Experiments with fruit

If you are a fruit freak, then the custard apple cultivated by Indian Institute of Horticultural Research of Bangalore is just the one for you. These huge fruits are like the common custard apple in certain ways but are far superior in many other ways.

Cultivated by IIHR, the custard apple is called Arka Sahan. September being the season for harvesting the fruit, the trees at the IIHR campus in Hesarghatta are laden with fruits, each weighing not less than 300 to 500 gms. Arka Sahan is the result of 17 years of constant experimentation by scientists - S H Jalikop and P Sampath Kumar.  The two scientists, it seems, have redefined the taste of sugar by way of these custard apples, which are also called sugar apples. Like many hybrid fruits and vegetables, the Arka Sahan variety is also big. The properties, especially the taste, match the size. 

Unlike the common custard apple, the pulp in the hybrid has to be scooped out with a spoon. There are fewer and smaller seeds which do not stick to the pulp. It has a mild pleasant aroma, making Arka Sahan a distinct one. Because the skin is tough, the ripening process is slow and storage is easier. The easy way to eat the fruit is to cut it open into two halves using a knife.

While Jalikop conducted experiments on developing the fruit without a break, Sampath Kumar worked on the project for eight years. Jalikop proudly says that no variety of custard apple in the world can match Arka Sahan. It has been developed by isolating an extremely rare recombinant from more than 3,000 hybrids in the family of Annona cherimola X A squamosa X A Squamosa.
 
Cross combination of Annona

In simple terms, the hybrid is a cross combination of species of Annona, which is a genus common in fruits like Sithaphala and Ramphala. There are nearly 120 species of Annona, but only six are edible.

A few flowers of Arka Sahan develop into fruits, as in other Annonas. To supplement this, artificial hand pollination was conducted which helped in achieving a very high fruit set, large size, symmetrical fruits by pollinating with the common custard apple pollen. With natural pollination, it is difficult to achieve the desired result. 

Jalikop insists that artificial pollination is simple and fast. It can be achieved by collecting Sithaphala pollen in a cup and smearing it on the stigma of Arka Sahan flowers using a small paint brush. Arka Sahan is nutritionally rich with 87%, 249% and 42% more crude protein, phosphorous and calcium respectively as compared to common custard apple. How difficult or easy was it for Jalikop to cultivate such a tasty fruit? “I have spent sleepless nights for years together. Cropping different types of Annona to make the dream fruit was a challenge. Sometimes, the combination which we put together yielded very sweet fruits, but they were found to be misshapen. When the shape matched the target, the seeds were more. Sometime in 1993, we identified the right plant. From 2003 onwards consistently we have achieved good, dependable results. Now, the international scientific community has acknowledged our efforts,” he says. The trees come to fruition three years after planting. From the seventh year onwards, 40 to 45 kgs of fruit can be harvested from each tree.

Great revenue

The fruits fetch good revenue because of their high quality. If it is planted on an acre, a return of Rs 1.3 to 1.5 lakh can be expected after investing about Rs 30,000 for cultivation and maintenance, the scientist says.

The Institute of Horticultural Research has sold more than two lakh saplings so far. But the fruits are available for sale in very limited numbers at the campus’ sale counter as the fruits are cultivated more for experiment than for sale. 

Is there a scope for improving Arka Sahan? “There could be. But I am happy with the produce because the target is achieved.” Why the name Arka Sahan?

“The Arkavathi river used to be close to IIHR. Now the river has gone dry. The names of all horticultural produce have been pre-fixed with Arka. Sahan means patience. Arka Sahan’s shelf-life is six to seven days which is not in case of common custard apple,” Jalikop points out.

Now the task for Jalikop is to develop pomegranates that are not only bacterial-resistant but also have large (like grape berry) grains and are the truly seedless variety.