The Practical Planter

Management Of Established

Banana Plantations

From “Banana Production in the South Pacific”, a handbook shortly to be released by the South Pacific Com mission, edited by MICHEL LAMBERT.

The yield of a banana plantation depends on a number of physical and climatic factors but also on management. Management may be defined as the aggregate of operations required to ensure high yields of quality fruit for several years. The bananas may be sold either on the local market or to importing countries.

It is noticed only too frequently that growers tend to neglect some of these operations or to carry them out too quickly and without due care. They must understand that a banana plantation will give a sufficient yield of quality fruit only if the maintenance work is carried out with care and as the need arises.

It will not necessarily have to be done following the order adopted here, which is simply designed to separate the operations for a clearer understanding of the text.

Hoeing and weed control

It is important to start weed control operations right from the establishment of the plantation, as this is the time when weeds will thrive with the preparation of the soil and its exposure to the elements.

Generally, weeds seek light and develop very quickly where there is no shade.

Weeds compete seriously with bananas because they absorb a part of the fertilising elements and water present in the soil. The development of the banana plant is thus impeded in the first stage of its growth; later, the clusters will be smaller and not so plentiful.

Weeding should, therefore, be carried out very thoroughly and this offers the opportunity to hoe around the butt of the plants to a depth of a few inches.

Hoeing is important, particularly in heavy loams. It breaks down the superficial soil crust and aerates the soil; this allows water to seep in.

However, care must be taken not to bruise the surface roots because these are the feeding organs of the plant.

Weeds should be left on the ground or, better still, heaped at the butt of the banana trees; they will maintain moisture and, as they rot, enrich the soil in humus.

Manual weeding operations should be repeated as often as necessary; however, as the plant grows, the shade becomes thicker under the

cover of its large leaves and the weeds find it more difficult to grow.

Chemical control

Herbicides can be of great help at the stage of land preparation and during the establishment of the plantation. They may also be used in well established plantations.

Further, to obviate the danger of erosion in certain soils it is some times necessary to leave some weeds

Weeds, leaves, banana pseudo-stems and suckers (when desuckering is carried out) are used to make mulch.

‘or a time: they can later be iestroyed by the use of herbicides mce the shade of the banana plants :overs the soil.

In all cases, and particularly in foung plantations which can be more mlnerable to the action of these chemical products, great care should ?e taken in their use and the instruc ions provided by the manufacturer mist be followed strictly.

Arsenical herbicides have proved to be both effective and economical but they can be dangerous for the user if he does not take all due srecautions; there is no residual toxicity for the plant. The Diuron mixtures (Karmex) and Paraquat also give satisfactory results, as does Dalapon.

It should be stressed, however, that the action and effectiveness of herbicides vary according to the area, climate, type of soil, plants to be treated, age of woods, etc. They should, therefore, be tested by the Research or Agricultural Department which would then advise as to the suitability of certain herbicides and their use in a plantation.

Desuckering

If nothing is done to the banana plant it will bunch out into a tuft which becomes larger and larger.

One notices also that when there is a large number of suckers, the conns are not so healthy. There fore, pruning is necessary and this pruning is called desuckering.

Desuckering is often the one operation in the management scheme which growers neglect the most.

They often believe that the more suckers there are the more bananas there will be. This is not true.

If one removes the excess suckers, the remaining ones grow stronger and produce larger clusters. On the other hand, if there are many suckers competition is such that they all remain small, thin and very low yielding.

On dense plantations one usually leaves the main stem, a sucker and a follower per plant. On sparsely spaced plantations one can leave more than one main stem; the same rule applies in rich soils containing ample mineral elements.

Suckers should be chosen at least two months before the mother-plant comes into bloom and desuckering should be done when the suckers to be removed are still small. This makes the work easier.

The time lapse between the pro duction of two clusters on two different suckers from the same stem depends on climatic conditions.

Through experience the grower will know how to choose suckers at the right time to obtain either the largest fruit when mature or a high yield during the peak market demand.

Generally the sucker is removed with a gouge which leaves a cone shaped hole; on young plantations a few drops of kerosene may be dropped into the hole. On estab lished plantations the sucker is re moved and there is no need for kerosene. This operation is usually carried out with a bush-knife which gives very satisfactory results.

At the time of desuckering it is advisable to keep the suckers which grow on the same side as the mother-plant so as to preserve the alignment of the banana plants.

This is, in any case, necessary in plantations where maintenance work is mechanised. The suckers chosen

to be left on the stool should be either well rooted or deeply buried; they grow better and offer better resistance to the wind.

Desuckering is an important operation which conditions the yield of the plantation and should there fore be carried out periodically, at least every two months.

Mulching

As mentioned previously, a light mulch may be spread at the butt of the banana plants after weeding the plantation but, obviously, if the grower can afford it or better still if he is willing to do the work, mulch may be spread on practically the whole area of the plantation.

This practice increases the growth and yield of the plants.

Mulching has the advantage of in creasing water conservation in the soil, it reduces evaporation and, when rotted, the mulch enriches the soil in humus. Mulch prevents the growth of weeds, reduces rain erosion and brings down soil tem perature. Its only disadvantage ap pears when the banana plantation becomes infected with banana weevil or other parasites for which it then provides a shelter.

However, under normal con ditions, the banana is the plant which responds the best to mulch ing. To this end, tall grasses, small branches and twigs from the surrounding bush as well as leaves and banana pseudo-stems, < suckers when desuckering is carried out, trash from banana clusters, etc. . . . may be used. All this plant material should be chopped up and heaped at the butt of the banana plants or dumped on the soil itself. (Over)

Desuckering the banana (pruning) is a much neglected operation, from left, during the first five months all the suckers must [?]e eliminated. On the sixth month after planting, or as soon as the flower appears, one sucker is allowed to grow. Right, a healthy tree following the bearer-follower-sucker system.

