EFFECTS OF STARCH WASTEWATER ON THE PERFORMANCE OF MAIZE (Zea mays L.) IN ABRAKA, DELTA STATE, NIGERIA

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INTRODUCTION
Maize (Zea mays L.) is a crop that belongs to grass family," Poaceae". This plant is globally cultivated being one of the most important cereal crops worldwide (Agbogidi et al., 2007). Z. mays is pollinated by wind and they usually can carry out both self and cross pollination. Mature pollen which are shed off can remain viable for about 10-30 minutes, however, when the condition is favourable, the seed may remain viable for a longer duration (Brunce et al., 2002). Maize is primarily a crop grown is warm weather but can still be grown in several ranges of climatic conditions (Sam et al., 2017). Maize can be grown successfully in areas that receives a mean annual rainfall of about 60cm. Maize plant does not develop or grow in the wild, It develops and survives only through human care (Adiaha et al., 2016). Maize has a wide range of uses; food, animal feed, industrial and pharmaceutical uses (Agbogidi et al., 2007). Starch can be gotten from cassava and cassava has been found to be amongst significant root crops grown in the tropics and used as a source energy to humans due to the presence of a high amount of carbohydrates and a highly nutritive roots (Akparobi, 2017). A mature cassava root is composed of about 30-35% carbohydrate, 1-2% fibre, 1-2% fat, 1-2% protein and 60 -70% moisture, as well as some quantities of minerals and vitamins (Ekebafe et al., 2012). A mature root of cassava may range in its content of starch from about 15 to 33%, depending on the climatic condition and time of harvest (Hasmadi et al., 2020). Firouzeh et al. (2007 stated that the area of the leaves of Glycine max (Soybean) reduced rapidly after exposure to starch effluent. Starch waste water is acidic and rich in minerals, vitamins and other organic compounds which are derived from the degradation of starch in the plant body (Pereira et al., 2016). Starch is widely used in food, pharmaceutical, paper and textile industry in large quantities (Akparobi, 2017). Cassava is used as a bulk source of starch production in various countries (Shubhaneel et al., 2018). Starch from (cassava) is obtained during the cassava milling process and it has numerous economic importance. Cassava starch also known as hydrogel (Superabsorbent polymers). They are materials that have the ability to absorb fluids which are about 15 times greater than their own dried weight examples are water, electrolyte solution, blood sweat and urine (Ekebafe et al., 2011). The starch waste water contains high amount of volatiles, dissolved chemicals used in modification, impurities from cassava processing, gluten and dextrose and characterized as high strength (Osunbitan, 2012). There is a significant pressure on plant life through the application of different hazardous pesticides and chemicals from fertilizers and this indeed threatens the ecosystems (Agbogidi, 2021a). Several other pollutants like waste water may also contain deleterious chemicals and free radicals that may pollute the soil and cause stress in plants (Agbogidi, 2021b;Agbogidi, 2021c). Very few data are available in the literature on the effects of starch wastewater on the performance of maize. It is against this background that a study as this has been embarked upon to evaluate the performance of maize as affected by starch wastewater with a view to recommending the same to maize farmers and rural inhabitants of Delta State for sustained land maximisation and without being a threat to the environment.

MATERIALS AND METHODS Study location
The study was carried out in a screen house at the Botanical Garden, Site III, Delta State University, Abraka. The study location is found between latitude 5° 45′ and 5° 5 0′ N and longitude 6° and 6° 15′ E. This area is defined by total annual rainfall of about 3.098mm with mean monthly rainfall ranging from 28.8mm. The soil temperature in this area is about 28 0 C and soil pH ranging from 4.5-8 (Achuba and Ja-anni, 2018).

Sample collection Soil samples collection
The fresh soil was collected into a polytene bag at Site III, Delta State University, Abraka.

Source of seeds
A local variety of maize seeds were obtained from the Abraka Market, Delta State.

Source and preparation of starch effluent
The starch effluent was prepared locally by adding water into the ground cassava. The ground cassava was collected from the grinding engine in Abraka Market, Delta State. The effluent was allowed to sit for 24 hours before use.

