Cowpea, Vigna unguiculata (L.) is an important legume grown in Botswana and the main yield losses incurred are from cowpea aphid, Aphis craccivora (Koch). Agriculture in Botswana is hampered by limitation in water resources. The objective of this study was to determine the effect of effluent water on cowpea aphid reproduction and population growth. This was randomized completely block design pot experiment conducted under net shade environment. Four treatments of 100%, 60%, 30% of effluent dilution and the control being clean tap water were used. This study revealed that the presence of N and K in the effluent water did not affect the population growth of aphids on cowpea plants. There was no significant difference among the effluent water treatments and the clean tap water. Therefore, effluent water in this study did not show any effect on cowpea aphid reproduction and population growth.

Seed size contributes to yield and it is also a consumer trait of cowpea in Ghana and other parts of the world. Ghanaian consumers tend to prefer large seeded cowpea to small sizes although, Ghanaian varieties have smaller seeds compared to the imported types. This might be a contributing factor to high importation of cowpea to Ghana. To breed cowpeas with large grains, it is paramount to understand the inheritance of the trait. Generation mean analysis was performed to estimate gene actions on seed size of cowpea using CB27 and Gh3710 as the large and small seeded parents respectively. It was observed that eight genes control seed size and that small seed is partially dominant over large seed. The estimated broad sense heritability was 84% while the narrow sense was 35%. Both additive and non-additive genes with their interactions in the exception of additive - additive had significant effect on seed size inheritance in cowpea. The inheritance of seed size was observed to be complex, it was suggested that combinations of methods such as single seed descent and backcross methods with selection from early generations through advanced level would help improve seed size of cowpea.

This study was initiated to validate a tomato powdery mildew, caused by Leveillula taurica (L´ev.) Arn., forecast model in Egypt. Environmentally acceptable control may be achieved using a weather based forecasting system due to the reduced use of agrochemicals and their residues in both environment and food. A computerized disease forecast model for tomato powdery mildew (Egy. Tom-PM) as named by the authors was validated during the 2006 and 2007 growing seasons. The micrometeorological parameters monitored hourly in tomato canopy were ambient air temperature, relative humidity, leaf wetness duration, wind speed and global radiation using a wireless real-time automatic Agro-weather station model (Adcon Telemetry model A733, add wave). Results indicated that Egy.Tom-PM forecast model accurately defined disease risk appearance and reduced number of sprays in both years compared with the routine application (10D) and (7D) sprays in 2006 and 2007 respectively. Basic roles of system analysis for model validation and evaluation are discussed.