THE HARDEST CUT?

(One of a series of articles about growing fruit trees in Samoa, written by Digby Gotts and published in the 'Samoa Observer' between December 2000 and April 2001)

One of the main things about growing fruit trees that seems to scare a lot of people is the need to prune them. After all, how come that by cutting out lots of a good tree, do you happen to get more fruit than before you cut it? This seems just a bit contradictory and so many of us take the easier path and leave the tree alone. The only tree I often see being pruned in Samoa is the Beach Almond, that spreading umbrella-like tree with the red leaves often has the top cut out to make it spread even more. Shade for sitting in is apparently important enough to stimulate some pruning action. The benefits of pruning citrus and many other trees are not as immediately apparent, but they are just as real in terms of improved fruit quality.

The main thing to remember with all the citrus is that the flowers, and then the fruit, develop on the new leaves at the end of branches. So if you can see new leaves or flowers, leave the tree alone as you will lose the crop that is forming. If the leaves are all old, then a tip prune followed by a rich nitrogen feed, will stimulate a vigorous new growth, followed by flowers and then the fruit. Because of Samoa’s warm wet climate, individual branches often do their own thing in their own time, so fruit form throughout the year instead of being restricted to one time. Tip pruning the whole tree will encourage a mass flowering. This would be a good thing for commercial growers, but a family might prefer to have their fruit scattered throughout the year, so they should tip prune sections of a tree.

Oranges and mandarins particularly, suffer from several fungal diseases causing whole branches to die slowly. Pruning out the dying wood as soon as it is seen, removing the branches from the vicinity, and burning them, will prevent the fungal spores spreading further. Apart from spraying fungicides regularly, and expensively, there is not much else that can be done about the dieback, so it is best to keep it pruned as the simple solution.

Mandarins tend to grow straight up, placing the fruit well out of reach of all but the most determined children. Again the solution is to cut the vertical branches in half. Their ends will branch out, and slow down the vertical growth, allowing everyone to reach some fruit much more easily.

Good quality citrus are grown by inserting buds into a strong seedling rootstock. The rootstock will continue to send out shoots from below the bud. Nafanua is now using a rootstock, (Trifoliata), which produces leaves with three parts to them, so the shoots from the rootstock can be easily recognised when compared to the normal single leaf. It is essential that the tree be inspected regularly and any shoots coming from the rootstock removed while they are still small. At one time last year, I found myself using a chainsaw to remove overgrown root shoots from some old forgotten oranges on a Savaii property. This is not to be recommended!

Nafanua has many types of oranges, mandarins, lemons, limes, pommelo and grapefruit that are suitable for Samoa. Every home should have at least one.