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2021, vol. 66, br. 3, str. 231-245
Učinak novih ranih hibrida kukuruza (Zea mays L.) obogaćenih provitaminom A u uslovima izmenjene savane u Nigeriji
Ladoke Akintola University of Technology (LAUTECH), Faculty of Agricultural Sciences, Department of Crop Production and Soil Science, Ogbomoso, Oyo State, Nigeria

e-adresaaokolawole@lautech.edu.ng
Sažetak
Kukuruz (Zea mays L.) je glavna namirnica za milione ljudi širom sveta i čini više od 30% ukupnih kalorija u ishrani. Međutim, normalnom endospermu nedostaje dovoljna količina prekursora vitamina A. Da bi se postigla prehrambena sigurnost i sprečila neuhranjenost, potrebno je da se usvoji gajenje ranog višestrukog hibrida kukuruza obogaćenog pro-vitaminom A tolerantnog na stres. Cilj ove studije bio je da se proceni agronomski učinak i prinos novorazvijenih hibrida kukuruza. Petnaest poboljšanih hibrida kukuruza i jedan komercijalni hibrid, koji je korišćen kao lokalna kontrola ocenjeni su u potpuno slučajnom blok dizajnu sa dva ponavljanja tokom dve godine na naučno-istraživačkom imanju Tehnološkog univerziteta Ladoke Akintola u Ogbomosu u Nigeriji. Hibridi su pokazali značajne varijacije (P < 0,01) u pogledu prinosa zrna, broja dana do cvetanja, visine klipa i ovojnih listova klipa. Tokom godina, prinos zrna hibrida kretao se između 4.780,8 kg ha-1 (PVAEH-19) i 7.886,9 kg ha-1 (PVAQEH-1), sa srednjom vrednošću od 6.354,2 kg ha-1. PVAEH-15 se pokazao kao najbolji na osnovu prinosa zrna, ranog cvetanja i čvrstih ovojnih listova klipa. Četrnaest hibrida je nadmašilo lokalnu kontrolu (4.947,2 kg ha-1), pet hibrida imalo je značajnu (P < 0,05) prednost u prinosu od > 26% u odnosu na lokalnu kontrolu. Dosledan učinak PVAEH-15 i PVAEH-16 tokom dvogodišnje procene ukazuje na potencijal hibrida da se prilagode lokalnim uslovima. Usvajanje ovih hibrida kukuruza od strane poljoprivrednika, povećaće proizvodnju kukuruza i sprečiti neuhranjenost u uslovima izmenjene savane u Nigeriji.

Introduction

Maize (Zea mays L.) is a staple crop and source of calories, proteins, vitamins and minerals. It accounts for an average of 15-20% of the daily calories in the diets of inhabitants of sub-Saharan Africa (SSA) and is the source of income for smallholder farmers (FAOSTAT, 2016). Maize adapts to different environments and serves as an important feed, fodder and industrial crop due to its popularity across regions (Randjelovic, 2011). It has been forecasted to become the crop with the highest production by 2025, and the demands will be doubled by 2050 (Rosegrant et al., 2008). The development and deployment of improved maize cultivars by international and national research institutes assured increased maize productivity in the savanna agro-ecologies.

The savanna agro-ecologies of Nigeria have great potential for food production because of their high solar radiation favouring maize production (Bello et al., 2012). Like the rainforest region, the derived savanna experiences adequate annual precipitation and ample solar radiation as the Guinea savanna. These weather conditions result in a suitable environment for agricultural production. In spite of the growing reputation of maize as a chief income earner for resource-limited farmers in SSA over the last few decades (Fakorede et al., 2003; FAOSTAT, 2016), its yields on smallholder farmers' fields remain low owing to diverse abiotic and biotic stresses (drought, heat waves, low soil nitrogen (low-N), foliar diseases, insect infestations and Striga hermonthica parasitism) among which drought is the most disturbing (Hao et al., 2011; Mir et al., 2012).

In the tropics, maize cultivation occurs mainly under rainfed conditions and is usually exposed to random drought, which results in crop losses and, occasionally, a total crop failure. This situation is worsened by the rising impact of global climate change, compelling maize production into marginal, drought-prone zones (Bello et al., 2012). Terminal drought during grain-filling growth phases can be devastating in maize breeding as a result of enhancing leaf senescence, reduction in leaf gas exchange parameters, chlorophyll content of the plant and consequently a reduction in grain yield (Habuš-Jerčić et al., 2018). With the occurrence of random drought in the derived savanna, early maturing maize genotypes that can avoid drought and other stress factors at flowering could be important in reducing losses (Olaoye et al., 2009; Hussain, 2011). Early maturing maize varieties can be beneficial in various cropping systems like intercropping and mixed cropping by competing less for moisture, light, and nutrients than the late-maturing varieties. Their planting period can also be adjusted, thereby aiding multiple planting cycles in a season to lessen the risk of losing a single crop to weather hazards (Pswarayi and Vivek, 2008). The unpredictable changes in environmental conditions affect the performance of maize genotypes. Thus, evaluating the performance of new maize hybrids in a specific agro-ecology is essential.

Furthermore, maize varieties of standard grain quality have a deficiency in amino acids (lysine and tryptophan) and micronutrient supplements (pro-vitamin A), which may result in widespread malnutrition. Micronutrient deficiency, also known as hidden hunger, is a health condition caused by the lack of essential vitamins and minerals required by the human body in small quantities (Nguyen et al., 2014). Vitamin A deficiency (VAD) has been established as a serious public health problem worldwide (Tsegaye Demissie et al., 2009; Akhtar et al., 2013). The menace of VAD is more pronounced in the developing economies of the world, where it is mainly caused by the inadequate consumption of foods that are rich in vitamin A (Tsegaye Demissie et al., 2009). In Africa, it has affected 54 million children and 4 million women (WHO, 2009; Mason and Shrimpton, 2010). β-carotene is a precursor of vitamin A and enhancing their concentration in maize grain enables better absorption of mineral nutrients (Kravić et al., 2014). However, maize may be used as a vehicle to tackle this deficiency through the utilization of improved quality varieties with the crop biofortification approach (Miller and Welch, 2013). Therefore, the adoption of early multiple stress-tolerant, pro-vitamin A (PVA) maize hybrid for cultivation by farmers will boost maize nutrient availability, productivity and income.

