April 2012. Fertilizer trials are being done in Mali to test eg Japtropha seed cake, farm yard manure, compost, commercial products, etc. The present trial was done at Kia Mali during the dry season. The trial was planted in January. A wilt has affected all the treatments, and the fruits have an apical rot when they reach maturity.

There were many suggestions:

• The wilt was thought to be caused by either Tomato spotted wilt virus or bacterial wilt. Look for black streaks on the stem and sometimes on leaves. If bacterial wilt, dip freshly cut end of a stem into a beaker of clear water and looking for the tell-tale cloudy fluid oozing out. These two diseases leave growers helpless all over the world. In other words, avoidance is the only way. Thrips are the vector of Tomato spotted wilt virus.
• If it is this virus, and symptoms occurred after a month, it probably means the plants were infected in the nursery. If that is the case, then aphid/thrips netting is needed. This will extend the time of infection by a month, by which time the plants will be near harvest.
• Bacterial wilt spreads through water, so avoid planting in poorly drained soil. Often, it is possible to see radial spread from a primary source. For this disease, crop rotation is important, maybe liming the soil, and resistant varieties.
• The symptoms on the fruit are blossom end rot, a physiological condition brought on by K and Ca imbalance in the soil. To reduce the incidence of the condition, keep the soil moist rather than alternating between wet and dry.
• Another suggestion was that the urea, NPK and possibly a sudden release of nutrients from one or more of the organic treatments has damaged the root hairs.