The first phase of our project proved that the organic pest control using neem leaves at certain formulation can be successful on head cabbage, Chinese cabbage and beans but not on tomato.
The results of the third trial confirm the findings of the first two trials. Neem tree leaves have been used for hundreds of years in India and some other South Pacific islands as an organic pest control alternative. However, neem is not as effective as the stronger, more potent commercial pest control available in the market. A 70% success rate means seven of 10 cabbage heads will be marketable, while 30% will still be affected by pest damage and thus will not be presentable. However, those not marketable still have interior parts of the head cabbage that are fine for consumption.
We intend to use neem tree parts for pest control and the trees for windbreaks.
Leaves without apparent symptoms of insect or disease attack were collected from neem trees grown at Rota fields in CNMI. The leaves were washed in running water and immersed for 5 minutes in a solution of NaCIP (bleaching agent) at 1%. The leaflets were then separated and washed in sterile distilled water and spread on a clean towel in the shade for approximately 1 hour for surface drying. Next, leaflets were ground in a blender, in the proportion of 300g to 500ml of sterile distilled water, to obtain the leaf aqueous extract at 60%. The extract was left alone for 12 hours, under room temperature in the dark and then filtered through a fine polyester tissue. After that, 250ml of leaf extract were used for the experiments.
On 500 heads of cabbage tested, I have determined that the use of the neem leaves extract as pest control is not as effective as the neem seed oil extract. Two trials were done, first with the neem leaves and the second trial with neem oil extract. The trial using neem leaves extract resulted in 70-75% control on pests, which means that 25-30% of the crops are still damaged and not marketable. The second trial with the same number of plants using neem oil extract resulted in an 80 to 85% control on pests, which means 15-20% of the crops are not marketable. Given the results, I believe that trials using neem leaves and oil extract as alternative pest control are a success compared to no treatment at all, which results in 90-100% damage to crops.
The results of my trials using extract from neem tree leaves and neem oil applied to long beans are similar to the results with the head cabbage. There was 25-30% damage using the leaves extract and 15-20% damage using the oil extract.
I discontinued the trial on the Chinese cabbage and tomatoes as the first trial showed a higher level of pest damage of more than 50%.
I hosted a workshop on my farm where I presented the results of my experiment and had two professors speak about the function and scientific aspect of the neem tree and the entomology of my work.