The maize improvement programme of the International Institute of Tropical Agriculture (IITA), Ibadan, Nigeria, possesses a genetically variable maize germplasm. They develop and maintain diverse genetic resources, which are useful sources of resistance and/or tolerance to biotic and abiotic stresses, higher grain yield potential, improved quality, earliness and wide adaptation. Improved genetic materials from the Institute's breeding programmes are disseminated to partners as either regional or international trials. The evaluation of the improved genotypes for adaptability and yield potential in the diverse growing environments will determine their suitability for cultivation by farmers in the agro-ecologies. Therefore, it is pertinent to assess the newly developed early maturing PVA enhanced maize hybrids for their reactions to other stress factors that may be unique to the derived savanna agro-ecology and also to identify hybrids that can replace existing cultivars for cultivation in farmers' fields. The objective of this study is, therefore, to assess the agronomic performance and yield of the early multiple stress-tolerant PVA enhanced maize hybrids, with the view to identify hybrids cultivated in the derived savanna agro-ecology of Nigeria.

Materials and Methods

Genetic materials

Sixteen (16) hybrid varieties comprising fifteen (15) multiple stress-tolerant PVA maize hybrids belonging to the early maturing group, which was originally part of international trials developed by the maize improvement programme (MIP) of IITA Ibadan, Nigeria, and a popular farmers' commercial hybrid, Oba Super 6, which is well adapted to the Savanna agro-ecologies, were used in this study (Table 1).

Table 1. The list of genetic materials used in this study.

Entry Hybrid Grain colour Origin
1 PVAEH-14 Orange IITA
2 PVAEH-15 Orange IITA
3 PVAEH-16 Orange IITA
4 PVAEH-17 Orange IITA
5 PVAEH-18 Orange IITA
6 PVAEH-19 Orange IITA
7 PVAEH-20 Orange IITA
8 PVAEH-21 Orange IITA
9 PVAEH-22 Orange IITA
10 PVAEH-23 Orange IITA
11 PVAEH-24 Orange IITA
12 PVAQEH-1 Orange IITA
13 PVAEH-25 Orange IITA
14 PVAQEH-2 Orange IITA
15 Check(RE) Yellow IITA
16 Oba super 6 Yellow Local Check

PVAEH = Pro-vitamin A early hybrid; PVAQEH = Pro-vitamin A QPM early hybrid; RE = Reference entry.

The hybrids were evaluated during the main growing seasons of 2018 and 2019 at the Teaching and Research (T&R) Farm of the Ladoke Akintola University of Technology (LAUTECH), Ogbomoso (8°10ʹN, 4°10ʹE, and altitude 341 m above sea level). The location is in the derived savanna agro-ecology of Nigeria. The annual mean rainfall of the experimental site ranges between 1,000 and 1,200 mm, while the daily temperature is between 28°C and 30°C. The soils are characterized as alfisol, which is generally low in nitrogen. The rainfall data for the years of the experiment (Figure 1) was obtained from the weather station situated at the Faculty of Agricultural Sciences, LAUTECH, Ogbomoso.

Figure 1 The monthly rainfall distribution pattern for Ogbomoso in 2018 and 2019.

Source: LAUTECH weather station, Ogbomoso, Nigeria.

The experiment for each year was established in the first week of June when the rains have become steady. The sixteen hybrids were planted each year in a randomized complete block design (RCBD) with two replications. Each plot was a double 5-m row spaced 0.75 m apart with 0.50-m spacing between plants within each row. Three seeds were planted per hole and were later thinned to two plants per stand 2 weeks after sowing to attain the optimum population density of 53,333 plants ha−1. NPK 15-15-15 fertilizer was applied at the rate of 60 kg N, 60 kg P, and 60 kg K per hectare at the time of sowing. Urea (45% N) was applied 4 weeks after sowing as top-dressing at the rate of 60 kg N ha−1 to achieve a total of 120 kg N ha-1 recommended for maize production in the zone. A mixture of herbicides including gramoxone (post-emergence) and primextra (pre-emergence) was applied at the rate of 5.0 l ha−1 at sowing, and manual weeding was subsequently done to keep the experimental plots weed-free.

Data collection and analyses

For each plot in each year's experiment, data were taken on the following traits: anthesis dates were recorded as the number of days from sowing to pollen shed for 50% of the plants in a plot; silking dates were taken as the number of days from sowing to silk emergence for 50% of the plants in a plot; anthesis-silking interval (ASI) was then calculated as the difference between silking and anthesis dates; plant height was measured in centimeters (cm) as the distance from the base of the plant to the height of the first tassel branch; ear height was also measured in cm as the distance from the base of the plant to the node bearing the upper ear; plant aspect was visually scored on a scale of 1-5, where 1 = excellent overall phenotypic appeal and 5 = poor overall phenotypic appeal; husk cover was visually rated on a scale of 1-5, where 1 = husks tightly arranged and extended beyond the ear tip and 5= ear tips exposed; ear aspect was also visually assessed on a scale of 1-5, where 1 = clean, uniform, large, and well-filled ears, and 5 = rotten, variable, small, and partially filled ears; number of ears per plant was calculated as the ratio of number of harvested ears to number of harvested plants; grain yield measured in kg ha−1 was extrapolated from field weight and grain moisture recorded at harvest and was adjusted to 15%.

A separate analysis of variance (ANOVA) was performed on the data collected on an individual year basis. The ANOVA results of 2018 and 2019 data show moderate heritability estimates (0.35-0.83) and a low coefficient of variation (2.34-24.26%) for all traits measured, thereby justifying the analysis across the years. The data for the two years were pooled for combined ANOVA, year and replications were considered as random factors, whereas the hybrids were considered as fixed effects. Entry means were generated for each trait and were separated using Fisher's protected least significant difference test (LSD) at P < 0.05 according to Steel and Torrie (1980). All analyses were performed using PROC GLM, in SAS (SAS Institute, 2011). A rank summation index (RSI) (Mulumba and Mock, 1978) was constructed to determine the overall performance of each entry. The index was obtained by ranking each entry for grain yield, number of days to anthesis, number of days to silking and tight husk cover. The 16 genotypes were ranked from the lowest to the highest for each trait, and RSI was calculated by summing the ranks to select the top five outstanding maize hybrids. Thus, the lowest index value obtained by an entry would be 4.0 if it was superior for all four traits.

