Slow Death in Durian Seedlings Grafted Plants.

Slow death in durian seedlings when grown in the field can be caused by many factors.The basic principle is that there is no SOURCE and SINK connection meaning that the continuity of the flow is stop. Source is referred to upper part of the plants that include leaves , shoots, twigs, upper stem (above ground)and branches while sink refers to roots, root hair hairs (below in the ground). Both source and sink must be harmonious . Either source or sink is affected , the plants will will be disturbed.

Upper portion of plants can be affected by diseases, insect , mechanical damage , limb breakage. The lower portion i.e. roots will also be affected by disease, insects, nutrient , water deficit etc. If one of these parts are affected then it will affect others in the plants. Meaning that growth will be affected which leads to plant injury, wilting, stress and death.

Sometimes it is very tricky to know what may cause death to the plants as shown . The leave drops slowly andn dry finally dies, 

Examine the roots where disease or something else might disrupt the uptake of water and nutrient

Leaves fall and plants become dry 

Disease occurrence in durian fruits

A farmer is not guaranteed to harvest fruits even there are  a lot of fruits.  The time to take from flowering till maturity depends on variety. Some early harvest clones such as D99 takes about 90 days to harves. D24 takes about 100 days  and most of the clones will takes about 105 to 110 days to harvest. Extra care must given during flowering and fruiting besides water is disease and insect pest control. Common disease is Phytopthora and common pest is black moth.

Fruit caaused by Phytopthora disease

Growth Performances of Durians in Field

To grow durian is not as easy to grow oil palms, rubber or bananas. Durian need extra care especially planting in the field. You can not take things for granted that once you have  planted that's all. Attention must be given for at least every week so that the plant established its growth. Some of the critical factor is water; too much or too little water might affect the growth.  Durian roots may easily rot due too much water particularly in waterlogged condition where water is not drained and stay stagnant. On the other hand, too little water may cause leaves to dry and wither which later wilting takes place. Then, precautions must be taken in dry weather condition such as mulching the plants which means to cover the surrounding areas planted using composts or dry gasses or leaves.

Grafted Durian Seedlings Problems in Nursery

There are many problems encountered in grafted seedlings in the nursery. The time taken for bud growth in the nursery undergoes many conditions such water shortage , malnutrient , pest, diseases problems etc. Obvious symptoms where plants had  dry stem and leaves fallen  is due to  lack of water.  Durian seedlings is very sensitive to shortage of water. However, water uptake can be estimated by several methods.  I calculate water consumption of plants by using 'actual  evapotranspiration (aET)' technique.

Malnutrition is another common problem such Nitrogen (N) and Potassium (K) deficiency. These deficiencies are mainly due to mobile ions in plants.

N deficiency in durian seedlings

K deficiency in durian seedling

Water problem

Salt problem (maybe Na or Cl toxicity)

Vital Points In Establishment of Durian Plantation

Before anyone who wants to embark on durian planting he or she should aware of a few things.

1. Land and climatic suitability

2. Land rehabilitation and  preparation

3. Irrigation and water source

The three elements are very basic and crucial to be  considered if the planting remains sustainably successful. They interact closely with each other in for plant growth. 

For example land , its series and chemical analysis should be known . The topography of the land which means the gradient of the land. There are certain degrees that land can be cultivated.

Crop suitability against soil gradient

Terrain Class	Slope (0)	Crop  Suitability
C1	0-20	ü  Suitable for suitable for short term crops
C2	2-60	ü  Suitable for medium term crops ü  Suitable for perennial crops
C3	6-120	ü  Not suitable for suitable for short term crops ü  Suitable for medium term crops ü  Suitable for perennial crops
C4	12-200	ü  Not suitable for suitable for short term crops ü  Not  suitable for medium term crops ü  Suitable for perennial crops
C5	20-250
C6	>250	ü  Not suitable for agriculture

As far as climate is concerned, the trend in rainfall pattern should be known so that water can supplied at the correct time.

In Malaysia, the country is endowed with good tropical climate characterized by high rainfall and temperatures throughout the year. Climatic variations follow the influence of the monsoon winds. The northeast monsoon blows from December to March, while the southeast monsoon occurs around June to October. The total average annual precipitation is an estimated 2,722 mm. There are two rainy seasons: from mid September to January and from mid April to mid July which had rainfall of 230 to 330 mm/month and between 200 mm/month, respectively. The dry months are March and August, of which both months received 150 mm/month. Similar trends followed with the number of raindays i.e 10 raindays per month. Reports showed the temperature is relatively uniform throughout the year, with an annual average of 27.9 °C, ranging from 23.8 to 32.1 °C. The drought months of March to April  and mid July  to August are the warmest. Owing to high temperatures and rainfall, humidity is high throughout the year with an average of 82 percent.

Why Durians Needs Shading for Plant Establishement?

Growing durians is not the SAME as growing mangos, rambutans or jackfruits, Durians are very sensitive at early growth. Before its domestication from the wild jungle, they used to grow under tall vegetative. Statistics showed that about two-third of durian growing in the country is grown from SEEDLINGs  meaning that no bud grafting take place.When bud grafted materials are introduced, farmers took less care about its planting. This is because at early stage of planting durians need extra care needed where it cannot be exposed to the direct sunlight totally. In the equatorial climate where sunshine hours are very tense and dry grafted seedlings need shades either live shades like bananas or gylceridia or plastic nettings.

What to Do When Durians Flowers

Flowering time is the time that farmers or growers are waiting for. This indicate that very soon the fruits could be harvested, But wait... you have to 'jaga'  look after your durian flowers. The reasons - they might drop due to insect or fungus attack, water stress, pollination problems and whats not. One thing to remember is that the compatibility in the pollens meaning that some clones are not compatible within each other. Research shows that only 1-2% flowers that emerge will form to fruits, the rest will abort.

