as U. maydis), is easily identified by tumor-like galls that form on actively growing host tissues and contain masses of dark, sooty teliospores. Throughout most of the world, common smut is considered to be a troublesome disease of corn, but in central Mexico, galls on ears of corn are considered an edible delicacy known as cuitlacoche (Syn. huitlacoche). In addition to the practical significance of causing a prevalent disease and being an edible fungus, U. maydis also has been used as a model organism to study a variety of interesting biological phenomena.
plant97
Prepared slide by Lieder www.lieder.com


 

Gooseberries under attack

  • gooseberry mildew plap20
Powdery mildew (Sphaerotheca mors-uvae) severely infects young shoots, stems and fruits of gooseberry (Ribes uva-crispa). Environmental friendly and biological control measures are being sought throughout the world. Especially in organic currant growing, effective control measures are needed, because powdery mildew infections may result in a total loss of the crop. In organic currant growing the number of adequate control methods is very limited.
plant95
Sulphur as a fungicide against powdery mildew in e.g., gooseberry or table grape growing is not recommendable due to possible bleaching of berries and scorching of tender shoots.

Various bicarbonate salts are suggested as a good option to control powdery mildew. In a series of experiments the effect of potassium bicarbonate (formulated and unformulated products) on powdery mildew of gooseberry was evaluated. In the trials different strategies were tested; i.e., preventive and curative strategies. The percent of infected berries, shoots and disease severity were assessed. Very high disease incidences were observed in the untreated control. All potassium bicarbonate treatments significantly reduced the powdery mildew severity in leaves and fruits compared to the untreated controls. The preventive strategies were very successful. However, the number of spray applications was high.

Frequently, a severe phytotoxicity caused by potassium bicarbonate was observed. Several experiments were performed with different dosages, timing of sprayings and spray intervals. The potential and limitations of potassium bicarbonate used to control powdery mildew in the field are being discussed.

Prepared slide by Lieder www.lieder.com


 

Pear rust and Junipers

  • Pear rust plap20mot10
Pear Rust is an increasingly common fungal disease in pear trees. This disease can significantly slow the growth of a pear tree, and the tree will also give less fruits. Pear Rust is a fungus that cannot stay the whole year on the pear: in winter the tree has no leaves and the fungus is only present there. In winter, the fungus needs a Juniper to overwinter. After the winter the fungus makes spores, which are spread through the air. The spores fall on the pear tree, causing the fungal disease.

Pear Rust is very easy to recognize. The disease begins with deep orange spots on the leaf, often with a brown core. These spots are often oval shaped, but not perfectly round. Later under the leaf, a large orange hump is formed on the same place as the spot, later even with light brown to white projections. From there, the fungus spores are spread. Below is a picture on which the disease can be recognized.

The best way to combat this disease is to remove the Junipers that transmit this disease. If all the Junipers in the area (this can be several hundred meters away) are removed, damaged leaves should be removed and the tree must be plucked bare in winter. If it is not possible to remove the Junipers, the disease can still be kept in check. The most effective method to do this is with a combination of the removal of degraded leaves before the disease further infects the tree, and spraying with a pesticide. The problem with this is that the treatment has to be repeated constantly: for example, spraying has to be done five times a year, depending on the severity of the disease. However the fungus will continue to hide in the Juniper and can just come back.
plant94
Pycnidia are asexual fruiting bodies. When ripe, an opening generally appears at the top,
through which the pycnidiospores escape.
Prepared slide by Lieder www.lieder.com