Azarian Journal of Agriculture
Volume:3 Issue: 5, Oct 2016

To further understand the importance of row spacing as an agronomic practice, a study was conducted to evaluate how levels of row spacing determines the critical period of weed control (CPWC) in cowpea (Vigna unguiculata). The experiment was laid out as a split-plot design with eight periods of weed interference as the main plots and three row spacing (60, 75 90 cm) as the subplots with three replications of each treatment combination. Period of weed interference consisted of weed removal for 14, 35, 54, and 77 days after emergence (DAE), and weed infestation for 14, 35, 54, and 77 DAE. Results indicated that the mean yield of cowpea was higher at narrow spacing (60 cm) than at wide spacing (90 cm) under season-long weed infestation plots but no difference in yield was found among the row spacing in the season-long weed removal plots. There was no difference in the beginning of the CPWC among the row spacing. However, 90 cm row spacing requires longer period of weed removal to avoid unacceptable yield loss when compared to 60 cm row spacing. The end of the CPWC coincides with the period of canopy closure by the crop. This finding suggests that it took the crop longer time to close canopy at wide row spacing (90 cm) compare to reduced row spacing. The differences in the duration of weed control intervention in crop row spacing suggest the importance of integrating decisions regarding row spacing and period of weed control in weed management strategies.

Field irrigation experiments were conducted to assess the varietal performance and correlation of pod yield and yield attributes under irrigation at the Teaching and Research Farm, University of Maiduguri, Nigeria, during 2015 and 2016 dry seasons. The results revealed that the most outstanding for fresh pod yield were okra cultivar Salkade, Y’ar gagure and Kwadag, in descending order with yield ranging from 34.69–4.83 t ha–1, while cultivar Y’ar kwami had the lowest value of pod yield (3.17 t ha–1) over the two years. The highest mean values for number of pods per plant and number of primary branches per plant were observed for Salkade and Y’ar gagure, respectively, Highest fresh pod length and fresh pod diameter were also exhibited for Salkade and Kwadag, respectively. Pods Genotypic coefficient of variation was higher than the phenotypic variation for all the yield contributing characters. Days to 50% flowering were positive and highly significance difference associated with plant height, number of pods per plant and fresh pod weight. Path coefficient analysis showed that number of pods per plant exhibited positive and direct effects on pod yield across years. Indirect effect of other yield components through this character also contributed mainly towards pod yield. Therefore, plant height, days to 50% flowering, number of pods per plant, pod length, pod diameter, number of primary branches per plant and fresh pod weight could be considered for selection and improvement for high yielding varieties in okra.

The study was conducted at Lower Loko west of song local Government, Adamawa state. Infiltration, bulk density, and some physicochemical analysis were carried out on the five sites, designated as site 1A and B, site 2A and B, site 3A and B, site 4A and B and site 5A and B, based on the preliminary survey to characterize the steady state infiltration rate. The study confirmed infiltration variability in the area both within the sites and across the sites. The soils are characterized by low to moderately rapid steady state infiltration rate range from 4.98 cmhr-1 to 11.61 cmhr-1 for all the five sites with the cumulative infiltration range from 1.00 cmhr-1 to 6.58 cmhr-1 on the average for all the five sites in 3hours of infiltration. Variability was influenced by differences in the texture, bulk density and water holding capacity. Moreover, improved infiltration, reduced erosion menace in low steady state infiltration sites. Flooding in the lake, use of integrated nutrient management on the fields and construction of drainages in the area is suggested.

Genetic improvement of Grape is limited by traditional methods. An effective regeneration system for tissues culture of transgenic adult plants could facilitate genetic modification of them. So it is necessary to develop and improve embryogenesis and regeneration systems in plants. Accordingly the aim of the present study was to evaluate the effects of ultrasound (0 (as control), 60, 120 and 240 second), tryptophan (0 (as control), 50,100, 200 µM) and proline content (0 (as control), 50, 100 and 200 µM) on grape stem internodes explants in Kodori cultivar. This project was performed in factorial experiment (two factors) in the basis of completely randomized design with three replications at tissue culture laboratory of Shahed University of Tehran. Results showed that both ultrasound and two explained amino acids had significant effects on studied characteristics such as callus frequency, callus length and width, fresh weight, embryo numbers in each callus and their germination percentage. Generally, using 100 µM tryptophan and proline coincide with 120 second ultrasound had highest positive effects on the most studied characteristics.