Establishing optimal planting windows for contrasting sorghum cultivars across diverse agro-ecologies of north-eastern Nigeria: a modelling approach

Open Access Journal; Published online: 28 Feb 2023In the context of climate change, the sowing date and cultivar choice can influence the productivity of sorghum, especially where production is constrained by low soil fertility and early terminal drought across the challenging agro-ecologies of north-eastern Nigeria. Planting within an optimal sowing window to fit the cultivar’s maturity length is critical for maximizing/increasing the crop yield following the appropriate climate-smart management practices. In this study, the APSIM crop model was calibrated and validated to simulate the growth and yield of sorghum cultivars with differing maturing periods sown within varying planting time windows under improved agricultural practices. The model was run to simulate long-term crop performance from 1985 to 2010 to determine the optimal planting windows (PWs) and most suitable cultivars across different agro-ecological zones (AEZs). The performance of the model, validated with the observed farm-level grain yield, was satisfactory across all planting dates and cropping systems. The model predicted a lower mean bias error (MBE), either positive or negative, under the sole cropping system in the July sowing month compared to in the June and August sowing months. The seasonal climate simulations across sites and AEZs suggested increased yields when using adapted sorghum cultivars based on the average grain yield threshold of ≥1500 kgha−1 against the national average of 1160 kgha−1. In the Sudan Savanna (SS), the predicted optimum PWs ranged from 25 May to 30 June for CSR01 and Samsorg-44, while the PWs could be extended to 10 July for ICSV400 and Improved Deko. In the Northern Guinea Savanna (NGS) and Southern Guinea Savanna (SGS), the optimal PWs ranged from 25 May to 10 July for all cultivars except for SK5912, for which predicted optimal PWs ranged from 25 May to 30 June. In the NGS zone, all cultivars were found to be suitable for cultivation with exception of SK5912. Meanwhile, in the SGS zone, the simulated yield below the threshold (1500 kgha−1) could be explained by the sandy soil and the very low soil fertility observed there. It was concluded that farm decisions to plant within the predicted optimal PWs alongside the use of adapted sorghum cultivars would serve as key adaptation strategies for increasing the sorghum productivity in the three AEZs

Effects of Crude Oil contaminated Water on the reproductive system of Female Wistar Rats

The rising level of infertility in the females have been associated with environmental pollutants and one such pollutants is crude oil. Crude oil pollution occurs in the Niger-Delta region of Nigeria and interaction with this toxicant by both humans and animals may adversely the female reproductive system. This study was designed to investigate the effect of crude oil contaminated water on reproductive functions in female Wistar rats. Fifteen (15) female rats weighing between 140g-230g were used for this study and the rats were divided into three (3) groups (1, 2 and 3) and each group had five rats. Group 1 was the control group while group 2 and 3 were the test groups receiving 2.5mls and 5mls of crude oil contaminated water twice daily for four weeks. The stages of Oestrus cycle of the rats were checked daily. The rats were sacrificed after four weeks and the blood collected were used for hormonal assays (Follicle stimulating hormone (FSH), Luteinizing hormone (LH), Testosterone). The uterus and ovaries were used for histology (Haematoxylin and Eosin staining), Superoxide dismutase (SOD) activity and Malondialdehyde (MDA) concentration. The results were analyzed using GraphPad Prism software for windows and data were expressed as mean±standard error of mean. Statistical significance was accepted at p<0.05. There was no significant changes (p>0.05) in the weights and relative reproductive organ weights (uterus and ovary) of among the three groups. FSH and LH in the test group of rats fed with crude oil contaminated water when compared with the control were not statistically significant (p<0.05). Oestradiol was significantly lower (p<0.05) in the test group whereas progesterone and progesterone-oestradiol ratio was significantly elevated (p<0.05) in the test groups when compared with the control. There were degenerative changes in the ovaries and uterus of rats fed with crude oil contaminated water when compared with the control. SOD was significantly reduced (p<0.05) in the test group while MDA was elevated in the ovaries and uterus of the test group. The oestrus cycle was irregular in the test groups.   Crude oil contaminated water has endocrine disrupting effects on the female reproductive system as well as inducing oxidative stress and this may adversely affect female reproductive functions and fertility. KEY WORDS: Crude oil contaminated water, Endocrine disruptor, Female reproductive functions, Oxidative stress DOI: 10.7176/JMPB/72-05 Publication date: June 30th 202

Vitamin C reduced Pausinytalia Yohimbe induced reproductive toxicity in female Wister rats

Medicinal plants have been used as a source of ailments healing for several years and had gained acceptance as well as widespread use in many cultures of the world. Pausinytalia Yohimbe (P.yohimbe) had been used in folklore medicine by tribes in Nigeria as aphrodisiac. Despite its beneficial effects as an aphrodisiac, we had demonstrated that chronic use of P.yohimbe had adverse effects on both male and female reproductive systems as evidenced by its effects on hormonal and structural changes in the reproductive systems. This study was done to determine if Vitamin C a potent anti oxidant can ameliorate the toxic effects of P.yohimbe. Twenty female Wistar rats weighing 160 -200g with normal estrus cycles were randomly allotted into four experimental groups of five rats each. Group A was the control group while groups B, C and D served as test groups. Group A received distilled water while group B received 5% Vitamin C only, group C received 150mg/kg body weight and D received vitamin C and 150mg/kg body weight of aqueous extract of P. yohimbe respectively for 4 weeks via oral gavage. Estrus cycles of the rats were evaluated daily and were sacrificed after 4 weeks. Blood samples obtained were used for hormonal assay (follicle stimulating hormone (FSH) and Luteinizing hormone (LH), estradiol and progesterone). Ovaries and uteri removed were used for Heamatoxylin and Eosin staining for histology. Vitamin C restored normal estrus cycle, improved gonadotropins (FSH and LH) production, and also ameliorated the degenerative changes in both ovaries and uteri of rats treated with P. yohimbe. Vitamin C had no significant effects on estradiol and progesterone production of rats treated with P. yohimbe. We concluded that Vitamin C ameliorated P. yohimbe induced reproductive toxicity in female Wistar rats. It may be that the mechanism of P. yohimbe induced reproductive tissue destruction and gonadotropins decrease is via oxidative stress. Vitamin C may be recommended for those chronically exposed to P. yohimbe for prevention. Keywords: Pausinytalia Yohimbe, Reproductive hormones, Reproductive toxicity, Vitamin C, Wister rats DOI: 10.7176/JMPB/72-06 Publication date: June 30th 202