Physiological and Agronomic Responses of Four Rice Varieties to Drought in the Rainforest.

The present investigation tested the hypothesis that there would be variation in physiological responses to water deficit among rice varieties from different production ecologies, with contrasting tolerance to water deficit under repeated cycle of soil moisture deficit, at reproductive growth stage. A screen house and a field trial were conducted at International Institute of Tropical Agriculture, Ibadan and Ikenne (Latitude 6° 52' N, Longitude 3° 43' E) respectively. Both experiments had rice varieties ('IR 64', 'WAB 56-104', 'IR 77298-1-2-B-10' and 'NERICA 4') and stress status (stress and control) as treatment factor's, arranged in a randomised complete block design with three replicates. In both trials, the physiological mechanism that underpins varietal differences with repeated cycles of water deficit at the reproductive growth stage was more balanced water status, improved foliar characters, efficient photosynthetic capacity and higher grain yield in comparatively drought tolerant upland rice varieties ('NERICA 4' and 'WAB 56-104'), as opposed with the results for the drought susceptible cultivar 'IR 64'. A converse pattern was observed on water stressed rice, despite fewer cycles of water deficit on the field. The results could have suggested that the initiation of water deficit is the rate limiting step rather than its intensity at the reproductive growth stage

Influence of walnut on the nutritional and physicochemical properties of biscuits made from whole wheat

In this study, the influence of walnut flour in biscuit production was studied. Biscuits were made from blends of whole wheat with walnut flours and were assessed for quality attributes and storability. Walnut was blended with whole-wheat thus: B (2%:98%); C (4%:96%); D (6%:94%); E (8%:92%) and F (10%:90%), while plain whole wheat flour served as control (Sample A). The biscuits were baked in the oven operated at 1800C for 20-30 minutes, cooled, packaged, stored for eight weeks, and analysed for physicochemical, microbial and sensory properties using standard methods. The results revealed that the proximate composition of the samples during storage were as follows: protein, moisture, ash, crude-fat, crude-fibre and carbohydrate values ranged thus: (9.30-14.26%), (10.28-12.06%), (2.20-2.92%), (13.24-16.66%), (0.69-1.17%) and (53.60-61.47%) respectively, with better nutrient stability in the treated samples when compared to the control. The colour varied with increasing substitution, while the essential amino acids were higher in the walnut-supplemented samples. The microbial load of the control was higher than those of the treated samples, due to high antioxidant activity of walnut. Sensory evaluation revealed that biscuit sample having 2% walnut flour was most preferred. Keywords: Whole wheat flour; walnut; proximate composition; antioxidant properties; shelf life