Results and Discussion

The combined ANOVA revealed that year was a significant (P < 0.01) source of variation for all measured traits, and its sums of squares, expressed as percentages of the corrected total sums of squares, accounted for 3-49% of the total variation for all agronomic traits measured. On the other hand, the mean square of hybrid x year interaction was significant (P < 0.05) only for number of days to anthesis, suggesting that the hybrids displayed consistent performance over the years of evaluation, therefore aiding the identification of potentially highyielding hybrids for the location. Previous authors have identified superior hybrids based on the absence of significant interaction between the hybrids and year for grain yield in maize (Menkir et al., 2014; Abera et al., 2016). The mean square of hybrids differed significantly (P < 0.05/0.01) for grain yield, number of days to anthesis and silking, ear height and husk cover. The observed variations may be a result of the diverse genetic makeups and backgrounds of the parental materials used in their formation. The coefficient of variation (CV) was > 20% only for ASI, ear aspect and husk cover ratings (Table 2).

Table 2. Combined mean squares for grain yield and other agronomic traits of the evaluated maize hybrids.

Source df Grain
yield
(kg ha-1)
Anthesis
(days)
Silking
(days)
Anthesis
-silking
interval
(days)
Plant
height
(cm)
Ear height (cm) Number
of ears
per
plant
Husk
cover
(1-5)
Plant
aspect
(1-5)
Ear
aspect
(1-5)
Year (Y) 1 318647490.5*** 7.6* 74.4** 34.5** 36247.4*** 47006.2*** 2.3** 18.1*** 93.8*** 6.9***
Replicate 1 68705325.7*** 18.5** 103.8*** 44.6** 15848.7*** 6353.2*** 0.1 0.1 24.0*** 0.8
Hybrid
(H)
15 3882455.8** 204.2*** 16.2*** 4.4 189.9 172.1* 0.3 0.5* 0.4 0.5
H × Y 15 1972515.7 4.4* 2.8 4.2 203.4 87.7 0.3 0.2 0.2 0.4
Error 32 1393889.5 2.2 6.2 4.7 195.7 114.0 0.2 0.4 0.5 0.3
CV 18.8 2.9 4.5 37.4 8.7 14.1 9.1 22.2 18.8 21.7

*, **, *** indicate mean squares significant at 0.05, 0.01 and 0.001 probability levels, respectively.

Considering the traits that showed significant variation, the year of 2018 was the most favourable for the expression of grain yield potential. Although the amount of rainfall was evenly distributed in both years, the year of 2018 had higher rainfall between June and August (Figure 1) which were crucial periods for growth, flowering and grain filling. Hence, grain yield varied between 7,509.4 kg ha-1 (PVAEH-19) and 11,349.3 kg ha-1 (PVAEH-23) with a mean of 9,272.9 kg ha-1. PVAEH-23 had the highest grain yield potential, which differed significantly (P < 0.05) from 9 of the early maturing PVA maize hybrids. All the early maturing PVA maize hybrids out-yielded the local check (6,656 kg ha-1), but only 8 hybrids had a significant (P < 0.05) yield advantage of > 25% over the local check. The hybrids shed pollen between 46 and 58 days, and number of days to silking was between 52 and 62 days after sowing (DAS) with PVAEH-16 and PVAEH-15 as the earliest for both traits. The hybrids also had vigorous growth, with ears placed at an average of 105.1 cm and a mean husk cover rating of 2.3. Incidentally, PVAEH-23, which had the highest grain yield, also was superior for tight husk cover (Table 3).

Table 3. The mean performance of maize hybrid traits with significant variations from the two years of evaluation.

Hybrid 2018
Grain yield
(kg ha-1)
Anthesis
(days)
Silking
(days)
Ear height
(cm)
Husk cover
(1–5)
PVAEH-14 8106.7 51.0 57.0 104.5 2.3
PVAEH-15 11093.4 47.5 52.5 111.5 2.3
PVAEH-16 8362.7 46.0 54.5 95.0 2.3
PVAEH-17 8192.0 51.5 55.5 100.0 2.0
PVAEH-18 8618.7 50.5 55.0 107.0 2.3
PVAEH-19 7509.4 51.0 54.5 104.5 2.8
PVAEH-20 9216.0 49.5 54.0 99.0 2.8
PVAEH-21 8960.0 51.0 53.5 108.0 2.3
PVAEH-22 7594.7 50.5 55.0 102.0 2.3
PVAEH-23 11349.3 50.5 54.5 106.5 1.5
PVAEH-24 8362.7 51.0 55.5 101.0 2.3
PVAEH-25 9386.7 49.0 53.5 103.0 2.3
PVAQEH-1 10922.7 52.5 58.5 113.0 2.3
PVAQEH-2 10752.0 51.0 55.0 116.0 2.3
Check(RE) 10666.7 49.5 53.0 105.5 2.8
Minimum 7509.4 46.0 52.5 95.0 1.5
Maximum 11349.3 52.5 58.5 116.0 2.8
Grand mean 9272.9 50.1 54.8 105.1 2.3
LSD (0.05) 2190.4 3.0 2.8 13.5 1.1
Local check 6656.0 58.0 61.5 113.0 1.8
Hybrid 2019
Grain yield
(kg ha-1)
Anthesis
(days)
Silking
(days)
Ear height
(cm)
Husk cover
(1–5)
PVAEH-14 5137.8 52.3 59.7 50.4 3.0
PVAEH-15 3808.0 49.0 57.0 58.4 3.0
PVAEH-16 4533.3 48.7 54.3 55.6 4.0
PVAEH-17 3868.4 50.3 58.0 64.8 2.7
PVAEH-18 4291.6 52.3 59.3 57.5 2.7
PVAEH-19 2961.8 51.7 59.7 49.4 3.7
PVAEH-20 4231.1 51.0 56.7 54.7 3.0
PVAEH-21 3445.3 52.0 57.0 60.3 3.7
PVAEH-22 4352.0 53.0 58.3 57.2 3.7
PVAEH-23 4714.7 52.0 59.0 49.2 2.7
PVAEH-24 4835.5 52.0 57.3 57.0 3.0
PVAEH-25 3928.9 52.0 58.3 33.0 3.7
PVAQEH-1 5863.1 52.3 60.0 61.7 3.0
PVAQEH-2 5319.1 51.0 58.0 55.4 3.0
Check(RE) 4835.6 52.7 57.3 56.8 3.0
Minimum 2961.8 48.7 54.3 33.0 2.7
Maximum 5863.1 53.0 60.0 64.8 4.0
Grand mean 4408.4 51.5 58.0 54.7 3.2
LSD (0.05) 1775.7 2.1 4.2 19.5 1.1
Local check 3808.0 53.3 62.3 69.4 3.0