Field work
The field work was conducted in a screen house located at the botanical garden, Site III, Delta State University, Abraka. Fresh soil with no history of pollution was collected, air dried and sieved and then 2kg was measured in 25 polytene bags. Out of the 25 polytene bags, 5 were the control plants (1 control and 4 replicates), the other 20 were contaminated with different concentrations (25, 50, 75 and 100%). Before planting, the maize seeds were tested for viability using the water floatation test. The soil of the samples were further polluted before planting (3 seeds) using the different concentrations.

Experimental design
A Randomized Complete Block Design (RCBD) was used. The experiment was observed for 4 weeks after planting (WAP).

Collection of data
The parameters collected were germination %, germination rate, days to germination, plant height, plant girth, leaf area and number of leaves.

Germination rate
Grain sprouting began 3-4 days after planting and when seedlings were 5 days old, germination counts were taken per treatment. The percentage germination was calculated as number of seedlings that sprouted over the number of seeds planted times 100

× 100
Seeds which failed to sprout after the fifth day were regarded as having not germinated following the methods of Agbogidi et al. (2007). Days to germinating were taken when the seeds started sprouting. The height of the plant was measured from level of the soil to terminal bud at a week after planting (WAP) using a measuring tape. The stem girth or plant girth was measured weekly using a measuring tape. The number of leaves was determined by mere counting of the leaves while the leaf area was determined with the length and breadth measurements of the longest leaf per plant while correlation factor of 0.75 was used to multiply the value following the procedure of Agbogidi et al. (2007).

Leaf colour
The colour of the leaves was examined daily by visual aid from the time of sprouting to four weeks.

Statistical analysis
The parameters were analysed using a one way ANOVA and the significant means were separated using the Duncan's Multiple Range Tests (DMRT) using the procedures of SAS (1996).

Chemical Analysis
The chemical analysis of the contaminant was conducted at Botany Laboratory located at Site II, Delta State University, Abraka. Substances analysed were oxidisable substances, calcium, magnesium, zinc, acidity and alkalinity. It was conducted using the method for test of water as stated in the British Pharmacopoeia (BP, 2019).

pH
The pH of the effluents (25, 50, 75 and 100%) and water was determined using a pocket pH Meter.

RESULTS AND DISCUSSION Results
The results obtained on germination parameters are presented in Table 1. The maize seeds sown in the control plots performed significantly better (P<0.05) viz: they had 100% germination, all the seeds germinated and sprouted three days after planting. Significant reductions (P<0.05) were recorded in seeds planted in the contaminated soils and germination performance was observed to be dependent on the level of the contaminant. The seeds sown in 100% starch effluent failed to germinate even after 10 days after planting. The performance of maize seedlings as affected by the contaminant in terms of plant height, stem girth, leaf area and number of leaves are presented in Tables 2, 3, 4 and 5 respectively. Table 2 shows that the highest heights were attained for the seedlings grown in the control when compared to the 25%. The mean plant height of 50% and 75% were higher unlike the 100% seedlings that didn't sprout at all.   Table 3 showed that there was a slow increase in the stem girth of the maize plants (25, 50 and 75%) with time when compared to 0% which showed a rapid appreciation. The stem girth was significantly different at P<0.05 from week one to week four.  From the results in Table 5, there was a significant difference (P<0.05) in the number of leaves between the seedlings grown in the contaminated soils and the control. The values obtained are concentration dependent.  50 ©2023 This is an Open Access article distributed under the terms of the Creative Commons Attribution 4.0 International license viewed via https://creativecommons.org/licenses/by/4.0/ which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is cited appropriately.

Discussion
Findings from the study indicated that starch wastewater significantly reduced the performance of maize including the germination characteristics and growth. The high acidity observed in the contaminated soils could have affected the performance of the maize plants. This agrees with the findings of Pereira at al. (2016). Similarly, the high amount of oxidisable substances, sodium and zinc could have also impacted the performance of the test plant.

CONCLUSION
This study examined the effects of starch waste water on the growth of maize. This study established that starch waste water does not encourage the growth of maize plant and thus may not encourage the growth of other plants in the environment. The effluent significantly reduced the germination parameters as well as the growth of maize seedlings. It is recommended that starch waste water should be carefully disposed in areas where it would not affect the distribution and growth of plants.