Associations of nectar volume, humidity of soil, and nectar concentration of C. macrostachyus indicated that medium plants taken from the area of soil humidity of 30.4 % had a moderate nectar concentration of 27.2% and youngest plants taken from the area of the soil humidity of 62.4 % had lower nectar concentration of 16.7% Oldest plants taken from the area of soil humidity of 27.29 % had highest nectar concentrations 36.5% this infers effect of soil humidity is significant on nectar concentration (p = 0.000). Effects of nectar concentration is significance on nectar volume (p = 0.000). Interaction of soil humidity and nectar concentration has no significant (p > 0.05) effects on nectar volume when nectar concentration increases, whereas nectar volume decreased. This finding is in line with the finding of (Rutikanga et al., 2016).
An effect of daylight time is significant on concentration of nectar (p = 0.000) and effects oftrees layers is significant on concentration of nectar (p = 0.000) (Figure 2).Interaction of daylight time and tree layers significantly affect nectar concentration with p > 0.05. Nectar concentration increased after lunch for the oldest, medium, and youngest age of C. macrostachyus. This infers the age of plants and daylight time determined volume and concentrations of nectar. A similar finding reportedthatnectar secretion largely growing trend early in the early hours of the day, peaking toward noontime (Adgaba et al., 2017).
The interaction among relative humidity, daylight time, and nectar volume of crotonindicated that daylight time and relative humidity affected nectar volume as shown below (Figure 3). An effect of relative humidity is significant on nectar volume (p = 0.000). An effect of daylight time is not significant on nectar volume (p > 0.05) and interaction of relative humidity and daylight time has no significant effects on nectar volume (p > 0.05). Nectar volume was higher before lunch than in after lunch for all three-age categories at the time where relative humidity was higher. This speculation in the morning more humidity is found in an air that increases nectar volume. Nectar volume was lower after lunch at the time relative humidity decreasedthat might be due to reduction of relative humidity because of increment of evaporation in the afternoon than in the morning since temperature increases.
Relative humidity has significant effects on nectar concentrations (p = 0.000) and daylight time has significant effect on nectar concentration with (p = 0.000) (Figure 4). Nectar concentration was lower at the time relative humidity was higher in the morning, but in the afternoon nectar, concentration was higher at the time relative humidity was lower which means relative humidity and nectar concentrations are inversely comparative to each other. Interaction of daylight time and relative humidity has significant effects on nectar concentration with p = 0.0001 and this result is parallel to reports on Callistemon citrinus L. (Kasim, 2019).
Figure 5: Below shows interactions of temperature, daylight time, and nectar concentrations of Croton macrostachyus. Temperature has significant effects on nectar concentration with (p = 0.000) and daylight time significantly affect nectar concentration with (p = 0.0098631) and their interactions also significantly affect nectar concentrations with (p = 0.0008304). After lunch nectar concentration increased this implies daylight time has a significant effect on nectar concentrations due to increment in temperature after lunch. Nectar concentrationwas lower before lunch than after lunch. Similarly, it was reported that there was an increasing concentration as temperature increases with a corresponding decrease in relative humidity (Adriana de Fidalgo and Astrid deep Kleinert, 201, Adjaloo, 2015 ).
Figure 6: Below shows interactions of temperature, daylight time, and nectar volume of Croton macrostachyus. Temperature has significant effects on nectar volume (p = 0.0002499). Daylight time did not significantly affect nectar volume (p > 0.05) and their interaction has also no significant with (p > 0.05). After lunch, nectar volume decreased which means that daylight time affects nectar volume due to higher temperature after lunch that decreased nectar volume. Similarly, reported as nectar volume of Melliferous plants was higher in the morning (Adjaloo, 2015). This implies nectar volume is affected by daylight time for different species also that might be due to temperature increases in the after lunch than in the pre-lunch hours of the day.
Temperature and soil moisture has significant effects on nectar volume (p =0.00016 and 0.0000) respectively, and their interactions has also significant effects with (p = 0.0005800) (Figure 7). Age and relative humidity have significant effects with (p = 0.000 and 0.000) respectively and their interaction has significance effects with (p = 0.0003717). Time has no significant effects on nectar volume with (p > 0.05), but age has significant effects on volume (p = 0.000), but their interaction has significant on volume with p-value of (p = 0.006993). This is in line with the finding demonstrated with defoliation experiments conducted on Impatiens glandulifera that only a fraction of the day’s nectar secretion depends on the day’s photosynthesis (Cawoy, 2008).
Age, humidification, then daylight time has significant effects with (p = 0.000, 0.000 and 0.0003643) respectively and their interaction has significant effects with (p = 0.0004939) (Figure 8). Interactions of age and layers of trees have significant effects with (p = 0.007700). Interaction of daylight time and humidification, has significant effects with (p = 0.0002). Interaction of age and daylight time has significant effects with (p = 0.000). This deduces age and daylight time has significant effects on nectar volume and youngest age produced more nectar volume than medium and oldest age that might be due to bleeding of water from several tissues of youngest than others. Daylight time, relative humidity and layers of trees significantly affect nectar concentration with (p = 0.0003643, 0.000 and 0.000) respectively and their interactions has significant effects on nectar concentration (p = 0.0024012). Interaction of temperature, age, layers, and daylight time has significant effects with (p = 0.041298). The highest nectar volume had the lowest sugar concentration and this finding is in line with the finding of (Rutikanga et al., 2016).