The abundant soil moisture at anthesis and silking in 2018 allowed each hybrid to express their yield potential. The hybrids flowered earlier and had a shorter ASI than the check. The early flowering results in early seed set, grain filling and maturity, which are important for drought escape (Shavrukov et al., 2017; Senapati et al., 2019). Lower ear height in comparison to the local check was desirable because plants with higher ear placement are usually more prone to root and stalk lodging.

On the other hand, the highest amount of rainfall in 2019 was between September and October towards the end of the grain filling period, and this resulted in a grain yield range of 2,961.8kg ha-1 (PVAEH-19) to 5,863.1 kg ha-1 (PVAQEH-1) with a mean of 4,370.9 kg ha-1. PVAQEH-1 had the highest grain yield potential, which differed significantly (P < 0.05) from five of the early maturing PVA maize hybrids, while the same hybrid (PVAEH-19) with the lowest yield in the previous year was still the poorest in terms of yield potential in 2019. Twelve hybrids had higher grain yield than the local check (3,808.0 kg ha-1), but only one hybrid (PVAQEH-1) had a significant (P < 0.05) yield advantage of 35% over the local check (Table 3). Number of days to anthesis was between 49 and 54 DAS, while silking dates varied between 54 and 63 DAS with PVAEH-16 as the earliest for both traits. The hybrids had a reduced mean ear height of 54.7 cm and a mean husk cover rating of 3.2, with PVAEH-17, PVAEH-18 and PVAEH-23 hybrids with the lowest husk cover rating (2.7).

Other agronomic traits from each year of the evaluation showed disparity for all traits measured (Table 4).

Table 4. Effects of years on the mean performance of grain yield and other measured agronomic traits of the evaluated PVA maize hybrids.

Traits 2018 2019 Mean±Standard error Mean
difference
Min. Max. Min. Max. 2018 2019
Grain yield (kg ha-1) 7509.4 11349.3 2961.8 5863.1 9272.9±345.9 4377.9±205.8 4895.0
Anthesis (days) 46.0 52.5 48.7 53.0 50.1±0.4 51.4±0.3 -1.3
Silking (days) 52.5 58.5 54.3 60.0 54.8±0.4 58.0±0.4 -3.3
Anthesis-silking interval (days) 2.5 8.5 5.0 8.0 4.6±0.4 6.6±0.3 -2.0
Plant height (cm) 188.0 220.0 115.4 146.6 201.7±2.4 132.9±2.3 68.8
Ear height (cm) 95.0 116.0 33.0 64.8 105.1±1.4 54.6±2.1 50.5
Husk cover (1–5) 1.5 2.8 2.7 4.0 2.3±0.1 3.2±0.1 -0.9
Plant aspect (1–5) 2.0 2.8 4.3 5.7 2.3±0.1 4.9±0.1 -2.6
Ear aspect (1– 5) 2.0 2.8 2.0 3.3 2.3±0.1 2.7±0.1 -0.4
Number of ears per plant 1.0 1.1 0.6 0.9 1.0±0.0 0.8±0.0 0.2

In the first year of evaluation, the flowering parameters were earlier, the hybrids had shorter ASI with a corresponding higher grain yield and number of ears per plant, taller plant and ear heights, lower husk cover, plant aspect and ear aspect ratings in comparison to the second year of the evaluation. Moreover, the grain yield of 11,349.3 kg ha-1 by PVAEH-23 in 2018 was more than twice the mean grain yield recorded (4,370.8 kg ha-1) in 2019 and close to double the mean grain yield of the top hybrid (5,863.1 kg ha-1) in 2019. Also, the commercial local check (Oba Super 6) showed instability for grain yield with a difference of 43% between the two years of the evaluation. The growth of the male and female flowers and their synchrony, which ensures good nicking, are dependent on the weather and edaphic features of the trial location. As a reflection of the weather pattern, growth and maturation progressions in 2018 were desirable in comparison to 2019. During the growing season of 2019, we experienced an unpredicted change in the rainfall pattern of Ogbomoso and its environs, which resulted in the form of random drought.

Likewise, armyworm (Spodoptera frugiperda) infested maize fields during the rainy season of 2019, causing serious devastation, which was unprecedented. The above exigencies contributed to the significant reduction in grain yield and poor agronomic performance of the maize hybrids evaluated in 2019. Consequently, the mean performance of all measured traits in the two years of the evaluation was adversely affected.

From the combined entry means over the two years, the grain yield of hybrids ranged between 4,780.8kg ha−1 (PVAEH-19) and 7,886.9 kg ha−1 (PVAQEH-1) with a mean of 6,354.2 kg ha−1 (Table 5).

Table 5. The combined mean performance for grain yield and other agronomic traits of the evaluated maize hybrids.

