Comparative Assessment of Adaptability and Agronomic Traits of Seventeen Tomato Varieties on Coarse-Textured Soil in Tropical Dry and Rainy Seasons

Though tomato is sensitive to humidity, tomato lines introduced to humid tropical environments are rarely assessed for relative performance in the prevailing seasons. The agronomic traits of 17 tomato varieties grown on a sandy-loam soil in the derived savannah were assessed in successive dry and rainy seasons. The varieties generally performed poorer in the dry than the rainy season, mostly showing incongruent trends in the two seasons. ‘Ekwunato’ and ‘Tomato Mmiri’ were the tallest with the most nodes in the dry and rainy seasons, respectively. ‘Ekwunato’ and ‘Yolince’ attained 1st flowering earliest, whereas ‘Ekwunato’ and NACGRAB-5 produced the most flowers and fruits in the dry and rainy seasons, respectively; ‘Starke Aryes’ had the fewest in both seasons. However, ‘Ronata’ and NACGRAB-9 gave the highest fruit weight per plant (3892 and 3820 g, respectively) in the dry season, before ‘Tropimech’ (3245 g). NACGRAB-9 gave the highest (8,475g) weight in the rainy season, before ‘Ekwunato’ and ‘Ronata’ (7632 and 7513 g, respectively). Positive character associations prevailed among numbers of nodes, leaves, trusses, flowers and fruits per plant in both seasons. Numbers of days to 1st and 50% flowering were negatively correlated to the number of fruits per plant. However, fruit weight per plant had no correlations with the other traits. ‘Ekwunato’ and NACGRAB-5 could serve as gene donors in breeding for enhanced flowering/fruiting in dry and rainy seasons, respectively. To increase tomato fruit yields, NACGRAB-9 or ‘Ronata’ is recommended, otherwise ‘Tropimech’ and ‘Ekwunato’ should be grown specifically in dry and rainy seasons, respectively

Comparative Assessment of Adaptability and Agronomic Traits of Seventeen Tomato Varieties on Coarse-Textured Soil in Tropical Dry and Rainy Seasons

Though tomato is sensitive to humidity, tomato lines introduced to humid tropical environments are rarely assessed for relative performance in the prevailing seasons. The agronomic traits of 17 tomato varieties grown on a sandy-loam soil in the derived savannah were assessed in successive dry and rainy seasons. The varieties generally performed poorer in the dry than the rainy season, mostly showing incongruent trends in the two seasons. ‘Ekwunato’ and ‘Tomato Mmiri’ were the tallest with the most nodes in the dry and rainy seasons, respectively. ‘Ekwunato’ and ‘Yolince’ attained 1st flowering earliest, whereas ‘Ekwunato’ and NACGRAB-5 produced the most flowers and fruits in the dry and rainy seasons, respectively; ‘Starke Aryes’ had the fewest in both seasons. However, ‘Ronata’ and NACGRAB-9 gave the highest fruit weight per plant (3892 and 3820 g, respectively) in the dry season, before ‘Tropimech’ (3245 g). NACGRAB-9 gave the highest (8,475g) weight in the rainy season, before ‘Ekwunato’ and ‘Ronata’ (7632 and 7513 g, respectively). Positive character associations prevailed among numbers of nodes, leaves, trusses, flowers and fruits per plant in both seasons. Numbers of days to 1st and 50% flowering were negatively correlated to the number of fruits per plant. However, fruit weight per plant had no correlations with the other traits. ‘Ekwunato’ and NACGRAB-5 could serve as gene donors in breeding for enhanced flowering/fruiting in dry and rainy seasons, respectively. To increase tomato fruit yields, NACGRAB-9 or ‘Ronata’ is recommended, otherwise ‘Tropimech’ and ‘Ekwunato’ should be grown specifically in dry and rainy seasons, respectively

Soil degradation-induced decline in productivity of Sub-Saharan African soils: the prospects of looking downwards the lowlands with the sawah ecotechnology

The paper provides an insight into the problem of land degradation in Sub-Saharan Africa, with emphasis on soil erosion and its effect on soil quality and productivity, and proposes a lowland-based rice-production technology for coping with the situation. Crop yields are, in addition to the degree of past and current erosion, determined by a number of interacting variables. This, coupled with the generally weak database on erosion-induced losses in crop yield in spite of the region’s high vulnerability to erosion, makes it difficult to attain a reliable inference on the cause-effect relationship between soil loss and productivity. Available data suggest, however, that the region is at risk of not meeting up with the challenges of agriculture in this 21st century. Based on the few studies reviewed, methodology appears to have an overwhelming influence on the erosion-productivity response, whereas issues bordering on physical environment and soil affect the shape of the response curve. We argue that the sawah ecotechnology has the potential of countering the negative agronomic and environmental impacts of land degradation in Sub-Saharan Africa. This is a farmer-oriented, low-cost system of managing soil, water, and nutrient resources for enhancing lowland rice productivity and realizing Green Revolution in the region.This article is available at http://dx.doi.org/10.1155/2012/673926The Ministry of Education, Culture, Sports, Science and Technology (MEXT) of the Japanese Government through the Monbukagakusho Scholarship, the Japan Society for the Promotion of Science (JSPS), and New Sawah Project of the Kinki University of Japan