Sunday 17 June 2012

Apples

You can grow virtually anything in Brazil (apart apparently from grapefruit, to my chagrin). This includes apples ("maçãs")  though until the 1970s hardly anyone bothered, there was only about 100 hectares of commercial orchards in the 1960s. This is surprising given a) the number of German and Pomeranian immigrants, many of whom were farmers, and b) imports of apples at the time accounted for about 100 million US dollars. Following considerable government and state investment in the 70s there are now 37,000 ha under cultivation, with 3,450 growers, and 1,253 thousand tons of apples were picked in 2009/2010. This investment included the importation of guaranteed virus free material from the famous research station at East Malling, England, which alone increased productivity by 25-50%.

 Granny Smith apple

The commonest variety at the start was Golden Delicious and some Granny Smith, but these have been mainly replaced by Gala and Fuji, which make up 90% of production between them. In fact, it is often the redder types of these varieties, such as Royal Gala, Imperial Gala, Maxi Gala, Brookfield, Fuji Suprema, Fuji Seleta and Mishima, as these export better. Another development was increased use of "drawfing rootstocks". When you see an apple tree you are not seeing one tree but two, the bottom half from one variety, the top from another, joined together as seedlings. This allows you to get strong healthy trees (from the bottom part, the root stock and delicious apples, from the top). Another advantage of this is that if you choose the right rootstock, you can get dwarf trees, an idea developed at East Malling in the 1930s. Admittedly these have fewer apples per tree, but you can have a lot more trees per hectare, from roughly 600 to 2,500. This means more apples per hectare, and they are a lot easier to pick!

Fuji apples

Now, one peculiarity of apples is that they need a winter, or rather they need a period of cold, to induce the production of buds and flowers for next years crop. Gala and Fuji, for example, need more than 600 chilling hours (hours less than 7 C) to give a good crop. Even in the south of Brazil where there can be frosty nights, and even snow some days, this isn´t guaranteed, so sprays are used to mimic this as in parts of Europe. Commercially you also need to add bee hives to the orchard, as otherwise there simply won't be enough bees to pollinate the flowers! Of course, that does give you honey as a particularly delicious byproduct.


One emerging trend in Brazil is cider. This tends to be based on French rather than English techniques, but made much faster, without much maturing. Brazilian cider, like Brazilian wine, is made with extra sugar and can seem sweet to north European tastes.

Thursday 14 June 2012

Fruit flies

Leave any fruit out for long in Brazil and you will soon see hoards of little fruit flies ("moscas das frutas") swarming around it. These can be, frankly, a damm nuisance, but for farmers they are worse than that. Worldwide they are a major cause of crop loss. To give an example, for the last two years about half the harvest for some varieties of orange in the Brazilian state of Espirito Santo has been lost to fruit flies. 

Ceratitis capitata, one of the commonest fruit flies (Wikipedia)

The flies lay their eggs in the fruit, just under the surface. When they hatch the little larvae  happily eat away, safe from any predators, or indeed insecticide.  When ready they emerge and drop to the ground where they pupate and later emerge to fly away, the whole process taking about 20-30 days. In at least some species the male fly then does a little dance to attract his mate. Of course all this does not make the fruit very attractive, and it also causes it to fall prematurely.

It's not just oranges - guava, peach, tangerine, cherry, cashew, mango, acerola, jabuticaba, passion fruit, cashew, hog plum, and star fruit all suffer. Arabica coffee as well, not so much as the others, but it can act as a nursery for fruit flies, who then fly to orchards nearby. One of the few fruits with some resistance is papaya, probably because of repellents and toxins in the latex of unripe fruit. Even then, if infected with sticky papaya disease up 60 pupae can be found in each fruit.

 Ceratitis capitata larva (Wikipedia)

There is not just one species of fruit fly, far from it. The small Brazilian state of Espirito Santo has at least 41 species recorded. Terry Pratchett invented a God of Beetles, who made each one individually, there should probably be such a God for fruit flies as well!

Of course fruit flies don´t have it all their own way. Farmers spray against them, although the larvae are safely inside the fruit, and it can take quite a lot of insecticide to cover an orchard. One novel solution is to spray just a few trees with sugar solution, which attracts all the adult flies where they can be dealt with in a killing zone. And of course, for any herbivore there are predators. Parasitic wasps lay their own eggs in the fly larvae, and this can be so devastating to fly numbers that artificial rearing of these wasps is being considered - not very nice, but it is environmentally friendly.

Monday 11 June 2012

Very big woodlice


 This startling creature is a "tatui". If it looks like a woodlouse, well it is a sort of cousin, but much, much, bigger! In fact Bathynomus giganticus, the largest species of tatui, can reach up to 76 centimetres long and weigh up to 1.7 kilograms! They can, slightly bizarrely, curl up into a ball just like their miniature cousins.

Tatuis live in the sea, and apparently, they are reasonably common along the Brazilian coast, but at depths of over 350m. Sometimes though they seem to appear much closer inland, and then they do get reported in local newspapers, usually when someone's toes have been nipped! They have quite a strong bite, eating sea urchins and other slow creatures on the sea floor, as well as scavenging whatever carcases they can find. Surprisingly, despite being heavily armoured, they themselves sometimes end up as meals for sharks.

An interesting video describing the (often disgusting) habits of marine isopods, including the tatui, can be found here....
http://www.bbc.co.uk/programmes/p00msplz