Hybrid Grain yield
(kg ha-1)
Anthesis
(days)
Silking
(days)
Anthesis-silking
interval (days)
Plant height
(cm)
PVAEH-14 6325.3 51.8 58.6 6.8 150.6
PVAEH-15 6722.1 48.4 55.2 6.8 172.6
PVAEH-16 6065.1 47.6 54.4 6.8 165.6
PVAEH-17 5597.9 50.8 57.0 6.2 163.2
PVAEH-18 6022.4 51.6 57.6 6.0 163.3
PVAEH-19 4780.8 51.4 57.6 6.2 158.6
PVAEH-20 6225.1 50.4 55.6 5.2 153.4
PVAEH-21 5651.2 51.6 55.6 4.0 162.3
PVAEH-22 5649.1 52.0 57.0 5.0 158.0
PVAEH-23 7368.5 51.4 57.2 5.8 156.6
PVAEH-24 6246.4 51.6 56.6 5.0 155.8
PVAEH-25 6112.0 50.8 56.4 5.6 163.0
PVAQEH-1 7886.9 52.4 59.4 7.0 166.3
PVAQEH-2 7492.3 51.0 56.8 5.8 153.0
Check(RE) 7168.0 51.4 55.6 4.2 167.7
Minimum 4780.8 47.6 54.4 4.0 150.6
Maximum 7886.9 52.4 59.4 7.0 172.6
Grand mean 6354.2 50.9 56.7 5.8 160.7
LSD (0.05) 1503.0 1.9 3.2 2.8 17.8
Local check 4947.2 55.2 62.0 6.8 167.0
Hybrid Ear height
(cm)
Husk cover
(1 – 5)
Plant aspect
(1 – 5)
Ear aspect
(1– 5)
Number of ears
per plant
PVAEH-14 72.0 2.7 3.6 2.4 0.9
PVAEH-15 79.6 2.7 3.5 2.7 0.8
PVAEH-16 71.3 3.3 4.0 2.6 0.9
PVAEH-17 78.9 2.4 3.6 2.7 0.8
PVAEH-18 77.3 2.5 3.9 2.4 0.9
PVAEH-19 71.4 3.3 4.3 2.9 0.9
PVAEH-20 72.4 2.9 4.0 2.7 0.9
PVAEH-21 79.4 3.1 4.1 2.7 0.9
PVAEH-22 75.1 3.1 3.6 2.5 0.9
PVAEH-23 72.1 2.2 3.8 2.0 1.0
PVAEH-24 74.6 2.7 4.0 2.6 0.9
PVAEH-25 61.0 3.1 4.1 2.9 0.9
PVAQEH-1 82.2 2.7 3.5 2.3 1.0
PVAQEH-2 79.6 2.7 4.3 2.5 0.9
Check(RE) 76.3 2.9 3.8 3.1 1.0
Minimum 61.0 2.2 3.5 2.0 0.8
Maximum 82.2 3.3 4.3 3.1 1.0
Grand mean 74.9 2.8 3.9 2.6 0.9
LSD (0.05) 13.6 0.8 0.9 0.7 0.1
Local check 86.8 2.5 4.4 3.2 0.8

Across the years, PVAQEH-1 had the highest yield, all of the early maturing PVA maize hybrids except for PVAEH-19 outyielded the local check (4947.2 kg ha-1), and five hybrids had a significant (P < 0.05) yield advantage of > 26% over the local check. The mean difference between the flowering dates of the hybrids and the local check was around 4-5 days, whereas ASI was just one day. Other measured traits of the hybrids were comparable to the local check except for ear height which was lower. The mean grain yield of 6.3 t ha-1 reported in this study is a reduction in yield expectation over the years. The disparity between the yields obtained in 2018 and 2019 is responsible for the lower average yields. The average hybrid maize grain yield between 8 and 10 t ha-1 has been previously reported under disease-free conditions in maize breeding (Ininda et al., 2006; Adebayo et al., 2014). Hence, the genetic potentials of the hybrids were influenced by the year variation, as having been similarly identified in previous studies as a cause of a possible yield reduction (Beyene et al., 2012; Chabala et al., 2015; Jaya et al., 2020).

The agronomic traits that showed significant variability among the hybrids evaluated were used to rank their performance. These desirable agronomic traits are essential in determining the suitability and adaptability of the hybrid to the derived savanna agro-ecology. Across the years, the rank summation index based on the aforementioned traits shows that PVAEH-15 ranked best and PVAQEH-2 ranked 5th, although PVAEQH-1 gave the highest grain yield (7,886.9) across the years. In 2018, three of the hybrids listed among outstanding hybrids constituted the top five across the years, whereas, in 2019, four of the hybrids listed among superior hybrids constituted the top five across the years. Ranking based on each year shows that both years had two hybrids (PVAEH-15 and PVAEH-16) in common listed among the top five (Table 6).

Table 6. The ranking of early maturing PVA maize hybrids based on traits with significant variations.

S/N Hybrid Grain yield
(kg ha-1)
Anthesis
(days)
Silking
(days)
Husk cover
(1-5)
Rank
summation
index
Hybrid
(2018 and 2019 combined)
1 PVAEH-15 6722.1 48.4 55.2 2.7 15
2 PVAEH-16 6065.1 47.6 54.4 3.3 23
3 PVAEH-20 6225.1 50.4 55.6 2.9 24
4 PVAEH-23 7368.5 51.4 57.2 2.2 25
5 PVAQEH-2 7492.3 51.0 56.8 2.7 27
Mean of top 5 6774.6 49.8 55.8 2.8
Grand mean 6354.2 50.9 56.7 2.8
LSD (0.05) 1503.0 1.9 3.2 0.8
    Hybrid (2018)
1 PVAEH-15 11093.4 47.5 52.5 2.3 9
2 PVAEH-23 11349.3 50.5 54.5 1.5 18
3 PVAEH-16 8362.7 46.0 54.5 2.3 22
4 PVAEH-25 9386.7 49.0 53.5 2.3 23
5 Check(RE) 10666.7 49.5 53.0 2.8 27
Mean of top 5 10171.7 48.5 53.6 2.2
Grand mean 9272.9 50.1 54.8 2.3
LSD (0.05) 2190.4 3.0 2.8 1.1
    Hybrid (2019)
1 PVAEH-20 4231.1 51.0 56.7 3.0 20
2 PVAEH-15 3808.0 49.0 57.0 3.0 21
3 PVAEH-16 4533.3 48.7 54.3 4.0 22
4 PVAQEH-2 5319.1 51.0 58.0 3.0 22
5 PVAEH-17 3868.4 50.3 58.0 2.7 23
Mean of top 5 4352.0 50.0 56.8 3.1
Grand mean 4408.4 51.5 58.0 3.2
LSD (0.05) 1775.7 2.1 4.2 1.1

