Preliminary evaluations have shown that indeterminate new tomato breeding lines produce high yields of large fruits. Pruning systems have been reported to regulate tomato fruit size and overall yield performance. A study to evaluate the effect of pruning levels (non pruning, single stem, two stems and three stems) on plant developmental cycle, yield, and quality of five indeterminate tomato breeding lines and one commercial cultivar was conducted from November 2009 to March 2010 at the Horticulture Unit of Sokoine University of Agriculture, Morogoro, Tanzania. Results showed that two stem pruned plants gave the highest number of marketable fruits per plant. The highest number of non marketable tomato fruits per hectare was observed in unpruned plants. Tomato lines differed in their performance, with the longest period of harvesting, highest number of flowers flowers, highest percentage of fruit-set, the highest yield, high number of marketable fruits observed in lines P20-(03) and 186-2(06), which is probably a result of their genetic characteristic. It was concluded that, the large fruit size of the new tomato breeding lines can be reduced to meet consumer's needs without reducing yield by two and three stem pruning in lines P20-03 and S186-2(07).

Msogoya et al. J. Appl. Biosci. 2014. Effect of harvesting stages on yield and nutritional quality of African eggplant (Solanum aethiopicum) fruits. ABSTRACT Objective: Farmers often harvest African eggplant (Solanum Aethiopicum L.) fruits at different stages of fruit maturity. The influence of these harvesting practices on fruit productivity and nutritional quality is not known. This study was conducted to determine the effect of harvesting stages on yield and nutritional quality of African eggplant varieties. Methodology and results:The experiment was laid out in a split plot arrangement in a complete randomized block design with three replications. Three African eggplant varieties (Tengeru white, AB2 and Manyire green) and three harvesting stages (1, 2 and 3) were used as main plot factor and sub plot factor, respectively. Harvesting stage 1 (immature fruits) was characterized by fruits with non-shiny peel, harvesting stage 2 (mature fruits) was characterized by fruits with shinny peel and harvesting stage 3 (overmature fruits) was characterized by fruits with yellow coloration at the bottom. Fruit yield was assessed based on number and weight of fruits per plant while fruit nutritional quality was assessed in the laboratory based on carbohydrate, fibres, calcium, potassium, magnesium, phosphorus, iron, β-carotene and ascorbic acid contents. The collected data were subjected to analysis of variance using MSTATC statistical software. Treatments mean separation was conducted based on Student-Newman Keuls at P < 5 %. Results showed that yield in number of fruits per hectare decreased while yield in metric tons per hectare increased with fruit development stages. Varieties Tengeru white and AB2 had the highest yields based on metric tons at harvesting stage 2 while Manyire green had the highest yield at harvesting stage 3. Carbohydrate and fibre contents increased while ascorbic acid, β-carotene and most minerals decreased with fruit development stages. Conclusion and application of results:This study recommends harvesting immature fruits for high vitamin and mineral contents and delayed harvesting for the highest yield. As yield and nutritional quality trends vary with varieties, further studies are required to determine the effect of harvesting stages on yield and nutritional quality of different varieties of African eggplant.

The storage of bulbs of onion (Allium cepa L.) is very crucial to ensure its availability throughout the year. Experiments were conducted at Sokoine University of Agriculture to evaluate the growth and yield characteristics of some tropical short-day onion cultivars and the storability of their bulbs after harvest. The first experiment in 1994 involved 21 cultivars evaluated for their growth and yield variables. The second experiment, involving six cultivars, was carried out in 1996 and in addition to performance evaluation, the storability of bulbs was investigated. Results showed significant differences among the cultivars in yield, yield components and storability. Granex 429 had the highest yield among cultivars in both trials, but had very poor storability. Serrana and XPH 6074 had long storability and maintained more than 50% of their weight after 5 months of storage. These two cultivars are promising as good sources of genes to incorporate storage traits in other cultivars of onion.

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