An Investigation of the Agroclimatic Potential of the Forest–savanna Transition Zone of Nigeria for the Cultivation of Sorghum

Abstract

The agroclimatic potential of the forest±savanna transition zone of Nigeria for the cultivation of sorghum (Sorghum bicolor) was investigated. Five phenological stages of the crop formed the basic unit of time for the investigation. Selected agroclimatological thermal and moisture indices were measured daily and processed into ten-day (decadal) averages for the 1993 and 1994 cropping seasons. The thermal indices, temperature and photoperiods were optimal for sorghum growth but, on the basis of the distribution of rainfall and actual water availability in relation to the crop's water consumption, the moisture indices were above optimum. However by relating eective water availability to the indices of moisture adequacy for the growth of the crop, it was found that the agroclimatological moisture indices were optimum during the moisture sensitive stages. A comparison of the vegetative growth and grain yield of sorghum in the study area and elsewhere in the savanna region con®rmed the agroclimatic potential of the forest±savanna transition zone for sorghum production.

Water Management for Sesame Under Different Sowing Dates

“…The lowest averages of seeds yield and its components were detected from the late sowing date (31 st of May). These results are consistent with those found by Mulkey et al (1987), Lee et al (1988), Ogunremi (1988), Bello(1997 and1999), Okeleye et al(1999), Olowe (2007), Badran (2009) and Ogbonna and Umar-Shaoba(2011).…”

“…tillage, fertilization, irrigation management, sowing dates and introducing highyielding varieties are needed for increasing sesame seed production. Lee et al (1988), Bello(1997 and1999), Okeleye et al (1999), Olowe(2007), Bdran (2009) and Ogbonna and Umar-Shaoba (2011), revealed that sowing date effects were significant on seed yield and all the yield attributes and the highest seed yield was recorded under the early sowing date whereas, delaying sowing date led to a decrease in yield productivity by. Yousef et al (1994) in Egypt, reported that delaying sowing date 3 or 6 weeks from Mid-April decreased seasonal water consumption from 45.79 cm to 43.24 cm and 40.13 cm, respectively, and water use efficiency decrease from 0.397 kg seeds/m 3 water consumed to 0.373 and 0.263 kg seeds/m 3 water consumed, respectively.…”

Investigating the optimum planting date for sorghum in the forest–savanna transition zone of Nigeria

“…Since the agro-climatic potential of this eco-climatic region for the cultivation of the Guinea species of sorghum has been con®rmed (Bello, 1997), two Guinea genotypes of sorghum, identi®able by their grain colour, have been studied. These cultivars known locally as Janare (red sorghum) and Farin Dawa (white sorghum) are late maturing (about 180 d duration from planting to grain maturity) and high yielding cultivars grown widely in the Guinea savanna region of Nigeria.…”

“…The agroclimatic potential of the forest±savanna transition zone of Nigeria for the cultivation of sorghum (Sorghum bicolor) has been investigated and con®rmed (Bello, 1997). However, a comparison of some yield components (plant height, leaf number per plant and grain yield) of sorghum grown in the forest±savanna transition zone with those of sorghum grown at locations in the Guinea savanna region showed that the vegetative growth of sorghum in the former was higher than in the latter.…”

“…Thus the amount of the ®nal grain yield of the crop that will suciently augment the grain supply from other sources (for example maize (Zea mays) and millet (Pennisetum glaucum) cultivation) is of major concern to farmers and particularly the Nigerian Grains Board both at the regional and national levels. Since the characteristic higher amount and pattern of distribution of rainfall in the forest±savanna transition zone encouraged sporadic and prolonged vegetative growth thereby leading to low ultimate grain yields of sorghum (Kassam and Kowal, 1973;Bello, 1997), it was believed that a method that accurately synchronizes the crop's growth cycle and moisture requirement with the period of actual water availability (AWA) may help to improve signi®cantly the grain yield of sorghum in the forest±savanna transition zone.…”