Although several PVA open-pollinated varieties and hybrids have been released for commercialization in SSA, their agronomic performance differs across several production environments, but adaptability to the specific environment will determine suitability for farmers' cultivation. It is imperative to note that the top five hybrids across the years (PVAEH-15, PVAEH-16, PVAEH-20, PVAEH-23 and PVAQEH-2) were also among the outstanding hybrids listed from each year of the evaluation based on superiority in grain yield, flowering traits and husk cover ratings. In spite of the disparity in the distribution and amount of rainfall in the two years of evaluation, the consistent performance of PVAEH-15 and PVAEH-16 across the years indicates potentials for adaptability of the hybrids to the agro-ecology, especially as they also out-yielded the local check. These hybrids can be especially important for small-scale farmers, providing stable food production from year to year. Hence, the adaptability of these outstanding hybrids to the growing environment will enhance sustainable productivity, and these early maturing PVA maize hybrids may be used to replace existing cultivars in the derived savanna agro-ecology of Nigeria.

Conclusion

Variations among the 15 early maturing multiple stress-tolerant PVA maize hybrids were attributed to grain yield, number of days to anthesis and silking, ear height and husk cover rating. The superior hybrids, viz. PVAEH-15, PVAEH-16, PVAEH-20, PVAEH-23 and PVAQEH-2, identified in this study, combined desirable agronomic traits and could increase maize yield and solve malnutrition problems. Consequently, these superior hybrids that flowered and matured early with high yield potential and tight husk cover may, if adopted, escape moisture stress and are therefore recommended for sustainable production in the derived savanna agro-ecology.

Dodatak

Acknowledgements

The authors appreciate the Maize Improvement Programme (MIP) of the International Institute of Tropical Agriculture (IITA), Ibadan, Nigeria, for supporting this research through the provision of genetic materials.

