Thanks for the welcome!
hegar wrote:Hello Bram,
welcome to the cactus forum. I am a transplant from the neighboring country of Germany and used to live only about two car driving hours from where you are! Also, I am an ex biology major and did study for and obtain a Master of Science in the field of Horticulture. I do work with cacti, because my agency is charged with the enforcement of the CITES regulations and almost all cacti are covered by the "Convention", as it is often called. Where does your father buy all the seed that is required to keep such a big operation going? Here in the U.S. southwest many growers probably do have their own breeding stock in order to produce seed for propagation.
Do you know anything about pests and disease problems that are associated with cacti?
Well, I hope that you are going to enjoy being a member of this forum. You will most likely notice, that almost all the people here are very friendly and will give advice and assistance whenever it is asked of them.
Harald
We have them from a dealer, I thought he is getting it from botanical gardens in the neighbourhood of the cacti's own habitat. But I don't know much about him, only that he like's to smoke cigars and travels alot in Latin America and South Africa. When we get imported plants we have CITES and phytosanitaric papers and stuff sended to us.
In the cacti we don't have a lot of diseases, the biggest problem is rootmealies, and sometimes normal mealies. Ant these are very hard to get rid of, that's why we use systematic chemicals. Actually we changed to a new chemical(imidacloprid) because the old chemical was taken out of the market.
But the mealies are not a mayor threat to the cacti, only when there in very high concentrations, but we have to lose them anyway because we cannot sell cacti with them.
other problems are footrot, but we only spray a few infected areas in a year.
in the seedlings there are a lot more problems, but they are very fragile so we try to prevent disease by keeping a good climate. We had some caterpillar plagues a few years ago but they were treated right with a Bacillus thuringiensis.
@ daiv: hehe and we may be one of the largest growers (with almost 3,5 hectares in summertime) in the area, we are definitly not the only grower. 1 know 1 grower which has around 8 hectares, and about 10 with at least 1 hectare. But i live in a area where the greenhouse was mainly developed, and it used to be the largest area with greenhouses for a long time.
The ceiling is high because the greenhouses are mostly built for tomatoes and other crops which are grown in even higher greenhouses now. (about 6 meters for the gutter an 7 or 8 meter high). But it also has to do with climatizing, it may be more expensive to heat, but the climate is easier to regulate and more airflow is allowed, it makes the climate inside much more natural.
You can see a trend in the height over the years 20 to 30 years ago they where made to walk normaly in the greenhouse, but now you have to climb much to get to the top.
And for reducing the heating costs we have 2 movable curtains for keeping to much sunlight out in summer and for keeping heat in at winter.