What to do?

The most important is water. If condition too dry flower may abort. What about too much rain during flowering? You have to do foliar spray  that contains Ca and B. You can also mix your foliar spray with fungicides like mancozeb or captan.

If the pollination is not good, you can put stingless bees that might help pollination.

Plant several clones meaning mixture of clones to encourage cross pollination might also help.

Flower formation, some dehisce 

Flowers pollinated small fruitlets produce

Very heavy flowering

How tom Turn Your Dusun Profitable?

Dusuns is Malay word for orchard. Unfortunately these orchards are grown with SEEDLING durians which that it is NOT grown from GRAFTED SEEDLINGS. For simple reasons ungrafted seedlings takes too long to mature to fruiting and fruits are very inconsistent in size, colour and shapes also taste varies. Often it is has very thin  pulp or flesh and had  a lot of seeds.

Dusun must be maintained  clean free of weeds

There is ways how to make your dusun profitable.
 Malay version :
1. Inventori bilangan pokok mengikut kesihatannya
2 Pembuangan pokok mati dan berpenyakit
3 Rawatan pokok yang terjejas
4 Penanaman semula dengan klon MK
5 Perolehan klon  durian (Musang King) dengan bahan tanaman cantuman dewasa (advanced planting materials -APM)  atau cantuman dewasa
6  Penyediaan semaian sementara
7 Pembajaan pokok-pokok yang sedia
8 Pembajaan pokok-pokok baharu
9 Kawalan mahkluk perosak dan penyakit
10 Pemangkasan dahan muda dan berpenyakit
11 Penuaian hasil
12 Pemantauan dan pemeriksaan pokok secara am
13 Analisa tanah dan daun didusun

English version:

1	Inventory of durian  plants according to their healthiness at each locality or blocks
2	Removal of  dead plants
3	Treatments of affected plants
4	Counting and Replanting of new plants
5	Purchasing clonal durian (Musang King) grafted  advanced planting materials (APM)  from accredited nurseries with
6	Transit Nursery field set-up
7	Fertilization  recommendation of present plants with
8	Fertilization  recommendation of new planting
9	Pest and disease application
10	Pruning new and old branches
11	Pre and post- harvest of fruits
12	Monitoring and inspection of trees
13	Soil and foliar analysis when necessary

Advance Planting Materials on Durians (APM)

People have said that it is very difficult to plant grafted durian seedlings in the field. Conventional planting of durians normally occurs when durians are grafted after six months in the nursery. Which means that the height of the grafted scion reached about 6 inches above, where the seedlings aged about one year old.

Field experiences showed that grafted plants (GP)  which are small are  small and left leaves are too delicate and sensitive to open environment. The best solution is to plant APM durians which can survive better and grows faster. Although APM plants may costs higher but  agronomic practices and  plant management is much easier.

APM plants are stronger and survive better in the field

APM plants spend more time in the nuresery

Planting Durians in Oil Palm Plantation

Durians are the most popular crop to be grown in Malaysia. Clonal durians or grafted seedlings have to be grown in order to obtain earliness in flowering as well as to get early investment return.

 

Compare to oil palm growing,  which a stable monthly income and high labour yet the amount is small i.e nine folds

Income comparison among crops grown in Malaysia.

Large scale Durian planting in Malaysia

Durians originally originates from the jungle of the tropical Asia. The origin of species was known to be from the Borneo Island,  Peninsular  Malaysia and Sumatra. There are many about 5 families of durio species found there i. D zibethenus, D. graveolens, D oxyleanus, D kutenjensis and D. graffiti. (?).

As durians are brought to open field for cultivation for domestication, they need the necessary requirement for growth. Formerly durians are grown from seeds by villagers or kampong people. Selections of good durians were made though natural selection where durians perform excellently at various localities in the states. There is why in Malaysia , we had almost 200 clones registered. 

In the 70's durians are not popular where prices only fetched around 50 sen pe kg or about 10 cents USD. I remembered in the 80's the price of durians was about 20 sen and clonal durians costed about RM2 to 3 especially D24. Since then, Malaysia concentrated its agriculture growth more on oil palms and rubber. Most of the FELDA scheme were planted by these crops.

The earliest research of durian in Malaysia was done by MARDI that takes about 30 years to produce clonal durians through proper plant breeding techniques by crossing and backcrossing procedures. People might asked why it takes so long to produce a single clone?. The process is tedious and slow where you have to find the true paternal and maternal parents which are distributed around the country. After pain staking steps been carried out through crossing, selection, GxE trials finally a few clones come out good like MDUR 78, MDUR 88 etc.

As time went on, people aware of its potentials  not only consume  as fresh but other products too like powder. There is a very large market to be tapped. Also there is technology that MARDI produced like "minimally processed" and deep freeze. It can be exported to any where in the world .

The taste of Malaysia durians are very different from Thai durians. Thai durians are sweet, and flat in taste, less odour and very 'full' when eating. Unlike Malaysian durians are sweet durian smell, sticky and irresistible when eating. It measn that it  they are so good or attractive that you cannot stop yourself from liking them or wanting them. See I want mean?. I can only eat one pulp of Thai durians but not Malaysian ones , oh its too yummy..

Lately I am involved in large scale durian planting. Wow , there a lot challenges, unexpectations and whats not. Large scale planting needs a professional to do the planning right from land suitability to marketing aspects. Agronomic practices, pest and diseases control and plant establishment at early start are the most crucial. What I mean is that to plant 1000 acres is not as easy to plant 1 acre, or 10 acres. In  large scale planting, even its  planting in one locality, the problems encountered is not the same because the heterogeny of the soils. In addition to plant durians in the fields that formerly from the jungle is not similar to plants durians from oil palms.