References

Abera, W., Hussein, S., Derera, J., Worku, M., & Laing, M. (2016). Heterosis and combining ability of elite maize inbred lines under northern corn leaf blight disease prone environments of the mid-altitude tropics. Euphytica, 208, 391-400. [Crossref]
Adebayo, M.A., Menkir, A., Blay, E., Gracen, V., & Danquaha, E.Y. (2014). Performance-based grouping of adapted and exotic drought tolerant maize (Zea mays L) inbred lines under stressed and non-stressed conditions. Maydica, 59, 115-123.
Akhtar, S., Ahmed, A., Randhawa, M.A., Atukorala, S., Arlappa, N., Ismail, T., & Ali, Z. (2013). Prevalence of Vitamin A Deficiency in South Asia: Causes, Outcomes, and Possible Remedies. J Health Popul Nutr, 31, 413-423. [Crossref]
Bello, O.B., Abdulmaliq, S.Y., Ige, S., Mahamood, J., Oluleye, F., Azeez, M.A., & Afolabi, M.S. (2012). Evaluation of early and late/intermediate maize varieties for grain yield potential and adaptation to a southern Guinea savanna agro-ecology of Nigeria. International Journal of Plant Research, 2, 14-21.
Beyene, Y., Mugo, S., Tefera, T., Gethi, J., Gakunga, J., Ajanga, S., Karaya, H., Musila, R., Muasya, W., Tende, R., & Njoka, S. (2012). Yield stability of stem borer resistant maize hybrids evaluated in regional trials in East Africa. African Journal of Plant Science, 6, 77-83.
Chabala, L.M., Kuntashula, E., Kaluba, P., & Miyanda, M. (2015). Assessment of Maize Yield Variations Due to Climatic Variables of Rainfall and Temperature. Journal of Agricultural Science, 7, 143-155. [Crossref]
Fakorede, M.A.B., Badu-Apraku, B., Kamara, A.Y., Menkir, A., Ajala, S.O., Naab, J.B., Manyong, V.N., Makinde, K.O., Coulibaly, O., & Abalu, G.I. (2003). Maize revolution in West and Central Africa. In: B. Badu-Apraku, M.A.B. Fakorede, M. Ouedraogo, R.J. Carsky, & A. Menkir, (Ed.). Proceedings of a regional maize workshop, IITA-Cotonou, Benin Republic. (pp. 3-5). WECAMAN & IITA.
FAOSTAT. (2016). Food and Agriculture Organization of the United Nations Statistics Division statistics database. Rome, Italy: Economic and Social Development Department. Retrieved from http://faostat3.fao.org/home/E on 13.06.2020.
Habuš-Jerčić, I., Barić, M., Kereša, S., Bošnjak-Mihovilović, A., Poljak, M., & Lazarević, B. (2018). Effect of terminal drought on yield and some physiological traits of winter wheat. Genetika, 50, 747-753.
Hao, Z., Li, X., Xie, C., Weng, J., Li, M., Zhang, D., Liang, X., Liu, L., Liu, S., & Zhang, S. (2011). Identification of Functional Genetic Variations Underlying Drought Tolerance in Maize Using SNP Markers. J Integr Plant Biol, 53, 641-652. [Crossref]
Hussain, N. (2011). Screening of maize varieties for grain yield at Dera Ismail Khan. Journal of Animal and Plant Sciences, 21, 626-628.
Ininda, J., Giruchu, L., Njuguna, J.G.M., & Lorroki, P. (2006). Performance of three-way cross hybrids for agronomic traits and resistance to maize streak virus disease in Kenya. African Crop Science Journal, 14, 287-296.
Jaya, I.K.D., Soemeinaboedhy, I.N., & Sudika, I.W. (2020). Maize yield in a dryland area as affected by rainfall variability. In IOP Conference Series: Earth and Environmental Science (Vol. 411, No. 1, p. 012067). IOP Publishing.[Crossref]
Kravić, N., Vančetović, J., Anđelković, V., Babić, V., & Dragičević, V. (2014). Maize local landraces as sources for improved mineral elements availability from grain. Selekcija i semenarstvo, 20(2), 37-46. [Crossref]
Mason, J., & Shrimpton, R. (2010). Progress in Nutrition: 6th Report on the World Nutrition Situation. United Nations Standing Committee on Nutrition.
Menkir, A., Gedil, M., Tanumihardjo, S., Adepoju, A., & Bossey, B. (2014). Carotenoid accumulation and agronomic performance of maize hybrids involving parental combinations from different marker-based groups. Food Chem, 148, 131-137. [Crossref]
Miller, D.D., & Welch, R.M. (2013). Food system strategies for preventing micronutrient malnutrition. Food Policy, 42, 115-128. [Crossref]
Mir, R.R., Zaman-Allah, M., Sreenivasulu, N., Trethowan, R., & Varshney, R.K. (2012). Integrated genomics, physiology and breeding approaches for improving drought tolerance in crops. Theor Appl Genet, 125, 625-645. [Crossref]
Mulumba, N.N., & Mock, J.J. (1978). Improvement of yield potential of the ETO blanco maize (Zea mays L.) population by breeding for plant traits [Mexico]. Egyptian Journal of Genetics and Cytology, 7, 40-51.
Nguyen, P.H., Nguyen, H., Gonzalez-Casanova, I., Copeland, E., Strizich, G., Lowe, A., Pham, H., Truong, T.V., Nguyen, S., Martorell, R., & Ramakrishnan, U. (2014). Micronutrient Intakes among Women of Reproductive Age in Vietnam. PLoS One, 9, e89504. [Crossref]
Olaoye, G., Menkir, A., Ajala, S.O., & Jacob, S. (2009). Evaluation of local maize (Zea mays L.) varieties from Burkina Faso as source of tolerance to drought. Journal of Applied Bioscience, 17, 887-898.
Pswarayi, A., & Vivek, B.S. (2008). Combining ability amongst CIMMYT's early maturing maize (Zea mays L.) germplasm under stress and non-stress conditions and identification of testers. Euphytica, 162, 353-362. [Crossref]
Ranđelović, V., Prodanović, S., Tomić, Z., Bijelić, Z., & Simić, A.S. (2011). Genotype and Year Effect on Grain Yield and Nutritive Values of Maize (Zea mays L.). Journal of Animal and Veterinary Advances, 10, 835-840.
Rosegrant, M.W., Msangi, S., Ringler, C., Sulser, T.B., Zhu, T., & Cline, S.A. (2008). International Model for Policy Analysis of Agricultural Commodities and Trade (IMPACT): Model Description. Washington, D.C.: International Food Policy Research Institute.
SAS Institute. (2011). Statistical analysis software proprietary software release 9.3. Cary, NC.
Senapati, N., Stratonovitch, P., Paul, M.J., & Semenov, M.A. (2019). Drought tolerance during reproductive development is important for increasing wheat yield potential under climate change in Europe. J Exp Bot, 70, 2549-2560. [Crossref]
Shavrukov, Y., Kurishbayev, A., Jatayev, S., Shvidchenko, V., Zotova, L., Koekemoer, F., de Groot, S., Soole, K., & Langridge, P. (2017). Early Flowering as a Drought Escape Mechanism in Plants: How Can It Aid Wheat Production? Front Plant Sci, 8, 1950. [Crossref]
Steel, R.G.D., & Torrie, J.H. (1980). Principles and procedures of statistics: A biometrical approach (2nd Edition). New York: McGraw Hill Book Co.
Tsegaye Demissie, A.A., Mekonnen, Y., Haider, J., & Umeta, M. (2009). Demographic and healthrelated risk factors of subclinical vitamin A deficiency in Ethiopia. J Health Popul Nutr, 27, 666-673.
World Health Organization. (2009). Global prevalence of vitamin A deficiency in populations at risk 1995-2005: WHO global database on vitamin A deficiency.
Reference
Abera, W., Hussein, S., Derera, J., Worku, M., Laing, M. (2016) Heterosis and combining ability of elite maize inbred lines under northern corn leaf blight disease prone environments of the mid-altitude tropics. Euphytica, 208(2): 391-400