It's a very demanding plant!

However, in areas badly affected by the Sigatoka disease or various Cercospora leaf spots, it is better to pluck and burn banana leaves rather than to use them for mulch ing, as they would constitute in fection foci.

Fertilisers

Contrary to general belief, the banana is a very demanding plant.

Usually only the leaves and the pseudo-stems are returned to the soil whereas the number of clusters taken away is often very large. Therefore, the plant should receive complete fertilising if it is to be maintained for a large number of years and give high yields.

Organic manure

This is important as it promotes the conservation of humus in the soil and often contributes to enrich the land in humus. Humus is of the greatest importance; it preserves moisture in the soil as well as the fertilising elements and liberates these as and when the plants need them.

Mulching has already been men tioned as a good way of providing organic matter. Mulching should be carried out before the dry season so as to reduce the evaporation of the water contained in the soil.

Naturally, farm manure spread at the foot of the plants is the best form of fertiliser but only growers who also keep cattle are in a position to use it; in its place, it is recommended to spread commercial fertilisers, compost, and/or rotting grasses.

Commercial fertilisers

This should only be envisaged if the plantation management is carried out regularly. Desuckering, weed control and pest control must have become an established practice before consideration is given to the use of commercial fertilisers. Also, the plantation must contain sufficient humus. If these conditions are not fulfilled the grower will be spending money uselessly in buying and spreading commercial fertilisers which are often very expensive.

Potash is the most important element in banana cultivation but it is often advisable to provide the two other major elements: nitrogen and superphosphate. Growers should therefore think in terms of com

plete fertilisers, but it is difficult to give definite instructions since the use of commercial fertilisers depends primarily on the fertility of the soil and its deficiencies in certain fertilising elements.

Complete fertilisers such as 12.12.20 and 10.10.18 may be sufficient in many places. If the soil is deficient in phosphoric acid either 9.15.20 or 8.10.16 should be used.

The application of commercial fertilisers must be started as early as the life of the plant and we have already recommended to place fertiliser in the planting hole.

Fertilising gives the best results if it is done before the cluster forms.

During the first year of the plantation, fertilisers should be applied in small doses but at regular intervals.

In established plantations fertilisers should be applied approximately every three months according to soil humidity, since a strong drought will delay their assimilation by the plant.

Fertiliser placement varies according to the plantation; it is recommended to place the fertiliser around the plant on flat land and on the upper side of the plant on sloping land. The first application of fertiliser can be at one foot from the plant and subsequent ones at two and three feet from the plant.

In well established plantations the fertiliser is broadcast and sub sequently dug into the soil when hoeing or desuckering processes are carried out. On flat land it is recom mended to broadcast the fertiliser between the rows.

When there is the possibility of the fertiliser being washed away by strong rains there are two solutions: either apply the fertiliser frequently and in small quantities or cover it up with a thin layer of soil.

Shoring

The banana plant may lean over under the weight of too heavy a cluster; any strong gust of wind would be fatal and the cluster would fall to the ground. The fruits are bruised, they no longer receive nourishment and may rot. There fore, the banana should be shored with a proper shoring perch or with two long poles crossed just below the cluster and well anchored to the ground. Bamboo stems or branches cut in the nearby forest can be used for this purpose.

If windbreaks are necessary at the time of the establishment of the plantation one should think ahead and use timber which can later be re-used for shoring.

Removal of the flowers

In some banana varieties, all the bracts do not break from the cluster

The banana must be shored with a proper shoring perch. This is done most success fully with two long poles crossed just below the cluster and well anchored to the ground.

'Open door’ to fungi

ind in this case they fall onto the Tuit; in rainy weather they may ;ause spots on the fruit and even ot. On the other hand, dead flowers nay remain attached to the stem md become hard and dry. If they ire broken by hand when the cluster s harvested or handled, the wound s an open door to fungi which are he source of serious rot diseases.

It is, therefore, recommended to •emove the bracts remaining on the dusters and to brush off the flowers vhich still adhere to the fruit at he time when removal is easiest, ;hat is, once the cluster is completely ’ormed.

Pest control

As all cultivated plants, the banana is attacked by pests. The grower must be in a position to control these and to do so he re quires spraying implements and :hemicals to destroy these pests or to reduce the damage they cause.

Insects and diseases likely to cause serious damage to plantations and the means which must be used to destroy them cannot be adequately dealt with here; nevertheless, it should be appreciated that this type of work forms an integral part of banana plantation management.

Growers should, therefore, keep a watchful eye and carry out in good time all the management work which alone can guarantee high yields of quality fruits, once the plantation is well-established.

Aitutaki banana

scheme progress

A total of 139 acres have come under banana production on Aitutaki, in the Cooks, 106 acres of them pre viously government banana nurseries.

A further 10 acres were producing in December and by the same time in 1970 it is expected to have 260 acres in production.

Since the scheme started three years ago, 22,000 cases have been shipped and a further 3,000 were ex pected to be shipped on the Decem ber voyage of the NZGV Moana Roct.

The original target was between 7,000 and 10,000 cases a month for the New Zealand market, and it was estimated that a minimum of 500 acres would have to be planted and the fruit grown under expert manage ment for the scheme to be success ful. (P/M, Jan., ’67, pp. 141-142.)