Comparing the growth and yield performance of six different varieties of frafra potato (Solenostemon rotundifluis Poir) grown under rain-fed conditions in the Guinea Savanna ecological zone of Ghana

: Aim: The study compared growth and yield performance of six varieties of Frafra potato under rain-fed conditions to help guide farmers in selecting high yielding varieties that grow well in deprived soils to improve household nutrition, income and food security. Methodology: Field experiments were conducted for two consecutive rainy seasons using sprouted tubers in Randomized Complete Ridge Design (RCRD) with four replications. Each ridge measured 0.5 m high, 0.7 m wide and 3 m long, covering 2.1 m 2 of land. Data collected fortnightly was analyzed using STATA 16.0. Results: The mean leaf area and plant height were 19.6 ± 6.8 cm 2 and 27.2 ± 10.0 cm respectively. The Local Variety had the highest leaf area (21.2 cm 2 ) while Manga-Moya recorded least leaf area (17.4 cm 2 ). Plants of WAAP Peisa were tallest (31.7 cm) as those of Local Variety were shortest (25.0 cm). Mean number of vine branches and canopy spread were 70 ±39 and 27.9 ± 9.4 cm respectively. The highest number of vine branches (88±56.7) was recorded in WAAP Peisa with the lowest of 57±33

Enter a financial disclosure statement that      The crop is reported to have the potential to grow to a height of about 15 cm, which can increase 68 to 60 cm under favourable conditions. It also produces very small flowers whose colours range 69 from pink, white, pale violet to blue, in a raceme-like inflorescence, which are hermaphrodites 70 (Enyiukwu et al., 2014). Though the crop is grown purposely for its underground tuberous roots, 71 the vegetative parts can be processed as feed to ruminants, especially in the dry season. It produces 72 ovoid-shaped tubers that are highly rich in nutrients, minerals, vitamins and phytochemicals (Hua    Conducting studies on the existing varieties of the crop, under similar growth conditions, will help 101 in comparing and identifying high yielding varieties and recommending same to farmers for 102 cultivation. This will help improve the fortunes of farmers producing the crop, and will soar up 103 production to enhance household food security, while safeguarding its extinction (Sugri et al.,

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The experiment was conducted in the rainy seasons of 2020 and 2021, but plants were sparingly 160 watered at the beginning prior to onset of rains. The field was weeded thrice after planting using 161 hoe. During weeding, soil was raised with hoe to support the base of the plants to prepare them for 162 shooting of pods for tuber formation. Weeds were also occasionally pulled out by hand.

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The foliage of the plants were regularly inspected for incidence of pests and diseases using 165 magnifying glasses. The insect pests, such as aphids, white flies, grasshoppers and caterpillar-like 166 larval forms were occasionally found and identified on the vegetative parts of the Frafra potato 167 crop. However, no pesticide was sprayed on the crops because, the pests were not at threshold 168 levels to cause appreciable damage or change on the growth and yield performance of the crop.

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Farmers generally do not experience or consider pests as a threat to Frafra potato crop, whose  quarters of the squares were covered by the leaf outline, they were counted as being fully covered, 193 which is x2. Then, the number of 1 cm 2 that were half-covered by the outline were counted to be y, 194 which was divided by two to obtain full 1 cm 2 that is y/2. Where at most a quarter of squares were 195 covered by the leaf outline, these were not counted. Therefore the total estimated area of the leaf 196 (cm 2 ) was obtained by adding the number of 1 cm 2 that were fully covered by the leaf outline (X1 Plate 4: Tracing the outline of a leaf on a graph in order to estimate its area.

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The analyzed soil results (Table 3.1) show that the soil texture of the study site is mainly sandy 233 loamy, with the proportion of sand being 84.7% before planting which decreased to 84.0% after 234 harvesting. The composition of silt decreased from 6.4% before planting to 5.7% after harvesting.

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On the contrary, the percentage of clay increased from 8.9% to 10.3% after harvesting. The soil was also found to be slightly acidic with an average pH value of 6.6 before planting,

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The contents of organic matter and organic carbon were low in the study soil before and after 256 harvest of corps of the varieties. Among the trace elements tested, manganese level was 15.4 mg/kg 257 before planting and increased to 21.2 mg/kg after harvesting.

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The total nitrogen (N) content before planting was 0.13% and after harvesting was 0.12%N,

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suggesting Frafra potato crop may sparingly utilize soil nitrogen for its growth and tuber 260 development, and can do well in nitrogen deficient soils. On the contrary, the available phosphorus 261 content before planting was 21.8%, but decreased to 17.5% after harvesting, suggesting that Frafra 262 potato make more use of soil phosphorus for its growth and development.

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The soil of the experimental site had limited concentration of nutrients, and may require fertilizer 264 or nutrient augmentation to optimize crop yield on the site. Though Frafra potato may sparingly 265 mine soil nutrients for its growth and development, the crop require adequate amounts of soil 266 nutrients, especially phosphorus, for its production. There is therefore the need for local farmers 267 to improve soil nutrients status of their fields for frafra potato production to maximize tuber yields. The mean values of the measured growth and development parameters are presented in Table 3.2.    The plant height also positively but weakly correlated to tuber yield in four (4) (Table 3.2).  (Tables 3.3, 3.3b). There is a higher 372 possibility that, when the number of vine branches are more, more leaves will be produced.

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Generally, the correlation between vegetative parts like plant height, canopy spread, vine branches 375 and leaf area is in synchrony with physiology, because growth of these vegetative parts is 376 dependent on synthesized food from the leaves. Thus, the larger the leaves, the higher the surface 377 area for trapping both carbon dioxide and sunlight for photosynthesis; and the greater the 378 assimilate availability for vegetative biomass production. Additionally, the growth performance of 379 these vegetative organs of Frafra potato could be determined by available soil water and nutrients, 380 thereby influencing tuber formation. The days to flowering of the six varieties ranged from 84 ±5 days in NT variety to 93±3 days in 384 NP variety, with an overall average of 89± 6.0 days (about 3 months) after planting. (Table 3.2). Though there was a decrease in rainfall by the 8 th WAP, and consequent decline in leaf growth; 438 the rate of increase in leaf area within 4-8 WAP was higher than from 10-12 WAP, when rains 439 were rather heavier (Fig 3.1). The reduction in the leaf expansion within that growth phase could 440 be due to plants approaching maturity, and leaves attaining their maximum sizes or due to too 441 much soil moisture (Enyiukwu et al., 2014).

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The MM variety however did not recover from the mild drought and continued at a reduced rate  The six varieties progressively grew taller with time, from 4-10 WAP (Fig 3.2). However, the sharply from the 6 th WAP till the 10 th WAP, when rains were in excess. Similar to their vertical 468 growth, the MM and WP varieties from the 6 th WAP increased steadily in vine branching until the 469 12 WAP (Fig 3.3). However, vine branching in the NT variety only increased appreciably from 470 the 8 th WAP to the peak at 12 th WAP. The reduction in rainfall at the 8 th WAP did not appreciably The canopy spread of the six varieties were at steady rate from 4 th to the 8 th WAP (Fig 3.4).

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However, canopy development in four (4) of the varieties (ML, MM, WP and LV) were slow in 483 the 8 th WAP probably due to limited rainfall. However, the canopy of the NP variety continued to 484 spread from 4 th WAP until the 12 th WP (Fig 3.4).     Plate 6: Tubers of the studied six varieties of Frafra potato. 23