Adebayo, M.A., Menkir, A., Blay, E., Gracen, V., Danquaha, E.Y. (2014) Performance-based grouping of adapted and exotic drought tolerant maize (Zea mays L) inbred lines under stressed and non-stressed conditions. Maydica, 59: 115-123
Akhtar, S., Ahmed, A., Randhawa, M.A., Atukorala, S., Arlappa, N., Ismail, T., Ali, Z. (2013) Prevalence of Vitamin A Deficiency in South Asia: Causes, Outcomes, and Possible Remedies. Journal of Health, Population and Nutrition, 31(4): 413-423
Bello, O.B., Abdulmaliq, S.Y., Ige, S., Mahamood, J., Oluleye, F., Azeez, M.A., Afolabi, M.S. (2012) Evaluation of early and late/intermediate maize varieties for grain yield potential and adaptation to a southern Guinea savanna agro-ecology of Nigeria. International Journal of Plant Research, 2: 14-21
Beyene, Y., Mugo, S., Tefera, T., Gethi, J., Gakunga, J., Ajanga, S., Karaya, H., Musila, R., Muasya, W., Tende, R., Njoka, S. (2012) Yield stability of stem borer resistant maize hybrids evaluated in regional trials in East Africa. African Journal of Plant Science, 6: 77-83
Chabala, L.M., Kuntashula, E., Kaluba, P., Miyanda, M. (2015) Assessment of Maize Yield Variations Due to Climatic Variables of Rainfall and Temperature. Journal of Agricultural Science, 7(11): 143-155
Fakorede, M.A.B., Badu-Apraku, B., Kamara, A.Y., Menkir, A., Ajala, S.O., Naab, J.B., Manyong, V.N., Makinde, K.O., Coulibaly, O., Abalu, G.I. (2003) Maize revolution in West and Central Africa. u: Badu-Apraku B., Fakorede M.A.B., Ouedraogo M., Carsky R.J., Menkir A. [ur.] Proceedings of a regional maize workshop, IITA-Cotonou, Benin Republic, WECAMAN, pp. 3-5
Food and Agriculture Organization of the United Nations Statistics Division (FAOSTAT)-Economic and Social Development Department (2016) Food and Agriculture Organization of the United Nations Statistics Division statistics database. Rome, Italy, Retrieved June 13, 2020, from http://faostat3.fao.org/home/E (accessed on 13 June 2020)
Habuš-Jerčić, I., Barić, M., Kereša, S., Bošnjak-Mihovilović, A., Poljak, M., Lazarević, B. (2018) Effect of terminal drought on yield and some physiological traits of winter wheat. Genetika, 50: 747-753
Hao, Z., Li, X., Xie, C., Weng, J., Li, M., Zhang, D., Liang, X., Liu, L., Liu, S., Zhang, S. (2011) Identification of Functional Genetic Variations Underlying Drought Tolerance in Maize Using SNP Markers. Journal of Integrative Plant Biology, 53(8): 641-652
Hussain, N. (2011) Screening of maize varieties for grain yield at Dera Ismail Khan. Journal of Animal and Plant Sciences, 21: 626-628
Ininda, J., Giruchu, L., Njuguna, J.G.M., Lorroki, P. (2006) Performance of three-way cross hybrids for agronomic traits and resistance to maize streak virus disease in Kenya. African Crop Science Journal, 14: 287-296
Jaya, I.K.D., Sudirman,, Rosmilawati,, Soemeinaboedhy, I.N., Sudika, I.W. (2020) Maize yield in a dryland area as affected by rainfall variability. IOP Conference Series: Earth and Environmental Science, 411(1): 012067
Kravić, N., Vančetović, J., Anđelković, V., Babić, V., Dragičević, V. (2014) Maize local landraces as sources for improved mineral elements availability from grain. Selekcija i semenarstvo, vol. 20, br. 2, str. 37-46
Mason, J., Shrimpton, R. (2010) Progress in Nutrition: 6th Report on the World Nutrition Situation. United Nations Standing Committee on Nutrition
Menkir, A., Gedil, M., Tanumihardjo, S., Adepoju, A., Bossey, B. (2014) Carotenoid accumulation and agronomic performance of maize hybrids involving parental combinations from different marker-based groups. Food Chemistry, 148: 131-137
Miller, B.D.D., Welch, R.M. (2013) Food system strategies for preventing micronutrient malnutrition. Food Policy, 42: 115-128
Mir, R.R., Zaman-Allah, M., Sreenivasulu, N., Trethowan, R., Varshney, R.K. (2012) Integrated genomics, physiology and breeding approaches for improving drought tolerance in crops. Theoretical and Applied Genetics, 125(4): 625-645
Mulumba, N.N., Mock, J.J. (1978) Improvement of yield potential of the ETO blanco maize (Zea mays L.) population by breeding for plant traits [Mexico]. Egyptian Journal of Genetics and Cytology, 7, 40-51
Nguyen, P.H., Nguyen, H.H., Gonzalez-Casanova, I., Copeland, E., Strizich, G., Lowe, A., Pham, H., Truong, T.V., Nguyen, S.H., Martorell, R., Ramakrishnan, U. (2014) Micronutrient Intakes among Women of Reproductive Age in Vietnam. PLoS One, 9(2): e89504
Olaoye, G., Menkir, A., Ajala, S.O., Jacob, S. (2009) Evaluation of local maize (Zea mays L.) varieties from Burkina Faso as source of tolerance to drought. Journal of Applied Bioscience, 17: 887-898
Pswarayi, A., Vivek, B.S. (2008) Combining ability amongst CIMMYT's early maturing maize (Zea mays L.) germplasm under stress and non-stress conditions and identification of testers. Euphytica, 162(3): 353-362
Ranđelović, V., Prodanović, S., Tomić, Z., Bijelić, Z., Simić, A.S. (2011) Genotype and Year Effect on Grain Yield and Nutritive Values of Maize (Zea mays L.). Journal of Animal and Veterinary Advances, vol. 10, br. 7, str. 835-840
Rosegrant, M.W., Msangi, S., Ringler, C., Sulser, T.B., Zhu, T., Cline, S.A. (2008) International Model for Policy Analysis of Agricultural Commodities and Trade (IMPACT): Model Description. Washington, D.C: International Food Policy Research Institute
SAS Institute (2011) Statistical analysis software proprietary software release 9.3. Cary, NC
Senapati, N., Stratonovitch, P., Paul, M.J., Semenov, M.A. (2019) Drought tolerance during reproductive development is important for increasing wheat yield potential under climate change in Europe. Journal of Experimental Botany, 70(9): 2549-2560
Shavrukov, Y., Kurishbayev, A., Jatayev, S., Shvidchenko, V., Zotova, L., Koekemoer, F., de Groot, S., Soole, K., Langridge, P. (2017) Early Flowering as a Drought Escape Mechanism in Plants: How Can It Aid Wheat Production?. Frontiers in Plant Science, 8, 1950
Steel, R.G.D., Torrie, J.H. (1980) Principles and procedures of statistics: A biometrical approach. New York: McGraw Hill Book Co, Second edition
Tsegaye, D.A.A., Mekonnen, Y., Haider, J., Umeta, M. (2009) Demographic and healthrelated risk factors of subclinical vitamin A deficiency in Ethiopia. Journal of Health, Population and Nutrition, 27: 666-673
World Health Organization (2009) Global prevalence of vitamin A deficiency in populations at risk 1995-2005: WHO global database on vitamin A deficiency
 

O članku

jezik rada: engleski
vrsta rada: izvorni naučni članak
DOI: 10.2298/JAS2103231K
primljen: 23.11.2020.
prihvaćen: 26.07.2021.
objavljen u SCIndeksu: 15.10.2021.
metod recenzije: dvostruko anoniman
Creative Commons License 4.0

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